Podcasts about g2 m

In this solo episode, I'm breaking down one of the most talked-about tools in the health optimization world right now—peptides. From healing faster to building lean muscle, improving fat loss, enhancing sleep, and even slowing down the aging process… peptides are powerful. But they're also misunderstood, under-regulated, and often misused. So in this episode, I'm walking you through exactly what peptides are, how they work, the most popular ones in each category, and both the pros and cons of using them. This is a no-BS, educational breakdown of everything you need to know before exploring peptides as a tool for better health, performance, or aesthetics. I also cover some legal and sourcing realities—because here's the truth: most peptides aren't FDA-approved, and you'll only find them labeled for “research purposes only.” This isn't an endorsement. It's a breakdown to help you make smarter, more informed decisions.   What I Cover in This Episode: What peptides are and how they're different from hormones or steroids Legal disclaimers and how they're commonly sourced Growth hormone peptides: CJC-1295, Ipamorelin, MK-677 Fat loss peptides: AOD 9604 and Tesamorelin Healing peptides: BPC-157 and TB-500 Anti-aging + cognitive peptides: GHK-Cu (Copper peptide), Epitalon, Semax, Selank Mitochondrial optimizer: MOTS-c and why it's a game-changer for metabolic health How to stack peptides and what to avoid Side effects, risks, and what to consider before diving in   Links & References: Biological Activities and Safety of Citrus spp. Essential Oils - Click Here Essential role of TRPC6 channels in G2/M phase transition and development of human glioma - Click Here   Final Take: Peptides can be a powerful tool—but they're not a magic bullet. If you're training hard, eating right, sleeping well, and want to push to the next level, they might offer that extra edge. Just make sure you're doing it smart, and not chasing shortcuts.   Register For 30-Strong - Register Here   Join The Collective - Join Here   Interested in working with a coach? Get a free nutrition consultation - Schedule Here   Join Us On Patreon - Join Here   Submit your questions to be featured on our Q&A episodes.   Order from Cured Supplement Order from Legion Supplements and get 20% off your first order by using discount code: keynutrition   Connect with us on Instagram Host Brad Jensen – @thesoberbodybuilder Next Level Nutrition – @mynextlevelnutrition   Episode Timestamps 00:00 "Peptides: Unapproved but Legally Sold" 04:38 Compounding vs. Big Pharma Conflict 07:44 Benefits of Growth Hormone 13:31 MK677's Effects on Body Composition 16:51 Water Retention from Low Dose? 18:30 Health Supplement: Benefits and Considerations 23:35 "GLP1s and Peptide Therapy Debate" 27:03 GHK-CU: Skin and Anti-Aging Benefits 28:14 Copper Peptides for Hair and Healing 32:39 Growth Hormones and Water Retention 34:41 Success with BPC and TB500 40:13 GLP1s Fat Loss: Efficacy Concerns 42:03 "Peptides vs. Steroids: Health Debate" 45:11 "Join the Daily Wellness Movement"

Dr. Evan Noch interviews Dr. Chunzhang Yang about his and his team's recent manuscript entitled "Abrogation of the G2/M checkpoint as a chemo sensitization approach for alkylating agents" published online in Neuro-Oncology in December 2023 Read Paper

A new research paper was published in Oncotarget's Volume 14 on June 21, 2023, entitled, “Diphenyl ditelluride anticancer activity and DNA topoisomerase I poisoning in human colon cancer HCT116 cells.” Diphenyl ditelluride (DPDT) is an organotellurium (OT) compound with pharmacological properties, including antioxidant, antigenotoxic and antimutagenic activities when applied at low concentrations. However, DPDT as well as other OT compounds also show cytotoxicity against mammalian cells when treatments occur at higher drug concentrations. The underlying mechanisms of toxicity of DPDT against tumor cells have previously been poorly explored. In this new study, researchers André Luiz Mendes Juchem, Cristiano Trindade, Juliana Bondan da Silva, Miriana da Silva Machado, Temenouga Nikolova Guecheva, Jaqueline Cesar Rocha, Jenifer Saffi, Iuri Marques de Oliveira, João Antonio Pêgas Henriques, and Alexandre Escargueil from the Federal University of Rio Grande do Sul, Sorbonne Université, Federal University of Health Sciences of Porto Alegre, Lutheran University of Brazil, Bulgarian Academy of Sciences, and University of Vale do Taquari aimed to investigate the effects of DPDT against both human cancer and non-tumorigenic cells. “Together, our results will help to better define DPDT as a potential drug candidate for treating CRC [colorectal cancer].” The researchers used the colonic HCT116 cancer cells and the MRC5 fibroblasts as models. Their results showed that DPDT preferentially targets HCT116 cancer cells when compared to MRC5 cells with IC50 values of 2.4 and 10.1 μM, respectively. This effect was accompanied by the induction of apoptosis and a pronounced G2/M cell cycle arrest in HCT116 cells. Furthermore, DPDT induces DNA strand breaks at concentrations below 5 μM in HCT116 cells and promotes the occurrence of DNA double strand breaks mostly during S-phase as measured by γ-H2AX/EdU double staining. Finally, DPDT forms covalent complexes with DNA topoisomerase I, as observed by the TARDIS assay, with a more prominent effect observed in HCT116 than in MRC5 cells. Taken together, the results of this study show that DPDT preferentially targets HCT116 colon cancer cells likely through DNA topoisomerase I poisoning. “This makes DPDT an interesting molecule for further development as an anti-proliferative compound in the context of cancer.” Read the full paper: DOI: https://doi.org/10.18632/oncotarget.28465 Correspondence to: João Antonio Pêgas Henriques, Alexandre Escargueil Email: pegas.henriques@ufrgs.br, alexandre.escargueil@gmail.com Sign up for free Altmetric alerts about this article - https://oncotarget.altmetric.com/details/email_updates?id=10.18632%2Foncotarget.28465 Subscribe for free publication alerts from Oncotarget - https://www.oncotarget.com/subscribe/ Keywords - colorectal cancer, HCT116, diphenyl ditelluride, organotellurium, topoisomerase I About Oncotarget Oncotarget is a primarily oncology-focused, peer-reviewed, open access journal. Papers are published continuously within yearly volumes in their final and complete form, and then quickly released to Pubmed. On September 15, 2022, Oncotarget was accepted again for indexing by MEDLINE. Oncotarget is now indexed by Medline/PubMed and PMC/PubMed. To learn more about Oncotarget, please visit https://www.oncotarget.com and connect with us: SoundCloud - https://soundcloud.com/oncotarget Facebook - https://www.facebook.com/Oncotarget/ Twitter - https://twitter.com/oncotarget Instagram - https://www.instagram.com/oncotargetjrnl/ YouTube - https://www.youtube.com/@OncotargetJournal LinkedIn - https://www.linkedin.com/company/oncotarget Pinterest - https://www.pinterest.com/oncotarget/ Reddit - https://www.reddit.com/user/Oncotarget/ Media Contact MEDIA@IMPACTJOURNALS.COM 18009220957

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.05.05.539557v1?rss=1 Authors: Christofidou, E., Tomazou, M., Voutouri, C., Michael, C., Stylianopoulos, T., Spyrou, G. M., Strati, K. Abstract: Oct4 is a pioneer transcription factor regulating pluripotency. However, it is poorly known whether Oct4 has an impact on somatic cells. We generated OCT4 knockout clonal cell lines using immortalized human skin keratinocytes to identify a functional role for the protein. Here we report that Oct4-deficient cells transitioned into a mesenchymal-like phenotype with enlarged size and shape, exhibited accelerated migratory behavior, decreased adhesion and appeared arrested at G2/M cell cycle checkpoint. Oct4 absence had a profound impact on cortical actin organization, with loss of microfilaments from cell periphery, increased puncta deposition in the cytoplasm and stress fiber formation. E-cadherin, beta-catenin and ZO1 were almost absent from cell-cell contacts while fibronectin deposition was markedly increased in ECM. Mapping of the transcriptional and chromatin profiles of Oct4-deficient cells revealed that Oct4 controls the levels of cytoskeletal, ECM and differentiation related genes, whereas epithelial identity is preserved through transcriptional and non-transcriptional mechanisms. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.03.26.534249v1?rss=1 Authors: Sugiyama, H., Goto, Y., Kondo, Y., Coudreuse, D., Aoki, K. Abstract: Cyclin-dependent kinase (CDK) plays an essential role in determining the temporal ordering of the cell cycle phases. However, despite significant progress in studying regulators of CDK, it remains elusive how they coordinately affect CDK activity at the single-cell level and how CDK controls the temporal order of cell cycle events. This could be due to the lack of tools to monitor CDK activity in living cells. Here, we elucidate the dynamics of CDK activity in fission yeast and mammalian cells by using a newly developed CDK activity biosensor, Eevee-spCDK, based on Forster Resonance Energy Transfer (FRET). Taking advantage of this system, we unravel the profile of CDK activity in vegetatively growing S. pombe cells. Thus, we detect a transient increase in S phase followed by a gradual increment during G2 phase. CDK activity then reaches its maximum in early M phase and rapidly decreases at mitotic exit. During G2 phase, CDK activity exhibits a biphasic pattern, i.e., an early slow increase and a late fast rise prior to the G2/M phase transition, as predicted from mathematical studies. Remarkably, although CDK activity does not necessarily correlate with cyclin levels, we find that it converges to the same level around mitotic onset in several mutant backgrounds, including pom1{Delta} cells and wee1 or cdc25 overexpressing cells. These data provide the first direct evidence that cells enter M phase when CDK activity reaches a high threshold, consistent with the quantitative model of cell cycle progression in fission yeast. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.03.01.530713v1?rss=1 Authors: Phongkitkarun, K., Chusorn, P., Kamkaew, M., Lam, E. W.- F., Promptmas, C., Sampattavanich, S. Abstract: Forkhead box protein M1 (FOXM1) is a proliferation-associated transcription factor contributing to the G2/M phase transition of the cell cycle. Although the upregulation of FOXM1 has been observed in different cancer types, how the regulation of FOXM1 dynamically alters during cell cycles and potentially contributes to tumorigenesis is not well understood. We showed here the development and application of a tunable FOXM1-DHFR (FOXM1-D) sensor that enables surveillance and manipulation of the FOXM1 abundance. Using trimethoprim (TMP) to stabilize the sensor, we measured the kinetics of FOXM1-D production, degradation, and cytosolic-to-nuclear translocation in the G1 and G2 cell-cycle phases. By controlling FOXM1-D stability in different synchronized cell cycle pools, we found that the G1- and S-synchronized cells finished their first cell division faster, although the G2-synchronized cells were unaffected. Our analysis of single-cell FOXM1-D dynamics revealed that the two-round dividing cells had a lower amplitude and later peak time than those arrested in the first cell division. Destabilizing FOXM1-D in the single-round dividing cells enabled these cells to re-enter the second cell division, proving that overproduction of FOXM1 causes cell cycle arrest and prevents unscheduled proliferation. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.11.03.514885v1?rss=1 Authors: Burclaff, J., Bliton, R. J., Breau, K. A., Cotton, M. J., Hinesley, C. M., Ok, M. T., Sweet, C. W., Zheng, A., Bankaitis, E. D., Ariel, P., Magness, S. T. Abstract: Background and Aims: The transcription factor SOX9 is expressed in many stem/progenitor cell populations and has biphasic correlations with proliferation rates across different biological systems. In murine intestinal crypts, distinct Sox9 levels mark three phenotypically different cell types, with lowest levels marking rapidly-dividing transit-amplifying (TA) cells, intermediate levels marking intestinal stem cells (ISCs), and highest levels marking slowly dividing label retaining secretory precursors. SOX9 expression levels and the impact of these levels on cell cycle and stem cell activity have not been characterized for humans. Methods: Monolayers of primary human ISCs isolated from healthy organ donors were engineered with stable SOX9-knockout (KO) and/or SOX9-overexpression (OE) genomic modifications to assess the impact of SOX9 levels on proliferative capacity by DNA content analysis, cell cycle phase length by live imaging for a PIPFUCCI reporter, stem cell activity via organoid formation assays, and cell fate after ISC differentiation by qPCR. Results: SOX9 was expressed at diverse levels in human intestinal crypt lineages in vivo, repressed proliferation in human ISC monolayers, and predominantly lengthened G1 by greater than 40% with lesser lengthening of S and G2/M phases. Over-expression of SOX9 caused slower proliferation yet increased organoid forming efficiency. Higher SOX9 levels biased ISC differentiation towards tuft cell and follicle-associate epithelium fates while loss of SOX9 biased cells toward absorptive enterocyte, goblet cell, BEST4 cell, and enteroendocrine cell fates. Conclusions: SOX9 is a master regulator of stem cell activity in human ISCs, lengthening cell cycle, promoting stemness, and altering differentiation fate. Interestingly, differences are noted between species, highlighting the importance of analyzing regulatory mechanisms in primary healthy human cells. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

In this JCO Precision Oncology Conversations podcast, JCO PO author Dr. Thanh Dellinger of City of Hope National Medical Center shares insights into the research published in her article, “Hyperthermic Intraperitoneal Chemotherapy–Induced Molecular Changes in Humans Validate Preclinical Data in Ovarian Cancer.” Podcast host Dr. Abdul Rafeh Naqash talks with Dr. Dellinger about hyperthermic intraperitoneal chemotherapy (HIPEC) and the various challenges of the treatment of epithelial ovarian cancer (EOC). The study described in this JCO PO article discusses protein expression, RNAseq alterations and signature, and whole-transcriptome sequencing and signatures. Read here  https://ascopubs.org/doi/full/10.1200/PO.21.00239   TRANSCRIPT Dr. Abdul Rafeh Naqash: Welcome to ASCO's Precision Oncology Conversations where we bring you the highlights and overview of precision oncology. This podcast is here to provide interactive dialogue focusing on the excellent research published in the JCO Precision Oncology. Our episodes will feature engaging conversations regarding precision oncology with the authors of a clinically relevant and highly significant JCO Precision Oncology article. You can find all our shows including this one at asco.org/podcasts, or wherever you get your podcasts. Hello, I am Dr. Abdul Rafeh Naqash. I'm a medical oncologist and a phase one clinical trialist at the OU Stephenson Cancer Center. You're listening to JCO Precision Oncology Conversations. I have no conflicts of interest related to this podcast. A complete list of disclosures is available at the end of each episode. Today, I will be talking with Dr. Thanh Dellinger from the City of Hope Comprehensive Cancer Center, who's a gynecological oncologist, and we'll be talking about her JCO Precision Oncology article, ‘Hyperthermic Intraperitoneal Chemotherapy-Induced Molecular Changes in Humans Validate Preclinical Data in Ovarian Cancer.' Dr. Dellinger does not have any conflicts of interest. Hi, Dr. Dellinger, welcome to our podcast! Dr. Thanh Dellinger: Hi, Dr. Naqash! It's such a pleasure to be on with you. Dr. Abdul Rafeh Naqash: We recently saw your paper published. It's one of those interesting, clinical translational papers that we felt needed to be highlighted in our Precision Oncology Podcast series. So, we're really excited to have you here today to take a deeper dive into the findings and some of the novel approaches that you used in your recent publication. So, for starters, could you give our listeners a brief idea of what HIPEC is, where it's used, and when it's used in ovarian cancer? Dr. Thanh Dellinger: Right! Thank you very much for this great introduction. So, HIPEC or Hyperthermic Intraperitoneal Chemotherapy has been used in ovarian cancer for quite some time. The most relevant data giving us an indication for ovarian cancer was published by Dr. van Driel in the OVHIPEC-1 randomized trial several years ago in the New England Journal of Medicine, which demonstrated that in stage 3 ovarian cancer patients who undergo an interval tumor debulking with HIPEC, that those patients appear to enjoy both progression-free and overall survival benefit. In fact, the overall survival benefit is nearly 12 months for those patients. So, with this in mind and a number of other data, the HIPEC treatment for those patients that interval debulking has been incorporated into the NCCN guidelines. Nonetheless, there have been some criticisms of HIPEC and it still remains to be seen who those patients are, the ovarian cancer patients who really best benefit from HIPEC, given the morbidity of HIPEC. We now know also that HIPEC is probably equivalent to just cytoreductive surgery alone in terms of morbidity. Dr. Abdul Rafeh Naqash: Thank you for that explanation. And especially for people like myself, who are not surgeons or gynecological oncologists, that was very helpful. So, my next question, and you probably partly answered it, but I'm going to still ask the question is: what is the reason you think that intraperitoneal chemotherapy overall, has not been as widely adopted? Dr. Thanh Dellinger: You touch on a very good point there. As many of the listeners may understand, IP chemotherapy has demonstrated a lot of efficacies in multiple clinical trials over the last decade or two decades even. And part of why, despite its benefit, it has not been taken up in the overall community may really be the difficulty and the complexity of doing IP chemotherapy in the community, especially the side effects are difficult sometimes to take care of. There's increased abdominal pain and there are catheter issues. And so, especially with more recent data, that with the presence of Avastin, IP chemotherapy may not necessarily be as beneficial. Unfortunately, IP chemotherapy hasn't been really taken up in daily oncologic care with ovarian cancer. Nonetheless, we know that there are a lot of theoretical benefits because of the peritoneal metastasis not being as best treated with intravenous chemotherapy as with regional therapy. Dr. Abdul Rafeh Naqash: Thank you! So, now going to the data that you published. I was very intrigued with some of the findings. And from what I understood, your main aim was to understand predictive biomarkers to identify patients or basically identify molecular characteristics for patients' selection for HIPEC. So, could you tell us more about why you initiated this study? And I understand this is one of the, I believe the first study in humans to evaluate some of these interesting biomarkers, both pre- and post-. So, what was the background of doing this trial? And what led to this interesting study? Dr. Thanh Dellinger: Thank you for pointing out this aim. There's a lot of criticism of HIPEC and part of it is that we may not exactly understand the mechanisms of HIPEC, why is it that it works so well in some patients? There's a lot of preclinical data supporting hyperthermia, especially with cisplatin. There's synergy between cisplatin and hyperthermia, and improving the DNA adduct formation. There's increased cytotoxicity seen when the temperature increases up to 43 degrees. And there's also a T-cell activation and immune response that occurs during hyperthermia. So, a lot of this, however, has been done in preclinical studies, in vitro data as well as preclinical mouse models. There hasn't been much or really anything published that, as far as I know, has been done in humans. And so, this particular study looked at both pre-treatments, pre-HIPEC specimens, peritoneal biopsies, as well as immediate post-operative peritoneal biopsies, tumors, and normal samples, and we wanted to look both at the whole transcriptomic sequencing profile, but also at the tumor microenvironment. Dr. Abdul Rafeh Naqash: From a logistic standpoint, from a trial design standpoint, was this a phase 1 study? I know you use the term pilot in the publication. So, were you trying to look at safety also, or was this primarily I would say, a biomarker, pharmacodynamic biomarker-driven study that you were trying to evaluate? Dr. Thanh Dellinger: You're correct. This was essentially a feasibility study. But we additionally looked at safety and feasibility with HIPEC at our institution. And in some respects, we also looked at the feasibility of giving intraperitoneal chemotherapy normothermically early after HIPEC, and so it was also an endpoint to look at safety. Dr. Abdul Rafeh Naqash: Understand! I believe there was some difference in the dose for the cisplatin, I believe, is the chemotherapy that you use. What was the rationale for the difference in the dose for 75 milligrams per meter square that you use in your study? Dr. Thanh Dellinger: The study was initiated at a time before the OVHIPEC-1 trial was published. And so, at that time, the HIPEC dose for cisplatin was still not established. 75 milligrams per meter square for cisplatin was actually used in other trials, and has been noted to be effective in other clinical trials. Dr. Abdul Rafeh Naqash: Thank you! Now going to the patient population for this trial. What type of patients were you enrolling? Was it just epithelial ovarian cancer patients, did these patients need to have peritoneal metastases when you were doing this cytoreductive surgery? What was the patient population that you were targeting in this trial? Dr. Thanh Dellinger: The majority of the patients did have epithelial ovarian cancer. We did enroll a few, actually 5, uterine cancer patients as well, which were not included in this specific publication. But the majority of them were epithelial ovarian cancer patients. Dr. Abdul Rafeh Naqash: Going to the interesting translational analysis. So, you had three subsets of patients based on the biopsy collection. What were your hypotheses, and what drove some of those translational studies to understand the biomarkers? Dr. Thanh Dellinger: The first translational analysis we conducted was the whole transcriptomic sequencing, and specifically, we wanted to look, one, for any potential transcriptomic signatures that may correlate with survival or improved response to HIPEC. The second one was to look at whole exome sequencing. Thirdly, we looked at whole transcriptomic sequencing differences before and after HIPEC treatment. And lastly, we looked at the tumor microenvironment through multiplexing of certain markers associated with T-cell response. Dr. Abdul Rafeh Naqash: From a clinical outcome standpoint - and we'll discuss the biomarkers in more detail - from a clinical standpoint, when I briefly looked over the PFS curves, were the results, as far as expected outcomes, were they similar to what you see with the current standard? Or were there any unusual safety signals? Or would you attribute any of the adverse events that you saw to intraperitoneal chemotherapy specifically? Because I believe some patients did have some chemotherapy pre-surgery, neoadjuvant if I'm correct. So, how would you attribute some of those AEs, and if at all, did you see any interesting safety signals of concern and outcomes as far as PFS is concerned? Dr. Thanh Dellinger: So, one of the major toxicities that we saw in the first half of our trial were actually renal toxicities. In fact, there were actually two patients who could not go on to adjuvant chemotherapy because they suffered chronic renal failure. And because of that, halfway through the trial, we did actually add a nephro protectant called sodium thiosulfate. And this actually dramatically improved those renal toxicities. And for the second half of our study, no patients suffered grade three or grade four renal adverse events. And so, that did change significantly. Dr. Abdul Rafeh Naqash: From a genomic standpoint, it's very interesting that you were able to do all these very cool and interesting translational biomarker studies, including multiplex immunofluorescence. From a genomic standpoint, though, would you say it's fair to say that there was no significant correlation based on the baseline genomics for some of the patients and their outcomes? Is that a fair assessment? Dr. Thanh Dellinger: Yes, that is a very fair assessment. I think that our cohort was really too small to make those kinds of assessments. I don't know whether you saw there recently was a paper published by the OVHIPEC-1 group looking at their cohort of over 200 patients that underwent the interval cytoreductive surgery in HIPEC and they did actually demonstrate benefit in patients who are HIV-positive but BRCA wild-type, but not necessarily in BRCA mutated patients. So, I think that I would point to that study to look for genomic effects with HIPEC patients. Dr. Abdul Rafeh Naqash: Understand. Now, again, going to the biomarkers that your team evaluated, it seems from among good responders especially, you saw an increase in tumor necrosis factor, alpha signaling, NF-kappa B signaling, KRAS signaling, and then you also saw some pathways that were downregulated, especially the G2-M checkpoint, and Myc targets. What would you say the correlation of these is in terms of future drug development in this specific setting? Dr. Thanh Dellinger: I think that we did see some increase in immune pathways in patients who did better in the end. And also, our multiplex results did demonstrate that E1 expression was increased in patients who had better responses after HIPEC. So, our hypothesis is that potentially, there's an activation of T-cell response with HIPEC and that potentially PD-1 inhibitor could be added in the future. This is a hypothesis that certainly would need to have more work, but it's something that is interesting enough to really look at in ways of how to improve HIPEC. Dr. Abdul Rafeh Naqash: Going to your point on the PD-1, I found really intriguing that you were able to see an increase in PD-1 expression on CD8+ T cells but no actual increase in the number of CD8+ T cells suggesting there's some sort of activation of this marker and this may not necessarily be a marker for T-cell exhaustion. So, would you interpret it in a way that in a different setting, perhaps a new adjuvant approach with immunotherapy, would perhaps somehow augment this and then you could see more upregulation? Is there any work being done in that field? How would you put this in the context of your findings? Dr. Thanh Dellinger: You bring up a really great point because to date HIPEC has been demonstrated to have benefit in the interval setting. But there was a more recent study done by, well not recent, a more recently published study by a Korean group that demonstrated no benefit in the adjuvant setting for HIPEC and still some benefit in the interval setting. And the question is, are these really two different types of cohorts who respond differently because of potential differences in immune response and tumor microenvironment? I think that that would be a great way of delving further into this. What are really the differences in tumor microenvironment changes in those two different settings? Dr. Abdul Rafeh Naqash: Definitely! It's very exciting. You've also shown upregulation of, as you mentioned earlier, immune pathways, as well as upregulation of genes related to heat shock proteins. Does that play into future drug development as far as HSP Inhibitors are concerned? Dr. Thanh Dellinger: That is a really great question. Certainly, in preclinical models, heat shock proteins are known to be elevated and they do activate dendritic cells and result in T-cell activation. Now, whether that can be spelled out into actually some future drug therapy definitely remains to be seen. To date, there hasn't been any success in using heat shock types of agents or inhibitors, unfortunately. So, I think while this is of great interest, I'm not entirely sure that this will translate into any drug therapy in the future. Dr. Abdul Rafeh Naqash: And I totally connect with you there as a phase 1 trialist. I completely agree that we see a lot of translational data, more often than not, going into the phase 1 site because many of these targets are not actionable. Now, from a DNA repair standpoint, you did see that there was interference with DNA repair, as far as some of the analyses that you did, but I did not specifically see any markers for DNA damage that were assessed on the biopsies such as Gamma-H2AX, RAD 51, or Phospho-NBS. Was there a reason why that was not looked at? Dr. Thanh Dellinger: I think that we did look at that and there weren't really any significant results. We did put some of the data into the supplementary data. I think that in the end, our cohort was really too small to really make any meaningful data. But I absolutely agree with you looking at HSP and DNA repair is really important. And as I mentioned that most recently published paper does address that. Dr. Abdul Rafeh Naqash: Excellent! Do you think that there could be any confounders in this analysis that could have led to the upregulation of some of these pathways and may not necessarily have been the intraperitoneal chemotherapy? Could you think of some other reasons that this could have been a confounding factor? Or would it primarily be attributed to the intraperitoneal chemotherapy that you guys have looked at in this interesting paper? Dr. Thanh Dellinger: Yeah, it is a rather small cohort. So, I think that more data is required to potentially repeat this in the larger cohort. But what is interesting is that we did have paired analysis. So, we had matched peritoneal samples from the same patients looking before the HIPEC and after the HIPEC, which is very unique and hasn't really been done in the setting before. And while you couldn't necessarily repeat the same exact peritoneal tumor it was very close. And so, in the best setting, I think that we did have a good paired analysis. Dr. Abdul Rafeh Naqash: That was one of the very interesting aspects of this study that I very much appreciated, that you were able to get some of those paired biopsies and do the analyses on samples and look at all these markers. So, this was all excellent work and definitely intrigues the mind into what other ways one could use some of these findings to develop future combination-based approaches, whether it's the neoadjuvant or the adjuvant setting for patients with ovarian cancer. Are there any next steps as part of this project that you are excited about that you can share? Dr. Thanh Dellinger: Right! I'm definitely very excited about trying to build on this and essentially developing a much larger predictive study using hundreds of ovarian cancer HIPEC-treated tumors in collaboration with others. We have definitely developed a great community of HIPEC investigators who are very interested in developing somewhat of a predictive signature for ovarian cancer undergoing HIPEC. So, I'm very excited to hopefully be able to develop this consortium of HIPEC transcriptomic research. And so, I'm looking forward to collaborating with my co-investigators on that. Dr. Abdul Rafeh Naqash: It was definitely exciting to talk to you about your work. Now, I want to ask you about you as an investigator or as a researcher. How did you end up in this field? What was your background while you were pursuing science and medicine? How did you end up in this field and how are you mentoring the next generation? Dr. Thanh Dellinger: When I was a fellow at UCI, my mentor Robert Bristow introduced me to HIPEC and that has really stuck. As a GYN oncologist, it is hard to really do both chemo and be a good surgeon. And in many ways, I have really specialized in surgical oncology more than in medical oncology. And HIPEC is really a very nice blend of the two. It allows you to do clinical trials while still doing surgery and giving some chemotherapy. Really, it was for the introduction of my more recent mentor, Elena Rodriguez, who really introduced me to genomics and applying this to HIPEC samples that this all came about. And so, I think that there are a lot of opportunities for surgical oncologists who do not give chemo and may think that clinical research is not for them, but there are a lot of translational opportunities and clinical trial opportunities for those who don't give chemotherapy, but are surgical oncologists. Dr. Abdul Rafeh Naqash: Thank you so much. We are really excited for all the work that you're doing and will continue to do and hopefully, we'll see more of this evolve as time progresses. Dr. Thanh Dellinger: Thank you so much, Dr. Naqash. It was such a pleasure meeting you and talking to you. Dr. Abdul Rafeh Naqash: Same here. Thank you for listening to JCO Precision Oncology Conversations. To listen to more, visit asco.org/podcasts, or find them on Google Play Spotify and Apple podcasts. To stay up to date, be sure to follow and share JCO Precision Oncology content on Twitter. The Twitter handle is @JCOPO_ASCO. All JCO PO articles and series can be found at ascopubs.org/journals/PO. The purpose of this podcast is to educate and inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience, and conclusions. Guest statements on the podcast do not express the opinions of ASCO. The mention of any product, service, organization, activity or therapy should not be construed as an ASCO endorsement.  Guest Bio Dr. Thanh Dellinger, MD, is a gynecologic oncologist and physician-scientist who specializes in ovarian and uterine cancer. She is an expert in hyperthermic (HIPEC) and pressurized aerosolized intraperitoneal chemotherapy (PIPAC), and is the primary investigator of clinical and translational studies focusing on these therapies. She received her medical degree at University of California Irvine, where she also completed a gynecologic oncology fellowship. She is leading the first U.S. clinical trial in PIPAC (pressurized intraperitoneal aerosolized chemotherapy), a novel therapy using pressurized aerosolized chemotherapy for ovarian cancer. Her current research focuses on innovative therapies for ovarian cancer using intraoperative chemotherapy, and novel antibody and nanoparticle therapies.

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.10.13.512167v1?rss=1 Authors: Shao, B., Panchenko, M. Abstract: Members of the conserved subfamily, JADE1S and JADE1L isoforms, are expressed in epithelial cells, fibroblasts, and epithelial cell lining in vivo. JADE1 proteins interact with histone acetyl transferase HBO1 complex. The two consecutive PHD zinc fingers of JADE1 bind chromatin. We recently reported novel effects of JADE1S on cytokinesis progression. JADE1S depletion facilitated G2/M-to-G1 transition and increased polyploidy and aneuploidy. JADE1S over-expression arrested cells in late cytokinesis, an effect reversed by AURKB inhibitor. In late cytokinesis cells JADE1S protein localized to the midbody. Results suggested a JADE1S role in final abscission delay. Here we investigated the expression of JADE1 in the central spindle, interactions with HBO1, and the role of PHD fingers in late cytokinesis arrest. The midzone begins to assemble in anaphase and forms into a midbody in cytokinesis. The midbody structure connects two daughter cells and is thought to bear factors controlling the final abscission. We questioned whether, similar to established factors, JADE1S is targeted to the central spindle structures in anaphase. Indeed, in cells transitioning from mitosis to cytokinesis, JADE1S was sequentially targeted to early midzone, midbody flanking zone, and midbody. The step-wise increase of JADE1S expression in midzone and midbody of synchronously dividing cells suggested protein recruitment. The increase of late cytokinesis arrest caused by recombinant JADE1S correlated with increased expression in midbody. Spatial analysis of the members of the chromatin passenger complex, microtubule associated proteins, and centralspindlin, revealed transient co-localization with JADE1S and mapped JADE1S within the cytokinesis bridge. Deletion of the two PHD zinc fingers inactivated JADE1S ability to arrest cells in late cytokinesis but did not affect its midbody localization. Thus, PHD zinc fingers are required for JADE1S cytokinesis delay but not for midbody targeting. Recombinant HBO1 protein decreased the proportion of late cytokinesis cells, prevented late cytokinesis arrest by JADE1S as well as its midbody localization. Enzyme inactive HBO1 mutant recapitulated the wild type phenotype. The results demonstrate antagonistic relationship and suggest HBO1-mediated midbody dislocation of JADE1S. Our study supports the role of JADE1S in cytokinesis delay and implicates protein partners. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

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醫學研究發現大蒜中的大蒜素可以抑制某些癌細胞，並且促進這些癌細胞的凋亡，例如乳癌和胃癌。有沒有人體試驗證實在人體也有這種功效呢？ 參考文獻： Bhaumika I, Pal k, Debnath U. Natural product inspired allicin analogs as novel anti-cancer agents. Bioorg Chem. 2019 May;86:259-272. Abstract A series of novel analogs of Allicin (S-allyl prop-2-ene-1-sulfinothioate) present in garlic has been synthesized in high yield. Synthesized 23 compounds were evaluated against different breast cancer cells (MDA-MB-468 and MCF-7) and non-cancer cells (WI38). Four compounds (3f, 3h, 3m and 3u) showed significant cytotoxicity against cancer cells whereas nontoxic to the normal cells. Based on the LD50 values and selectivity index (SI), compound 3h (S-p-methoxybenzyl (p-methoxyphenyl)methanesulfinothioate) was considered as most promising anticancer agent amongst the above three compounds. Further bio-chemical studies confirmed that compound 3h promotes ROS generation, changes in mitochondrial permeability transition and induced caspase mediated DNA damage and apoptosis. Gastric cancer remains high prevalence and fatality rates in China even though its morbidity has been decreased drastically. Allicin, which is from an assistance food-garlic (Allium Sativum L), was found to be effective in gastric cancer treatment. It is a defensive substance with a board biological properties: inhibition of bacteria, fungus, virus, controlled hypertension, diabetes, and chemoprevention of several cancers, etc. Experiments have shown that allicin can be chemopreventive to gastric cancer by inhibiting the growth of cancer cells, arresting cell cycle at G2/M phase, endoplasmic reticulum (ER) stress, and mitochondria-mediated apoptosis, which includes the caspase-dependent/-independent pathways and death receptor pathway. Those mechanisms probably involve in modulating enzymatic activity, restraining DNA formation, scavenging free radicals, and affecting cell proliferation and even tumor growth. Therefore, this review is focus on the mechanism of allicin in gastric cancer. 各位朋友，若您有醫美、減肥、健康相關問題，請直接到「景升診所」官網任一頁面留言，或用下列方法與我們聯絡： 直接撥打24小時專線 +886-931919066 Line id=“Gscline" WeChat id=“Gscline" 哈囉，大家好: 我們有幾個不同的頻道： Grand Health 大健康 （健康加財富、知足就是福）https://goo.gl/6EGLMd Grand Beauty 大醫美 （好好愛自己、就從現在起）https://goo.gl/g1E1rq Grand Touring 大旅遊 （大叔向前跑、永遠沒煩惱）https://goo.gl/7HN4bk 歡迎大家欣賞，喜歡就請按個讚，想獲取最新訊息就按「訂閱」吧！ 我們會提供更多更新的知識和訊息給大家。 感謝以下單位的幫助： ✪景升診所 https://www.genesis-clinic.org https://www.gscline.com ✪愛瘦美官網 https://www.isome.com.tw ✪邱醫師醫話園 https://www.okclinic.gscline.com ✪隆乳 https://www.gscline.com/ifatgraft/breast-adsc-htm ✪減肥 https://www.gscline.com/islimcenter-htm/fat-htm ✪自體脂肪隆乳 https://www.gscline.com/ifatgraft/breast-adsc-htm ✪瘦臉 https://www.gscline.com/ilipolysis-htm/fll-face-htm ✪瘦手臂 https://www.gscline.com/ilipolysis-htm/fll-arm-htm ✪瘦小腹 https://www.gscline.com/ilipolysis-htm/fll-abdomen-htm ✪瘦腿 https://www.gscline.com/ilipolysis-htm/fll-leg-htm ✪瘦大腿 https://www.gscline.com/ilipolysis-htm/fll-thigh-htm ✪抽脂 https://www.gscline.com/liposuction-new-technique/fat_liposuction-htm ✪男性女乳 https://www.gscline.com/ihair-htm/fll-gynecomastia-htm ✪狐臭 https://www.gscline.com/ihair-htm/laserhyperhidrosis-htm

染色体分配時におけるKi-67の機能性に関する論文を紹介しました。Show notes 周期ゼミ Periodical cicadas … 全米における周期ゼミの分布について 論文の縦読み … 同じオーサーの論文を時間軸で読む、論文の縦読みについてはresearchat.fmのep57にて説明しました。 Cuylen-Haering et al., Nature (2020) … “Chromosome clustering by Ki-67 excludes cytoplasm during nuclear assembly” Gerlich et al. Cell (2003) … “Global Chromosome Positions Are Transmitted through Mitosis in Mammalian Cells” Cuylen et al., Nature (2016) … “Ki-67 acts as a biological surfactant to disperse mitotic chromosomes” Samwer et al., Cell (2017) … “DNA Cross-Bridging Shapes a Single Nucleus from a Set of Mitotic Chromosomes” Daniel Gerlich 植物の細胞で染色体が分配される様子 … 1956に撮影されたAfrican Blood Lilyの細胞における染色体分配と細胞分裂の様子。植物には中心体が存在しないので少し動物細胞のものとは趣が異なる。64年前に撮影された動画だが未だ色褪せず様々な洞察を与えてくれる。無染色・ライブセルで行われた驚異的なイメージング。 上記動画に関するツイート … 海外勢もかなりコメントをくれているのがわかる。 体細胞分裂 … prophase->prometaphase->metaphase->anaphase->telophase->cytokinesis。英語だとmitosis DNA複製 遺伝情報 減数分裂 … 英語だとmeiosis HeLa細胞 染色体 核(細胞核) ミトコンドリア … パラサイト・イヴでご存知の方も多いだろう。 細胞小器官 核小体 … 仁とも呼ばれていた。 リボソーム リボソームRNA 倍数性 姉妹染色体/姉妹染色分体 コヒーシン … 姉妹染色体を接着させるために重要なタンパク質 Locke. JCS (1990) … “Is there somatic inheritance of intracellular patterns?” transvection mitophagy ヒストン ヌクレオソーム クロマチン … ヒストン、ヌクレオソーム、クロマチン、染色体についてはどこかでじっくり話します。 CFP, YFP … 蛍光タンパク質 細胞周期 … G1->S->G2->M. G1->S->G2が間期、Mが分裂期 FRAP(Fluorescence recovery after photobleaching) FISH Kimura and Cook. J Cell Biol (2001) … “Kinetics of core histones in living human cells: little exchange of H3 and H4 and some rapid exchange of H2B” 染色体テリトリー Cremer and Cremer. Cold Spring Harb Perspect Biol. (2010) … “Chromosome Territories”: ドンピシャタイトルのThomas CremerによるChromosome territoryのレビュー。 Carl Rabl Theodor Boveri Sutton-Boveriの染色体説 キネトコア セントロメア スピンドル … 紡錘体 微小管 … microtuble RNAi ki-67 G0期 核膜 核膜孔 open mitosis/closed mitosis Nuclear envelope break down … 核膜の崩壊 ノコダゾール コルヒチン FCS 両親媒性 Crasta et al., Nature (2012) … “DNA breaks and chromosome pulverization from errors in mitosis” micro nucleiに関する最近の代表的な研究 スプライシング コンデンシン Delarue et al. Cell (2018) … “mTORC1 Controls Phase Separation and the Biophysical Properties of the Cytoplasm by Tuning Crowding”: GEMs(genetically encoded multimeric nanoparticles)を開発した論文。これは激アツである！ Akita et al., JCS (2007) … “The crystal structure of a virus-like particle from the hyperthermophilic archaeon Pyrococcus furiosus provides insight into the evolution of viruses”: Delarue et al. (2018)で使われたencapsulinに関する論文。これも激アツである！ 養王田先生の科研費報告書 … “Encapsulinとは単一のシェルタンパク質で構成される内部が空洞のナノ構造体であり、一部の微生物細胞内に形成されている。” 核移行シグナル Görisch et al., JCS (2005) … “Histone acetylation increases chromatin accessibility”: クロマチンへのaccessibilityをイメージングで示そうとした論文 Dextran Flavopiridol Trichostatin A (TSA) Angelika Amon Breakthrough Prize in Life Sciences 染色体の異数性 … aneuploidy 出芽酵母 Ünal et al., Science (2011) … “Gametogenesis Eliminates Age-Induced Cellular Damage and Resets Life Span in Yeast”: 老化した出芽酵母は減数分裂に進みにくいことを示した定量解析。Amon labからの研究。 King et al., eLife (2019) … “Meiotic cellular rejuvenation is coupled to nuclear remodeling in budding yeast”: 上記のFirst authorであるÜnal labから出た論文。年老いた出芽酵母が減数分裂に進んだ場合の”Nuclear rejuvenation”(核若返り)に関するイメージング研究 エピジェネティクス(epigenetics) Conrad Hal Waddington … epigeneticsの提唱者。 Editorial notes 素人にもロジックが追いやすかった気がする (soh) 綿々と続くドイツの細胞生物学/染色体学研究の系譜はまたどこかで話せたらと思います。(tadasu) figureがモンスターボールみたいですね (coela)

The cover for issue 37 of Oncotarget features Figure 7, "The combination of romidepsin and KU60019 is synergistic in a xenograft model of MCL," by Scotto, et al. which reported that the antiproliferative effect induced by histone deactylase inhibitors is associated with the up-regulated expression of the cyclin-dependent kinase inhibitor p21. Paradoxically, the increased expression of p21 correlates with a reduced cell killing to the drug. HDAC inhibitors appear to activate p21 expression via ataxia telangiectasia mutated activity. The Oncotarget authors explored the potential synergistic interaction of the ATM inhibitor with romidepsin, given the potential complementary impact around p21. A synergistic cytotoxic effect was observed in all lymphoma cell lines examined when the HDACi was combined with KU60019. The increase in apoptosis correlates with decreased expression of p21 due to the ATM inhibitor. KU60019 decreased expression of the cyclin-dependent kinase inhibitor at the transcriptional level, compromising the ability of HDACi to induce p21 and cell cycle arrest and ultimately facilitating a shift toward the apoptotic phase. Central to the increased apoptosis observed when romidepsin is combined with KU60019 is the reduced expression of p21 and the absence of a G2/M cell cycle arrest that would be exploited by the tumor cells to evade the cytotoxic effect of the HDAC inhibitor. Dr. Owen A. O'Connor from The Columbia University Medical Center said, "HDAC inhibitors (HDACi) have emerged as valuable drugs in the treatment of select lymphomas and synergize with a diverse range of pharmacological and biological agents." The observation leads to the following hypothesis: if induction of p21 compromises the efficacy of HDAC inhibitors, then strategies to mitigate HDAC inhibitor induced p21 expression could lead to promising synergistic combinations. Induction of p21 by HDAC inhibitors is compromised in A-T cells given that ATM activity is essential for HDAC inhibitor-induced p21 expression. Collectively, these observations have led to the following hypothesis: If ATM activity is necessary for HDAC inhibitor mediated p21 induction, then selective ATM inhibitors could mitigate the HDAC induced p21 expression and potentiate its cytotoxic effect. The ATM inhibitor nullifies HDAC induction of p21 expression resulting in a synergistic interaction. KU60019 reduces p21 expression at the transcriptional level and antagonizes romidepsin transcriptional induction of p21. In both instances, the result is a markedly down-regulation of p21 expression at the protein level. The O'Connor Research Team concluded in their Oncotarget Research Paper that it is intuitive that pleotropic drugs like HDACi are likely to have both favorable and unfavorable effects on cell growth and survival. Strategies directed toward understanding how to mitigate the unfavorable influences of the class can lead to improved efficacy in rational combinations. Many examples of drug synergy with HDAC inhibitors have been driven by random efforts in mixing and matching in order to identify possible complementary partners. Obviously, a clear understanding of the molecular pharmacologic features of pleotropic drug classes like HDAC inhibitors can afford unique opportunities to think about logical combinations. Ultimately, these approaches need to be translated to the clinic in order to establish therapeutic merit in the clinic. Sign up for free Altmetric alerts about this article DOI - https://doi.org/10.18632/oncotarget.27723 Full text - https://www.oncotarget.com/article/27723/text/ Correspondence to - Owen A. O'Connor - owenaoconnor@gmail.com Keywords - lymphoma, HDAC inhibitor, ATM inhibitor, p21, cell cycle About Oncotarget Oncotarget is a weekly, peer-reviewed, open access biomedical journal covering research on all aspects of oncology. To learn more about Oncotarget, please visit https://www.oncotarget.com

Volume 11, Issue 25 of @Oncotarget reported that to examine the role of RSK in AML, the authors analyzed apoptosis and the cell cycle profile following treatment with BI-D1870, a potent inhibitor of RSK. BI-D1870 treatment increased the G2/M population and induced apoptosis in Acute Myeloid Leukemia cell lines and patient Acute Myeloid Leukemia cells. Therefore, the authors investigated whether BI-D1870 potentiates the anti-leukemic activity of vincristine by targeting mitotic exit. Combination treatment of BI-D1870 and vincristine synergistically increased mitotic arrest and apoptosis in acute leukemia cells. These data show that BI-D1870 induces apoptosis of AML cells alone and in combination with vincristine through blocking mitotic exit, providing a novel approach to overcoming vincristine resistance in AML cells. Dr. Kathleen M. Sakamoto from Stanford University School of Medicine said, "Acute myeloid leukemia (AML) is a genetically and phenotypically heterogeneous hematologic malignancy characterized by the accumulation of immature myeloid blasts with resultant peripheral blood cytopenia." Treatment of cells with microtubule targeting agents, including paclitaxel and the vinca alkaloid vincristine, blocks the proper formation of the mitotic spindle through inhibition of microtubule dynamics, resulting in the prolonged mitotic arrest of cancer cells. MTAs-treated mitotic arrested cells may undergo apoptosis in mitosis, however, the rapid degradation of Cyclin B due to an insufficient SAC leads to the mitotic slippage into tetraploid G1 stage in resistant cells. Though vinca alkaloid microtubule-destabilizing compounds have shown clinical efficacy against various hematological malignancies and were included in combination chemotherapy of the VAPA study, they are not currently used in induction chemotherapy for AML due to their high toxicity against lymphoid cells and rapid degradation by myeloperoxidase in AML cells. In this study, they demonstrate that BI-D1870, a potent inhibitor of RSK, induces mitotic arrest, and apoptosis in AML cells without inhibiting CDC2 and CDC25C. Furthermore, BI-D1870 synergizes with vinca alkaloid vincristine in AML cells, suggesting that inhibition of mitotic exit with BI-D1870 could be a promising novel approach for AML therapy in combination with MTAs. The Sakamoto Research Team concluded in their Oncotarget Research Paper that BI-D1870 is a reversible pan-RSK inhibitor, showing > 500-fold higher activity for RSK than other AGC kinases. BI-D1870 also inhibits the activity of PLK1, Aurora-B, MELK, PIM3, MST2, and GSK3β at higher concentrations than for RSK. BI-D1870 and BRD7389 have been reported to inhibit proliferation and significantly increase the G2/M population in melanoma cells. BI-D1870 does not have proper physicochemical properties for clinical application. Future structure-activity relationships study for BI-D1870 is required to improve solubility and pharmacokinetic profiles for in vivo preclinical and clinical studies. Sign up for free Altmetric alerts about this article DOI - https://doi.org/10.18632/oncotarget.27630 Full text - https://www.oncotarget.com/article/27630/text/ Correspondence to - Kathleen M. Sakamoto - kmsakamo@stanford.edu Keywords - acute myeloid leukemia, BI-D1870, RSK, vincristine, spindle assembly checkpoint About Oncotarget Oncotarget is a weekly, peer-reviewed, open access biomedical journal covering research on all aspects of oncology. To learn more about Oncotarget, please visit https://www.oncotarget.com or connect with: Facebook - https://www.facebook.com/Oncotarget/ Twitter - https://twitter.com/oncotarget LinkedIn - https://www.linkedin.com/company/oncotarget Pinterest - https://www.pinterest.com/oncotarget/ Reddit - https://www.reddit.com/user/Oncotarget/ Oncotarget is published by Impact Journals, LLC please visit http://www.ImpactJournals.com or connect with @ImpactJrnls Media Contact MEDIA@IMPACTJOURNALS.COM 18009220957x105

For a long time cyclin dependent kinase 5 (Cdk5) was thought to be of exclusive importance in neuronal cells. However, recently increasing evidence suggests a function of Cdk5 in cancer progression. In the present study, we examined the role of Cdk5 in hepatocellular carcinoma (HCC), a highly chemoresistant cancer with poor prognosis. Consequently, development of novel targeted therapies for HCC is of paramount clinical importance. Analysis of human HCC patient samples showed an increased expression of Cdk5 as compared to normal liver tissues. Functional ablation of Cdk5 significantly decreases HCC cell proliferation and clonogenic survival, and reduces cell motility and invasion. Of note, genetic as well as pharmacologic inhibition of Cdk5 also shows in vivo efficacy in a HCC xenograft mouse model. Investigating the mechanism behind these functional effects revealed that Cdk5 is most active in the nucleus of cells in G2/M phase. In this cell cycle phase DNA damage response takes place, which is affected by Cdk5 inhibition. Furthermore, Cdk5 leads to phosphorylation of Ataxia Telangiectasia Mutated (ATM) and thereby influence its downstream signaling. Importantly, combination of Cdk5 inhibition with different DNA damage inducing chemotherapeutics or the first-line systemic drug sorafenib inhibits synergistically HCC tumor progression. In conclusion, we introduce: 1. Cdk5 as a novel drugable target for treatment of HCC 2. The combination of Cdk5 inhibition and DNA damage agents as a novel therapeutic approach 3. An increased efficacy of sorafenib treatment by combing with Cdk5 inhibition

In patients with lung cancer whose tumors harbor activating mutations in the EGF receptor (EGFR), increased responses to platinum-based chemotherapies are seen compared with wild-type cancers. However, the mechanisms underlying this association have remained elusive. Here, we describe a cellular phenotype of crosslinker sensitivity in a subset of EGFR-mutant lung cancer cell lines that is reminiscent of the defects seen in cells impaired in the Fanconi anemia pathway, including a pronounced G2–M cell-cycle arrest and chromosomal radial formation. We identified a defect downstream of FANCD2 at the level of recruitment of FAN1 nuclease and DNA interstrand crosslink (ICL) unhooking. The effect of EGFR mutation was epistatic with FANCD2. Consistent with the known role of FANCD2 in promoting RAD51 foci formation and homologous recombination repair (HRR), EGFR-mutant cells also exhibited an impaired RAD51 foci response to ICLs, but not to DNA double-strand breaks. EGFR kinase inhibition affected RAD51 foci formation neither in EGFR-mutant nor wild-type cells. In contrast, EGFR depletion or overexpression of mutant EGFR in wild-type cells suppressed RAD51 foci, suggesting an EGFR kinase-independent regulation of DNA repair. Interestingly, EGFR-mutant cells treated with the PARP inhibitor olaparib also displayed decreased FAN1 foci induction, coupled with a putative block in a late HRR step. As a result, EGFR-mutant lung cancer cells exhibited olaparib sensitivity in vitro and in vivo. Our findings provide insight into the mechanisms of cisplatin and PARP inhibitor sensitivity of EGFR-mutant cells, yielding potential therapeutic opportunities for further treatment individualization in this genetically defined subset of lung cancer.

Human cells have evolved protective mechanisms such as DNA repair and cell cycle checkpoints in order to promote stability of the genome. Studies on hereditary instability syndromes associated with a higher incidence of malignancies like Xeroderma pigmentosum or Nijmegen breakage syndrome demonstrated that genetic defects and subsequent dysfunction of a specific DNA repair mechanism trigger the development of cancer. Within the last years, the investigation of cell cycle checkpoints gained increasing importance in cancer research. Checkpoints are signaling cascades that halt the cell cycle in response to DNA damage, thereby providing time for repair and preventing accumulation of DNA alterations. While the p53-dependent G1-S checkpoint has been extensively investigated, little is known about other checkpoints in humans such as the G2-M or the S-phase progression checkpoint. Studies on the human cancer syndrome ataxia telangiectasia (AT) showed that AT cells fail to induce several checkpoints in response to ionizing radiation (IR), indicating that a checkpoint gene defect is responsible for the AT-associated cancers. The responsible gene (ATM) has significant sequence homology to the checkpoint kinase gene sprad3 in the fission yeast Schizosaccharomyces pombe (S. pombe). In S. pombe, spRad3 regulates G2-M checkpoint activation in response to DNA damage. Defects in the sprad3 gene, like defects in ATM, sensitize the organisms to radiation and radiomimetic drugs, suggesting conservation of checkpoint pathways from yeast to humans as well as a potential role of the G2-M checkpoint in carcinogenesis. The discovery of G2-M checkpoint-deficient yeast mutants led to the cloning of additional checkpoint genes in yeast and their human homologs. This group of novel human genes includes homologs of sprad9 (hRAD9), sphus1 (hHUS1), and sprad1 (hRAD1). In S. pombe, these genes are required for activation of spRad3, and defects in one or more of these genes render the yeast more sensitive to genotoxic agents. Mutations within the human rad genes may bring about an increased rate of mutations and genomic instability as shown for p53 or AT and may be responsible for inherited predisposition to cancer. In view of this potential importance of human rad genes in the process of carcinogenesis, we have undertaken a cellular and molecular analysis of the novel human checkpoint proteins hRad9, hHus1, and hRad1 in the leukemia cell line K562 and in human keratinocytes. Using specific antibodies to the hRad9, hHus1, and hRad1 proteins we demonstrated with co-immunoprecipitation and Western-blot experiments that the human checkpoint proteins hRad9, hHus1, and hRad1 associate in a biochemical complex similar to the spRad9-spHus1-spRad1 complex reported in fission yeast. To generate a model system of checkpoint protein function amenable to biochemical analysis, we prepared epitope-tagged expression vectors for hRad9, hHus1, and hRad1, which were transfected into K562 cells by electroporation, resulting in transient expression of epitope-tagged protein. By simultaneous expression of hRad9, hHus1, and hRad1 we showed that transiently expressed epitope-tagged checkpoint proteins hRad9, hHus1, and hRad1 recapitulate complex formation of endogenous proteins. Immunoprecipitation studies with lysates of hRad9-overexpressing cells revealed that hRad9 undergoes complex post-translational modifications. Co-expression of hRad9 with hHus1, and hRad1 resulted in a large increase of the amount of a highly modified form of hRad9, suggesting that hRad1 and hHus1 either promote formation of, or stabilize the modified form of hRad9. Previously, a direct correlation between checkpoint protein phosphorylation and activation of DNA damage checkpoints in yeast was proposed. In this study, we show that hRad9 is phosphorylated in response to DNA damage, and that phosphorylated hRad9 interacts with hHus1 and hRad1 as well. The present results suggest that the hRad9-hHus1-hRad1 complex actively participates in an evolutionarily conserved DNA damage-induced signaling cascade. hRad1 seems to possess exonuclease activity. The presence of a putative DNA-metabolizing protein in the multimolecular checkpoint complex, coupled with genetic data that place spRad9, spHus1, and spRad1 early in the response pathway of checkpoint activation suggests that the complex may function as a sensor that scans the genome for damaged DNA. Once damaged DNA is detected, this complex may initiate endonucleolytic processing of the lesions and trigger interactions with downstream signaling elements, or may link unknown damage recognition components to downstream signal-transducing pathways that include the ATM kinase, which is implicated in actively enforcing cell cycle arrest after DNA damage. Potential goals of checkpoint research include the implementation of screening tests to identify familial cancer predisposition and treatment of checkpoint gene defects by gene transfer. Another aim of checkpoint research is the development of checkpoint-based cancer therapy. More than 50% of all human malignant tumors contain mutated p53, and p53-deficient tumor cells lack induction of the G1-S checkpoint in response to DNA damage. One emerging hypothesis is that selective inhibitors of the compensating G2-M checkpoint would preferentially radiosensitize p53-deficient tumor cells. Thus, the investigation of checkpoint function in humans provides further targets for chemotherapeutic agents and will help to design future strategies in cancer therapy.