Podcasts about notch1

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Best podcasts about notch1

Latest podcast episodes about notch1

PaperPlayer biorxiv cell biology
Liver-specification of human iPSC-derived endothelial cells transplanted into mouse liver

PaperPlayer biorxiv cell biology

Play Episode Listen Later Jun 29, 2023


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.06.28.546913v1?rss=1 Authors: Yap, K. K., Schroeder, J., Gerrand, Y.-W., Kong, A., Fox, A. M., Knowles, B., Banting, S. W., Elefanty, A. K., Stanley, E. G., Yeoh, G. C., Lockwood, G. P., Cogger, V. C., Morrison, W. A., Polo, J. M., Mitchell, G. M. Abstract: Liver sinusoidal endothelial cells (LSECs) play an important role in liver development, regeneration and pathophysiology, but the differentiation process that generates their unique tissue-specific phenotype is poorly understood and difficult to study as primary cells are only available in limited quantities. To address this, we hypothesised that human induced pluripotent stem cell (hiPSC)-derived endothelial cells (iECs) can produce hiPSC-derived LSECs upon transplantation into the livers of Fah-/-/Rag2-/-/Il2rg-/- mice, and serve as a model to study LSEC specification. Progressive and long-term repopulation of the liver vasculature was observed, as iECs expanded along the sinusoids that run between hepatocytes and increasingly produced human factor VIII, indicating differentiation into LSEC-like cells. To chart the developmental profile associated with LSEC specification, the bulk transcriptome of transplanted cells at time-points between 1 and 12 weeks were compared against primary human adult LSECs, which demonstrated a chronological increase in LSEC markers, LSEC differentiation pathways, and zonation. Bulk transcriptome analysis suggested that the transcription factors NOTCH1, GATA4, and FOS play a central role in LSEC specification, interacting with a network of 27 transcription factors. Novel markers associated with this process include EMCN and CLEC14A. Additionally, single cell transcriptomic analysis demonstrated that transplanted iECs at 4 weeks contain zonal subpopulations with a region-specific phenotype. Collectively, this study confirms that hiPSC can adopt LSEC-like features and provides insight into LSEC specification. This humanised xenograft system can be applied to further interrogate LSEC developmental biology and pathophysiology, bypassing current logistical obstacles associated with primary human LSECs. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

PaperPlayer biorxiv cell biology
Transcriptional Activation of Regenerative Hematopoiesis via Vascular Niche Sensing

PaperPlayer biorxiv cell biology

Play Episode Listen Later Mar 29, 2023


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.03.27.534417v1?rss=1 Authors: Itkin, T., Houghton, S., Schreiner, R., Lin, Y., Badwe, C., Voisin, V., Murison, A., Seyedhassantehrani, N., Kaufmann, K. B., Garcia-Prat, L., Booth, G. T., Geng, F., Liu, Y., Gomez-Salinero, J. M., Shieh, J.-H., Redmond, D., Xiang, J. Z., Josefowicz, S. Z., Trapnell, C., Spencer, J. A., Zangi, L., Hadland, B., Dick, J. E., Xie, S. Z., Rafii, S. Abstract: Transition between activation and quiescence programs in hematopoietic stem and progenitor cells (HSC/HSPCs) is perceived to be governed intrinsically and by microenvironmental co-adaptation. However, HSC programs dictating both transition and adaptability, remain poorly defined. Single cell multiome analysis divulging differential transcriptional activity between distinct HSPC states, indicated for the exclusive absence of Fli-1 motif from quiescent HSCs. We reveal that Fli-1 activity is essential for HSCs during regenerative hematopoiesis. Fli-1 directs activation programs while manipulating cellular sensory and output machineries, enabling HSPCs co-adoptability with a stimulated vascular niche. During regenerative conditions, Fli-1 presets and enables propagation of niche-derived Notch1 signaling. Constitutively induced Notch1 signaling is sufficient to recuperate functional HSC impairments in the absence of Fli-1. Applying FLI-1 modified-mRNA transduction into lethargic adult human mobilized HSPCs, enables their vigorous niche-mediated expansion along with superior engraftment capacities. Thus, decryption of stem cell activation programs offers valuable insights for immune regenerative medicine. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

PaperPlayer biorxiv cell biology
Notch1 forms nuclear transcriptional condensates that drive target gene expression.

PaperPlayer biorxiv cell biology

Play Episode Listen Later Mar 18, 2023


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.03.17.533124v1?rss=1 Authors: Foran, G., Hallam, R. D., Megaly, M., Turgambayeva, A., Li, Y., Necakov, A. Abstract: The Notch receptor is a titratable, context-specific counter of intercellular interactions that translates productive interactions with ligands on neighbouring cells into corresponding changes in gene expression via the nuclear localization of the Notch intracellular Domain (NICD). Using an Optogenetic Notch1 construct in combination with a live imaging transcriptional reporter and super-resolution imaging, we show that the N1ICD activates gene expression through spontaneous self-assembly into transcriptional condensates whose phase separation is driven by C-terminal Intrinsically Disordered Regions (IDR) of the N1ICD. N1ICD condensates recruit and encapsulate a broad set of core transcriptional proteins, thereby facilitating gene expression and promoting super enhancer-looping. We produced a model of Notch1 activity, whereby discrete changes in nuclear NICD abundance is translated into precise changes in target gene expression through the assembly of phase separated N1ICD molecular crucibles that catalyze gene expression in a concentration-dependent manner by enriching essential transcriptional machineries at target genomic loci. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

PaperPlayer biorxiv cell biology
Novel determinants of NOTCH1 trafficking and signaling in breast epithelial cells

PaperPlayer biorxiv cell biology

Play Episode Listen Later Mar 6, 2023


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.03.05.531156v1?rss=1 Authors: Kobia, F. M., Castro e Almeida, L., Carminati, F., Andronache, A., Lavezzari, F., Wade, M., Vaccari, T. Abstract: The evolutionarily conserved Notch pathway controls cell-cell communication during development and in adult metazoans. It influences cell fate decisions, cell proliferation and cell differentiation, and contributes to the maintenance of normal tissue homeostasis. Consequently, misregulation of the Notch pathway is associated with a wide range of diseases, including congenital disorders and cancers with little to no cure. Signaling by Notch receptors is regulated by a complex set of cellular processes that include maturation and trafficking to the plasma membrane, endocytic uptake and sorting, lysosomal and proteasomal degradation, and ligand-dependent and independent proteolytic cleavages. We devised assays to follow quantitively the lifetime of endogenous human NOTCH1 receptor in breast epithelial cells in culture. Based on such analysis, we executed a high-content screen of 2749 human genes for which modulatory compounds exist, to identify new regulators of Notch signaling activation that might be amenable to pharmacologic intervention. We uncovered 39 new NOTCH1 genetic modulators that affect different steps of NOTCH1 cellular dynamics. In particular, we find that PTPN23 and HCN2 act as positive NOTCH1 regulators by promoting endocytic trafficking and NOTCH1 maturation in the Golgi apparatus, respectively, while SGK3 serves as a negative regulator that can be modulated by pharmacologic inhibition. Our findings might be relevant in the search of new strategies to counteract pathologic Notch signaling. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

PaperPlayer biorxiv cell biology
Notch1 cortical signaling regulates epithelial architecture and cell-cell adhesion

PaperPlayer biorxiv cell biology

Play Episode Listen Later Jan 23, 2023


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.01.23.524428v1?rss=1 Authors: White, M. J., Jacobs, K. A., Singh, T., Kutys, M. L. Abstract: Notch receptors control tissue morphogenic processes that involve coordinated changes in cell architecture and gene expression, but how a single receptor can produce these diverse biological outputs is unclear. Here we employ a 3D organotypic model of a ductal epithelium to reveal tissue morphogenic defects result from loss of Notch1, but not Notch1 transcriptional signaling. Instead, defects in duct morphogenesis are driven by dysregulated epithelial cell architecture and mitogenic signaling which result from loss of a transcription-independent Notch1 cortical signaling mechanism that ultimately functions to stabilize adherens junctions and cortical actin. We identify that Notch1 localization and cortical signaling are tied to apical-basal cell restructuring and discover a Notch1-FAM83H interaction underlies stabilization of adherens junctions and cortical actin. Together, these results offer new insights into Notch1 signaling and regulation, and advance a paradigm in which transcriptional and cell adhesive programs might be coordinated by a single receptor. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Oncotarget
Trending With Impact: Are NOTCH1 Variants Prognostic in Breast Cancer?

Oncotarget

Play Episode Listen Later Feb 24, 2022 6:47


The genetic changes that occur within the protein-coding gene NOTCH1 have not yet been fully studied or classified. Despite a lack in research, previous studies have suggested that NOTCH1 may be a potential target for novel cancer therapies, particularly against triple-negative breast cancer (TNBC). NOTCH1 variants in TNBC tend to cluster in the PEST region and have previously been linked to gamma secretase inhibitor (GSI) sensitivity and chemotherapy resistance. “Furthermore, TNBC patients with increased Notch1 expression have demonstrated increased aggressive phenotypes and lower median overall survival [25].” Since TNBC is well-known for a lack of actionable therapeutic targets, aggressive phenotypes and poor prognoses, there is an important need to develop new targeted therapies—as well as predictive markers for those therapies. Researchers from The Johns Hopkins University School of Medicine, Vanderbilt University Medical Center and The Vanderbilt-Ingram Cancer Center experimented in vitro with NOTCH1 variants and their ability to predict TNBC responsiveness to GSIs and standard of care chemotherapies. Their trending research paper was published by Oncotarget on February 16, 2022, and entitled, “NOTCH1 PEST domain variants are responsive to standard of care treatments despite distinct transformative properties in a breast cancer model.” Full blog - https://www.oncotarget.org/2022/02/24/trending-with-impact-are-notch1-variants-prognostic-in-breast-cancer/ DOI - https://doi.org/10.18632/oncotarget.28200 Correspondence to - Ben Ho Park - ben.h.park@vumc.org Sign up for free Altmetric alerts about this article - https://oncotarget.altmetric.com/details/email_updates?id=10.18632%2Foncotarget.28200 Keywords - NOTCH1, TNBC, breast cancer, PEST About Oncotarget Oncotarget is a peer-reviewed, open access biomedical journal covering research on all aspects of oncology. 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/OncotargetYouTube 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: https://www.ImpactJournals.com Media Contact MEDIA@IMPACTJOURNALS.COM 18009220957

Yale Vascular Review
Episode 4: Abdominal Aortic Aneurysms

Yale Vascular Review

Play Episode Listen Later Dec 27, 2021 24:08


Hosts: Ocean Setia is a PGY-4 Vascular Surgery Integrated Resident. Keyuree Satam is a 4th year medical student at Yale.Papers:Multicentre Outcomes of Redo Fenestrated/Branched Endovascular Aneurysm Repair to Rescue Failed Fenestrated Endografts Prospective Multicentre Cohort Study of Fenestrated and Branched Endografts After Failed Endovascular Infrarenal Aortic Aneurysm Repair with Type Ia EndoleakFenestrated-Branch Endovascular Repair After Prior Abdominal Aortic Aneurysm RepairComparison of treatment options for aortic necks outside standard endovascular aneurysm repair instructions for useAnatomic eligibility for endovascular aneurysm repair preserved over 2 years of surveillancePreoperative risk score accuracy confirmed in a modern ruptured abdominal aortic aneurysm experienceNot all risk scores are created equal: A comparison of risk scores for abdominal aortic aneurysm repair in administrative data and quality improvement registriesLimb Graft Occlusion Following Endovascular Aneurysm Repair for Infrarenal Abdominal Aortic Aneurysm with the Zenith Alpha, Excluder, and Endurant Devices: a Multicentre Cohort StudyPostoperative imaging follow-up at 2 years as a predictor of long-term outcomes after endovascular aneurysm repair Tailored Sac Embolization During EVAR for Preventing Persistent Type II EndoleakOutcomes of translumbar embolization of type II endoleaks following endovascular abdominal aortic aneurysm repairCombined Detection of Plasma TNF-α Converting Enzyme and Notch1 is Valuable in Screening Endoleak After Endovascular Abdominal Aortic Aneurysms RepairFollow Us: Twitter @YaleVascular, Instagram @yalevascularEmail: ocean.setia@yale.edu, keyuree.satam@yale.edu

PaperPlayer biorxiv bioinformatics
Bioinformatic Analysis Linking Genomic Defects to Chemosensitivity and Mechanism of Action

PaperPlayer biorxiv bioinformatics

Play Episode Listen Later Nov 20, 2020


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.11.20.391029v1?rss=1 Authors: Covell, D. G. Abstract: A joint analysis of NCI60 small molecule screening data, their genetically defective genes and mechanisms of action (MOA) of FDA approved cancer drugs screened in the NCI60 is proposed for identifying links between chemosensitivity, genomic defects and MOA. Self-organizing-maps (SOMs) are used to organize the chemosensitivity data. Students t-tests are used to identify SOM clusters with chemosensitivity for tumor cells harboring genetically defective genes. Fishers exact tests are used to reveal instances where defective gene to chemosensitivity associations have enriched MOAs. The results of this analysis find a relatively small set of defective genes, inclusive of ABL1, AXL, BRAF, CDC25A, CDKN2A, IGF1R, KRAS, MECOM, MMP1, MYC, NOTCH1, NRAS, PIK3CG, PTK2, RPTOR, SPTBN1, STAT2, TNKS and ZHX2, as possible candidates for roles in chemosensitivity for compound MOAs that target primarily, but not exclusively, kinases, nucleic acid synthesis, protein synthesis, apoptosis and tubulin. This analysis may contribute towards the goals of cancer drug discovery, development decision making, and explanation of mechanisms. Copy rights belong to original authors. Visit the link for more info

ASCO eLearning Weekly Podcasts
ASCO Guidelines: Initial Diagnostic Workup of Acute Leukemia Guideline

ASCO eLearning Weekly Podcasts

Play Episode Listen Later Dec 19, 2018 12:40


If you enjoyed this podcast, make sure to subscribe for more weekly education content from ASCO University. We truly value your feedback and suggestions, so please take a moment to leave a review. If you are an oncology professional and interested in contributing to the ASCO University Weekly Podcast, email ascou@asco.org for more information. TRANSCRIPT The purpose of this podcast is to educate and to 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. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement. [MUSIC PLAYING] Hello and welcome to the ASCO Guidelines podcast series. My name is Shannon McKernin and today I'm interviewing Dr. Valerie de Haas from Princess Máxima Center for Pediatric Oncology in the Netherlands, lead author on "Initial Diagnostic Workup of Acute Leukemia: ASCO Clinical Practice Guideline Endorsement of the CAP and ASH Guideline.” Thank you for being here today, Dr. de Haas. Thank you. So first, can you give us a general overview of what this guideline covers? Well, yes. The laboratory evaluation of patients who are suspected of having acute leukemia is very complex, and it has evolved significantly with the incorporation of advanced laboratory techniques. The traditional backbone of initial workup of AL, of acute leukemia, is composed of ctyomorphology, cytochemistry, immunophenotyping, and molecular cytogenetics. These techniques are the backbone of the initial diagnostic workup of acute leukemia. This is leading to risk stratification and fine tuning of the therapy by molecular signatures. The advanced molecular diagnostics, such as next-generation sequencing, has become more important in the diagnosis and in the risk stratification of acute leukemia. This guideline is meant for both pediatric and adult patients, and it was initially published in 2017. This year, we reviewed this guideline, and we have taken into account two important developments. First, since 2017, we've seen that there are major advances in molecular techniques and also that we can identify and validate new molecular markers. And those two events have contribute to a better risk stratification. And the second development is the effect that the WHO classification was revised in 2017 which also has led to new risk recoveries and refined subclassifications. So what are the key recommendations of this guideline? Well, in total, we have reviewed 27 guideline statements by the ASCO endorsement expert panelists. And discussion points are used to summarize issues that were identified from the updated literature. The ASCO expert panel determined that the recommendations from the guideline as published in 2016 are clear, thorough, and they are based upon the most relevant scientific evidences. We fully endorse the CAP-ASH guideline on initial diagnostic workup of acute leukemia. And we decided to include some discussion points according to clinical practice and according to the updated literature. In fact, we identified four categories of key recommendations. The first one is the initial diagnostics focusing on basic diagnostics and determination of risk parameters. This concerns, in total, about 11 guideline recommendations, and they give an overview of the initial workup varying from the collection of the clinical history of the patient to initial basic diagnostics by cytomorphology, flow cytometry and molecular cytogenetic analysis of peripheral blood, bone marrow, and cerebrospinal fluids. Secondly, the second category were molecular markers and MRD detection, and they were addressed by 10 of the recommendations. And these recommendations give a structural overview of the molecular and cytogenetic workup for acute lymphoblastic leukemia versus acute myeloid leukemia identifying different prognostic markers. Also, the detection of MRD is taken into account in this recommendation. There is a major difference between children and adults, and this part is given most attention in the discussion part as the developments have been major during the past few years. The third one is the context of referral to another institution with expertise in the management of acute leukemia. This is addressed by four recommendations, emphasizing the point that referral to an institution with specific expertise is of major importance for the central workup of acute leukemia. And finally, the final reporting and report keeping is reflected in three recommendations, mainly supporting conclusions from 2017 which were describing the fact that the complete report with basic diagnostics in one central report should be available within 48 to 72 hours. And this should be followed by complete, final, comprehensive report in one or two weeks. So can you tell us about those discussion points that were made and why the panel decided to include these? The discussion points include mostly issues regarding diagnostics that involve flow cytometry and molecular techniques as addressed in part one and two of the guidelines. We think that the cytomorphologic assessment is essential for initial diagnosis of acute leukemia. Multicolor flow cytometry using 8 to 10 colors has led to a better distinction between myeloids, lymphoid, and mixed lineage blast origin. Even when the number of cells are limited, for instance in CNS involvement, fine needle aspirate of extramedullary leukemic infiltration, or skin biopsy for leukemic cutis. Also, it was suggested to better assess the central nervous system involved in leukemia. The expert panel recommends the immunophenotyping studies as an additional detection technique next to the cytomorphological examination of cytospins and particularly for those with a low level involvement of acute leukemia that cannot be well addressed by a morphologic examination only. The TDT immunohistochemistry staining of cytospins has alternatively been used for detection of CNS disease in AML and evaluation of CSF by multicolor flow cytometry has been recently adopted in some centers. Flow cytometry, using at least six, but we now use in some laboratories, even 8 to 10 colors has led to a much more specific in tentative diagnosis. And this has improved the detection of CNS involvement. The use of molecular tools, for instance, polymerase change reaction, PCR, NGS for low-level CSF involvement is still under study, and therefore, we did not recommend this in our discussion. Regarding the molecular markers and MRD detection, the discussion here was mainly based upon the results of translational research supported by better molecular detection techniques. And those molecular diagnoses have been developing in the past few years with the inclusion of many more molecular markers. And they included one of the key diagnostic criteria in the revised WHO classification, which was revised in 2017. And we made substantial changes that have been made in the ASH-CAP guidelines concerning molecular diagnostics. Those newly identified targets by advanced molecular techniques give possibilities for better risk stratification. Some examples of better molecular characterization of acute lymphoblastic leukemia are, for instance, additional testing for MLL translocations. Furthermore, we can look in patients with T-ALL for NOTCH1, and FBXW7 mutations. The Ikaros family zinc finger gene, the IKZF1 gene is frequently deleted in adults as well in children with B-ALL. And it was shown to have an independent prognostic significance and was also associated with poor clinical outcome. In the current text of the current risk that the protocols IKZF1 should be regularly included in the screening panels for all ALL patients. If we look for examples for better characterization of AML, acute myeloid leukemia, we have found an increasing number of additional cytogenetic aberrations, like for instance FLT3 ITD which is associated with poor outcome. Another example is appropriate mutational analysis for kids, which can be detected both in adult patient as pediatric patients with a confirmed core binding factor acute myeloid leukemia. So this is myeloid leukemia with a translocation A21, RUNX1, or inversion 16. This recommendation is very strong in adults, whereas in children, this prognostic fact impact remains unclear. So there have been proven several publications which refer to a similar prognosis for children and others who refer to a poor prognosis in comparison to known mutated genes. So we suggest to test for this mutation in adults, especially, but also in children to learn from it. Finally, emerging evidence supports molecular studies as principle test for monitoring minimal residual disease of acute leukemia. And there are several key molecular markers that are included in the initial workup, which will be carried on for monitoring MRD, for instance, PML- RAR-alpha, RUNX1-RUNXT1, CBFB-MYH11, and NPM1, CEBP-alpha and others. Beside those aforementioned markers, it's very important to screen for other molecular markers that have predictive or prognostic value in the individual. And it is possible to use them for MRD. We have found a recent consensus from the European Leukemia Net MRD Working Group, who was proposing that for detection of molecular MRD, and they refer the RT PCR platform to NGS and digital PCR platforms. Although all those molecular techniques have been developed very quickly and it is very tempting to use them for initial diagnostics, currently, not all laboratories will have all those techniques available. So the expert panel strongly advises understanding to make distinction between diagnostic that are needed in the first phase to start treatment and subsequently, treatment stratification, in contrast to the usual dose findings in a broader research. For instance, available karyotyping, FISH, PCR techniques, if possible, NGS can be used in the initial start of treatment, whereas techniques like whole exome sequencing, whole genome sequencing, RNA sequencing, and epigenomic studies are meant for a broader research. And finally, how will these guideline recommendations affect patients? Well, in the end, the patients will receive better and especially, more personalized treatment. If we have results available within two weeks from diagnosis, it will be possible to better identify which basis will better benefit from more intensified and more personalized treatment, whereas others may need less intensive treatment with less toxicity. If you use traditional techniques to do this supported by molecular techniques like karyotyping, FISH, and PCR techniques, and in the end, following MRD to see which patients are responding to treatment, MRD detection will help to identify these patients and stratify them finally to the best treatment. Great. Thank you for your work on this important guideline, and thank you for your time today, Dr. de Haas. OK. Thanks a lot. And thank you to all of our listeners for tuning in to the ASCO Guidelines podcast series. If you've enjoyed what you've heard today, please rate and review the podcast and refer this show to a colleague.

ASCO Guidelines Podcast Series
Initial Diagnostic Workup of Acute Leukemia Guideline

ASCO Guidelines Podcast Series

Play Episode Listen Later Dec 3, 2018 12:40


The purpose of this podcast is to educate and to 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. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement. [MUSIC PLAYING] Hello and welcome to the ASCO Guidelines podcast series. My name is Shannon McKernin and today I'm interviewing Dr. Valerie de Haas from Princess Máxima Center for Pediatric Oncology in the Netherlands, lead author on "Initial Diagnostic Workup of Acute Leukemia: ASCO Clinical Practice Guideline Endorsement of the CAP and ASH Guideline.” Thank you for being here today, Dr. de Haas. Thank you. So first, can you give us a general overview of what this guideline covers? Well, yes. The laboratory evaluation of patients who are suspected of having acute leukemia is very complex, and it has evolved significantly with the incorporation of advanced laboratory techniques. The traditional backbone of initial workup of AL, of acute leukemia, is composed of ctyomorphology, cytochemistry, immunophenotyping, and molecular cytogenetics. These techniques are the backbone of the initial diagnostic workup of acute leukemia. This is leading to risk stratification and fine tuning of the therapy by molecular signatures. The advanced molecular diagnostics, such as next-generation sequencing, has become more important in the diagnosis and in the risk stratification of acute leukemia. This guideline is meant for both pediatric and adult patients, and it was initially published in 2017. This year, we reviewed this guideline, and we have taken into account two important developments. First, since 2017, we've seen that there are major advances in molecular techniques and also that we can identify and validate new molecular markers. And those two events have contribute to a better risk stratification. And the second development is the effect that the WHO classification was revised in 2017 which also has led to new risk recoveries and refined subclassifications. So what are the key recommendations of this guideline? Well, in total, we have reviewed 27 guideline statements by the ASCO endorsement expert panelists. And discussion points are used to summarize issues that were identified from the updated literature. The ASCO expert panel determined that the recommendations from the guideline as published in 2016 are clear, thorough, and they are based upon the most relevant scientific evidences. We fully endorse the CAP-ASH guideline on initial diagnostic workup of acute leukemia. And we decided to include some discussion points according to clinical practice and according to the updated literature. In fact, we identified four categories of key recommendations. The first one is the initial diagnostics focusing on basic diagnostics and determination of risk parameters. This concerns, in total, about 11 guideline recommendations, and they give an overview of the initial workup varying from the collection of the clinical history of the patient to initial basic diagnostics by cytomorphology, flow cytometry and molecular cytogenetic analysis of peripheral blood, bone marrow, and cerebrospinal fluids. Secondly, the second category were molecular markers and MRD detection, and they were addressed by 10 of the recommendations. And these recommendations give a structural overview of the molecular and cytogenetic workup for acute lymphoblastic leukemia versus acute myeloid leukemia identifying different prognostic markers. Also, the detection of MRD is taken into account in this recommendation. There is a major difference between children and adults, and this part is given most attention in the discussion part as the developments have been major during the past few years. The third one is the context of referral to another institution with expertise in the management of acute leukemia. This is addressed by four recommendations, emphasizing the point that referral to an institution with specific expertise is of major importance for the central workup of acute leukemia. And finally, the final reporting and report keeping is reflected in three recommendations, mainly supporting conclusions from 2017 which were describing the fact that the complete report with basic diagnostics in one central report should be available within 48 to 72 hours. And this should be followed by complete, final, comprehensive report in one or two weeks. So can you tell us about those discussion points that were made and why the panel decided to include these? The discussion points include mostly issues regarding diagnostics that involve flow cytometry and molecular techniques as addressed in part one and two of the guidelines. We think that the cytomorphologic assessment is essential for initial diagnosis of acute leukemia. Multicolor flow cytometry using 8 to 10 colors has led to a better distinction between myeloids, lymphoid, and mixed lineage blast origin. Even when the number of cells are limited, for instance in CNS involvement, fine needle aspirate of extramedullary leukemic infiltration, or skin biopsy for leukemic cutis. Also, it was suggested to better assess the central nervous system involved in leukemia. The expert panel recommends the immunophenotyping studies as an additional detection technique next to the cytomorphological examination of cytospins and particularly for those with a low level involvement of acute leukemia that cannot be well addressed by a morphologic examination only. The TDT immunohistochemistry staining of cytospins has alternatively been used for detection of CNS disease in AML and evaluation of CSF by multicolor flow cytometry has been recently adopted in some centers. Flow cytometry, using at least six, but we now use in some laboratories, even 8 to 10 colors has led to a much more specific in tentative diagnosis. And this has improved the detection of CNS involvement. The use of molecular tools, for instance, polymerase change reaction, PCR, NGS for low-level CSF involvement is still under study, and therefore, we did not recommend this in our discussion. Regarding the molecular markers and MRD detection, the discussion here was mainly based upon the results of translational research supported by better molecular detection techniques. And those molecular diagnoses have been developing in the past few years with the inclusion of many more molecular markers. And they included one of the key diagnostic criteria in the revised WHO classification, which was revised in 2017. And we made substantial changes that have been made in the ASH-CAP guidelines concerning molecular diagnostics. Those newly identified targets by advanced molecular techniques give possibilities for better risk stratification. Some examples of better molecular characterization of acute lymphoblastic leukemia are, for instance, additional testing for MLL translocations. Furthermore, we can look in patients with T-ALL for NOTCH1, and FBXW7 mutations. The Ikaros family zinc finger gene, the IKZF1 gene is frequently deleted in adults as well in children with B-ALL. And it was shown to have an independent prognostic significance and was also associated with poor clinical outcome. In the current text of the current risk that the protocols IKZF1 should be regularly included in the screening panels for all ALL patients. If we look for examples for better characterization of AML, acute myeloid leukemia, we have found an increasing number of additional cytogenetic aberrations, like for instance FLT3 ITD which is associated with poor outcome. Another example is appropriate mutational analysis for kids, which can be detected both in adult patient as pediatric patients with a confirmed core binding factor acute myeloid leukemia. So this is myeloid leukemia with a translocation A21, RUNX1, or inversion 16. This recommendation is very strong in adults, whereas in children, this prognostic fact impact remains unclear. So there have been proven several publications which refer to a similar prognosis for children and others who refer to a poor prognosis in comparison to known mutated genes. So we suggest to test for this mutation in adults, especially, but also in children to learn from it. Finally, emerging evidence supports molecular studies as principle test for monitoring minimal residual disease of acute leukemia. And there are several key molecular markers that are included in the initial workup, which will be carried on for monitoring MRD, for instance, PML- RAR-alpha, RUNX1-RUNXT1, CBFB-MYH11, and NPM1, CEBP-alpha and others. Beside those aforementioned markers, it's very important to screen for other molecular markers that have predictive or prognostic value in the individual. And it is possible to use them for MRD. We have found a recent consensus from the European Leukemia Net MRD Working Group, who was proposing that for detection of molecular MRD, and they refer the RT PCR platform to NGS and digital PCR platforms. Although all those molecular techniques have been developed very quickly and it is very tempting to use them for initial diagnostics, currently, not all laboratories will have all those techniques available. So the expert panel strongly advises understanding to make distinction between diagnostic that are needed in the first phase to start treatment and subsequently, treatment stratification, in contrast to the usual dose findings in a broader research. For instance, available karyotyping, FISH, PCR techniques, if possible, NGS can be used in the initial start of treatment, whereas techniques like whole exome sequencing, whole genome sequencing, RNA sequencing, and epigenomic studies are meant for a broader research. And finally, how will these guideline recommendations affect patients? Well, in the end, the patients will receive better and especially, more personalized treatment. If we have results available within two weeks from diagnosis, it will be possible to better identify which basis will better benefit from more intensified and more personalized treatment, whereas others may need less intensive treatment with less toxicity. If you use traditional techniques to do this supported by molecular techniques like karyotyping, FISH, and PCR techniques, and in the end, following MRD to see which patients are responding to treatment, MRD detection will help to identify these patients and stratify them finally to the best treatment. Great. Thank you for your work on this important guideline, and thank you for your time today, Dr. de Haas. OK. Thanks a lot. And thank you to all of our listeners for tuning in to the ASCO Guidelines podcast series. If you've enjoyed what you've heard today, please rate and review the podcast and refer this show to a colleague.

AACR 2016
Non-coding mutations driving chronic lymphocytic leukaemia

AACR 2016

Play Episode Listen Later Aug 11, 2017 13:41


Dr Xose Puente speaks with ecancertv at AACR2016 about his discoveries of mutations in non-coding regions driving tumourigensis in chronic lymphocytic leukaemia. Using a library of genomic data from CLL patients, Dr Puente's lab were able to determine point mutations outside of the coding regions of patients DNA that gave rise to altered gene expression. A single substitution in the 3' tail of Notch1, a cell cycle regulator, is reported as introducing a novel splicing site resulting in the deletion of 500 base pairs, including those which determine Notch1 persistence in healthy cells. Another mutation in an intragenic region results in down-regulation of Pax5, essential for B cell maturation. These results are among the first to indicate the clinical significance of non-coding DNA to cancer development.

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 12/19
Molekularbiologische Charakterisierung eines CEA424/SV 40 large T-Antigen – induzierten Magentumors im transgenen Mausmodell

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 12/19

Play Episode Listen Later Feb 17, 2011


HINTERGRUND: Krebserkrankungen sind nach kardiovaskulären Erkrankungen die zweithäufigste Krankheitsgruppe überhaupt in der Medizin. Nach dem aktuellen Stand der Forschung entstehen Tumoren durch Fehlregulation von Proliferation und Differenzierung einzelner Zellen. Diese Vorgänge können in Tiermodellen nachgebildet werden. Eine besonders hohe Aussagekraft haben dabei Tiermodelle, bei denen durch Verwendung eines hybriden Onkogens spontan ein Tumor entsteht. Ein hybrides Onkogen ist aus einem organspezifischen Promotor und einem bekannten Onkogen zusammengesetzt und führt zur Tumorentwicklung in einem bestimmten Organ. Ein Beispiel hierfür sind CEA424/SV 40 large T-Antigen – transgene Mäuse, sie entwickeln reproduzierbar einen Tumor im Antrum des Magens. ZIELSETZUNG: An diesem Tiermodell sollten die Faktoren der organselektiven Entwicklung des Tumors aufgeklärt werden. Hypothesen hierzu waren einerseits, dass dies durch die Integration des Transgens verursacht ist, andererseits, dass im betroffenen Organ spezifische Stimulatoren wirken. Zudem sollte auf der Grundlage von Genexpressionsdaten der Phänotyp der Tumorzellen identifiziert werden. METHODEN: Zunächst wurde mit Walking-PCR die Integrationsstelle identifiziert. Darüber hinaus wurde mit RT-PCR gezielt die Expression von Genen untersucht, welche an der Regulation von Proliferation und Differenzierung des Magens beteiligt sind. Mikroarray-Analysen und ihre computergestützte Auswertung dienten zudem zur Erstellung von Genexpressionsprofilen für verschiedene Zeitpunkte der Tumorentwicklung. ERGEBNISSE: Das Transgen wurde auf dem Chromosom 4 der transgenen Mäuse lokalisiert. Ein Einfluss der Integrationsstelle auf die organspezifische Tumorentstehung konnte dabei nicht gesehen werden. Die Genexpressionsanalyse ergab, dass im Verlauf der Tumorentwicklung die Wnt-Signalkaskade hochreguliert ist. Dieser Signalweg ist als wichtiger Stimulator der Proliferation vor allem in Stammzellmilieus des Gastrointestinaltraktes bekannt. Weiterhin zeigte sich für die Differenzierungsfaktoren Ihh, Notch1 und Pdx1 sowie für das Hormon Gastrin mit fortschreitender Tumorentwicklung eine verminderte Expression, was auf einen Verlust bestimmter Differenzierungswege im Tumorgewebe schließen lässt. In den Genexpressionsprofilen zeigte sich ein neuroendokriner Phänotyp der Tumorzellen.