Comprehensive genomic sequencing of urothelial tumors to identify rare driver genomic alterations in SMARCB1 in a subset of patients.

2017 ◽  
Vol 35 (6_suppl) ◽  
pp. 385-385
Author(s):  
Sumati Gupta ◽  
Daniel Joseph Albertson ◽  
David Gaston ◽  
Marta Elise Heilbrun ◽  
Neeraj Agarwal ◽  
...  

385 Background: Multiple genomic alterations leading to overlapping dysregulation of cell cycle, kinase and phosphotidyl \inositol-3-OHkinase signaling and chromatin remodeling are the hallmark of urothelial carcinoma (UC). ARID1A and SMARCA2 loss are frequently altered leading to SWI/SNF nucleosome-remodeling complex dysregulation in urothelial cancers. Mutations affecting components of the SWI/SNF complex lead to aggressive de-differentiated neoplasms. SMARCB1 loss has been implicated in malignant rhabdoid tumors, epithelioid sarcoma and renal medullary carcinoma. Upper tract UC patients with SMARCB1 loss may represent a novel, rare subset. Methods: Tissue from UC patients (n=1099) was assayed by hybrid-capture based comprehensive genomic profiling (CGP) in the course of clinical care to evaluate genomic alterations (GA: base substitutions, indels, amplifications, copy number alterations, fusions/rearrangements) and targeted therapy opportunities; 315 genes frequently altered in cancer were assayed. One patient had an advanced poorly differentiated neoplasm and received conventional chemotherapy. Results: CGP identified 10 (1%) patients with SMARCB1 alterations and different patterns overall in GAs. Three patients (1 kidney, 1 ureter, and 1 bladder) had bi-allelic loss of SMARCB1, and 7 others had a loss of function alteration with loss of heterozygosity. These patients with SMARCB1 bi-allelic loss had few or no additional alterations, notably no alterations in TP53, CDKN2A/B, or TERT, which are observed in greater than 50% of urothelial tumors, or RB1 alterations observed in ~22% of UC. The patient treated with cisplatin based chemotherapy achieved a pathologic CR. Conclusions: Genomic profiles of tumors from patients with UC revealed a rare population of patients with alterations impacting chromatin regulation and tumor suppression, specifically through loss of SMARCB1. Tumors with SMARCB1 loss have a very low burden of genetic alterations and SMARCB1 loss or deletion may be the sole driving mutation. Conventional chemotherapy may be effective. Inhibitors of EZH2, HDAC and CDK4 may be potential treatment strategies to target this subset of tumors.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 4124-4124
Author(s):  
Kumiko Umemoto ◽  
Hiroyuki Yamamoto ◽  
Ritsuko Oikawa ◽  
Hiroyuki Takeda ◽  
Ayako Doi ◽  
...  

4124 Background: Cancers of the pancreas and biliary tract remain one of the unfavorable malignant tumors with few driver genomic alterations. Tumor-agnostic approaches are promising for cancers with poor prognosis, with some potentially actionable alterations, such as BRCA1/2 mutations, ERBB2 amplification, MSI-High, or tumor mutational burden (TMB)-High. However, co-existing alterations, clinical significance of other genomic alterations, or frequency of alterations by clinical and genomic background are unclear. Here we investigated the genomic profile in a large cohort of advanced pancreatobiliary cancers to help refine and discover new targets for improved cancer therapies. Methods: Comprehensive genomic profiling was performed at Foundation Medicine, on patients with RWD tested during the course of routine clinical care. Hybrid capture was carried out on up to 395 cancer-related genes and select introns from up to 31 genes frequently rearranged in cancer. 16,913 pancreatic cancer (PC) patients and 3,031 biliary tract cancer (BTC) patients were available for analyses and were stratified by age (≥40/ < 40), MSI status, TMB status (High ≥10/Low < 10 Muts/Mb), and select gene alterations. Using a chi-square test with Yate’s correction, frequencies of genetic alterations were analyzed according to clinical or genomic background. Results: KRAS (84.8%), TP53 (73.3%), CDKN2A (51.2%), CDKN2B (26.5%), and SMAD4 (23.2%) were frequently altered in PC patients, versus TP53 (60.6%), CDKN2A (33.5%), KRAS (27.1%), CDKN2B (20.6%) and SMAD4 (16.9%) in BTC patients. The frequency of MSI-High and TMB-High in BTC was 1.2% and 5.7%, respectively, while these were lower in PC (0.48% and 2.1%, respectively). In PC patients, the KRAS alteration rate was significantly lower in both MSI-High (57.3%, P< 0.001) and TMB-High populations (51.3%, P< 0.001). In BTC patients, the rate of ERBB2 amplification was 6.4% in TMB-High and 8.6% in TMB-Low population. Interestingly, CDK12 rearrangement was observed in BTC patients with ERBB2 amplified tumors but not in those without ERBB2 amplified tumors. In patients of pediatric/adolescents and young adults ( < 40 years old), the mutation rate of KRAS/ TP53/ CDKN2A/ SMAD4 was lower, and FGFR2 rearrangement (4%) was observed in PC patients; GATA6 amplification (11.1%) and rearrangement of BRAF (2.8%), FGFR2 (5.6%) were observed in BTC patients. Conclusions: A large real-world dataset showed differences in genomic landscape according to clinical or genomic background, and some potential targets for the development of novel drugs in advanced pancreatobiliary cancers. These findings may lead to the improvement of cancer therapies in PC and BTC patients with poor prognosis.


2020 ◽  
Author(s):  
Tae Yoon Park ◽  
Mark D.M. Leiserson ◽  
Gunnar W. Klau ◽  
Benjamin J. Raphael

AbstractRecent genome-wide CRISPR-Cas9 loss-of-function screens have identified genetic dependencies across many cancer cell lines. Associations between these dependencies and genomic alterations in the same cell lines reveal phenomena such as oncogene addiction and synthetic lethality. However, comprehensive characterization of such associations is complicated by complex interactions between genes across genetically heterogeneous cancer types. We introduce SuperDendrix, an algorithm to identify differential dependencies across cell lines and to find associations between differential dependencies and combinations of genetic alterations and cell-type-specific markers. Application of SuperDendrix to CRISPR-Cas9 loss-of-function screens from 554 cancer cell lines reveals a landscape of associations between differential dependencies and genomic alterations across multiple cancer pathways in different combinations of cancer types. We find that these associations respect the position and type of interactions within pathways with increased dependencies on downstream activators of pathways, such as NFE2L2 and decreased dependencies on upstream activators of pathways, such as CDK6. SuperDendrix also reveals dozens of dependencies on lineage-specific transcription factors, identifies cancer-type-specific correlations between dependencies, and enables annotation of individual mutated residues.


Cancers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 4546
Author(s):  
Jakub Krejcik ◽  
Mike Bogetofte Barnkob ◽  
Charlotte Guldborg Nyvold ◽  
Thomas Stauffer Larsen ◽  
Torben Barington ◽  
...  

Multiple myeloma (MM) is a heterogeneous plasma cell malignancy differing substantially in clinical behavior, prognosis, and response to treatment. With the advent of novel therapies, many patients achieve long-lasting remissions, but some experience aggressive and treatment refractory relapses. So far, MM is considered incurable. Myeloma pathogenesis can broadly be explained by two interacting mechanisms, intraclonal evolution of cancer cells and development of an immunosuppressive tumor microenvironment. Failures in isotype class switching and somatic hypermutations result in the neoplastic transformation typical of MM and other B cell malignancies. Interestingly, although genetic alterations occur and evolve over time, they are also present in premalignant stages, which never progress to MM, suggesting that genetic mutations are necessary but not sufficient for myeloma transformation. Changes in composition and function of the immune cells are associated with loss of effective immune surveillance, which might represent another mechanism driving malignant transformation. During the last decade, the traditional view on myeloma treatment has changed dramatically. It is increasingly evident that treatment strategies solely based on targeting intrinsic properties of myeloma cells are insufficient. Lately, approaches that redirect the cells of the otherwise suppressed immune system to take control over myeloma have emerged. Evidence of utility of this principle was initially established by the observation of the graft-versus-myeloma effect in allogeneic stem cell-transplanted patients. A variety of new strategies to harness both innate and antigen-specific immunity against MM have recently been developed and intensively tested in clinical trials. This review aims to give readers a basic understanding of how the immune system can be engaged to treat MM, to summarize the main immunotherapeutic modalities, their current role in clinical care, and future prospects.


2019 ◽  
Vol 56 (4) ◽  
pp. 199-208 ◽  
Author(s):  
Joana Figueiredo ◽  
Soraia Melo ◽  
Patrícia Carneiro ◽  
Ana Margarida Moreira ◽  
Maria Sofia Fernandes ◽  
...  

CDH1 encodes E-cadherin, a key protein in adherens junctions. Given that E-cadherin is involved in major cellular processes such as embryogenesis and maintenance of tissue architecture, it is no surprise that deleterious effects arise from its loss of function. E-cadherin is recognised as a tumour suppressor gene, and it is well established that CDH1 genetic alterations cause diffuse gastric cancer and lobular breast cancer—the foremost manifestations of the hereditary diffuse gastric cancer syndrome. However, in the last decade, evidence has emerged demonstrating that CDH1 mutations can be associated with lobular breast cancer and/or several congenital abnormalities, without any personal or family history of diffuse gastric cancer. To date, no genotype–phenotype correlations have been observed. Remarkably, there are reports of mutations affecting the same nucleotide but inducing distinct clinical outcomes. In this review, we bring together a comprehensive analysis of CDH1-associated disorders and germline alterations found in each trait, providing important insights into the biological mechanisms underlying E-cadherin’s pleiotropic effects. Ultimately, this knowledge will impact genetic counselling and will be relevant to the assessment of risk of cancer development or congenital malformations in CDH1 mutation carriers.


2021 ◽  
Vol 10 (13) ◽  
pp. 2803
Author(s):  
Carolin Czauderna ◽  
Martha M. Kirstein ◽  
Hauke C. Tews ◽  
Arndt Vogel ◽  
Jens U. Marquardt

Cholangiocarcinomas (CCAs) are the second-most common primary liver cancers. CCAs represent a group of highly heterogeneous tumors classified based on anatomical localization into intra- (iCCA) and extrahepatic CCA (eCCA). In contrast to eCCA, the incidence of iCCA is increasing worldwide. Curative treatment strategies for all CCAs involve oncological resection followed by adjuvant chemotherapy in early stages, whereas chemotherapy is administered at advanced stages of disease. Due to late diagnosis, high recurrence rates, and limited treatment options, the prognosis of patients remains poor. Comprehensive molecular characterization has further revealed considerable heterogeneity and distinct prognostic and therapeutic traits for iCCA and eCCA, indicating that specific treatment modalities are required for different subclasses. Several druggable alterations and oncogenic drivers such as fibroblast growth factor receptor 2 gene fusions and hotspot mutations in isocitrate dehydrogenase 1 and 2 mutations have been identified. Specific inhibitors have demonstrated striking antitumor activity in affected subgroups of patients in phase II and III clinical trials. Thus, improved understanding of the molecular complexity has paved the way for precision oncological approaches. Here, we outline current advances in targeted treatments and immunotherapeutic approaches. In addition, we delineate future perspectives for different molecular subclasses that will improve the clinical care of iCCA patients.


Author(s):  
Johann Kaspar Lieberwirth ◽  
Pascal Joset ◽  
Anja Heinze ◽  
Julia Hentschel ◽  
Anja Stein ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Woon Yong Jung ◽  
Kyueng-Whan Min ◽  
Young Ha Oh

AbstractThe histological classification of lung adenocarcinoma includes 5 types: lepidic, acinar, papillary, micropapillary and solid. The complex gene interactions and anticancer immune response of these types are not well known. The aim of this study was to reveal the survival rates, genetic alterations and immune activities of the five histological types and provide treatment strategies. This study reviewed the histological findings of 517 patients with lung adenocarcinoma from The Cancer Genome Atlas (TCGA) database and classified them into five types. We performed gene set enrichment analysis (GSEA) and survival analysis according to the different types. We found six oncogenic gene sets that were higher in lung adenocarcinoma than in normal tissues. In the survival analysis of each type, the acinar type had a favorable prognosis, and the solid subtype had an unfavorable prognosis; however, the survival differences between the other types were not significant. Our study focused on the solid type, which had the poorest prognosis. The solid type was related to adaptive immune resistance associated with elevated CD8 T cells and high CD274 (encoding PD-L1) expression. In the pathway analyses, the solid type was significantly related to high vascular endothelial growth factor (VEGF)-A expression, reflecting tumor angiogenesis. Non-necrosis/low immune response affected by high VEGF-A was associated with worse prognosis. The solid type associated with high VEGF-A expression may contribute to the development of therapeutic strategies for lung adenocarcinoma.


Author(s):  
Holger Hengel ◽  
Shabab B. Hannan ◽  
Sarah Dyack ◽  
Sara B. MacKay ◽  
Ulrich Schatz ◽  
...  

2021 ◽  
Vol 162 ◽  
pp. S48
Author(s):  
Kathryn Miller ◽  
Herman Chui ◽  
Sarah Chiang ◽  
Lora Ellenson ◽  
Britta Weigelt ◽  
...  

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii300-iii300
Author(s):  
Chen Shen ◽  
David Picketts ◽  
Oren Becher

Abstract Diffuse Intrinsic Potine Glioma (DIPG) is a rare pediatric brain tumor for which no cure or efficacious therapies exist. Previous discoveries have revealed that, DIPG harbors distinct genetic alterations, when compared with adult high-grade glioma (HGG) or even with non-DIPG pediatric HGGs. ATRX alteration is found in 9% of clinical cases of DIPG, and significantly overlaps with H3.3K27M mutation and p53 loss, the two most common genetic changes in DIPG, found in 80% and 77% clinical cases, respectively. Here we developed genetically engineered mouse model of brainstem glioma using the RCAS-Tv-a system by targeting PDGF-B overexpression, p53 loss, H3.3K27M mutation and ATRX loss-of function to Nestin-expression brainstem progenitor cells of the neonatal mouse. Specifically, we used Nestin-Tv-a; p53 floxed; ATRX heterozygous female and Nestin-Tv-a; p53 floxed; ATRX floxed male breeders, generated offsprings with ATRX loss of function (n=18), ATRX heterozygous females (n=6), and ATRX WT (n=10). Median survial of the three groups are 65 days, 88 days and 51 days, respectively. Also, ATRX null mice is lower in tumor incidence (44.4%), compared with ATRX WT (80%). We evaluated the pathological features of DIPG with or without ATRX alteration, RNA-seq is performed to identify differentially expressed genes between ATRX WT and loss-of-function. In conclution, this study generated the first genetically modified mouse model studying ATRX loss-of-function in DIPG, and suggested that ATRX loss-of-function in DIPG may slow down tumorigenesis and decrease tumor incidence.


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