1,189 research outputs found
Association of EWS-FLI1 Type 1 Fusion with Lower Proliferative Rate in Ewing’s Sarcoma
The Ewing's sarcoma (ES) family of tumors, including peripheral neuroectodermal
tumor (PNET), is defined genetically by specific chromosomal translocations
resulting in fusion of the EWS gene with a member of the ETS family of
transcription factors, either FLI1 (90-95%) or ERG (5-10%). A second level of
molecular genetic heterogeneity stems from the variation in the location of the
translocation breakpoints, resulting in the inclusion of different combinations
of exons from EWS and FLI1 (or ERG) in the fusion products. The most common type
of EWS-FLI1 fusion transcript, type 1, is associated with a favorable prognosis
and appears to encode a functionally weaker transactivator, compared to other
fusion types. We sought to determine whether the observed covariation of
structure, function, and clinical course correlates with tumor cell kinetic
parameters such as proliferative rate and apoptosis, and with expression of the
receptor for insulin-like growth factor I (IGF-1R). In a group of 86 ES/PNET with
defined EWS-ETS fusions (45 EWS-FLI1 type 1, 27 EWS-FLI1 non-type 1, 14 EWS-ERG),
we assessed proliferation rate by immunostaining for Ki-67 using MIB1 antibody (n
= 85), apoptosis by TUNEL assay (n = 66), and IGF-1R expression by immunostaining
with antibody 1H7 (n = 78). Ki-67 proliferative index was lower in tumors with
EWS-FLI1 type 1 than those with non-type 1 EWS-FLI1, whether analyzed as a
continuous (P = 0.049) or categorical (P = 0.047) variable. Logistic regression
analysis suggests that this association was secondary to the association of type
1 EWS-FLI1 and lower IGF-1R expression (P = 0.04). Comparing EWS-FLI1 to EWS-ERG
cases, Ki-67 proliferative index was higher in the latter (P = 0.01, Mann-Whitney
test; P = 0.02, Fisher's exact test), but there was no significant difference in
IGF-1R. TUNEL results showed no significant differences between groups. Our
results suggest that clinical and functional differences between alternative
forms of EWS-FLI1 are paralleled by differences in proliferative rate, possibly
mediated by differential regulation of the IGF-1R pathway
Kidney: Renal cell carcinoma with t(6;11)(p21;q12) MALAT1/TFEB
Review on Renal cell carcinoma with t(6;11)(p21;q12) MALAT1/TFEB, with data on clinics, and the genes involved
Kidney: Renal cell carcinoma with t(X;17)(p11;q23) CLTC/TFE3
Review on Renal cell carcinoma with t(X;1)(p11;q21) PRCC/TFE3, with data on clinics, and the genes involv
Kidney: Renal cell carcinoma with inv(X)(p11q12) NONO/TFE3
Review on Renal cell carcinoma with inv(X)(p11q12) NONO/TFE3, with data on clinics, and the genes involved
Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context
Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts
Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas
This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing
molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
High frequency of IDH-1 mutation links glioneuronal tumors with neuropil-like islands to diffuse astrocytomas
Spatial Organization and Molecular Correlation of Tumor-Infiltrating Lymphocytes Using Deep Learning on Pathology Images
Beyond sample curation and basic pathologic characterization, the digitized H&E-stained images
of TCGA samples remain underutilized. To highlight this resource, we present mappings of tumorinfiltrating lymphocytes (TILs) based on H&E images from 13 TCGA tumor types. These TIL
maps are derived through computational staining using a convolutional neural network trained to
classify patches of images. Affinity propagation revealed local spatial structure in TIL patterns and
correlation with overall survival. TIL map structural patterns were grouped using standard
histopathological parameters. These patterns are enriched in particular T cell subpopulations
derived from molecular measures. TIL densities and spatial structure were differentially enriched
among tumor types, immune subtypes, and tumor molecular subtypes, implying that spatial
infiltrate state could reflect particular tumor cell aberration states. Obtaining spatial lymphocytic
patterns linked to the rich genomic characterization of TCGA samples demonstrates one use for
the TCGA image archives with insights into the tumor-immune microenvironment
Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas
Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN
The p.Ser64Leu and p.Pro104Leu missense variants of PALB2 identified in familial pancreatic cancer patients compromise the DNA damage response
PALB2 has been identified as a breast and pancreatic cancer susceptibility gene. Utilizing a targeted sequencing approach, we discovered two novel germline missense PALB2 variants c.191C>T and c.311C>T, encoding p.Ser64Leu and p.Pro104Leu, respectively, in individuals in a pancreatic cancer registry. No missense PALB2 variants from familial pancreatic cancer patients, and few PALB2 variants overall, have been functionally characterized. Given the known role of PALB2, we tested the impact of p.Ser64Leu and p.Pro104Leu variants on DNA damage responses. Neither p.Ser64Leu nor p.Pro104Leu have clear effects on interactions with BRCA1 and KEAP1, which are mediated by adjacent motifs in PALB2. However, both variants are associated with defective recruitment of PALB2, and the RAD51 recombinase downstream, to DNA damage foci. Furthermore, p.Ser64Leu and p.Pro104Leu both largely compromise DNA double-strand break-initiated homologous recombination, and confer increased cellular sensitivity to ionizing radiation (IR) and the poly (ADP-ribose) polymerase (PARP) inhibitor Olaparib. Taken together, our results represent the first demonstration of functionally deleterious PALB2 missense variants associated with familial pancreatic cancer and of deleterious variants in the N-terminus outside of the coiled-coil domain. Furthermore, our results suggest the possibility of personalized treatments, using IR or PARP inhibitor, of pancreatic and other cancers that carry a deleterious PALB2 variant
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