Combined PD-1 and CCR5 Inhibition for the Treatment of Refractory Microsatellite Stable mCRC
Ontology highlight
ABSTRACT:
DISEASE(S): Metastatic Colorectal Cancer,Colorectal Neoplasms,Mss
PROVIDER: 2253718 | ecrin-mdr-crc |
REPOSITORIES: ECRIN MDR
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Project description:mRNA assays were performed on 51 samples of human colorectal tumors using Affymetrix HuGeneFL arrays containing 7129 probe-sets. We compared 38 microsatelite stable (MSS) tumors with 13 microsatellite instable-high (MSI) tumors to form a list of genes differing between the two types. In order to identify molecular signatures characterizing MSI tumors, we examined only MSI-high cancers and not MSI-low ones. Keywords: disease state analysis Human samples of 38 microsatellie stable and 13 microsatellite instable-high colorectal tumors, each from a separate patient, had mRNA assays performed using Affymetrix HuGeneFL arrays, with 7129 probe-sets. A supplementary Excel file (Colon_HuFL_logs.xls) is attached below that gives the log-transformed probe-set values. It also gives the p-values from T-tests comparing these values between MSS and MSI samples, as well as an estimated average fold-difference, for which the mathematical functions are explicitly given.
2009-04-10 | E-GEOD-11543 | biostudies-arrayexpress
Project description:Treatment with immune checkpoint inhibitors in colorectal cancer (CRC) has largely benefited patients with microsatellite instability–high (MSI-H) and not the larger proportion of patient with microsatellite-stable (MSS) tumors. This clinical dichotomy has fueled the view that high mutational burden is the dominant driver of tumor immunogenicity and that MSS CRC fails to respond because it is “antigen poor”. To directly test this premise and define the origins of presented tumor antigens, we integrated HLA class I immunopeptidomics and matched RNA-seq from 26 primary CRC tumors spanning MSI-H and MSS subtypes. Using patient-specific canonical and cancer-specific proteogenomic databases, we identified 115,292 unique MHC-associated peptides (MAPs) across 61 HLA alleles, with a mean of 9,292 MAPs per tumor and no significant difference in MAP counts between MSI-H and MSS tumors. In toto, we identified 266 tumor antigens, all coded by unmutated genomic sequences, comprising 70 aberrantly expressed tumor-specific antigens (aeTSAs) and 196 tumor-associated antigens (TAAs). In our cohort, MSS tumors presented more TAAs and a comparable number of aeTSAs per tumor relative to MSI-H tumors. In TCGA-COAD stratified analyses (483 tumors), MSS tumors yielded more presentable aeTSAs and TAAs per patient than MSI-H tumors. Across both subtypes, aeTSAs arose predominantly from intronic translation, UTR usage, retroelement activation, and germline-like transcription, including recurrent aeTSAs from PIWIL1, L1TD1, and endogenous retroviral loci. Together, these data demonstrate that MSS CRC is not antigen poor and highlight non-canonical translation as a major, previously underappreciated contributor to the CRC immunopeptidome.
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2016-03-02 | E-GEOD-63624 | biostudies-arrayexpress
Project description:A large proportion of indigenous African (IA) colorectal cancer (CRC) patients in South Africa are young (<50years), with no unique histopathological or molecular characteristics. Anatomical site as well as microsatellite instability (MSI) status have shown to be associated with different clinicopathological and molecular features. This study aimed to ascertain key histopathological and miRNA expression patterns in microsatellite stable (MSS) and low-frequency MSI (MSI-L) patients, to provide insight into the mechanism of the disease. This study revealed distinct histopathological features for Left Colon Cancer (LCC), and suggests BAT25/26, miRNAs let-7a-5p and miRNA-125a/b-5p as negative prognostic markers in African CRC patients.
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Project description:Background. Colorectal cancer develops through two main genetic instability pathways characterized by distinct pathologic features and clinical outcome. Results. We investigated colon cancer samples (23 characterized by microsatellite stability, MSS, and 16 by high microsatellite instability, MSI-H) for genome-wide expression of microRNA (miRNA) and mRNA. Based on combined miRNA and mRNA gene expression, a molecular signature consisting of twenty seven differentially expressed genes, inclusive of 8 miRNAs, could correctly distinguish MSI-H versus MSS colon cancer samples. Among the differentially expressed miRNAs, various members of the oncogenic miR-17-92 family were significantly up-regulated in MSS cancers. The majority of protein coding genes were also up-regulated in MSS cancers. Their functional classification revealed that they were most frequently associated with cell cycle, DNA replication, recombination, repair, gastrointestinal disease and immune response. Conclusions. This is the first report that indicates the existence of differences in miRNA expression between MSS versus MSI-H colorectal cancers. In addition, the work suggests that the combination of mRNA/miRNA expression signatures may represent a general approach for improving bio-molecular classification of human cancer.
2007-09-07 | E-TABM-326 | biostudies-arrayexpress
Project description:mRNA assays were performed on 51 samples of human colorectal tumors using Affymetrix HuGeneFL arrays containing 7129 probe-sets. We compared 38 microsatelite stable (MSS) tumors with 13 microsatellite instable-high (MSI) tumors to form a list of genes differing between the two types. In order to identify molecular signatures characterizing MSI tumors, we examined only MSI-high cancers and not MSI-low ones. Keywords: disease state analysis
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Project description:Clinical Significance: Understanding the differences in colorectal cancer (CRC) aggressiveness and clinical outcomes in relation to tumor stage and different molecular subsets is at most important for designing treatment regimens. However, molecular signatures for specific phenotypic subsets that predict the aggressiveness and clinical outcomes of CRC, specifically in advanced disease stage are lacking. Therefore, for the first time, the current study has identified a set of molecular markers that are associated with aggressive Stage III CRCs that exhibited microsatellite stable and mutant p53 phenotypic features. These findings might aid in designing aggressive treatment regimens and help to provide insights into the development of novel therapeutic targets. Results: Increased incidence of p53 mutations in MSS CRCs (58%) was associated with higher CRC-specific mortality than MSS-p53 wild-type phenotypes (log-rank, P=0.025; and hazard ratio, 2.52; 95% confidence interval, 1.25-5.08). Of 49 down-regulated genes, LPAR6, PDLIM3 and PLAT and of 35 up-regulated genes, TRIM29, FUT3, IQGAP3, and SLC6A8, were confirmed by qNPA, qRT-PCR, and IHC platforms. Conclusions: p53 mutations are associated with poor prognosis of Stage III microsatellite stable CRCs.
2012-01-26 | GSE27157 | GEO
Project description:Microsatellite stable/proficient mismatch repair (MSS/pMMR) colorectal cancer (CRC) is characterized by a cold tumor microenvironment, marked by sparse CD8⁺ T cell infiltration and resistance to immune checkpoint inhibitors (ICIs). To uncover regulators that limit CD8⁺ T cell infiltration in MSS CRC, we conducted an in vivo CRISPR/Cas9 screen targeting genes in CD8⁺ T cells using a CMT93 cell-derived tumor model. This screen identified Arid3b as a key negative regulator of CD8⁺ T cell tumor infiltration and antitumor activity. Genetic ablation of Arid3b in CD8⁺ T cells significantly enhanced their intratumoral accumulation and mediated robust tumor control. Mechanistically, Arid3b deficiency upregulated Runx3, promoting a tissue-resident memory phenotype and effector function. Notably, the benefits conferred by Arid3b knockout were abrogated by Runx3 deletion, indicating a Runx3-dependent mechanism. In summary, targeting ARID3B could offer a promising strategy to reshape the tumor microenvironment and sensitize MSS CRC to immunotherapy.
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