Tumor Infiltrating Lymphocytes and Macrophages Improve Survival in Microsatellite Unstable Colorectal Cancer.

ABSTRACT: Due to the loss of DNA repair mechanisms in colorectal cancer (CRC) with microsatellite instability (MSI), somatic mutations accumulate within DNA; making them more prone to attack by tumor infiltrating lymphocytes (TIL) and macrophages. We hypothesize that MSI-High (MSI-H) patients have favorable survival due to increased tumor immunogenicity. The Cancer Genome Atlas (TCGA) was used to evaluate gene expression from 283 patients with CRC, comparing MSI-H and microsatellite stable (MSS) patients. CIBERSORT algorithm estimated the fraction of immune cell types. We found that low expression of DNA repair genes (MLH1, MLH3, PMS1, PMS2, ATR, PRKDC, ATM, BRCA2) associated with MSI-H. MSI-H was directly associated with Helper T-cells (p = 0.034) and M1 macrophages (p < 0.0001). MSI-H tumors assoc

SUBMITTER: Narayanan S 

PROVIDER: S-EPMC6748965 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature