HCT116 colorectal cancer cells treated with 2.5 mM Metformin

Metformin is a drug used in the treatment of type 2 diabetes mellitus. Various studies have elucidated its anticancer properties. In this study, the effect of metformin on the differentiation and tumor microenvironment of colorectal cancer cells (CRC) was evaluated. For our study, we have used HCT116 colorectal cancer cell line and treated the cells with Metformin. Maximum tolerable non-toxic dose of metformin on HCT116 cells was determined by MTT assay. Cells were treated with 2.5 mM Metformin for 2 weeks. Analysis of apoptosis was done by flow cytometry using Annexin V / PI. CSC population was determined by flow cytometry using CSC markers CD44 and CD166. Metformin's ability to induce differentiation in CSC was assessed by analyzing Cytokeratin 20 (CK20) by flow cytometry and CDX1 (transcription factor for CK20), by RT-QPCR. Expression of Ki67 (proliferation marker) was done by RT-QPCR. RNA was isolated from 2.5 mM Metformin-treated and untreated cells populations. Microarray of untreated and 2.5 mM Metformin-treated RNA was done to study the whole genome transcriptomic changes. 8x60k whole genome expression arrays for comparing transcriptome of HCT116 colorectal cancer cells (n=4) with HCT116 cells treated with 2.5 mM Metformin (n=4).