In vitro characterization of stem cell-like properties of drug-resistant colon cancer subline.

The objective of this study was to investigate the stem cell-like properties of drug-resistant colon cancer cells. Oxaliplatin was used to induce the drug-resistant subline of HCT116(p53+/+) cell line. The stem cell-like characteristics of the drug-resistant subline were assayed for the proliferation capacity, cell cycle, adhesion, invasion, multiple drug resistance, and clone sphere formation capacity. The expression of ABCG2 (ATP-binding cassette superfamily G member 2) and "stemness" indicators SOX2 (SRY-related HMG box-containing transcription factor-2) and OCT4 (octamer-binding transcription factor 4) was determined by Western blot. We established the HCT116(p53+/+)-oxaliplatin subline (HCT116(p53+/+)OXA), which was resistant to oxaliplatin with a resistance index (RI) of 3.03 ± 0.14. The HCT116(p53+/+)OXA was also resistant to Taxol, showing lower proliferation, higher adhesion and invasion ability, greater proportion of G0/G1 phase, and higher sphere-forming capacity than its parental cells. SOX2, OCT4, and ABCG2 were expressed at higher levels in drug-resistant cells than in their parental cells. We verified that the HCT116(p53+/+)OXA was enriched with cancer stem cell properties and provided an ideal cell model for drug-resistance study.