Fig. 1.

More resistance of colon cancer cells to chemotherapy under hypoxia, accompanied by HIF-1α and MDR1 overexpression

Three colon cancer cells were cultured under normoxic (20% O₂) or hypoxic (1% O₂) conditions with 5-FU (a) or oxaliplatin (b) for 24 h, and cell viability was examined using MTT assays. Overexpressions of HIF-1α and MDR1 were detected in both mRNA (c) and protein (d) levels after the cancer cells were exposed to hypoxia. Data are expressed as mean±SD of triplicate experiments. ^* P<0.05, ^** P<0.01, ^*** P<0.005, compared to normoxia. N: normoxia; H: hypoxia