Adverse Cell Culture Conditions Mimicking the Tumor Microenvironment Upregulate ABCG2 to Mediate Multidrug Resistance and a More Malignant Phenotype
Figure 1
Quantitative real-time RT-PCR analysis showing the upregulation of ABCG2 in S1 and HCT-116 pretreated for 16 h with 2-DG (20 mM), low pH (pH 5) or hypoxia. 16 h treatment was selected because HIF-1 induction was found to reach the maximum after exposure to 16 h hypoxia treatment (data not shown). Expression of PGK1, a hypoxia response gene, was also measured to indicate the activation of the glycolytic pathway by hypoxia. mRNA expressions were normalized with GAPDH. Results for each gene are expressed relative to that in the untreated cells (2-DG = 2-deoxyglucose). Mean SD from three independent experiments is shown. The Student’s -test was used to compare the gene expression between the cells with or without the various treatment (). ABCG2 mRNA expression was not affected significantly after the various treatments in S1M1-80 cells.
