[Prolonged hypoxia induces GST-pi expression and drug resistance in lung adenocarcinoma cell line SPCA1]

To investigate the association of hypoxia with GST-pi expression in lung adenocarcinoma cells SPCA1 and the drug resistance in hypoxic condition.

RNA and protein in SPCA1 cells treated with hypoxia (0.5% O(2)) for 16 h were isolated. HIF-1alpha and GST-pi mRNA expression was detected by real time RT-PCR, and HIF-1alpha protein was detected by Western blotting analysis. GST-pi protein was finally analyzed on a FACScan flow cytometer using Cellquest software. Sensitivity of Doxorubicin and Mitomycin in hypoxic SPCA1 cells was detected using cell clonogenic assay.

HIF-1alpha expression was up-regulated on mRNA and protein levels in hypoxic SPCA1 cells, so as was GST-pi expression. Doxorubicin resistance was increased, but hypoxia had no significant influence on Mitomycin resistance. GST-pi expression had no significant change after HIF-1alpha was down-regulated by RNA interfering.

Though prolonged hypoxia can induce GST-pi expression and increase drug resistance such as to Doxorubicin, HIF-1alpha expression has no correlation with GST-pi expression.