FIG. 8.

Effect of overexpression of HIF-1α or HIF-2α on growth of 786-O cells as monolayers or tumor xenografts. (A) Immunoblots for HIF-1α and HIF-2α of whole-cell lysates from 786-O polyclonal pools of cells that were selected with G418 after infection with retroviral supernatants made from pBMN-Neo containing an empty cassette (LacZ spliced out) as a control (C), HIF-1α (H1), or HIF-2α (H2). (B) Growth of selected polyclonal pools of 786-O cells stably infected with the indicated retroviruses. Growth was measured under standard tissue culture conditions for 9 days, and there was no significant difference in the proliferation rate between the groups. Error bars indicate standard deviations. (C) Tumor weights approximately 5.5 weeks after subcutaneous injection of polyclonal pools of 786-O cells stably infected with the indicated retroviruses. There were 14 tumors analyzed for each group, and error bars indicate 1 standard error. Two-tailed, unpaired Student t tests comparing each HIF-α overexpressing group to the control group were performed, and statistically significant difference is indicated by asterisks for P < 0.005. (D) Growth curves indicated as tumor volume over a 90-day period after subcutaneous injection of polyclonal pools of 786-O cells stably infected with the indicated retroviruses. Five mice with single tumors were analyzed for each group.