Fig. 6. Tumor cell-intrinsic PD-L1 regulates proliferation, mTOR signaling, and autophagy in human ovarian cancer cells.
A. Flow cytometry for PD-L1 expression of in vitro cultured ES2 human ovarian cancer cells showing PD-L1 knock-down by shRNA. B. PD-1 and PD-L1 expression by flow cytometry. C. Proliferation in vitro of ES2 cells determined by MTT versus control (ctrl, set at 100%). p-value, unpaired t test. D. Western blot for LC3I/II in ES2 cell lysates from basal conditions. E. Confocal images of autophagosome formation by LC-3 aggregation (red) in control versus PD-L1lo ES2 under basal or serum starved (24 h) conditions. Blue, DAPI for nuclei. F. Western blot for P70S6KT389 and AktS473 phosphorylation in ES2 cells under basal conditions. G. Control and PD-L1lo ES2 cells were cultured with 50 μM chloroquine and proliferation inhibition (100%-% proliferation by MTT, with control set at 0%) assessed 72 h later. P-values, unpaired t test.