CD151 influences STAT3 activation. A, Mouse derived skin cell lines were lysed in 1% Triton X-100, and blotted for pSTAT3 (Tyr705, mAb from Cell Signaling Co.), total STAT3 (rabbit polyclonal Ab, Santa Cruz Co.), and β actin. B, CD151 was stably ablated in human A431 cells. Knockdown and control cells were treated with TPA (50 ng/ml) for indicated times, lysed, and then blotted as in part A. CD151 was detected using mAb 1A5. CD151 knockdown was >90% (bottom panel). Bar graphs, based on densitometry scans, show relative STAT3 activation C, Epidermis from +/+ and −/− mice was isolated 24 hr following DMBA treatment, and lysate proteins were blotted for activated STAT3, total STAT3 and β actin. Bar graphs show relative STAT3 activation. N = 5; *, P < 0.01. D, Epidermis from +/+ and −/− mice was isolated 24 hr following the last TPA treatment, and lysate proteins were blotted for activated STAT3, total STAT3 and β actin. Bar graphs show relative STAT3 activation. N = 5; *, P<0.02