FIGURE 6.

Knockdown of TC-PTP in keratinocytes on the regulation of UVB-induced apoptosis. A, representative Western blot analysis of apoptotic proteins in total cell lysates. 3PC keratinocytes were cultured and transfected with control or TC-PTP siRNA. Cells were collected at the indicated time after UVB irradiation (5 mJ/cm²). B, relative levels of PARP were quantified by densitometry. Results are the mean ± S.D. (error bars) from three independent experiments. *, p < 0.05 by Student's t test for equality of means. C, relative levels of cleaved caspase-3 were quantified by densitometry. D, caspase-3 activity was measured at 24 h after UVB irradiation.