The activity of PLCγ1 and PKCα, estimated by Western blot analysis. (A) Compared to a control siRNA transfection, transient receptor potential melastatin (TRPM)-2 expression levels were reduced by >80% in the presence of a specific TRPM2 siRNA; (B) PLCγ1 and phosphorylated PLCγ1 at tyrosine 783 were detected by Western blot analysis. The protein levels were normalized with respect to β-actin. 16HBE cells treated with H2O2 free DMEM for 4 h were set as negative control. (n = 6 for each condition) * p < 0.05 for the TRPM2 siRNA transfection + H2O2 exposure group and negative controls; (C) PKCα was detected in both particulate and soluble extracts. To investigate whether TRPM2 depletion would influence the activity of PKCα, TRPM2 specific siRNA or control siRNA was transfected into 16HBE cells. (n = 6 for each condition), #p > 0.05 compared to the control; (D) PKCα was detected in both particulate and soluble extracts. 16HBE cells treated with H2O2-free DMEM for 4 h were set as negative control, (n = 6 for each condition), * p < 0.05, compared to the negative control, ** p < 0.05, compared to either the U73122 + H2O2 group or the negative control.