Role And Mechanism Of Extracellular Signal Regulated Kinase(ERK1/2) In ALA-PDT Killing Skin Squamous Cell Carcinoma

Objective To explore the role and mechanism of extracellular signal regulatedkinase (ERK) pathway in ALA-PDT damaging skin squamous cell carcinomaSCL-1cells, to provide new laboratory basis for ALA-PDT treated with patientswith squamous cell carcinoma of the skin.Methods SCL-1cells were divided into control group, red light group, ALAgroup, ALA-PDT group and inhibitor of ERK group. Western blot was used todetect the expression of protein products and phosphorylation protein products ofERK1/2after intervening30min,60min and90min in each of SCL-1cells.Immunofluorescence chemistry was used to detect the expression ofphosphorylation protein products of ERK1/2after intervening30min,60min and90min in each group of SCL-1cells. Calculating the cell survival rate, opticaldensity value of each group were obtained at24h,48h,72h by MTT; Flowcytometry with annexin V-FITC/PI double staining was employed to detectapoptosis of each group cell after intervening24h,48h and72h. Electronmicroscope technique was used to observe the ultrastructure changes of eachgroup of SCL-1cells after intervening24h,48h, and72h.Result By western-blot testing, the expression of ERK1/2had no obviousdifference in each group of SCL-1cells, the expression of phosphorylation ERK1/2had no evident difference in control group, red light group and ALA group, but theexpression of phosphorylation ERK1/2was obviously higher in ALA-PDT groupthan the other group, the expression of phosphorylation ERK1/2was evidently lower in inhibitor of ERK group than the other group. The immunofluorescencechemistry detection results were consistent with western–blot. MTT detectionresults show that the cell survival rate had no obvious difference in control group,ALA group and red light group, but it had difference in ALA-PDT group thatcompared to the other group, it was obviously lower in inhibitor of ERK groupthan the rest of the group. Flow cytometry instrument testing results showed thatthe rate of apoptosis had no difference in control group, ALA group and red lightgroup, but it had difference in ALA-PDT group that compared to the other group,it was significantly higher in inhibitor of ERK group than the other groups.Electron microscope test results indicated that the changes in cell structure had nodifference in control group, ALA group and red light group, but the damage wasobvious in ALA-PDT group compared with the other groups and it was moreobviously in inhibitor of ERK group compared with the other groups.Conclusions Blocking ERK pathway can reduce the expression ofphosphorylation ERK1/2and enhance the cell damage effect of ALA-PDT toSCL-1cells.