144 Expression and significance of RIPK3 in the cutaneous squamous cell carcinoma

Abstract

Background: The cutaneous squamous cell carcinoma is a malignant tumor that occurs in the epidermis or accessory cells. It accounts for about 20% of all non-melanoma skin cancers and is the second most common skin malignancy. RIPK3, a member of the receptor-interacting protein kinase family, is a TNFR1-regulated transcription factor that plays an important role in cellular stress of various factors and may be involved in regulating cell cycle, inhibiting apoptosis, and regulating programmed cell death, etc. But the role of RIPK3 in the cSCC has not been reported. Objective: To compare the expression of RIPK3 in normal skin tissues and cSCC lesions, and to analyze the clinical significance of RIPK3 in cSCC. Materials and Methods: 30 cases of normal skin tissue and 30 cases of cSCC lesions were collected. The expression of RIPK3 protein was detected by immunohistochemical SP method. Cutaneous squamous cell carcinoma cell lines SCL-1, HSC-1 and A431 cells were cultured, and the primary keratinocytes HEKa cells were used as the control group. The expression of RIPK3 was detected by western blot and qRT-PCR. Results: In normal skin tissues, RIPK3 protein was mainly expressed in the basal layer of the epidermis and the lower part of the spinous layer. The positive expression rate was 60%, while in the cSCC lesions, the expression was significantly decreased. The positive expression rate was 0%. The positive expression rate and expression intensity of RIPK3 were statistically significant (*** P<0.001, vs. Ctrl). Western blot and qRT-PCR results showed that RIPK3 expression was decreased in SCL-1, HSC-1 and A431 cells compared with the control group (*** P<0.001, vs. Ctrl). Conclusion: The expression of RIPK3 protein in cSCC lesions and cells is significantly lower than that in control. It can be seen that the abnormal expression of RIPK3 may play a role in the development of cutaneous squamous cell carcinoma.