Investigation of the protein level of vitamin D receptor, calcium-sensing receptor and β-catenin in skin squamous cell carcinoma

Squamous cell skin cancer (SCC) is a malignant and invasive tumor which is originated from epidermis with a high incidence among non-melanoma skin cancers. These tumors is formed from sun damaged skin keratinocytes due to impaired proliferation and differentiation function of keratinocytes. Keratinocyte proliferation and differentiation is regulated by a number of factors including vitamin D, Wnt / β-catenin signaling pathway. In this study, we aimed to determine whether vitamin D receptor (VDR), calcium-sensing receptor (CaSR) and β-catenin (CTNNB1) protein levels have an effect on squamous cell skin cancer. For this purpose, VDR, CaSR and β-catenin protein levels in tissue samples of patient and control group were analyzed by immunohistochemistry (IHC), fluorescence-immunohistochemistry (FIHC) and western blot (WB) method. It was determined that the difference between VDR and β-catenin protein expression levels in the patient and the control groups were statistically significant (p= 0.006, p= 0.012, respectively), but not for CaSR (p= 0.3326) according to Independent Sampling T Test analysis. The results obtained from the immunohistochemistry study are as follows according to One-Way ANOVA Test analysis. There was no significant difference between VDR and β-catenin expression rates in patient tissues (p=0.980). When VDR expression rates in the patient samples were compared with control VDR, control CaSR, control β-catenin and patient CaSR ratios, the difference were found to be significant (p =0.016, p =0.002, p =0.005, p =0.003, respectively). It was determined that the difference between β-catenin expression in the patient group and control VDR, control CaSR, control β-catenin and patient CaSR ratios were a significant (p= 0.003, p= 0.0001, p= 0.001, p= 0.001, respectively). While the VDR and β-catenin expression rates obtained by the IHC method could be supported by WB results, the WB bands for CaSR could not be shown. The findings suggest that expression rates of VDR and β-catenin in SCC may have an effect on the disease.