Over-expression of protein kinase C isoforms (α, δ, θ and ζ) in squamous cervical cancer.

Protein kinase C was found to be significantly over-expressed in cancer samples compared to adjacent normal cervical tissues by proteomics in our previous study. The aim of this study was to examine protein kinase C expression and to analyze the expression patterns of protein kinase C isoforms in squamous cervical cancer at the protein levels and their associations with clinical and pathologic factors of squamous cervical cancer. First, Western blotting was used to examine protein kinase C expression in the specimens of tumors and matched adjacent normal tissues which were collected from 12 patients with squamous cervical cancer. Protein kinase C isoforms (α, δ, θ and ζ) expression were then detected by immunohistochemistry in other 43 cases of squamous cervical cancer tissues, 32 cases of corresponding adjacent normal cervical squamous epithelial tissue and 31 cases of cervical intraepithelial neoplasia. Western blot analysis revealed that protein kinase C expression was positive in squamous cervical cancer while it was not expressed in normal cervical tissues. On the other hand, immunohistochemical analysis suggested that, protein kinase C isoforms (α, δ, θ and ζ) expression was significantly higher in squamous cervical cancer compared to cervical intraepithelial neoplasia, as well as in cervical intraepithelial neoplasia compared with normal tissues, respectively.High levels of protein kinase C α expression were associated with cellular differentiation(P<0.05). Protein kinase C δ was significantly associated with tumor stage (P<0.05) and protein kinase C ζ was associated with lymphatic metastasis (P < 0.05). These findings indicate that protein kinase C isoforms expression in cervical lesions was associated with carcinogenesis and might play important roles throughout the process of cervical cancer development.