PRR14 acts a novel oncogene activating the PI3K signal pathway in human cutaneous squamous cell carcinoma

Proline rich protein 14 (PRR14) is considered as a new component of the nuclear fiber layer, it may be a key molecule in mediating nuclear morphological changes and functional changes in tumorigenesis. But, it's still unclear in human cutaneous squamous cell carcinoma (cSCC). In the study, the expression profiles of PRR14 in patients with cSCC were investigated by immunohistochemistry (IHC), also the PRR14 expression in cSCC tissues were detected using the methods of real-time quantitative PCR (RT-qPCR) and Western blot; cell counting kit-8 (CCK-8) assay, wound healing assay, matrigel-based transwell assay and Annexin V-FITC and PI double-staining with flow cytometry assay were used to investigate the biological functions of PRR14 in A431 and HSC-1 cSCC cells. Overexpression of PRR14 in cSCC patients was reported firstly in this study and its high expression was related to differentiation, thickness and tumor node metastasis (TNM) stage of cSCC. PRR14 inhibition with RNA interfering (RNAi) method resulted in the suppression of cell proliferation, migration and invasion but promotion the apoptosis of cSCC cells, and upregulation of the protein phosphorylation levels of mammalian target of rapamycin (mTOR), phosphoinositide 3-kinase (PI3K) and Akt. The study shows PRR14 maybe an activator of cSCC carcinogenesis through PI3K/Akt/mTOR signal pathway, and it also maybe a prognostic factor and new therapeutical target for cSCC treatment.