Decreased Expression of Karyopherin-α 1 is Related to the Malignant Degree of Cervical Cancer and is Critical for the Proliferation of Hela Cells

Abstract

Karyopherin α (KPNA) proteins are involved in nucleocytoplasmic trafficking and are critical for protein subcellular localization. Recent studies have suggested that KPNA proteins are abnormally expressed in various solid tumors. The objective of this study was to investigate the expression of KPNA1 and KPNA2 in cervical cancer tissue with different histologic grades and cell lines, as well as the effects of the KPNA1 expression level on Hela cell proliferation. We collected the medical data of 106 patients with cervical cancer and investigated the protein expression of KPNA1 and KPNA2 by immunohistochemistry and western blot. The results revealed a significantly lower expression of KPNA1 in cervical cancer compared to normal tissue. Conversely, stronger staining intensity for KPNA2 was observed in cervical tumor samples. The expression levels of KPNA1 and KPNA2 were significantly associated with the tumor histologic grade. The weakest KPNA1 expression and strongest staining for KPNA2 were observed in grade III tumor tissue. The expression levels of KPNA1 were lower in Hela and C33A cells compared with normal human cervical epithelial cells; however, the expression of KPNA2 exhibited an opposite trend. The up-regulation of KPNA1 significantly suppressed the proliferation of Hela cells and relevant proteins expression, as well as promoted transportation of IRF3 into nucleus. Our results suggest the downregulation of KPNA1 expression is related to the malignant degree of cervical cancer and is closely associated with the proliferation of cervical cancer cells.