KLF5-mediated Eppk1 expression promotes cell proliferation in cervical cancer via the p38 signaling pathway
Background: Epiplakin1 (Eppk1) is part of the EGF signal and is involved in cytoskeleton reorganization and cell proliferation. However, the role of Eppk1 in cervical cancer remains unknown. Objective: To determine the role of EPPK1 on cell proliferation in cervical cancer. Methods: The expression of Eppk1 and KLF5 as well as their correlation were assessed by RNA-seq, qRT-PCR, TCGA database and immunofluorescence staining. In CC cell lines, adenovirus-mediated overexpression or knockdown of
... 5 and Eppk1 as well as corresponding assessment of cell proliferation and signaling were determined by western blot and CCK8 experiments. Assays of lucifase reporter gene and CHIP were used to investigate mechanism between KLF5 and Eppk1 . Results: Eppk1 expression was markedly in CC tissues and cell lines companied by KLF5 upregulation. The results of immunofluorescence staining further showed that the increased expression of Eppk1 and KLF5 correlated with progression of cervical tumorigenesis. Overexpression of KLF5 significantly increased Eppk1 expression at transcription and translation levels. Conversely, the knockdown of KLF5 by siRNA against KLF5 decreased Eppk1 expression. Mechanical studies showed that KLF5 activated Eppk1 transcription by direct binding to the Eppk1 promoter. Gain- and loss-of-function experiments showed that KLF5 promoted cell proliferation in Hela by upregulating Eppk1 expression. Moreover, KLF5-mediated the activation of EGFR and p38 signaling significantly decreased after Eppk1 knockdown companied with reduction of proliferating activity, suggesting that Eppk1 lies upstream of p38 signaling affecting cell proliferation in CC. Finally, the expression of Eppk1 positively correlated with tumor size. Conclusions: Eppk1 may be an effective therapeutic target on affecting EGFR-associated p38 signaling pathway and cell proliferation in cervical cancer.