PHF5A facilitates the development and progression of gastric cancer through SKP2-mediated stabilization of FOS

Abstract

BACKGROUND: Gastric cancer (GC) is the fifth most common cancer and the third most common cause of cancer death worldwide. Plant homeodomain (PHD)-finger domain protein PHF5A has been demonstrated to play a promoting role in a variety of cancers. This study aimed to clarify the role of PHF5A in the progression of GC and its potential mechanism of action. METHODS: Immunohistochemical staining experiments were performed based on tissues from clinical GC patients to reveal PHF5A expression. A series of functional experiments in vitro and in vivo were used to clarify the role of PHF5A in GC. RESULTS: Clinically, PHF5A was abundantly expressed in GC and existed clinical value indicating poor prognosis. In addition, GC cells with knockdown of PHF5A expression showed slowed proliferation, enhanced sensitivity to apoptosis and inhibition of migration. Mechanically, knockdown of PHF5A led to decreased protein stability of FOS, which was mediated ubiquitination of E3 ubiquitin ligase S-phase kinase-associated protein 2 (SKP2). Moreover, downregulation of FOS attenuated the promotion of PHF5A overexpression on GC cells. Consistently, Pladienolide B (PHF5A inhibitor) treatment reversed the induction of PHF5A overexpression on the malignant phenotypes and tumor formation of GC cells. CONCLUSION: Knockdown of PHF5A inhibited the progression of GC through SKP2-mediated ubiquitination of FOS, which may be a promising candidate target with potential therapeutic value.