Golgi Phosphoprotein 3 Promotes Malignant Phenotypes via FAK/Raf/MEK and Wnt/β-Catenin Signaling Pathways in Human...

Golgi phosphoprotein 3 (GOLPH3), a proto-oncogene product, is significantly increased during the progression of several types of cancer. However, its biological role and underlying mechanism in the development of renal cell carcinoma (RCC) remain poorly understood. In this study, GOLPH3 was found to be highly expressed in RCC specimens compared to the corresponding non-tumor tissues. In vitro, ectopic overexpression of GOLPH3 substantially promoted the proliferative and invasive capacity of RCC cells, while the depletion of GOLPH3 significantly inhibited proliferation and invasion of RCC cells. Furthermore, the average tumor volume was significantly increased in mice injected with 769-P cells highly expressing GOLPH3, whereas GOLPH3 knockdown reduced the tumor growth rate. Mechanistically, using a high-throughput phospho-proteome array verified by Western blotting, we have identified that phosphorylated proteins (FAK, Raf1, MEK, and GSK3β) were upregulated, activating, in turn, FAK/Raf1/MEK and Wnt/β-catenin signaling pathways in RCC cells. Taken together, our findings demonstrate that GOLPH3, whose expression is related to enhanced cell proliferation and invasion via activation of GOLPH3-FAK/Raf1/MEK axis or Wnt/β-catenin signaling pathways, may provide a new therapeutic target to treat renal cell carcinoma.