TPX2 in human clear cell renal carcinoma: Expression, function and prognostic significance

Targeting protein for Xenopus kinesin-like protein 2 (TPX2) is a microtubule-associated protein. TPX2 is considered to be an important gene in tumorigenesis; however, the particular function of TPX2 in the development of human renal cell carcinoma (RCC) is unknown. In the present study, the expression, function and prognostic significance of TPX2 in human RCC was analyzed. A total of 286 tissue samples from patients with RCC who had undergone nephrectomies were utilized. Subsequently, the expression of TPX2 protein was investigated using immunohistochemistry and western blotting, and TPX2 mRNA expression was examined using reverse transcription-quantitative polymerase chain reaction. To establish the effect of TPX2 on the proliferation and invasion of the RCC cells, TPX2 expression was increased by stable transfection with a TPX2 vector and TPX2 expression was decreased using small interfering RNA. Proliferation of the RCC cells was analyzed using a WST-1 assay and an animal xenograft model with BALB/c nude mice, whilst invasion of the RCC cells was examined using a Matrigel-coated invasion chamber. It was demonstrated that TPX2 expression was significantly higher in the RCC tissues compared with normal kidney tissues (P<0.05). Furthermore, TPX2 expression was associated with tumor size, histological grade and tumor stage (P<0.05), and was observed to markedly increase the proliferation and invasion of the RCC cells. It may be concluded that the expression of TPX2 is significantly upregulated in RCC tissue, subsequently increasing the proliferative and invasive ability of RCC cells. Therefore, the protein may serve as a therapeutic target and independent prognostic factor in the treatment of human RCC.