Polo-like kinase 1 (Plk1) is an interesting molecule both as a
biomarker and as a target for highly specific
cancer therapy for several reasons. However, the functional significance of Plk1 in
renal cell carcinoma (RCC) has not been reported. To explore whether Plk1 plays a general role in
renal carcinoma, we examined the expression of
Plk1 protein in renal urothelial
carcinoma and cell lines, and analyzed the relationship between
Plk1 protein expression and development, proliferation, and invasion of
renal carcinoma. Immunohistochemisty was used to detect the expression of Plk1 in 100
renal carcinoma tissues. Moreover, the expression of Plk1 was analyzed by western blot and real-time polymerase chain reaction (PCR) in 80
renal carcinoma tissues and 20 normal renal tissues.
CCK-8 assay, colony formation assay, and Transwell assay were used to examine proliferation and invasion ability of
renal cancer cells with treatment of
scytonemin (the specific inhibitor of Plk1). Statistical analysis was used to discuss the association between Plk1 expression and clinicopathologic parameters, and proliferation and invasion ability of
renal cancer cells. Plk1 expressions were greater in cancerous tissues than in normal tissues (P<0.05). With an increase in
tumor grade and stage,
tumor metastasis, and recurrence, the level of Plk1 increased significantly in renal cancerous tissues. Moreover, there was a significantly higher expression of Plk1 in higher degree of malignant
renal adenocarcinoma cell ACHN than that in
renal adenocarcinoma cell 769-P. With increasing concentration of
scytonemin, we found that cell proliferation and invasion activity decreased significantly. Plk1 expression status was closely correlated with important histopathologic characteristics (grades, stages,
metastasis, and recurrence) of
renal carcinomas. Furthermore, Plk1 played an important function on
renal cancer cells' proliferation and invasion.