Holliday junction‑recognition protein modulates apoptosis, cell cycle arrest and reactive oxygen species stress in human renal cell carcinoma.

Holliday junction recognition protein (HJURP) is involved in the regulation of mortality in various cell types, including renal cell carcinoma (RCC) cells. The specific mechanisms by which HJURP regulates RCC cell apoptosis and the cell cycle have not been previously investigated, to the best of our knowledge. In the present study, the expression of HJURP in RCC tissues and adjacent paracancerous renal tissue, as well as in RCC cell lines, was analyzed using reverse transcription‑quantitative PCR and western blot analysis. The A498 RCC cells were transfected with an HJURP overexpression vector, which resulted in reduced proliferation, as demonstrated using immunofluorescence staining, a Cell Counting Kit‑8 assay and a colony formation assay. Flow cytometry and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labelling assays were used to determine the effect of HJURP on the cell cycle and apoptosis of RCC cells. Proteins associated with the reactive oxygen species (ROS) status were analyzed using western blot analysis. The expression of HJURP was lower in RCC tissues and cells compared with that in the adjacent paracancerous renal tissues and control cells. Furthermore, overexpression of HJURP resulted in a decrease in cell viability and proliferation in vitro. Overexpression of HJURP resulted in cell cycle arrest at the G0/G1 phase, cell apoptosis and an increase in ROS stress. In addition, the phosphorylated/total sirtuin 1 (SIRT1) protein ratio was decreased, whereas the expression of peroxisome proliferator‑activated receptor (PPAR)γ was increased in the HJURP‑overexpressing RCC cells. In clinical practice, decreased HJURP expression may be associated with poor prognosis in patients with RCC. These results suggest that HJURP may regulate cell apoptosis and proliferation in RCC cells and this may be mediated by PPARγ/SIRT1. Thus, HJURP may be used as a predictor of prognosis in patients with RCC.