Abstract: Abstract: Objective To investigate the expression levels of regulator of G-protein signaling 4 (RGS4) in pediatric nephroblastoma and pericancerous tissues, and explore the relationship between RGS4 and the occurrence and development of pediatric nephroblastoma. Methods Thirty- seven samples of pediatric nephroblastoma tissues and 8 samples of pericancerous tissues were collected after surgery to detect the expression of RGS4 protein by immunohistochemistry. Another 8 samples of fresh cancer tissues and corresponding pericancerous tissues were collected to detect the mRNA and protein levels of RGS4 by qRT-PCR and Western blot assay, respectively. Results Immunohistochemistry results showed that RGS4 protein was positively expressed both in pediatric nephroblastoma and pericancerous tissues, and its high expression rate was lower in pediatric nephroblastoma than that in pericancerous tissues [(37.83% (14/37) vs. 87.5% (7/8), 2χ =4.675, P<0.05]. The expression level of RGS4 mRNA was significantly lower in pediatric nephroblastoma than that in pericancerous tissues (1.064 ± 0.549 vs. 5.374 ± 0.735, t=13.290, n=8, P < 0.01). Western blot results showed that the expression level of RGS4 protein was lower in pediatric nephroblastoma than that of pericancerous tissues (0.301±0.092 vs. 0.779 ± 0.041, t=13.424, n=8, P < 0.01). Conclusion The expression level of RGS4 is down- regulated in pediatric nephroblastoma, which may be related to the occurrence and development of pediatric nephroblastoma.

Key words: kidney neoplasms, RGS proteins, pediatric nephroblastoma, RGS4, gene expression