Open AccessChromobox homolog 8 is a predictor of muscle invasive bladder cancer and promotes cell proliferation by repressing the p53 pathway
Author(s) -
Yuan Gangjun,
Chen Xin,
Lu Jun,
Feng Zihao,
Chen Siliang,
Chen Rixin,
Wei Wensu,
Zhou Fangjian,
Xie Dan
Publication year - 2017
Publication title -
cancer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 1347-9032
DOI - 10.1111/cas.13383
Subject(s) - bladder cancer , cancer research , gene knockdown , biology , carcinogenesis , cancer , cell growth , cell cycle , downregulation and upregulation , cell culture , gene , biochemistry , genetics
Chromobox homolog 8 ( CBX 8), also known as human polycomb 8, is a repressor that maintains the transcriptionally repressive state in various cellular genes, and has been reported to promote tumorigenesis. In the present study, we examined CBX 8 expression in eight pairs of muscle invasive bladder cancer tissues and adjacent non‐tumor tissues, and found that CBX 8 was frequently upregulated in muscle invasive bladder cancer tissues when compared to adjacent non‐tumor tissues. Analysis showed that high expression of CBX 8 in 152 muscle invasive bladder cancer specimens was associated with progression of the T, N, and M stages ( P = 0.004, 0.005, <0.001, respectively). Furthermore, Kaplan–Meier survival analysis and log–rank test showed that muscle invasive bladder cancer patients with high CBX 8 expression had a poor rate of overall survival ( P < 0.001) and 5‐year recurrence‐free survival ( P < 0.001) compared to patients with low CBX 8 expression. High CBX 8 expression predicted poor overall survival and 5‐year recurrence‐free survival in T and N stages of muscle invasive bladder cancer patients. Moreover, knockdown of CBX 8 inhibited cell proliferation of urothelial carcinoma of the bladder both in vitro and in vivo . In addition, CBX 8 depletion resulted in cell cycle delay of urothelial carcinoma cells of the bladder at the G2/M phase by the p53 pathway. The data suggest that high expression of CBX 8 plays a critical oncogenic role in aggressiveness of urothelial carcinoma cells of the bladder through promoting cancer cell proliferation by repressing the p53 pathway, and CBX 8 could be used as a novel predictor for muscle invasive bladder cancer patients.