Abstract: Objective To study the expression of RNA PolymeraseⅢ Subunit G (POLR3G) expression in muscle-invasive bladder cancer (MIBC) and its relationship with response to adjuvant chemotherapy (ACT) or prognosis.Methods 42 consecutive MIBC patients were recruited from March 2016 to January 2022 and treated by radical cystectomy in our hospital.Quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the expression of POLR3G in MIBC clinical samples,to construct the relationship between tissue POLR3G expression and clinical characteristics of patients,and to further analyze clinical outcomes.Results In clinical cohort analysis,higher expression of POLR3G mRNA in MIBC tissues was associated with higher tumor grade and pT stage (P＜0.05).Kaplan-Meier survival analysis showed that OS (median:9.5 months vs.25.0 months) and PFS (median:15.0 months vs.25.0 months) in patients with high POLR3G expression were significantly shorter than those in the low POLR3G expression subgroup (P＜0.05).In addition,the overexpression of POLR3G in tissues was an independent prognostic indicator of poor PFS (P=0.003) and OS (P=0.048) in MIBC patients.Compared with pT3/4 or N+ MIBC patients with high POLR3G expression receiving ACT,patients with pT3/4 or N+ MIBC with low POLR3G expression receiving ACT had significantly longer OS (P＜0.001).Conclusion POLR3G mRNA expression is upregulated in MIBC tissues,which may be a potential prognostic indicator of MIBC,and may be a candidate marker for predicting adjuvant chemotherapy in patients with local progression.

Key words: RNA polymeraseⅢsubunit G, muscle-invasive bladder cancer, adjuvant chemotherapy response, prognosis, the Cancer Genome Atlas Database