A Preliminary Study of NER and MMR Pathways Involved in Chemotherapy Response in Bladder Transitional Cell Carcinoma: Impact on progression-free survival

One of the main genotoxic drugs used in bladder cancer chemotherapy is cisplatin. While it is applied in most types of cancers, resistance to cisplatin is wildly common. In order to overcome drug resistance, it is necessary to determine a predictive marker. This study was conducted to provide basic data for selecting and designing a gene profile for further cohort and RCT studies in the future to improve response to treatment in bladder cancer. The expression levels of ERCC1, MLH1, MSH2, and CTR1 mRNA were determined in the tumor tissue using real-time q-PCR. Progression-free survival (PFS) was analyzed in term of the level of genes expression. The results revealed that the level of ERCC1 mRNA expression was higher in the recurrence (R) group compared to the no recurrence (NR) group. Moreover, the PFS time was increased in the patients with an ERCC1 expression level of below 1.57. The level of MLH1 and MSH2 mRNA expression was lower in the R group compared to the NR group; therefore, PFS time was increased in the patients with MLH1 and MSH2 gene expression levels above the cutoff point. While the level of CTR1 mRNA expression was higher in the R group versus the NR group, the PFS time was longer in the patients with CTR1 expression levels of below 1.265 compared to the patients with high levels of CTR1 expression. It can be concluded that the level of ERCC1, MLH1, MSH2, and CTR1 mRNA expression may be associated with PFS time as possible therapeutic targets for decreasing cisplatin resistance.