MRE11A and SKP2 genes are associated with the increased cytotoxicity induced by the synergistic effects of cisplatin and gemcitabine in bladder cancer cells

Abstract

The combination of gemcitabine and cisplatin has been shown previously to elicit a synergistic therapeutic effect on bladder cancer cell lines and result in reduced cell survival. However, the precise mechanism by which cells die has not been elucidated. Cell cycle-related genes are the predominant targets of chemotherapeutic protocols. Therefore, molecular biomarkers that are predictive of therapeutic outcomes associated with tumor sensitivity might be important for optimal treatment protocol selection. The aim of this study was to investigate the changes in gene expression in cell cycle-related genes that were induced by cisplatin, gemcitabine or a combined treatment using both agents in a low-grade urinary bladder transitional carcinoma cell line (RT4). The following three treatment protocols were used: 1.0 μM cisplatin, 1.56 μM gemcitabine and a combination of 1.0 μM cisplatin and 1.56 μM gemcitabine. Cytometry and morphology analysis (by phase-contrast photomicrography) were performed in addition to pathway-specific gene expression analysis using quantitative RT-PCR gene arrays. The following results were observed after 1.0 μM cisplatin treatment: (1) a decrease in cell number, (2) an increased percentage of scattered cells and (3) downregulated expression of genes related to cell cycle arrest, G1/S-to-mitotic cell cycle transition, DNA repair, apoptosis, transcription and mitosis. Treatment with 1.56 μM gemcitabine, or with both drugs simultaneously, induced the following effects: (1) a decrease in cell number, (2) an increased percentage of scattered and elongated cells, (3) the modulation of genes that are predominantly involved in DNA repair and (4) a significant upregulation of genes related to cell cycle arrest. Reduced cell density was observed after the combined treatment compared to the two other single-agent protocols. The downregulation of MRE11A and SKP2 was observed only in cells subjected to the combined treatment. In conclusion, cisplatin, gemcitabine and the combination of both drugs elicited distinct toxicogenomic effects in the RT4 bladder transitional carcinoma cell line, although disruptions in the expression of cell cycle control-related genes and other pathways responsible for cell survival were observed for all of the protocols. MRE11A and SKP2 downregulation appeared to be responsible for the synergistic therapeutic effects elicited by cisplatin and gemcitabine.

Gemcitabine/Cisplatin Treatment Induces Concomitant SERTAD1, CDKN2B and GADD45A Modulation and Cellular Changes in Bladder Cancer Cells Regardless of the Site of TP53 Mutation

“…Four genes were significantly modulated in only the 5637 cells, while 16 genes were significantly modulated in only the T24 cells. In a previous study we have also suggested that MRE11A (which is involved in the response to a DNA damage stimulus and the cellular response to stress) and SKP2 (involved in the negative regulation of the cell cycle) downregulation seemed be responsible for the synergistic therapeutic effects of cisplatin and gemcitabine in wild type TP53 cell line [28]. This discrepancy in the expression profile intensities of these genes supports the notion that complex mechanisms are involved in carcinogenesis.…”

Synergistic and Pharmacotherapeutic Effects of Gemcitabine and Cisplatin Combined Administration on Biliary Tract Cancer Cell Lines

“…Although synergistic effects of GC for other cancer cell lines have been reported [9,11,12,14], the methodologies, drug concentrations, and other quantitations were different among the reports. In the current study, we examined the synergistic effects of GEM and CDDP using two assessment methods, BM and CI.…”

“…GC evaluation based on BM indicated synergistic effects in all cell lines, and evaluation of GC at a 7:1 molar ratio based on the CI revealed that all cell lines exhibited either synergistic or additive effects. One possible reason for this difference could be that the effects were not necessarily associated with the drug concentration [14,29]. These facts suggested the possibility of complex pharmacological factors in drug combinations.…”

“…To understand the synergistic effects of GC therapy and to improve outcomes for patients with advanced or recurrent BTC, we consider that the efficacy of GC should first be elucidated in a preclinical-style study. The synergistic effects of GC administration in vitro have been reported for ovarian cancer, head and neck cancer, lung cancer, neuroblastoma, and bladder carcinoma [8,9,10,11,12,13,14]. However, as far as we know, there have been no detailed studies on the pharmacotherapeutic activity, synergistic effect, and plasma clearance of GC.…”

Function and mechanism of F-box proteins in gastric cancer (Review)

“…Thirdly, SKP2 acetylation could promote its oncogenic function by regulating the downstream targets such as p21 and FOXO1, and upregulated the acetylation of SKP2 promoted cell growth (20,21). Fourthly, SKP2 genes were associated with the increased cell cytotoxicity induced by drugs like platinum (22). Recently, research has shown that SKP2 predicts poor prognosis and maintains a cancer stem cell pool (23)(24)(25).…”