ABSTRACT. The aim of this study was to evaluate the role of GSTM1 null/present, GSTT1 null/present, and GSTP1 IIe105Val polymorphisms in the clinical response to chemotherapy and treatment outcome of patients with breast cancer. A total of 262 subjects were randomly selected from among patients with a histologically confirmed breast cancer. The genotypes of GSTM1, GSTT1, and GSTP1 IIe105Val polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism analysis. Our study found that the null genotype of GSTM1 was associated with a better response to chemotherapy, and the odds ratio [95% confidence interval (CI)] was 1.78 GST polymorphisms and breast cancer prognosis (1.03-3.08). In the Cox proportional hazard model, the hazard ratio (95%CI) for overall survival (OS) in patients carrying the null genotype of GSTM1 was 0.57 (0.32-0.98) using the non-null genotype as the reference variable. However, we observed no significant association between the GSTT1 and GSTP1 polymorphisms and response to chemotherapy and OS in patients with breast cancer. In conclusion, our study found that the GSTM1 polymorphism plays an important role in influencing the chemotherapy response and OS in patients with breast cancer.

ABSTRACT. The purpose of this study was to screen the key genes and pathways of renal cell carcinoma (RCC) and lay the foundation for its diagnosis and therapy. Microarray data of normal subjects and RCC patients at different stages of disease were used to screen differentially expressed genes (DEGs). Based on the DEGs in the four disease stages, four co-expression networks were constructed using the Empirical Bayes method and hub genes were obtained by centrality analysis. The enriched pathways of the DEGs and the mutual hub genes in the cluster of each disease stage were investigated. The mutual hub genes of the four disease stages in RCC tissue were validated using reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis. A total of 432 DEGs were screened, including 233 upregulated and 199 downregulated genes, by statistical analysis. Centrality analysis of co-expression networks in different disease stages suggested that PLXDC1, IKZF1, RUNX2, and RNF125 were mutual hub genes. Pathway analysis showed that the DEGs were significantly enriched in seven terms. The hub modules in stage I disease were significantly enriched in the complement coagulation cascade pathway and the hub modules of the other three disease stages were enriched in natural killer cell-mediated cytotoxicity. The expression levels of PLXDC1, IKZF1, RUNX2, and RNF125 were significantly different between normal subjects and RCC patients by RT-PCR and western blot. Our study revealed four hub genes (PLXDC1, IKZF1, RUNX2, and RNF125) and two biological pathways that might be underlying biomarkers involved in RCC.