Association of CASP7 polymorphisms and survival of patients with non-small cell lung cancer with platinum-based chemotherapy treatment

Role of CASP7 polymorphisms in noise-induced hearing loss risk in Han Chinese population

Genetic factors and gene-environment interaction may play an important role in the development of noise induced hearing loss (NIHL). 191 cases and 191 controls were selected by case-control study. Among them, case groups were screened from workers exposed to noise in binaural high-frequency hearing thresholds greater than 25 dB (A). Workers with hearing thresholds ≤ 25 dB (A) in any binaural frequency band were selected to the control group, based on matching factors such as age, exposure time to noise, and operating position. The blood samples from two groups of workers were subjected to DNA extraction and SNP sequencing of CASP3 and CASP7 genes using the polymerase chain reaction ligase detection reaction method. Conditional logistic regression correction was used to analyze the genetic variation associated with susceptibility to NIHL. There was an association between rs2227310 and rs4353229 of the CASP7 gene and the risk of NIHL. Compared with the GG genotype, the CC genotype of rs2227310 reduced the risk of NIHL. Compared with CC genotype, the TT genotype of rs4353229 reduced the risk of NIHL. Workers carrying the rs2227310GG and rs4353229CC genotype had an increased risk of NIHL compared to workers without any high-risk genotype. There were additive interaction and multiplication interaction between CASP7rs2227310 and CNE, and the same interaction between CASP7rs4353229 and CNE. The interaction between the CASP7 gene and CNE significantly increased the risk of NIHL. The genetic polymorphisms of CASP7rs2227310GG and CASP7rs4353229CC were associated with an increased risk of NIHL in Han Chinese population and have the potential to act as biomarkers for noise-exposed workers.

Association of genetic polymorphisms in CASP7 with risk of ischaemic stroke

Caspase 7 (CASP7) is located on chromosome 10q25.3 that has been identified to be a susceptibility locus of ischaemic stroke (IS) by genome-wide association study. Elevated CASP7 was observed in IS, acting as a key apoptotic mediator in the development of IS. The aim of this study was to investigate the association between genetic polymorphisms in CASP7 and risk of IS. The CASP7 polymorphisms were genotyped using a TaqMan allelic discrimination assay. The expression levels of CASP7 mRNA were examined using quantitative polymerase chain reaction and luciferase activity was analyzed using the Dual Luciferase reporter assay. The rs12415607 in the promoter of CASP7 was associated with a reduced risk of IS (AA vs. CC: adjusted OR = 0.55, 95% CI: 0.38-0.80, P = 0.002; CA/AA vs. CC: adjusted OR = 0.70, 95% CI: 0.54-0.91, P = 0.007; AA vs. CC/CA: adjusted OR = 0.64, 95% CI: 0.46-0.90, P = 0.01; A vs. C: adjusted OR = 0.74, 95% CI: 0.62-0.89, P = 0.001). Moreover, the rs12415607 AA genotype carriers exhibited lower levels of CASP7 mRNA and the rs12415607 A allele decreased the promoter activity. These findings indicate that the rs12415607 A allele induces lower levels of transcriptional activity and CASP7 mRNA, and thus is associated with a reduced risk of IS.

MicroRNA-related polymorphisms in apoptosis pathway genes are predictive of clinical outcome in patients with limited disease small cell lung cancer

We examined the impact of single nucleotide polymorphisms (SNPs) at miRNA binding sites in the 3'-UTRs of genes in the apoptosis pathway on the prognosis of patients with limited disease-small cell lung cancer (LD-SCLC). Twelve tagSNPs in seven genes were genotyped using blood samples from 146 LD-SCLC patients treated with chemoradiotherapy. Cox proportional hazard regression models and recursive partitioning analysis were performed to identify SNPs significantly associated with overall survival. Three SNPs, CASP8: rs1045494 (C > T), PIK3R1: rs3756668 (A > G) and CASP7: rs4353229 (T > C), were associated with longer overall survival in LD-SCLC patients after chemoradiotherapy. The adjusted hazard ratios (95% confidence intervals) were 0.480 (0.258-0.894), 0.405 (0.173-0.947) and 0.446 (0.247-0.802), respectively, and remained significant after multiple comparison correction. Moreover, subset analysis showed these SNPs were still predictive of overall survival in stage III patients. Recursive partitioning analysis enabled patients to be classified into three risk subgroups based on unfavorable genotype combinations of the rs1045494 and rs4353229 SNPs. These findings suggest miRNA-related polymorphisms in the apoptosis pathway may be useful biomarkers for selection of LD-SCLC patients likely to benefit from chemoradiotherapy.

RICTOR polymorphisms affect efficiency of platinum-based chemotherapy in Chinese non-small-cell lung cancer patients

AIM

We investigated the association between RICTOR polymorphisms and clinical outcomes of platinum-based chemotherapy for Chinese non-small-cell lung cancer patients.

MATERIALS & METHODS

Ten tag SNPs were genotyped in 1004 patients to assess their association with clinical benefit, overall survival, progression-free survival, gastrointestinal toxicity, neutropenia, anemia and thrombocytopenia.

RESULTS

rs6878291 was significantly associated with clinical benefit (odds ratio: 2.037; p = 0.001) and reduced progression-free survival (hazard ratio: 1.461; p = 0.001). Stratified analysis showed that their most significant interaction was in nonsmokers. No association was observed between SNPs and other clinical outcomes.

CONCLUSION

The study showed evidences for RICTOR polymorphisms' role in platinum-based chemotherapy efficiency, which could provide new insight to lung cancer management.

Pharmacogenomics of platinum-based chemotherapy sensitivity in NSCLC: toward precision medicine

Lung cancer is one of the leading causes of cancer-related death in the world. Platinum-based chemotherapy is the first-line treatment for non-small-cell lung cancer (NSCLC), however, the therapeutic efficiency varies remarkably among individuals. A large number of pharmacogenomics studies aimed to identify genetic variations which can be used to predict platinum response. Those studies are leading NSCLC treatment to the new era of precision medicine. In the current review, we provided a comprehensive update on the main recent findings of genetic variations which can be used to predict platinum sensitivity in the NSCLC patients.

Systems biology of cisplatin resistance: past, present and future

The platinum derivative cis-diamminedichloroplatinum(II), best known as cisplatin, is currently employed for the clinical management of patients affected by testicular, ovarian, head and neck, colorectal, bladder and lung cancers. For a long time, the antineoplastic effects of cisplatin have been fully ascribed to its ability to generate unrepairable DNA lesions, hence inducing either a permanent proliferative arrest known as cellular senescence or the mitochondrial pathway of apoptosis. Accumulating evidence now suggests that the cytostatic and cytotoxic activity of cisplatin involves both a nuclear and a cytoplasmic component. Despite the unresolved issues regarding its mechanism of action, the administration of cisplatin is generally associated with high rates of clinical responses. However, in the vast majority of cases, malignant cells exposed to cisplatin activate a multipronged adaptive response that renders them less susceptible to the antiproliferative and cytotoxic effects of the drug, and eventually resume proliferation. Thus, a large fraction of cisplatin-treated patients is destined to experience therapeutic failure and tumor recurrence. Throughout the last four decades great efforts have been devoted to the characterization of the molecular mechanisms whereby neoplastic cells progressively lose their sensitivity to cisplatin. The advent of high-content and high-throughput screening technologies has accelerated the discovery of cell-intrinsic and cell-extrinsic pathways that may be targeted to prevent or reverse cisplatin resistance in cancer patients. Still, the multifactorial and redundant nature of this phenomenon poses a significant barrier against the identification of effective chemosensitization strategies. Here, we discuss recent systems biology studies aimed at deconvoluting the complex circuitries that underpin cisplatin resistance, and how their findings might drive the development of rational approaches to tackle this clinically relevant problem.