Polymorphism in XRCC1 gene modulates survival and clinical outcomes of advanced North Indian lung cancer patients treated with platinum-based doublet chemotherapy

Association of hTERT MNS16A polymorphism with clinical outcomes of North Indian lung cancer patients undergoing platinum-based doublet chemotherapy

BACKGROUND

Telomerase has been linked to aging and cancer. The MNS16A polymorphism in the hTERT gene plays a significant role in modulating telomerase activity and highlights the complexity of telomere-related genetics in cancer research.

EXPERIMENTAL DESIGN

We genotyped 401 lung-cancer samples treated with platinum-based chemotherapy to identify the MNS16A polymorphism. We assessed overall survival using the Kaplan-Meier method and Cox regression analysis for adjusted hazard ratios. Stratified analyses evaluated risks for subgroups based on clinicopathologic parameters, outcomes, and toxicity calculated.

RESULTS

Our findings show no significant link between MNS16A polymorphism and lung-cancer survival. However, in squamous cell carcinoma (SQCC) patients, the SS genotype was associated with poorer survival (p = 0.004). Patients with LS + SS genotypes responded better to gemcitabine in univariate (p = 0.003) and multivariate analyses (p = 0.014). The LS genotype was linked to a lower risk of progression to stage 4 (p = 0.011) and metastasis (p = 0.015) but an increased risk of T4 tumor size (p = 0.026). No significant correlations were found between MNS16A polymorphism and treatment-related toxicities.

CONCLUSION

The MNS16A polymorphism does not significantly impact overall lung-cancer survival but affects specific subgroups, influencing certain lung-cancer subtypes and treatment responses while having limited predictive value for overall outcomes or toxicity risks.

Genetic polymorphisms as potential pharmacogenetic biomarkers for platinum-based chemotherapy in non-small cell lung cancer

Platinum-based chemotherapy (PBC) is a widely used treatment for various solid tumors, including non-small cell lung cancer (NSCLC). However, its efficacy is often compromised by the emergence of drug resistance in patients. There is growing evidence that genetic variations may influence the susceptibility of NSCLC patients to develop resistance to PBC. Here, we provide a comprehensive overview of the mechanisms underlying platinum drug resistance and highlight the important role that genetic polymorphisms play in this process. This paper discussed the genetic variants that regulate DNA repair, cellular movement, drug transport, metabolic processing, and immune response, with a focus on their effects on response to PBC. The potential applications of these genetic polymorphisms as predictive indicators in clinical practice are explored, as are the challenges associated with their implementation.

Chemical stability of active ingredients in diluted veterinary disinfectant solutions under simulated storage conditions

Introduction: The product labels of veterinary disinfectants specify their expiration dates to prevent the use of outdated products, as these may result in disinfection and biosecurity failures during outbreak situations. However, a clear standard for the storage conditions of diluted disinfectant solutions has not yet been established, and the effects of storage conditions have scarcely been investigated. To fill this research gap, our study examined the stability of the active ingredients of diluted veterinary disinfectants based on their change in concentrations when stored at various temperatures for various time periods. Methods: Twenty veterinary disinfectants effective against either foot-and-mouth disease or avian influenza viruses were selected. The disinfectants were diluted to effective concentrations following the manufacturer's instructions. Using selective analytical techniques, the concentrations of the active ingredients of the samples that had been stored for varying intervals at different temperatures (4, 20, 30, and 45°C) were determined. These samples included soaps and detergents, acids, oxidizing agents, aldehydes, and copper compounds. The active ingredient concentrations of two of the samples were determined following freezing/thawing cycle, to establish their stability when exposed to simulated winter conditions. Results: Our results showed that most of the active ingredients had concentrations of 90% or greater of their initial concentrations, indicating ≥90% stability over a 21-day period under the experimental storage conditions. However, there were some exceptions. Glutaraldehyde, formaldehyde, and malic acid are over 90% stable at ≤ 30°C for 21 days, but their concentrations decreased to below 90% of their initial concentrations at 45°C, indicating a decline in stability when stored at 45°C for 21 days. The concentrations of potassium peroxymonosulfate and peracetic acid rapidly declined with increasing time and temperature to less than 90% of their initial concentrations. Discussion: Based on our findings, we propose that diluted disinfectant solutions should preferably be prepared daily. However, if the daily preparation of a diluted disinfectant solution is not feasible, then our results can be used as a reference, providing basic scientific data on the chemical stability of diluted disinfectant solutions commonly used in the veterinary field, thus indicating suitable storage conditions.

The roles of risk model based on the 3-XRCC genes in lung adenocarcinoma progression

Background

The abnormal expression of deoxyribonucleic acid (DNA) repair genes might be the cause of tumor development and resistance of malignant cells to chemotherapeutic drugs. A risk model based on the X-ray repair of cross-complementary (XRCC) genes was constructed to improve the diagnosis and treatment of lung adenocarcinoma (LUAD) patients.

Methods

The expression levels, diagnostic values, and prognostic values of XRCC genes were identified, and the roles and regulatory mechanisms of the risk model based on the XRCC4/5/6 in LUAD progression was explored via The Cancer Genome Atlas (TCGA) and Oncomine databases.

Results

XRCC1/2/3/4/5/6, XRCC7 (PRKDC), and XRCC9 (FANCG) were overexpressed, and had diagnostic value for LUAD. The XRCC genes were involved in DNA repair, and participated in the regulation of non-homologous end-joining, homologous recombination, etc. The overall survival (OS), tumor (T) stage, and survival status of patients were significantly different between the Cluster1 and Cluster2 groups. XRCC4/5/6 were independent risk factors affecting the prognosis of LUAD patients. The risk score was related to the prognosis, sex, clinical stage, T, lymph node (N), and metastasis (M) stage, as well as the survival status of LUAD patients. The clinical stage and risk score were independent risk factors for poor prognosis in LUAD patients. The risk model was involved in RNA degradation, cell cycle, basal transcription factors, DNA replication etc. The risk scores were significantly correlated with the expression levels of TGFBR1, CD160, TNFSF4, TNFRSF14, IL6R, CXCL16, TNFRSF25, TAPBP, CCL16, and CCL14.

Conclusions

The risk model based on the XRCC4/5/6 genes could predict the progression of LUAD patients.

Genetic Polymorphisms and the Efficacy of Platinum-Based Chemotherapy: Review

Previous studies have indicated that genetic variations in individuals may result in changes in gene expression and amino acids. The effect of these changes may lead to different responses to platinum-based chemotherapy. A vast response rate interval and a short survival rate indicate that the efficacy and efficiency of the selection of chemotherapy have not been optimized. This article aims to illustrate the potential relationship of various genetic polymorphisms in response to platinum-based chemotherapy for several types of cancer. This review was conducted using articles from the last three- and five-year periods (2014-2019) that use gene polymorphism and its relationship to the efficacy of platinum-based chemotherapy as their theme. A total of 26 out of 488 relevant articles were included based on specific criteria. Through various mechanisms, genes, including ERCC1, ERCC2/XPD, XPC, XPA, XRCC1, APE-1, PARP1, OGG1, ABCC2, MRP, GSTP1, GSTM1, GSTT1, MATE1, and OCT2, have been associated with patient response to platinum-based chemotherapy. We conclude that genetic polymorphism analysis is recommended for the management of cancer so that each patient can be administered therapy based on his or her genetic profile to achieve an effective and efficient outcome.

XRCC1 632 as a candidate for cancer predisposition via a complex interaction with genetic variants of base excision repair and double strand break repair genes

Aim: The DNA repair system safeguards integrity of DNA. Genetic alterations force the improper repair which in conjugation with other factors ultimately results in carcinogenesis. Materials & methods: PCR-restriction fragment length polymorphism was used for genotyping, which was followed by statistical analysis using logistic regression analysis, multifactor dimensionality reduction and classification and regression analysis tree, elaborating the association with lung cancer subjects. Results: Combination of XRCC1 632 and OGG1326 showcased a high risk of eightfold (odds ratio: 7.92; 95% CI: 2.68–23.4; p = 0.0002; false discovery rate (FDR) p = 0.002). Similarly, XRCC1 632 and MUTYH 324 (odds ratio: 5.07; 95% CI: 2.6–9.67; p < 0.0001; FDRp = 0.002) had a high risk. Multifactor dimensionality reduction analysis revealed five factor model as the best model with prediction error of 0.37 (p = 0.02). Conclusion: There was a clear indication that high order interactions were major role players in the study.

Polymorphisms of rs4787050 and rs8045980 are associated with lung cancer risk in northeast Chinese female nonsmokers

Aim: We studied the association between two single-nucleotide polymorphisms (SNPs: rs4787050 and rs8045980) in RBFOX1 and lung cancer risk, and explored the interaction between the two SNPs and exposure to cooking oil fume on lung cancer risk in northeast Chinese female nonsmokers. Methods: Northeast Chinese female nonsmokers were enrolled into the study (people with lung cancer, 647; people without lung cancer, 675). All statistical analyses were performed using SPSS software. Results: The SNPs rs4787050 and rs8045980 showed a significant association with susceptibility to lung cancer. Moreover, cooking oil fume exposure was found to increase the risk of lung cancer. However, no gene-environment interactions were discovered. Conclusion: The present study revealed that rs4787050 and rs8045980 in RBFOX1 may be meaningful as a novel biomarker for lung cancer susceptibility.

Discovery of Novel Biomarkers of Therapeutic Responses in Han Chinese Pemetrexed-Based Treated Advanced NSCLC Patients

Pemetrexed, one of the most commonly used drugs in advanced non–small cell lung cancer (NSCLC) therapies, often leads to various therapeutic responses in patients. These therapeutic responses to pemetrexed, including adverse drug reactions (ADRs) and its intended therapeutic effects, have been demonstrated to be highly individual-specific. Such difference in therapeutic responses across individuals may be caused by the unique genetic variations in each patient. However, only a few pemetrexed-based studies have been performed using Han Chinese patients. In this study, we aimed to identify genetic signatures of therapeutic responses of pemetrexed-based treatment using 203 Han Chinese patients with advanced NSCLC. All the participants received two different types of therapies: 1) treatment with only pemetrexed and 2) treatment with both pemetrexed and platinum (mainly cisplatin and carboplatin). We then performed a genetic association analysis on 16 selected single-nucleotide polymorphisms (SNPs) in 7 genes using these 2 groups. The analysis of patients receiving only pemetrexed suggests that the SNP rs1051298 on the SLC19A1 gene (c.*746C > T) increased the risk of all ADRs (collected all types of ADRs) in different cycles of pemetrexed therapy [1-2 cycles: P = 0.0059, odds ratio (OR) = 3.143; 1-4 cycles: P = 0.0072, OR = 2.340; 1-6 cycles: P = 0.0071, OR = 2.243]. This influence of rs1051298 is particularly significant in terms of liver injury (1-4 cycles: P = 0.0056, OR = 3.863; 1-6 cycles: P = 0.0071, OR = 3.466). In all the patients, including patients who received both pemetrexed and platinum, SNP rs1801133 on the MTHFR gene (665C > T) was found to be significantly associated with hematological ADRs in 1 to 2 cycles (P = 0.0079, OR = 3.566). Additionally, we discovered that SNP rs12995526 (c.815-102T > C) in the ATIC gene and SNP rs11545077 (c.91G > T) in the GGH gene were associated with both ADRs and therapeutic effects. In summary, our study identified several potential biomarkers that were significantly associated with ADRs and therapeutic effects of pemetrexed-related treatments using Han Chinese patients. Our discoveries will provide important clues for personalized pemetrexed-based treatment design for Han Chinese NSCLC patients in the future.

Efficient Single-Strand Break Repair Requires Binding to Both Poly(ADP-Ribose) and DNA by the Central BRCT Domain of XRCC1

XRCC1 accelerates repair of DNA single-strand breaks by acting as a scaffold protein for the recruitment of Polβ, LigIIIα, and end-processing factors, such as PNKP and APTX. XRCC1 itself is recruited to DNA damage through interaction of its central BRCT domain with poly(ADP-ribose) chains generated by PARP1 or PARP2. XRCC1 is believed to interact directly with DNA at sites of damage, but the molecular basis for this interaction within XRCC1 remains unclear. We now show that the central BRCT domain simultaneously mediates interaction of XRCC1 with poly(ADP-ribose) and DNA, through separate and non-overlapping binding sites on opposite faces of the domain. Mutation of residues within the DNA binding site, which includes the site of a common disease-associated human polymorphism, affects DNA binding of this XRCC1 domain in vitro and impairs XRCC1 recruitment and retention at DNA damage and repair of single-strand breaks in vivo.

Association of MLH1 single nucleotide polymorphisms with clinical outcomes of first-line irinotecan-based chemotherapy in colorectal cancer

PURPOSE

Several studies have proved that single nucleotide polymorphisms (SNPs) of mismatch repair system genes are closely related to the development of colorectal cancer (CRC) by causing microsatellite instability, while effects of the SNPs of MMR system-related genes on the clinical outcomes of cytotoxic chemotherapy are less understood. The aim of this study explored the influence of MLH1 SNPs on clinical outcomes of first-line irinotecan-based chemotherapy in CRC.

PATIENTS AND METHODS

A total of 125 metastatic colorectal cancer (mCRC) patients who received first-line irinotecan-based chemotherapy (none of them combined with bevacizumab or cetuximab) were enrolled in this study. Blood samples or formalin-fixed paraffin-embedded tissues of study population were taken. DNA isolation and genotyping analyzed were obtained for potential functional polymorphisms of MLH1 rs1800734 by real-time PCR. Progression-free survival (PFS) was the primary endpoint and tumor response rate (RR) was the secondary endpoint of this study.

RESULTS

Of all the assessable population, the result showed no statistical difference among the three types SNPs of MLH1 rs1800734 (AA, AG, GG) for RR (P=0.859), and also without significant difference for AA + AG combined variants vs GG variant (P=0.849). The median PFS for AA, AG, and GG variants of MLH1 rs1800734 SNPs were 9.4 months, 7.0 months, and 6.9 months, respectively (log-rank P=0.031). Interestingly, compared with AA variant of MLH1 rs1800734 SNPs, GG variant showed a shorter PFS (HR: 3.49; 95 CI: 1.02-11.94; P=0.046). Furthermore, the median PFS of AA + AG combined variants and GG variant were 8.3 months and 6.9 months (log-rank P=0.037), and GG variant have a decreased trend with no significant difference (HR: 1.57; 95 CI: 0.98-2.53; P=0.061).

CONCLUSION

The AA variant of MLH1 rs1800734 SNPs has a longer PFS in first-line irinotecan-based chemotherapy for mCRC patients, and the result needs to be further confirmed by prospective studies in the future.

Genetic Investigation of Polymorphic OGG1 and MUTYH Genes Towards Increased Susceptibility in Lung Adenocarcinoma and its Impact on Overall Survival of Lung Cancer Patients Treated with Platinum Based Chemotherapy

Genes OGG1 and MUTYH are the two primary genes in Base excision repair pathway. OGG1 hydrolyzes the sugar phosphate backbone and remove the damaged base creating abasic site. MUTYH complements OGG1 as it particularly remove adenine mispaired with 8-oxo-G. Both OGG1 and MUTYH act as a check for the mis-incorporation of bases may be due to damages incurred on DNA. DNA isolation for 326 lung cancer cases and 330 controls was followed by genotyping making use of PCR-RFLP. Logistic regression was done to analyze the risk towards lung cancer. Patients were followed through telephonic conversation. Kaplan meier and Cox-regression were used for survival analysis. OGG1 presented a high risk towards lung cancer (CG: OR = 2.44, p = 0.0003; CG + GG: OR = 1.88, p = 0.0093). On the same lines adenocarcinoma for OGG1 were potent risk factors towards lung cancer (CG: OR = 4.72, p = 0.0002; CG + GG: OR = 3.63, p = 0.0018). Single allelic carriers for MUTYH gene imposed a high risk towards overall lung susceptibility and for all the three histology. Stratified analysis for chemotherapeutic drugs revealed administration of Cisplatin/Carboplatin + Pemtrexed for OGG1Ser ³²⁶ Cys showed a better survival (MST CG vs. CC: 9.1 vs. 0.56, p = <0.0001; HR =0.051, p = 0.0025). Whereas, MUTYH Gln³²⁴His showed a smaller survival for mutant genotype (CC) (MST CC vs. GG: 4.0 vs. 9.4, p = 0.05; HR = 1.75, p = 0.26). Single allelic carriers for both OGG1 and MUTYH were risk factors towards lung cancer. The risk was amplified on combining both OGG1 and MUTYH.

Polymorphisms of rs1347093 and rs1397529 are associated with lung cancer risk in northeast Chinese population

Lung cancer is one of the malignant tumors with the highest morbidity and mortality all over the world. Here we researched the association between two SNPs (rs1347093 in MIR217HG and rs1397529 in Gab1) and the risk of lung cancer in northeast Chinese population, including 825 cases and 766 controls. We carried out χ2 test, unconditional logistic regression analysis and crossover analysis to estimate the relationship between SNPs and lung cancer risk and the interaction between SNPs and smoking on susceptibility to lung cancer. The results indicated that rs1347093, rs1397529 polymorphisms were associated with lung cancer risk, especially with adenocarcinoma risk. Dominant genetic model of the rs1347093 was associated with reduced risk of lung cancer compared to CC genotype (AC+AA vs. CC: adjusted OR = 0.599, 95%CI = 0.418-0.858, P=0.005). For rs1347093, the similar result was found. Dominant genetic model of the rs1397529 was associated with reduced risk of lung cancer compared to AA genotype (AC+CC vs. AA: adjusted OR = 0.664, 95%CI = 0.491-0.897, P=0.008). There is no significant interaction between rs1347093, rs1397529 polymorphism and smoking on susceptibility to lung cancer. Our study might demonstrate that rs1347093 in MIR217HG and rs1397529 in Gab1 could be meaningful as the novel biomarker for lung cancer risk.

Polymorphisms of CCNB1 Associated With the Clinical Outcomes of Platinum-Based Chemotherapy in Chinese NSCLC Patients

As a crucial cell cycle regulator and G2/M phase promotor, CCNB1 played an essential role in progression of chemotherapy related cell death. Platinum-based chemotherapy is still the first-line chemotherapy regimen for most advanced NSCLC patients. We aim to investigate the correlation of CCNB1 polymorphisms to the efficiency of platinum-based chemotherapy in Chinese advanced NSCLC patients. We enrolled 972 patients with advanced NSCLC, and extracted DNA from their peripheral blood for genotyping CCNB1 four tagSNPs which selected from the Hapmap database. We analyzed the association of CCNB1 four tagSNPs with efficiency of platinum-based chemotherapy. We found that rs2069429 and rs2069433 of CCNB1 were associated with the OS of advanced NSCLC patients. Patients with GG genotype of rs2069429 had longer OS than non-GG patients (HR=0.81, 95%CI=0.68-0.95, p=0.009); and patients with AA genotype of rs2069433 had longer OS than non-AA patients (HR=0.78, 95%CI=0.61-0.98, p=0.036). And the haplotype GAAA of CCNB1 was a putative factor in subgroup patients with clinical stage IV. The association of CCNB1 polymorphisms and toxicities after platinum-based chemotherapy was assessed. Rs2069433 and rs350104 were related with gastrointestinal toxicity of platinum-based chemotherapy. The patients with GG genotype of rs2069433 (p=0.013) and/or non-GG genotype of rs350104 (p=0.042) may have a severe gastrointestinal toxicity after chemotherapy, and then clinician may can reduce the dosage of chemotherapy agents to avoid sever toxicities in these patients. In summary, CCNB1 polymorphisms may contribute to the clinical efficiency of platinum-based chemotherapy in advanced NSCLC patients, and it is helpful for the personalized treatment.