Multi-loci analysis reveals the importance of genetic variations in sensitivity of platinum-based chemotherapy in non-small-cell lung cancer

Genetic Navigation: A Narrative Review of XRCC1 Polymorphism Impact on Platinum-Based Chemotherapy Outcomes in NSCLC Patients

Non-small cell lung cancer (NSCLC) is the most common form of lung cancer, accounting for 85% of all cases, with a poor 5-year survival rate of less than 20%. The majority of NSCLC patients are diagnosed at an advanced stage, contributing to the low survival rate. Platinum-based chemotherapy, including cisplatin and carboplatin, remains the cornerstone of treatment for advanced NSCLC. However, DNA repair mechanisms often hinder treatment efficacy, notably Base Excision Repair (BER), mediated by the X-ray Repair Cross Complementing 1 (XRCC1) protein. This review aims to investigate the role of XRCC1 polymorphisms in platinum resistance, focusing on their impact on DNA repair efficiency. XRCC1's involvement in the BER pathway is critical for repairing DNA damage caused by platinum agents, and polymorphisms in XRCC1 have been linked to altered repair capacity, influencing clinical outcomes and resistance to platinum-based chemotherapy in NSCLC patients.

Polygenic risk of genes involved in the catecholamine and serotonin pathways for ADHD in children

It is general acknowledged that genes play a vital role in the etiology of attention deficit/hyperactivity disorder (ADHD). The relationship between the genes involved in catecholamine (dopamine, noradrenaline)/serotonin transmissions and ADHD has been widely described in medical literature. A pathway-based study was conducted in this study to test the association of gene-gene interaction and the cumulative effect of genetic polymorphisms within the dopamine, norepinephrine, and serotonin neurotransmitter pathways with ADHD susceptibility. A case-control study was conducted among Chinese children, and 168 ADHD patients and 233 controls were recruited using a combination diagnosis according to the DSM-IV ADHD rating scale. Classification and regression tree (CART) analysis was conducted to explore the gene-gene interaction, and logistic regression modal was applied to estimate the polygenic risk of the potential multiple genetic variants. The results of CART analyses indicated that the children carrying the combination of ADRA2A rs553668GG/GA and SLC6A4 rs6354 GG/GT genotypes displayed a 6.15-fold increased risk of ADHD, compared to those with the combination of ADRA2A rs553668 AA and ANKK1 rs1800497 AA genotypes. The unfavorable alleles of ADRA2A rs553668 G, DRD2 rs1124491 G and SLC6A4 rs6354 G showed cumulative effects on ADHD, and the OR for ADHD may increase by 1.42 times when the number of unfavorable allele number increased by one. Those findings reveal the importance of the gene-gene interactions and polygenic effects of many common variants to ADHD susceptibility, even the effect of each variant is very small.

The potential role of clock genes in children attention-deficit/hyperactivity disorder

BACKGROUND

Attention deficit/ hyperactivity disorder (ADHD) is a chronic neurodevelopmental disorder and is thought to be associated with circadian system.

METHODS

We performed a pathway-based study to test individual single nucleotide polymorphisms (SNPs) and the overall evidence of genetic polymorphisms involved in the circadian pathway in association with children ADHD susceptibility among a Chinese population. A community-based case-control study was conducted among Chinese children, and 168 ADHD patients and 233 controls were recruited using a combination diagnosis based on the diagnostic and statistical manual of mental disorders iv (DSM-IV) ADHD rating scale, Swanson, Nolan, and Pelham rating scale (SNAP-IV) rating scale, and semi-structured clinical interview.

RESULTS

The results of single-loci analyses identified that PER1 rs2518023 and ARNTL2 rs2306074 were nominally association with ADHD susceptibility (P < 0.05). Next, we applied multifactor dimensionality reduction (MDR), and classification and regression tree (CART) analyses to explore high-order gene-gene interactions among the functional SNPs to ADHD risks. The results indicated that interactions among the PER1 rs2518023, ARNTL2 rs2306074 and NR1D1 rs939347 were associated with the risk of ADHD in children. Individuals carrying the combination genotypes of the PER1 rs2518023 GG or GT, ARNTL2 rs2306074 TC or TT and NR1D1 rs939347 GA or AA displayed a significantly higher risk for ADHD than who carry the PER1 rs2518023 TT and CRY2 rs2292910 CA/CC genotypes (adjusted OR = 4.37, 95% CI = 2.16-8.85, P < 0.001).

CONCLUSIONS

These findings revealed the importance of genetic variations related to the circadian clock system to the susceptibility of children ADHD.

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.

The interaction effects between TLR4 and MMP9 gene polymorphisms contribute to aortic aneurysm risk in a Chinese Han population

Background

A cross-talk between Toll-like receptor 4 (TLR4) and matrix metalloproteinase 9 (MMP9) plays a vital role in aortic pathophysiology. The objective of this study was to evaluate the interactions between TLR4 and MMP9 polymorphisms in the risk of aortic aneurysm (AA) and its subtypes.

Methods

KASP method was used to detect polymorphisms of TLR4 (rs11536889 and rs1927914) and MMP9 (rs17576) in 472 AA patients and 498 controls. According to location and size, AA patients were further classified into abdominal AA (AAA), thoracic AA (TAA), and large AA (>5.0 cm), small AA(≤5.0 cm), respectively.

Results

The significant interaction effect of TLR4rs1927914 with MMP9rs17576 polymorphisms was observed for the risk of TAA (P_interaction = 0.038, OR = 6.186) and large AA (P_interaction = 0.044, OR = 5.892). There were epistatic effects between TLR4rs1927914 and MMP9rs17576 polymorphisms on the risk of overall AA, AAA, TAA and large AA when they were present together. Moreover, the cumulative effects of the pairwise interaction TLR4rs1927914-MMP9rs17576 were associated with an increased risk of overall AA (P_trend = 0.032) and AAA (P_trend = 0.031).

Conclusions

The novel interaction between TLR4rs1927914 and MMP9rs17576 polymorphisms could increase the risk of AA disease or its subtypes by exerting epistatic and cumulative effects.

Electronic supplementary material

The online version of this article (10.1186/s12872-019-1049-8) contains supplementary material, which is available to authorized users.

Predictive Value of Two Polymorphisms of ERCC2, rs13181 and rs1799793, in Clinical Outcomes of Chemotherapy in Gastric Cancer Patients: A Meta-Analysis

Background

Several researchers have investigated the relationship between ERCC2 rs13181 and rs1799793 polymorphisms and chemotherapy efficacy in terms of tumour response and prognosis in gastric patients. However, the published data have shown inconsistencies.

Methods

PubMed, Elsevier, and Chinese National Knowledge Infrastructure databases were searched for relevant articles published before August 1, 2017. Thirteen studies including 3096 gastric cancer patients treated with chemotherapy were included.

Results

For rs1799793, in the overall analyses, no relationships were found between four genetic models and clinical response (AA vs. GG: OR = 1.17, 95% CI, 0.70–1.95; GA vs. GG: OR = 0.94, 95% CI, 0.69–1.27; GA + AA vs. GG: OR = 1.12, 95% CI, 0.85–1.46; and AA vs. GG + GA: OR = 1.24, 95% CI, 0.81–1.92). In stratified analyses, the results remained negative. We also found no relationship between each of the genetic models and overall survival time in the overall analyses. In the stratified analyses, for Asians, the A carrier genotype might be more closely associated with shorter survival time and higher risk of death for patients than the GG genotype (AA vs. GG: HR = 1.77, 95% CI, 1.20–2.6; GA + AA vs. GG: HR = 1.62, 95% CI, 1.26–2.09), but the results were negative for Caucasians. No significant relationships were found between the rs13181 polymorphism and OR or OS.

Conclusions

This meta-analysis suggested that the ERCC2 rs1799793 polymorphism might be a predictor of prognosis in gastric cancer patients subjected to platinum-based chemotherapy.

Association of genetic variations in the serotonin and dopamine systems with aggressive behavior in the Chinese adolescent population: Single- and multiple-risk genetic variants

BACKGROUND

Genetic predisposition is an important factor leading to aggressive behavior. However, the relationship between genetic polymorphisms and aggressive behavior has not been elucidated.

METHODS

We identified candidate genes located in the dopaminergic and serotonin system (DRD3, DRD4, and FEV) that had been previously reported to be associated with aggressive behavior. We investigated 14 tag single-nucleotide polymorphisms (SNPs) using a multi-analytic strategy combining logistic regression (LR) and classification and regression tree (CART) to explore higher-order interactions between these SNPs and aggressive behavior in 318 patients and 558 controls.

RESULTS

Both LR and CART analyses suggested that the rs16859448 polymorphism is the strongest individual factor associated with aggressive behavior risk. In CART analysis, individuals carrying the combined genotypes of rs16859448TT/GT-rs11246228CT/TT-rs3773679TT had the highest risk, while rs16859448GG-rs2134655CT had the lowest risk (OR = 5.25, 95% CI: 2.53-10.86).

CONCLUSION

This study adds to the growing evidence on the association of single- and multiple-risk variants in DRD3, DRD4, and FEV with aggressive behavior in Chinese adolescents. However, the aggressive behavior scale used to diagnose aggression in this study did not account for comorbid conditions; therefore, further studies are needed to confirm our observations.

FAS and FASL genetic polymorphisms impact on clinical outcome of malignant pleural mesothelioma

Background

FAS-670 A>G (rs1800682) and FASL-844 C>T (rs763110) polymorphisms have been previously correlated with clinical outcome of non-small cell lung cancer (NSCLC) and breast and bladder cancers. We investigated the influence of these polymorphisms on clinical outcome of malignant pleural mesothelioma (MPM) patients.

Patients and methods

In this cohort study (NCT02269878), 68 epithelioid MPM Egyptian patients treated with first-line platinum-based chemotherapy were recruited in the period between April 2014 and May 2015. The genotype analysis was performed using TaqMan^® single-nucleotide polymorphism genotyping assay. The association between the selected polymorphisms and response rate, progression-free survival (PFS) and overall survival (OS) at 18 months was evaluated.

Results

The median age of patients was 55 years and 45.6% of them received platinum in combination with pemetrexed, while 54.4% received platinum in combination with gemcitabine. FASL-844 CC genotype was more common than expected in early-stage tumor (P=0.042). It was found that there was no association between the investigated polymorphisms and response rate or 18-month OS. However, the PFS rate at 18 months for FASL-844 CC genotype carriers was 45% versus 10.6% for FASL-844 CT/TT genotypes carriers (log-rank: 6.2; P=0.013). Also, the number of platinum-based cycles and tumor stage were found to be significant variables for PFS by univariate analysis (P≤0.001 and P=0.006, respectively). Stratified Cox regression showed that the carriers of FASL-844 CT/TT genotypes were still more susceptible to disease progression than carriers of FASL-844 CC genotype (adjusted HR =3.77, 95% CI: 1.34–10.62, P=0.012).

Conclusion

The results of this study suggest that FASL-844 C/T polymorphism could predict PFS in MPM patients receiving platinum-based chemotherapy; therefore, this should be further evaluated as a potential marker for the prediction of clinical outcome in patients with MPM.

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.

Predictive assessment in pharmacogenetics of XRCC1 gene on clinical outcomes of advanced lung cancer patients treated with platinum-based chemotherapy

Published data have shown inconsistent results about the pharmacogenetics of XRCC1 gene on clinical outcomes of advanced lung cancer patients treated with platinum-based chemotherapy. This meta-analysis aimed to summarize published findings and provide more reliable association. A total of 53 eligible studies including 7433 patients were included. Patients bearing the favorable TrpTrp and TrpArg genotypes of Arg194Trp were more likely to better response rates to platinum-based chemotherapy compared to those with the unfavorable ArgArg genotype (TrpTrp+TrpArg vs. ArgArg: odds ratio (OR) = 2.02, 95% CI, 1.66–2.45). The GlnGln and GlnArg genotypes of Arg399Gln were significantly associated with the poorer response rates compared to those with the ArgArg genotype (GlnGln +GlnArg vs. ArgArg: OR = 0.68, 95% CI, 0.54–0.86). The GlnGln genotype might be more closely associated with shorter survival time and higher risks of death for patients (GlnGln vs. ArgArg: hazard ratio (HR) = 1.14, 95% CI, 0.75–1.75). Our cumulative meta-analyses indicated a distinct apparent trend toward a better response rate for Arg194Trp, but a poorer response rate in Arg399Gln. These findings indicate a predictive role of XRCC1 polymorphisms in clinical outcomes. The use of XRCC1 polymorphisms as predictive factor of clinical outcomes in personalized chemotherapy treatment requires further verification from large well-designed pharmacogenetics studies.

The Roles of Genes in the Neuronal Migration and Neurite Outgrowth Network in Developmental Dyslexia: Single- and Multiple-Risk Genetic Variants

Abnormal regulation of neural migration and neurite growth is thought to be an important feature of developmental dyslexia (DD). We investigated 16 genetic variants, selected by bioinformatics analyses, in six key genes in the neuronal migration and neurite outgrowth network in a Chinese population. We first observed that KIAA0319L rs28366021, KIAA0319 rs4504469, and DOCK4 rs2074130 were significantly associated with DD risk after false discovery rate (FDR) adjustment for multiple comparisons (odds ratio (OR) = 0.672, 95 % confidence interval (CI) = 0.505-0.894, P = 0.006; OR = 1.608, 95 % CI = 1.174-2.203, P = 0.003; OR = 1.681, 95 % CI = 1.203-2.348, P = 0.002). The following classification and regression tree (CART) analysis revealed a prediction value of gene-gene interactions among DOCK4 rs2074130, KIAA0319 rs4504469, DCDC2 rs2274305, and KIAA0319L rs28366021 variants. Compared with the lowest risk carriers of the combination of rs2074130 CC, rs4504469 CC, and rs2274305 GG genotype, individuals carrying the combined genotypes of rs2074130 CC, rs4504469 CT or TT, and rs28366021 GG had a significantly increased risk for DD (OR = 2.492, 95 % CI = 1.447-4.290, P = 0.001); individuals with the combination of rs2074130 CT or TT and rs28366021 GG genotype exhibited the highest risk for DD (OR = 2.770, 95 % CI = 2.265-6.276, P = 0.000). A significant dose effect was observed among these four variants (P for trend = 0.000). In summary, this study supports the importance of single- and multiple-risk variants in this network in DD susceptibility in China.

CD226 rs727088A>G polymorphism increases the susceptibility to gastric cancer in Chinese populations

Gastric cancer (GC) is one of the most common cancers worldwide, especially in Asia. The development of GC is a multifactorial process and numerous studies have linked genetic variation to GC risk. In this study, we evaluated the effects of single nucleotide polymorphisms (SNPs) of CD226 on GC susceptibility in Chinese populations including 687 cancer patients and 936 control subjects. We found that the G allele of the rs727088A>G polymorphism in the 3'-untranslated region of CD226 was significantly associated with risk of GC using logistic regression (P<10(-3)). GC patients who harbored the rs727088G allele had significantly increased cancer risk (odds ratio=1.43, 95% confidence interval=1.23-1.67) compared with those patients harboring the rs727088A allele. Moreover, functional relevance was further performed that individuals carrying the rs727088G allele were correlated with lower expression level of CD226 than individuals carrying the rs727088AA homozygous genotype. These findings indicated that functional polymorphism rs727088A>G in CD226 might modify the susceptibility for the development of GC.

DNA repair pathways and their therapeutic potential in lung cancer

SUMMARY: 

Lung cancer is the leading cause of cancer-related mortality. According to WHO, 1.37 million deaths occur globally each year as a result of this disease. More than 70% of these cases are associated with prior tobacco consumption and/or cigarette smoking, suggesting a direct causal relationship. The development and progression of lung cancer and other malignancies involves the loss of genetic stability, resulting in acquisition of cumulative genetic changes; this affords the cell increased malignant potential. As such, an understanding of the mechanisms through which these events may occur will potentially allow for development of new anticancer therapies. This review will address the association between lung cancer and genetic instability, with a central focus on genetic mutations in the DNA damage repair pathways. In addition, we will discuss the potential clinical exploitation of these pathways, both in terms of biomarker staging, as well as through direct therapeutic targeting.

The interaction effects of pri-let-7a-1 rs10739971 with PGC and ERCC6 gene polymorphisms in gastric cancer and atrophic gastritis

Background

The aim of this study was to investigate the interaction effects of pri-let-7a-1 rs10739971 with pepsinogen C (PGC) and excision repair cross complementing group 6 (ERCC6) gene polymorphisms and its association with the risks of gastric cancer and atrophic gastritis. We hoped to identify miRNA polymorphism or a combination of several polymorphisms that could serve as biomarkers for predicting the risk of gastric cancer and its precancerous diseases.

Methods

Sequenom MassARRAY platform method was used to detect polymorphisms of pri-let-7a-1 rs10739971 G→A, PGC rs4711690 C→G, PGC rs6458238 G→A, PGC rs9471643 G→C, and ERCC6 rs1917799 in 471 gastric cancer patients, 645 atrophic gastritis patients and 717 controls.

Results

An interaction effect of pri-let-7a-1 rs10739971 polymorphism with ERCC6 rs1917799 polymorphism was observed for the risk of gastric cancer (P_interaction = 0.026); and interaction effects of pri-let-7a-1 rs10739971 polymorphism with PGC rs6458238 polymorphism (P_interaction = 0.012) and PGC rs9471643 polymorphism (P_interaction = 0.039) were observed for the risk of atrophic gastritis.

Conclusion

The combination of pri-let-7a-1 rs10739971 polymorphism and ERCC6 and PGC polymorphisms could provide a greater prediction potential than a single polymorphism on its own. Large-scale studies and molecular mechanism research are needed to confirm our findings.

Genetic variations in radiation and chemotherapy drug action pathways and survival in locoregionally advanced nasopharyngeal carcinoma treated with chemoradiotherapy

Background and Purpose

Treatment outcomes vary greatly in patients with nasopharyngeal carcinoma (NPC). The purpose of this study is to evaluate the influence of radiation and chemotherapy drug action pathway gene polymorphisms on the survival of patients with locoregionally advanced NPC treated with cisplatin- and fluorouracil-based chemoradiotherapy.

Material and Methods

Four hundred twenty-one consecutive patients with locoregionally advanced NPC were prospectively recruited. We utilized a pathway approach and examined 18 polymorphisms in 13 major genes. Polymorphisms were detected using the LDR-PCR technique. Multifactor dimensionality reduction (MDR) analysis was performed to detect potential gene-gene interaction.

Results

After adjustment for clinicopathological characteristics, overall survival was significantly decreased in patients with the MPO rs2243828 CT/CC genotype (HR=2.453, 95% CI, 1.687-3.566, P<0.001). The ERCC1 rs3212986 CC (HR=1.711, 95% CI, 1.135-2.579, P=0.010), MDM2 rs2279744 GT/GG (HR=1.743, 95% CI, 1.086-2.798, P=0.021), MPO rs2243828 CT/CC (HR=3.184, 95% CI, 2.261-4.483, P<0.001) and ABCB1 rs2032582 AT/AA (HR=1.997, 95% CI, 1.086-3.670, P=0.026) genotypes were associated with poor progression-free survival. Prognostic score models based on independent prognostic factors successfully classified patients into low-, intermediate-, and high-risk groups. Furthermore, MDR analysis showed no significant interaction between polymorphisms.

Conclusions

Four single nucleotide polymorphisms were associated with survival in patients with locoregionally advanced NPC treated with cisplatin- and fluorouracil-based chemoradiotherapy. Combining clinical prognostic factors with genetic information was valuable in identifying patients with different risk.

Polymorphisms in XPD gene could predict clinical outcome of platinum-based chemotherapy for non-small cell lung cancer patients: a meta-analysis of 24 studies

OBJECTIVE

Xeroderma pigmentosum group D (XPD) is an essential gene involved in the nucleotide excision repair (NER) pathway. Two commonly studied single nucleotide polymorphisms (SNPs) of XPD (Lys751Gln, A>C, rs13181; Asp312Asn, G>A, rs1799793) are implicated in the modulation of DNA repair capacity, thus related to the responses to platinum-based chemotherapy. Here we performed a meta-analysis to better evaluate the association between the two XPD SNPs and clinical outcome of platinum-based chemotherapy in non-small cell lung cancer (NSCLC) patients.

METHODS

A comprehensive search of PubMed database was conducted to identify relevant articles. Primary outcomes included objective response (i.e., complete response + partial response vs. stable disease + progressive disease), progression-free survival (PFS) and overall survival (OS). The pooled and 95% confidence intervals (CIs) of ORs (odds ratios) and HRs (hazard ratios) were estimated using the fixed or random effect model.

RESULTS

Twenty-four studies were eligible according to the inclusion criteria. None of the XPD Lys751Gln/Asp312Asn polymorphisms was associated with objective response, PFS or OS in NSCLC patients treated with platinum drugs. However, in stratified analysis by ethnicity, the XPD Lys751Gln (A>C) polymorphism was not significantly associated with increased response in Caucasians (OR=1.35, 95%CI=1.0-1.83, P=0.122 for heterogeneity) but was associated with decreased PFS in Asians (HR=1.39, 95%CI=1.07-1.81, P=0.879 for heterogeneity). Furthermore, a statistically significant difference existed in the estimates of effect between the two ethnicities (P=0.014 for TR; P<0.001 for PFS).

CONCLUSIONS

XPD Lys751Gln (A>C) may have inverse predictive and prognostic role in platinum-based treatment of NSCLC according to different ethnicities. Further studies are needed to validate our findings.

ERCC1 and ERCC2 variants predict survival in gastric cancer patients

Purpose

ERCC1 and ERCC2 play critical roles in the nucleotide excision repair pathway that effectively repairs DNA damage induced by chemotherapeutic agents. Therefore, functional single nucleotide polymorphisms (SNPs) in these genes could have an impact on clinical outcomes in cancer patients who received chemotherapy. However, few studies have simultaneously investigated the roles of ERCC1 and ERCC2 SNPs in clinical outcomes in gastric cancer patients.

Experimental Design

We genotyped by the TaqMan assay three common, potentially functional ERCC1 (rs3212986) and ERCC2 SNPs (rs13181 and rs1799793) in 360 gastric cancer patients. We used both Kaplan-Meier tests and Cox proportional hazards models to evaluate the effects of ERCC1 and ERCC2 genotypes and haplotypes on clinical outcomes.

Results

We found that, compared with ERCC2 rs1799793 GG+AG genotypes, the homozygous variant AA genotype was associated with significantly poorer overall survival (OS) (AA vs. GG+AG, log-rank P = 0.012) and significantly higher risk of death (AA vs. GG+AG, Adjusted hazards ratio [HR] 2.13; 95% CI, 1.28 to 3.56; P = 0.004). In combined analyses, patients with any one of the three unfavorable genotypes (i.e. ERCC1 rs3212986 TT, ERCC2 rs13181 GG and rs1799793 AA) had statistically significant hazards of poor prognosis (Adjusted HR, 1.54; 95% CI, 1.06 to 2.25; P = 0.025), compared with those without any unfavorable genotypes. Furthermore, the haplotype A-G-G (rs1799793/rs13181/rs3212986) had a significant impact on OS (Adjusted HR, 1.57; 95% CI, 1.11 to 2.21; P = 0.011), compared with the common haplotype G-T-G.

Conclusion

ERCC1 and ERCC2 functional SNPs may jointly affect OS in Caucasian gastric cancer patients. Additional large prospective studies are essential to confirm our findings.

Association between XRCC1 and XRCC3 polymorphisms with lung cancer risk: a meta-analysis from case-control studies

Many studies have reported the association of X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln, Arg194Trp, Arg280His, −77T>C, and X-ray repair cross-complementing group 3 (XRCC3) T241M polymorphisms with lung cancer risk, but the results remained controversial. Hence, we performed a meta-analysis to investigate the association between lung cancer risk and XRCC1 Arg399Gln (14,156 cases and 16,667 controls from 41 studies), Arg194Trp (7,426 cases and 9,603 controls from 23 studies), Arg280His (6,211 cases and 6,763 controls from 16 studies), −77T>C (2,487 cases and 2,576 controls from 5 studies), and XRCC3 T241M (8,560 cases and 11,557 controls from 19 studies) in different inheritance models. We found that −77T>C polymorphism was associated with increased lung cancer risk (dominant model: odds ration [OR] = 1.45, 95% confidence interval [CI] = 1.27–1.66, recessive model: OR = 1.73, 95% CI = 1.14–2.62, additive model: OR = 1.91, 95% CI = 1.24–1.94) when all the eligible studies were pooled into the meta-analysis. In the stratified and sensitive analyses, significantly decreased lung cancer risk was observed in overall analysis (dominant model: OR = 0.83, 95% CI = 0.78–0.89; recessive model: OR = 0.90, 95% CI = 0.81–1.00; additive model: OR = 0.82, 95% CI = 0.74–0.92), Caucasians (dominant model: OR = 0.82, 95% CI = 0.76–0.87; recessive model: OR = 0.89, 95% CI = 0.80–0.99; additive model: OR = 0.81, 95% CI = 0.73–0.91), and hospital-based controls (dominant model: OR = 0.81, 95% CI = 0.76–0.88; recessive model: OR = 0.89, 95% CI = 0.79–1.00; additive model: OR = 0.80, 95% CI = 0.71–0.90) for XRCC3 T241M. In conclusion, this meta-analysis indicates that XRCC1 −77T>C shows an increased lung cancer risk and XRCC3 T241M polymorphism is associated with decreased lung cancer risk, especially in Caucasians.

Predictive value of XPD polymorphisms on platinum-based chemotherapy in non-small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

The correlation between xeroderma pigmentosum group D (XPD) polymorphisms (Lys751Gln and Asp312Asn) and clinical outcomes of non-small cell lung cancer (NSCLC) patients, who received platinum-based chemotherapy (Pt-chemotherapy), is still inconclusive. This meta-analysis was aimed to systematically review published evidence and ascertain the exact role of XPD polymorphisms.

METHODS

Databases of MEDLINE and EMBASE were searched up to April 2013 to identify eligible studies. A rigorous quality assessment of eligible studies was conducted according the Newcastle-Ottawa Quality Assessment Scales. The relationship between XPD polymorphisms and response to Pt-chemotherapy and survival was analyzed.

RESULTS

A total of 22 eligible studies were included and analyzed in this meta-analysis. The overall analysis suggested that the XPD Lys751Gln polymorphism was not associated with response to Pt-chemotherapy or survival. However, the XPD 312Asn allele was significantly associated with poor response to Pt-chemotherapy compared with the Asp312 allele (Asn vs. Asp: OR = 0.435, 95% CI: 0.261-0.726). Additionally, the variant genotype of XPD Asp312Asn polymorphism was associated with favorable survival in Caucasian (AspAsn vs. AspAsp: HR = 0.781, 95% CI: 0.619-0.986) but unfavorable survival in Asian (AspAsn+AsnAsn vs. AspAsp: HR = 1.550, 95% CI: 1.038-2.315).

CONCLUSIONS

These results suggest that XPD Asp312Asn polymorphism may function as a predictive biomarker on platinum-based chemotherapy in NSCLC and further studies are warranted.

XRCC3 Thr241Met polymorphism and clinical outcomes of NSCLC patients receiving platinum-based chemotherapy: a systematic review and meta-analysis

Introduction

X-ray repair cross-complementing protein 3 (XRCC3) is an essential gene involved in the double-strand break repair pathway. Published evidence has shown controversial results about the relationship between XRCC3 Thr241Met polymorphism and clinical outcomes of non-small cell lung cancer (NSCLC) patients receiving platinum-based chemotherapy.

Methods

A systematic review and meta-analysis was performed to evaluate the predictive value of XRCC3 Thr241Met polymorphism on clinical outcomes of advanced NSCLC receiving platinum-based chemotherapy. Response to chemotherapy, overall survival (OS) and progression-free survival (PFS) were analyzed.

Results

A number of 11 eligible studies were identified according to the inclusion criteria. Carriers of the variant XRCC3 241Met allele were significantly associated with good response to platinum-based chemotherapy (ThrMet/MetMet vs. ThrThr: OR  = 1.509, 95% CI: 1.099–2.072, P_{heterogeneity}  = 0.618). The XRCC3 Thr241Met polymorphism was not associated with OS (MetMet vs. ThrThr, HR  = 0.939, 95% CI:0.651–1.356, P_{heterogeneity}  = 0.112) or PFS (MetMet vs. ThrThr, HR  = 0.960, 95% CI: 0.539–1.710, P_{heterogeneity}  = 0.198). Additionally, no evidence of publication bias was observed.

Conclusions

This systematic review and meta-analysis shows that carriers of the XRCC3 241Met allele are associated with good response to platinum-based chemotherapy in advanced NSCLC, while the XRCC3 Thr241Met polymorphism is not associated with OS or PFS.

Tumor site- and stage-specific associations between allelic variants of glutathione S-transferase and DNA-repair genes and overall survival in colorectal cancer patients receiving 5-fluorouracil-based chemotherapy

Introduction

Our retrospective cohort study investigated the effect of tumor site and stage on the associations between the allelic variants of glutathione S-transferase (GST) and DNA-repair genes and overall survival (OS) in CRC patients treated with 5-fluorouracil (5-FU)-based adjuvant chemotherapy.

Material and Methods

We genotyped GSTM1, GSTT1, GSTP1 Ile105Val, XRCC1 Arg399Gln, XRCC3 Thr241Met, and XPD Lys751Gln in 491 CRC patients between 1995 and 2001. A Cox proportional-hazards model was used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) for the relationships between the allelic variants and OS. Survival analyses were performed for each allelic variant by using the log-rank test and Kaplan-Meier analysis.

Results

The CRC patients with the XPD Gln allelic variants had poorer survival than patients with the Lys/Lys genotype (HR  = 1.38, 95% CI  = 1.02–1.87), and rectal cancer patients had the poorest survival among them (HR  = 1.87, 95% CI  = 1.18–2.95). A significantly shorter OS was observed among stage II/III colon cancer patients with the XRCC1 Gln allelic variants (HR  = 1.69, 95% CI  = 1.06–2.71), compared to those with XRCC1 Arg/Arg genotype. In the combined analysis of the XRCC1 and XPD genes patients with stage II/III tumors, the poorest OS occurred in colon cancer patients with the XRCC1 Gln and XPD Gln allelic variants (HR  = 2.60, 95% CI  = 1.19–5.71) and rectal cancer patients with the XRCC1 Arg/Arg and XPD Gln allelic variants (HR  = 2.77, 95% CI  = 1.25–6.17).

Conclusion

The XPD and XRCC1 allelic variants may be prognostic markers for CRC patients receiving 5-FU based chemotherapy. The contributions of the XPD and XRCC1 allelic variants to OS are tumor site- and/or stage-dependent.

Vectors for inhaled gene therapy in lung cancer. Application for nano oncology and safety of bio nanotechnology

Novel aerosol therapeutic modalities have been investigated for lung cancer. Inhaled gene therapy has presented safety and effectiveness previously in cystic fibrosis. However, safety concerns have been raised regarding the safety of non-viral vectors for inhaled gene therapy in lung cancer, and therefore small steps have been made towards this multifunctional treatment modality. During the last decade, numerous new nanocomplexes have been created and investigated as a safe gene delivery nano-vehicle. These formulations are multifunctional; they can be used as either local therapy or carrier for an effective inhaled gene therapy for lung cancer. Herein, we present current and future perspectives of nanocomplexes for inhaled gene therapy treatment in lung cancer.