Pharmacogenetics of platinum-based chemotherapy: impact of DNA repair and folate metabolism gene polymorphisms on prognosis of non-small cell lung cancer patients

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.

Gene polymorphism and prediction of toxicity to platinum-based chemotherapy in patients with gynecologic cancer

The relationship between single nucleotide polymorphisms (SNPs) at various loci and adverse drug reactions (ADRs) in patients with gynecologic cancer receiving platinum-based chemotherapy (PPCT) remains unexplored. This research aimed to investigate the correlation between SNPs at several loci (e.g., GSTP1 rs1695, MTHFR rs1801133, XPC rs2228001, TP53 rs1042522, and ERCC1 rs3212986) and ADRs in patients with gynecologic cancer receiving PPCT. A total of 244 patients with gynecologic cancer who received first-line PPCT were included in this retrospective study. Blood fluorescence quantitative polymerase chain reaction was used to detect genotypes. Logistic regression, Pearson's Chi-square test, and Fisher's exact test were used to explore the correlations between these SNPs and the occurrence of ADRs. The logistic regression results showed that different genotypes of the five genes had no statistical significance in the overall grade greater than or equal to 3 ADRs. The results of Pearson's Chi-square test showed the same results. On specific adverse reactions, we found that the rs1042522 GG genotype significantly increased the risk of grade greater than or equal to 3 leucopenia compared with the CG and the CC genotypes (p = 0.002). The rs1695 AG genotype showed higher correlation for grade greater than or equal to 3 neutropenia (p = 0.020). The rs2228001 CC genotype also had a higher risk for grade greater than or equal to 3 neutropenia (p = 0.003). This study found that whereas the overall grade greater than or equal to 3 adverse reactions in patients with gynecologic cancer receiving PPCT were not associated with SNPs, specific SNPs (rs1042522 GG, rs1695 AG, and rs2228001 CC) were linked to higher risks of leucopenia and neutropenia, indicating their potential as predictors of hematotoxicity in PPCT-treated patients with gynecologic cancer.

X-ray cross-complementing family: the bridge linking DNA damage repair and cancer

Genomic instability is a common hallmark of human tumours. As a carrier of genetic information, DNA is constantly threatened by various damaging factors that, if not repaired in time, can affect the transmission of genetic information and lead to cellular carcinogenesis. In response to these threats, cells have evolved a range of DNA damage response mechanisms, including DNA damage repair, to maintain genomic stability. The X-ray repair cross-complementary gene family (XRCC) comprises an important class of DNA damage repair genes that encode proteins that play important roles in DNA single-strand breakage and DNA base damage repair. The dysfunction of the XRCC gene family is associated with the development of various tumours. In the context of tumours, mutations in XRCC and its aberrant expression, result in abnormal DNA damage repair, thus contributing to the malignant progression of tumour cells. In this review, we summarise the significant roles played by XRCC in diverse tumour types. In addition, we discuss the correlation between the XRCC family members and tumour therapeutic sensitivity.

Association of APEX1 and XRCC1 Gene Polymorphisms With HIV-1 Infection Susceptibility and AIDS Progression in a Northern Chinese MSM Population

Background: Some studies have shown that the base excision repair (BER) pathway has an effect on HIV-1 replication. APEX1 and XRCC1 as key BER genes may affect DNA repair capacity. However, the roles of single nucleotide polymorphisms (SNPs) in APEX1 and XRCC1 and their impact on HIV-1 infection and AIDS progression remain unclear.

Methods: A custom-designed 48-Plex SNPscan Kit was used for detection of single nucleotide polymorphisms. 601 HIV-1-infected men who have sex with men (MSM) and 624 age-matched healthy individuals were recruited in northern China. Four SNPs (rs1130409, rs1760944, rs2307486 and rs3136817) in APEX1 gene and three SNPs (rs1001581, rs25487 and rs25489) in XRCC1 gene were genotyped. The generalized multifactor dimension reduction (GMDR) method was used to identify the SNP-SNP interactions.

Results: In this study, rs1130409 G allele, rs1001581 C allele and rs25487 C allele were associated with a higher risk of HIV-1 infection susceptibility (p = 0.020, p = 0.007 and p = 0.032, respectively). The frequencies of APEX1 haplotype TT and XRCC1 haplotype CT showed significant differences between cases and controls (p = 0.0372 and p = 0.0189, respectively). Interestingly, stratified analysis showed that the frequency of rs1001581 C allele was significantly higher in AIDS patients with the CD4⁺ T-lymphocyte count <200 cells/μl than those with >200 cells/μl (p = 0.022). Moreover, significant gene-gene interactions among rs1130409, rs1001581 and rs25487 were identified by GMDR (p = 0.0107). Specially, individuals with five to six risk alleles have a higher susceptibility to HIV-1 infection than those with zero to two risk alleles (p < 0.001).

Conclusion:APEX1 and XRCC1 gene polymorphisms were associated with the susceptibility to HIV-1 infection and AIDS progression in MSM populations in northern China.

Systematic review and meta-analysis of the predictive power of MTHFR polymorphisms for pemetrexed drug efficacy and toxicity in non-small cell lung cancer patients

We conducted a meta-analysis to determine if MTHFR polymorphisms are effective biomarkers for non-small cell lung cancer (NSCLC) patient survival and pemetrexed (PEM) treatment toxicity. Because of data heterogeneity, fixed or random effects models were chosen, and pooled HRs and 95% confidence intervals (CIs) were calculated. No correlation between MTHFR 677 C > T polymorphism and progression-free survival (PFS) or overall survival (OS) was detected in NSCLC patients; however, patients with the T allele benefited more than those with the wild-type allele. Two papers reported hematologic toxicity of single-agent PEM treatment in patients with the MTHFR 677 C > T polymorphism. However, data on MTHFR polymorphisms and toxicity could not be combined, even though publication bias and sensitivity analysis results were stable and reliable. We conclude that the MTHFR 677 C > T polymorphism could not predict PEM efficacy in NSCLC patients; however, the T allele may increase the risk of haematological toxicity. A large-scale clinical trial is recommended.

High Tumor Mutation Burden and DNA Repair Gene Mutations are Associated with Primary Resistance to Crizotinib in ALK-Rearranged Lung Cancer

Background

About 20% of patients with ALK-rearranged non-small cell lung cancer (NSCLC) develop acquired resistance to tyrosine kinase inhibitor (TKI) during the first 6 months. This study aimed to examine the molecular mechanisms of early TKI resistance and prognosis in ALK-rearranged NSCLC.

Methods

Ten patients with ALK-rearranged NSCLC were included: five who developed rapid resistance to crizotinib (progression-free survival (PFS) ≤3 months) and five who exhibited a good response to crizotinib (PFS ≥36 months). The tumor specimens were subjected to whole-exome sequencing (WES). The validation cohort included 19 patients with ALK-rearranged NSCLC who received crizotinib; targeted sequencing of 43 selected genes was performed. The effect of the TP53 G245S mutation on crizotinib sensitivity was tested in H3122 cells.

Results

Mutations in DNA repair-associated genes were identified in primary resistance to crizotinib. Patients with a poor response to crizotinib harbored a greater burden of somatic mutations than those with a good response [median somatic mutations, 136 (range, 72-180) vs 31 (range, 10-48)]. Compared with the patients carrying wild-type TP53 or TP53 exon 3 deletion, 29 patients with TP53 G245S mutation showed a shorter survival time (P < 0.05), with a median PFS of 3 (95% CI: 1.9-4.1) months and a median overall survival of 7 (95% CI: 3.4-10.5) months. TP53 mutation promoted the proliferation of EML4-ALK-rearranged H3122 cells by approximately 3 folds (P < 0.001). H3122 cells with TP53 mutant were more sensitive to crizotinib compared with control cells.

Conclusion

A higher mutation burden and mutations in DNA repair gene, including TP53, were potentially associated with primary resistance to crizotinib in ALK-rearranged NSCLC. An immune-checkpoint inhibition strategy could be examined, which might overcome primary resistance to crizotinib in ALK-rearranged NSCLC.

Association of T2285C polymorphism in PARP1 gene coding region with its expression, activity and NSCLC risk along with prognosis

Poly (ADP-ribose) polymerase-1(PARP1), a DNA repair gene, is the crucial player in the maintenance of genome integrity. T2285C polymorphism in coding region of PARP1 has been reported to be associated with susceptibility to tumors. We explored the relation and mechanism of T2285C polymorphism of PARP1 to its expression and activity along with risk and prognosis in NSCLC. mRNA expression was measured using qRT-PCR assay or collected from TCGA dataset. Protein expression was examined with immunoblotting assay. Genotypes were determined by PCR-RFLP and sequencing approaches. PARP1 activity was determined with enzyme activity assay. Regulation of SIRT7 to PARP1 were determined by over-expression and small interference experiment. Association of PARP1 T2285C polymorphism with NSCLC risk was evaluated via multiple logistic regression analysis. Comparison of treatment response and PFS of NSCLC patients among different genotypes or regimens was made by Chi-square test. Results indicated that mRNA and protein expression of PARP1 dramatically increased in NSCLC tissues in comparison to paired para-carcinoma tissues (P<0.05). TC/CC mutant genotypes were associated with markedly enhanced PARP1 mRNA level compared with TT genotype (P=0.011). No significant difference was discovered in PARP1 protein expression among TT, TC or CC genotypes (P>0.05). Subjects with variant allele C had higher risk of NSCLC in comparison to allele T carriers [odds ratio (OR) =1.560; P=0.000]. NSCLC patients carrying mutational TC or CC genotypes were correlated with unfavorable response to platinum-based chemotherapy (TT vs.TC vs.CC, P=0.010), and shorter PFS compared to TT genotype (TT vs.TC vs.CC, P=0.009). T2285C mutation of PARP1 resulted in the enhancement of its mRNA, but the decrease of enzyme activity in tumor cell. Overexpression of SIRT7 attenuated PARP1 expression and activity. These findings suggest the variant allele C of T2285C polymorphism of PARP1 linked to an increase of NSCLC risk, and unfavorable efficacy and prognosis of NSCLC patients with platinum-based chemotherapy, which might be associated with enhancement of its mRNA expression and the diminishment of activity. Identification of PARP1 T2285C polymorphism and mRNA expression may be the promising way for the individualized treatment of NSCLC.

The Significant Interaction of Excision Repair Cross-complementing Group 1 Genotypes and Smoking to Lung Cancer Risk

BACKGROUND

The study aims to evaluate the contribution of excision repair cross-complementing group 1 (ERCC1), which plays an important role in genome integrity maintenance, to lung cancer risk.

MATERIALS AND METHODS

ERCC1 rs11615 and rs3212986 genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism analysis and their association with lung cancer risk was examined among 358 lung cancer patients and 716 controls.

RESULTS

The proportions of CC, CT and TT for the rs11615 genotype were 43.6%, 41.6% and 14.8% in the case group and 50.0%, 41.1% and 8.9% in the control group, respectively (p for trend=0.0082). Allelic analysis showed that ERCC1 rs11615 T-allele carriers have a 1.32-fold higher risk of lung cancer than wild-type C-allele carriers [95%confidence interval (CI)=1.09-1.60, p=0.0039]. In addition, a significant interaction between the rs11615 genotype and smoking status was observed.

CONCLUSION

The T allele of ERCC1 rs11615 jointly with smoking habits may contribute to a higher lung cancer risk in Taiwan.

The association between the ERCC1/2 polymorphisms and radiotherapy efficacy in 87 patients with non-small cell lung cancer

Background

This study sought to investigate the association between the ERCC1/2 single-nucleotide polymorphisms (SNPs) and the efficacy of radiotherapy and prognosis in patients with non-small cell lung cancer (NSCLC).

Methods

We examined 6 SNPs in the ERCC1 and ERCC2 genes in 87 consecutive patients with NSCLC who were treated with definitive radiotherapy. The objective remission rates (ORR), overall survival (OS), and progressive-free survival (PFS) were assessed. A Cox regression analysis was conducted to analyze the independent factors related to death and recurrence.

Result

Patients with the G allele had better OS than patients with the A allele, and there was a statistical difference between the two groups (30.9 vs. 16.2 months; P=0.003). Patients with the AA genotype had significantly worse OS than patients with the AG or GG genotypes (6.8 vs. 19.8 vs. 30.9 months, respectively; P=0.000). The median PFS of the G allele was 18.9 months, which was significantly better than that of the A allele (P=0.040). The median PFS of patients with the GG genotype, the AG genotype, and the AA genotype was 18.9, 11.3, and 5.1 months, respectively; the difference among the three groups was statistically significant (P=0.019). Patients with the G allele also had better PFS than those with the A allele (18.9 vs. 11.3 months, P=0.040). The multivariate cox proportional hazard analysis showed that the ERCC1 gene rs11615 was an independent survival indicator [HR: 1.623, 95% confidence interval (CI): 1.018–2.591, P=0.042] but not an independent recurrence indicator (HR: 1.497, 95% CI: 0.932–2.404, P=0.095).

Conclusions

The ERCC1 rs11615 SNP may be a potential biomarker for predicting survival prognosis in Chinese NSCLC patients who have undergone definitive radiotherapy. Patients with the G allele had better OS than those with the A allele.

Pharmacogenetic Association between XRCC1 Polymorphisms and Response to Platinum-Based Chemotherapy in Asian Patients with NSCLC: A Meta-Analysis

Background

Platinum-based chemotherapy plays an antitumor role by damaging DNA. X-ray repair crosscomplementing protein 1 (XRCC1) participates in DNA repair and thus affects the sensitivity to platinum drugs. Two polymorphisms of XRCC1, rs25487 (Arg399Gln) and rs1799782 (Arg194Trp), have been widely studied for the association with clinical outcomes of platinum-based chemotherapy in Asian patients with non-small-cell lung cancer (NSCLC), but the results remain inconclusive. Thus, we performed the present meta-analysis.

Methods

Literature search was performed in PubMed, Web of Science, and EMBASE up to June 2019. Odds ratios (ORs) for objective response ratio (ORR), Cox proportional hazard ratios (HRs) of overall survival (OS) and progression-free survival (PFS), and the corresponding 95% confidence intervals (95% CIs) were calculated to assess the association strengths between XRCC1 polymorphisms and clinical outcomes. Comparisons were performed in homozygous, heterozygous, dominant, and recessive models.

Results

Finally, a total of 23 studies involving 5567 patients were included in the meta-analysis. Compared to ArgArg of rs25487, GlnGln (OR = 1.71, 95% CI: 1.16-2.52, p = .007, I² = 56.8%) and GlnArg (OR = 1.23, 95% CI: 1.07-1.40, p = .003, I² = 29.0%) were associated with higher ORR. Meanwhile, GlnGln indicated a favorable OS (HR = 0.60, 95% CI: 0.40-0.88) and PFS (HR = 0.64, 95% CI: 0.46-0.90). We also found positive associations between rs1799782 and ORR in all comparison models with low between-study heterogeneity. The association strength increased with the number of variant alleles (TrpTrp vs. ArgArg: OR = 1.73, 95% CI:1.31-2.27; TrpArg vs. ArgArg: OR = 1.28, 95% CI: 1.06-1.55), suggesting a gene dosage effect. In addition, TrpTrp predicted a longer OS.

Conclusion

Our results showed that rs25487 and rs1799782 of XRCC1 are potential markers to predict clinical outcomes of platinum-based chemotherapy in Asian patients with NSCLC.

Interaction effects of environmental response gene polymorphisms and benzene exposure on telomere length in shoe-making workers

Benzene is a globally occurring environmental and occupational pollutant that causes leukemia. To better understand telomere length (TL) as a function of benzene toxicity, we recruited 294 shoe-making workers and 102 controls from Wenzhou, China in 2011. Biomarkers of TL, cytokinesis-block micronucleus (MN) frequency, and white blood cells (WBC) were measured. In total, 18 polymorphic sites in environmental response genes, including metabolic and DNA repair genes, were analyzed. Results indicate that benzene exposure led to a longer TL at a threshold of 32 mg/m³-year of cumulative exposure dose (CED). Furthermore, the TL was longer in members of the damaged group, when evaluated for MN frequency (P < 0.001) and reduced WBC (P < 0.001), than in those of the normal group. Workers carrying genotype TT (β = 0.32, P = 0.042) in rs3212986 of ERCC1 and genotype TC (β = 0.24, P = 0.082) in rs1051740 of mEH exon3 were associated with a longer TL as compared to the wild-type group. TA (β = -0.53, P < 0.001) in rs6413432 of CYP2E1 was associated with a shorter TL. Benzene exposure interacted with the TA type in rs6413432 (β = 0.003, 95% CI: 0, 0.006, P = 0.042) and the CC type in rs1051740 (β = 0.007, 95% CI: 0.001, 0.013, P = 0.015) after adjusting for confounding factors. Our results indicate that benzene induces an increase in TL at a threshold of CED ≥32mg/m³-year. Rs1051740, rs3212986, and rs6413432 were found to be involved in benzene-induced telomere growth; in particular, rs1051740 and rs6413432 interacted with the benzene exposure, resulting in an extended TL.

The Association Between Heat-Shock Protein Polymorphisms and Prognosis in Lung Cancer Patients Treated With Platinum-Based Chemotherapy

Objective

Lung cancer is one of the most prevalent cancers and the leading cause of cancer-related death in the world. Platinum-based chemotherapy plays an important role in lung cancer treatment, but the therapeutic effect varies from person to person. Heat shock proteins (HSPs) have been reported to be associated with the survival time of lung cancer patients, which may be a potential biomarker in lung cancer treatment. The aim of this study was to investigate the association between genetic polymorphisms and the prognosis in lung cancer patients treated with platinum-based chemotherapy.

Methods

We performed genotyping in 19 single nucleotide polymorphisms (SNPs) of HSP genes and Rho family genes of 346 lung cancer patients by SequenomMassARRAY. We used Cox proportional hazard models, state and plink to analyze the associations between SNPs and the prognosis of lung cancer patients.

Results

We found that the polymorphisms of HSPB1 rs2070804 and HSPA4 rs3088225 were significantly associated with lung cancer survival (p=0.015, p=0.049*, respectively). We also discovered the statistically significant differences between rs2070804 with age, gender, histology and stage, rs3088225 with gender and stage, which can affect lung cancer prognosis.

Conclusion

The results of our study suggest that HSPB1 rs2070804 (G>T) and HSPA4 rs3088225 (A>G) may be useful biomarkers for predicting the prognosis of lung cancer patients treated with platinum-based chemotherapy.

Interaction between common variants of MDM2 and PPP1R13L and CD3EAP and TP53 SNPs in relation to lung cancer risk among Chinese

Background

Lung cancer is a complex disease that diagnosed the most common cancer and led cause of cancer death. MDM2 (MDM2 proto-oncogene) encodes a nuclear-localized E3 ubiquitin ligase. The encoded protein can promote tumor formation by targeting tumor suppressor proteins, such as TP53, for proteasomal degradation. Epidemiology studies have investigated the association of MDM2 single nucleotide polymorphisms (SNP) and interaction between genetic and environmental factors with lung cancer.

Methods

This Chinese case-control study comprised 627 cases and 633 controls explored the role of MDM2 five htSNPs (rs1690924, rs1846402, rs2291857, rs3730581 and rs3730635, haplotype-tagging SNP) tagging 95% of the common haplotypes across the gene and the interactions of MDM2, PPP1R13L, CD3EAP and TP53 in the same pathological pathway on lung cancer risk, together with smoking-duration.

Results

None of the htSNPs in MDM2 were associated with lung cancer risk in co-dominant, dominant, recessive, and log-additive models (adjusted for smoking-duration). Haplotype analysis showed that global haplotype association was statistically significant (P=0.0036, adjusted for smoking-duration) and haplotype5 (rs1690924^A-rs1846402^G-rs2291857^C-rs3730581^G-rs3730635^A) was associated with reduced risk of lung cancer [OR (95%) =0.52 (0.33–0.82), P=0.0053, adjusted for smoking-duration]. MDR interaction analysis showed that two the best significant models and strong synergy between MDM2 and TP53.

Conclusions

MDM2 five-htSNPs haplotype exhibited association with lung cancer susceptibility, interaction of MDM2 and TP53 htSNPs and smoking-duration contributed to lung cancer risk and strong synergy between MDM2 and TP53 htSNPs influenced lung cancer predisposition. Our results suggest that MDM2, TP53 and smoking-duration interact in relation to lung carcinogenesis.

Genetic Polymorphisms and Platinum-Based Chemotherapy-Induced Toxicities in Patients With Lung Cancer: A Systematic Review and Meta-Analysis

Background: Platinum-based agents, including cisplatin, carboplatin, and oxaliplatin, are indispensable for the treatment of lung cancer. The development of toxicity frequently necessitates dose reduction or discontinuation of therapy, despite the clinical response. Pharmacogenomics studies were reviewed to identify the possible genetic variants that underlie individual susceptibility to platinum-related toxicities. Method: We conducted a systematic search in PubMed and Embase for pharmacogenomics reports that focused on commonly reported platinum-induced toxicities, such as gastrointestinal (GI), hematological, neurological, and other toxicities, in patients diagnosed with lung cancer. Meta-analyses were conducted to determine the association between genetic polymorphisms and platinum-induced toxicity by checking the odds ratio (OR) and 95% confidence interval (CI) using random or fixed-effects models as appropriate. Results: Twenty eligible studies that met the inclusion criteria with sufficient data were extracted and presented comprehensively. A total of 16 polymorphisms from 11 genes were included in the meta-analysis. MTHFR rs1801131 and MDM2 rs1690924 were significantly correlated with platinum-induced GI toxicity (P = 0.04 and P = 0.02, respectively). Patients with the MTHFR rs1801131AA and MDM2 rs1690924TC/CC genotype tended to have a higher risk of GI toxicity than patients with other genotypes did (OR = 1.73, 95% CI = 0.86-2.18; and OR = 0.51, 95% CI = 0.29-0.88, respectively). Compared to carriers of the MTHFR rs1801133CC genotype, carriers of the CT/TT genotype had a significantly increased risk of hematological toxicity (P = 0.01, OR = 1.68, 95% CI = 1.12-2.52). Conclusion: In the future, physicians should pay careful attention to MTHFR and MDM2 for personalized chemotherapy treatment among patients with lung cancer.

Promoter polymorphisms of TOP2A and ERCC1 genes as predictive factors for chemotherapy in non-small cell lung cancer patients

Background

Topoisomerase 2‐alpha (TOP2A) is an enzyme that controls topologic changes in DNA during transcription and replication. ERCC1 is an enzyme that takes part in DNA repair processes. The purpose of this study was to assess the predictive role of particular single nucleotide polymorphisms (SNPs) in the promoter regions of TOP2A and ERCC1 genes in non‐small cell lung cancer patients (NSCLC) treated with chemotherapy.

Materials and methods

We enrolled 113 NSCLC patients treated in the first line with platinum‐based chemotherapy. Effectiveness was available for 71 patients. DNA was isolated from whole blood using the Qiamp DNA Blood Mini kit (Qiagen). We examined five SNPs: rs11615 (ERCC1), rs3212986 (ERCC1), rs13695 (TOP2A), rs34300454 (TOP2A), rs11540720 (TOP2A). Quantitative PCR using the TaqMan probe (ThermoFisher) was performed on a Eco Illumina Real‐Time PCR system device (Illumina Inc).

Results

Patients with the A/A genotype in rs11615 of the ERCC1 gene had significantly longer median progression free survival (PFS) (8.5 months; P = .0088). Patients with the C/C genotype in rs3212986 of the ERCC1 gene had longer median PFS (7 months; P = .05). Patients with the C/C genotype in rs34300454 of TOP2A gene had significantly higher median PFS (7.5 months; P = .0029). Carriers of the C/C genotype in rs34300454 of the TOP2A gene had significantly longer median OS (15.5 months; P = .0017). Patients with the A/A genotype in rs11615 of the ERCC1 gene had significantly higher risk of neutropenia (P = .0133).

Conclusions

Polymorphisms of the TOP2A and ERCC1 genes may be a predictive factor of toxicities and survival for chemotherapy in NSCLC patients.

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.

Rs3212986 polymorphism, a possible biomarker to predict smoking-related lung cancer, alters DNA repair capacity via regulating ERCC1 expression

Single nucleotide polymorphisms (SNPs) in 3'UTR of key DNA repair enzyme genes are associated with inter-individual differences of DNA repair capacity (DRC) and susceptibility to a variety of human malignancies such as lung cancer. In this study, seven candidate SNPs in 3'UTR of DRC-related genes including ERCC1 (rs3212986, rs2336219, and rs735482), OGG1 (rs1052133), MLH3 (rs108621), CD3EAP (rs1007616), and PPP1R13L (rs6966) were analyzed in 300 lung cancer patients and controls from the northeast of China. Furthermore, we introduced ERCC1 (CDS+3'UTR) or CD3EAP (CDS) cDNA clone to transfect HEK293T and 16HBE cells. Cell viability between different genotypes of transfected cells exposed to BPDE was detected by CCK-8 assay, while DNA damage was visualized using γH2AX immunofluorescence and the modified comet assay. We found that minor A-allele of rs3212986 could reflect a linkage with increasing risk of NSCLC. Compared with CC genotype, AA genotype of ERCC1 rs3212986 was a high-risk factor for NSCLC (OR = 3.246; 95%CI: 1.375-7.663). Particularly stratified by smoking status in cases and controls, A allele of ERCC1 rs3212986 also exhibited an enhanced risk to develop lung cancer in smokers only (P < 0.05). Interestingly, reduced repair efficiency of DNA damage was observed in 293T ERCC1(AA) and 16HBE ERCC1(AA), while no significant difference was appeared in two genotypes of CD3EAP (3' adjacent gene of ERCC1) overexpressed cells. Our findings suggest that rs3212986 polymorphism in 3'UTR of ERCC1 overlapped with CD3EAP may affect the repair of the damage induced by BPDE mainly via regulating ERCC1 expression and become a potential biomarker to predict smoking-related lung cancer.

The association of XRCC1 polymorphism with osteosarcoma risk, clinicopathologic features, and prognosis in a Chinese Han population

Introduction

The association of single-nucleotide polymorphisms at X-ray repair cross-complementing group-1 (XRCC1) with osteosarcoma (OS) development has not been fully clear to date. The aim of the present study is to evaluate the association of XRCC1 polymorphisms with risk, clinicopathologic features, and prognosis in Chinese OS patients.

Methods

A total of 146 patients with primary OS and 248 age- and gender-matched controls were included in the present study. The frequencies of four XRCC1 polymorphisms (rs25487, rs1799782, rs25489, and rs3213245) were determined between OS patients and controls. The association of XRCC1 polymorphism with clinicopathologic characteristics, prognosis, and XRCC1 expression was further evaluated.

Results

Compared with TT genotype, individuals carrying the minor C allele (TC+ CC) of rs3213245 had significantly increased risk of OS development (OR =1.83, 95% CI 1.14–3.00). OS patients carrying TC genotype and C allele at rs3213245 were more likely to be with larger tumor size and metastasis. Survival analysis demonstrated that OS patients carrying C allele (TC + CC) at rs3213245 had shorter survival time than those with TT genotype. The T to C substitution at rs3213245 could decrease XRCC1 gene transcriptional activity in vitro. XRCC1 mRNA and protein expression levels were lower in OS patients carrying TC or CC genotype at rs3213245. Besides, no significant association of rs25487, rs1799782, and rs25489 with OS was observed.

Conclusion

In conclusion, these findings revealed that XRCC1 rs3213245 polymorphism was associated with increased risk of OS, which could affect XRCC1 expression in vitro and in vivo.