Associations of polymorphisms in DNA repair genes and MDR1 gene with chemotherapy response and survival of non-small cell lung cancer

Global trends in BRCA-related breast cancer research from 2013 to 2022: A scientometric analysis

Introduction

Since the mid-2000s, breast cancer incidence among women has slowly increased at about 0.5% per year. In the last three decades, Breast Cancer Susceptibility Gene (BRCA) has been proven to be the crucial gene in encouraging the incidence and development of breast cancer. However, scientometric analysis on BRCA-related breast cancer is in shortage. Thus, to have a clear understanding of the current status and catch up with the hotspots, a scientometric analysis was conducted on specific academic publications collected from the Web of Science (WoS).

Methods

We searched the Web of Science Core Collection (WoSCC) to procure associated articles as our dataset. Bibliometric, CiteSpace, VOSviewer, and HistCite software were then applied to conduct visual analyses of countries, institutions, journals, authors, landmark articles, and keywords in this research field.

Results

A total of 7,266 articles and 1,310 review articles published between 2013 to 2022 were retrieved eventually. The annual output steadily rose year by year and peaked in 2021. The USA led the way in the number of published works, total citations, and collaboration. Breast Cancer Research and Treatment was the most favoured journal in this research field. Narod SA from the University of Toronto produced the most publications. At last, the most prominent keywords were "breast cancer" (n=1,778), "women" (n=1,369), "brca1" (n=1,276), "ovarian cancer" (n=1,259), "risk" (n=1,181), and "mutations" (n=929), which exposed the hotspots within the BRCA domain of breast cancer study.

Conclusion

The tendency in the BRCA research field over the past decade was presented by the scientometric analysis. The current research focus is the clinical trials of poly-adenosine diphosphate ribose polymerase inhibitors (PARPi) drugs and their resistance mechanisms.

Current Insights into Interethnic Variability in Testicular Cancers: Population Pharmacogenetics, Clinical Trials, Genetic Basis of Chemotherapy- Induced Toxicities and Molecular Signal Transduction

Testicular cancer is an aggressive malignancy with a rising incidence rate across the globe. Testicular germ cell tumors are the most commonly diagnosed cancers, and surgical removal of the testes is often a radical necessity along with chemotherapy and radiotherapy. While seminomas are receptive to radiotherapy as well as chemotherapy, non-seminomatous germ cell tumors respond to chemotherapy only. Due to the singular nature of testicular cancers with associated orchiectomy and mortality, it is important to study the molecular basis and genetic underpinnings of this group of cancers across male populations globally. In this review, we shed light on the population pharmacogenetics of testicular cancer, pediatric and adult tumors, current clinical trials, genetic determinants of chemotherapy-induced toxicity in testicular cancer, as well as the molecular signal transduction pathways operating in this malignancy. Taken together, our discussions will help in enhancing our understanding of genetic factors in testicular carcinogenesis and chemotherapy-induced toxicity, augment our knowledge of this aggressive cancer at the cellular and molecular level, as well as improve precision medicine approaches to combat this disease.

A meta-analysis on the relationship of exosomes and the prognosis of lung cancer

BACKGROUND

A lot of research evidence shows that exosomes play an indelible role in the prognosis of lung cancer, but there are many disputes. Therefore, we conduct a meta-analysis to further demonstrate.

METHODS

A literature retrieval was performed through a search of PubMed, Embase, Web of Science, Cochrane, CKNI, Wanfang, and other databases to locate documents from the literature that satisfied the inclusion criteria. There were four outcome indicators: overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS), and progression-free survival (PFS). Subgroup analysis was conducted according to sample size, country, detection method, analysis method, and pathological type. Stata 14.0 software was used to evaluate the prognostic value of exosomes in lung cancer.

RESULTS

A total of 2456 patients with lung cancer from 29 studies in 16 articles were included. The expression level of exosomes was closely associated with the OS and DFS of patients, although no statistical difference was observed between exosomes and DSS or PFS. Eighteen studies with 2,110 patients were evaluated to examine the prognostic value of exosomes in lung cancer by exploring the association between exosomes and OS. The results showed that exosomes were strongly associated with worse OS, and the combined hazard ratio (HR) was 2.01 (95% confidence interval [CI]: 1.70-2.39, P = .000). Six studies investigated the association between exosomes and DFS, and showed a pooled HR of 2.48 (95% CI: 1.75-3.53, P = .000).

CONCLUSION

Our analysis indicated that the expression level of exosomes was closely associated with the OS and DFS of patients with lung cancer, suggesting that exosomes are associated with poor prognosis of lung cancer. Exosomes may be a new biomarker for the prognosis of lung cancer, although a large number of prospective studies are still needed to support this.

Contribution of XPD and XPF Polymorphisms to Susceptibility of Non-Small Cell Lung Cancer in High-Altitude Areas

BACKGROUND

We aimed to explore the relation of XPD and XPF variants with non-small cell lung cancer (NSCLC) risk and the effect of these variants on the sensitivity to cisplatin-based chemotherapy among the Chinese Han population in high-altitude areas.

METHODS

Eight single-nucleotide polymorphisms (SNPs) in XPD and XPF were genotyped by Agena MassARRAY platform among 506 NSCLC cases and 510 healthy controls. Correlation of XPD and XPF gene polymorphisms with NSCLC susceptibility and the response of cis-platin-based chemotherapy were analyzed with logistic regression by calculating odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

XPD rs13181 (OR = 1.53, 95% CI: 1.04-2.24, p = 0.029) and rs1052555 (OR = 1.63, 95% CI: 1.05-2.53, p = 0.029) possibly contributed to the increased risk of lung adenocarcinoma, while XPD rs238406 (OR = 0.63, 95% CI: 0.43-0.94, p = 0.024) was a protective factor for lung squamous cell carcinoma. Age, gender, BMI, smoking, and drinking might affect the correlation of XPD and XPF polymorphisms with NSCLC risk. More importantly, XPD rs13181 (OR = 2.91, p = 0.015), XPD rs1052555 (OR = 2.67, p = 0.022), and XPF rs231127 (OR = 4.15, p = 0.008) were associated with treatment response in NSCLC patients underwent cisplatin-based chemotherapy.

CONCLUSION

This study found that XPD and XPF variants might contribute to NSCLC risk and the response of cisplatin-based chemotherapy among the Chinese Han population in high-altitude areas.

A Drosophila platform identifies a novel, personalized therapy for a patient with adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is a rare cancer type that originates in the salivary glands. Tumors commonly invade along nerve tracks in the head and neck, making surgery challenging. Follow-up treatments for recurrence or metastasis including chemotherapy and targeted therapies have shown limited efficacy, emphasizing the need for new therapies. Here, we report a Drosophila-based therapeutic approach for a patient with advanced ACC disease. A patient-specific Drosophila transgenic line was developed to model the five major variants associated with the patient's disease. Robotics-based screening identified a three-drug cocktail—vorinostat, pindolol, tofacitinib—that rescued transgene-mediated lethality in the Drosophila patient-specific line. Patient treatment led to a sustained stabilization and a partial metabolic response of 12 months. Subsequent resistance was associated with new genomic amplifications and deletions. Given the lack of options for patients with ACC, our data suggest that this approach may prove useful for identifying novel therapeutic candidates.

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Personalized therapy was developed for patient with Adenoid Cystic Carcinoma

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Genomics analysis was leveraged to establish a Drosophila ‘personalized patient avatar’

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A robotics-based screen identified a novel three drug therapeutic cocktail

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12 months response was followed by relapse and significant tumor genomic re-wiring

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.

Effect of ERCC2 rs13181 and rs1799793 polymorphisms and environmental factors on the prognosis of patients with lung cancer

PURPOSE

The 5-year survival rate of patients with lung cancer in China is < 20%, and predicting their prognosis is difficult. Here, we investigated the association between two common non-synonymous single-nucleotide polymorphisms (SNPs) in the excision repair cross-complementing 2 (ERCC2) genes (rs13181 and rs1799793) and the prognosis of patients with lung cancer.

METHODS

Genomic DNA was extracted from the blood samples of 839 patients with lung cancer and genotyped using the SNPscan technique. The association between patient prognosis and the ERCC2 genotype was analyzed using a multivariate Cox proportional hazards model adjusted for multiple potential confounders.

RESULTS

The presence of ERCC2 rs13181 T>G significantly increased the risk of death (adjust hazard ratio (HR) = 1.29, 95% CI: 1.06-1.56, P = 0.009). Patients with the rs13181 TG genotype (adjust HR = 1.34, 95% CI: 1.08-1.65, P = 0.007) and rs13181 dominant mode TG+GG (adjust HR = 1.33, 95% CI: 1.08-1.63, P = 0.007) had significantly worse overall survival. Moreover, stratified analyses showed that patients with the TG and TG+GG rs13181 genotypes who were male, elderly (≥60 years), had a history of smoking, or without family history of malignant tumors had a significantly increased risk of death. In patients with adenocarcinoma lung cancer (ADC), the rs1799793 genotype CT (adjust HR = 1.49, 95% CI: 1.06-2.09, P = 0.023) and dominant model CT+TT (adjust HR = 1.45, 95% CI = 1.04-2.02, P = 0.027) were associated with an increased risk of death.

CONCLUSION

ERCC2 rs13181 and rs1799793 SNPs may be significant prognostic factors for the risk of death among patients with lung cancer.

Genetic variation in ABCB5 associates with risk of hepatocellular carcinoma

Expression of ATP‐binding cassette B5 (ABCB5) has been demonstrated to confer chemoresistance, enhance cancer stem cell properties and associate with poor prognosis in hepatocellular carcinoma (HCC). The aim of this study was to evaluate the genetic variations of ABCB5 in HCC patients with reference to healthy individuals and the clinicopathological significance. A pilot study has examined 20 out of 300 pairs HCC and paralleled blood samples using conventional sequencing method to cover all exons and exon/intron regions to investigate whether there will be novel variant sequence and mutation event. A total of 300 HCC and 300 healthy blood DNA samples were then examined by Sequenom MassARRAY genotyping and pyrosequencing for 38 SNP and 1 INDEL in ABCB5. Five novel SNPs were identified in ABCB5. Comparison of DNA from blood samples of HCC and healthy demonstrated that ABCB5 SNPs rs75494098, rs4721940 and rs10254317 were associated with HCC risk. Specific ABCB5 variants were associated with aggressive HCC features. SNP rs17143212 was significantly associated with ABCB5 expression level. Nonetheless, the paralleled blood and tumour DNA sequences from HCC patients indicated that ABCB5 mutation in tumours was not common and corroborated the TCGA data sets. In conclusion, ABCB5 genetic variants had significant association with HCC risk and aggressive tumour properties.

The Therapeutic Potential of DNA Damage Repair Pathways and Genomic Stability in Lung Cancer

Despite advances in our understanding of the molecular biology of the disease and improved therapeutics, lung cancer remains the most common cause of cancer-related deaths worldwide. Therefore, an unmet need remains for improved treatments, especially in advanced stage disease. Genomic instability is a universal hallmark of all cancers. Many of the most commonly prescribed chemotherapeutics, including platinum-based compounds such as cisplatin, target the characteristic genomic instability of tumors by directly damaging the DNA. Chemotherapies are designed to selectively target rapidly dividing cells, where they cause critical DNA damage and subsequent cell death (1, 2). Despite the initial efficacy of these drugs, the development of chemotherapy resistant tumors remains the primary concern for treatment of all lung cancer patients. The correct functioning of the DNA damage repair machinery is essential to ensure the maintenance of normal cycling cells. Dysregulation of these pathways promotes the accumulation of mutations which increase the potential of malignancy. Following the development of the initial malignancy, the continued disruption of the DNA repair machinery may result in the further progression of metastatic disease. Lung cancer is recognized as one of the most genomically unstable cancers (3). In this review, we present an overview of the DNA damage repair pathways and their contributions to lung cancer disease occurrence and progression. We conclude with an overview of current targeted lung cancer treatments and their evolution toward combination therapies, including chemotherapy with immunotherapies and antibody-drug conjugates and the mechanisms by which they target DNA damage repair pathways.

Genetic polymorphisms and haplotypes of BRCA1 gene associated with quality of life and survival among patients with non-small-cell lung cancer

PURPOSE

Quality of life (QoL) and prognosis of lung cancer (LC) patients are poor. Previous studies focused less on the relationship between genetic factors and the QoL of LC patients. The current study is intended to explore the association of SNPs and haplotypes of BRCA1 and the QoL and survival of patients with LC.

METHODS

QOL of 291 non-small-cell LC patients was measured by EORTC Core Quality of Life Questionnaire (QLQ-C30) and EORTC Quality of Life Questionnaire-Lung Cancer 13 (QLQ-LC13) before discharge. Three tag SNPs of the BRCA1 gene (rs1799966, rs3737559, rs8067269) were detected using an improved multiplex ligation detection reaction (iMLDR) technique. Haplotype analysis was conducted using the software Haploview 4.2. The patients' survival was followed up every six months until March 2019.

RESULTS

rs8067269 was associated with physical functioning (β = 7.97, p = 0.024) and diarrhea (Odds ratios (OR) 0.32, p = 0.042). rs1799966-rs3737559-rs8067269 haplotype was associated with several domains of QoL, including physical functioning (TCG vs. CCA: β = 6.21, p = 0.010), worse dyspnea (TCG vs. CTA: OR 2.05, p = 0.031) and peripheral neuropathy (TCG vs. CTA: OR 3.91, p = 0.030). BRCA1 rs1799966 CC genotype, rs8067269 AA genotype and CCA haplotype were associated with longer survival time of LC patients (p < 0.05).

CONCLUSION

SNPs and haplotypes of BRCA1 gene were associated with the QoL and survival of patients with LC. Patients with certain genotypes and haplotypes (i.e., rs8067269 AA genotype, or CCA haplotype) had better QoL and prognosis.

Inhibition of MDR1 Overcomes Resistance to Brentuximab Vedotin in Hodgkin Lymphoma

PURPOSE

In classical Hodgkin lymphoma, the malignant Reed-Sternberg cells express the cell surface marker CD30. Brentuximab vedotin is an antibody-drug conjugate (ADC) that selectively delivers a potent cytotoxic agent, monomethyl auristatin E (MMAE), to CD30-positive cells. Although brentuximab vedotin elicits a high response rate (75%) in relapsed/refractory Hodgkin lymphoma, most patients who respond to brentuximab vedotin eventually develop resistance.

PATIENTS AND METHODS

We developed two brentuximab vedotin-resistant Hodgkin lymphoma cell line models using a pulsatile approach and observed that resistance to brentuximab vedotin is associated with an upregulation of multidrug resistance-1 (MDR1). We then conducted a phase I trial combining brentuximab vedotin and cyclosporine A (CsA) in patients with relapsed/refractory Hodgkin lymphoma.

RESULTS

Here, we show that competitive inhibition of MDR1 restored sensitivity to brentuximab vedotin in our brentuximab vedotin-resistant cell lines by increasing intracellular MMAE levels, and potentiated brentuximab vedotin activity in brentuximab vedotin-resistant Hodgkin lymphoma tumors in a human xenograft mouse model. In our phase I trial, the combination of brentuximab vedotin and CsA was tolerable and produced an overall and complete response rate of 75% and 42% in a population of patients who were nearly all refractory to brentuximab vedotin.

CONCLUSIONS

This study may provide a new therapeutic strategy to combat brentuximab vedotin resistance in Hodgkin lymphoma. This is the first study reporting an effect of multidrug resistance modulation on the therapeutic activity of an ADC in humans. The expansion phase of the trial is ongoing and enrolling patients who are refractory to brentuximab vedotin to confirm clinical activity in this population with unmet need.

Survivin expression modulates the sensitivity of A549 lung cancer cells resistance to vincristine

Lung cancer is the leading cause of cancer-associated mortalities worldwide. Chemotherapeutic drug vincristine is widely used to treat lung cancer; however, the acquisition of drug resistance is the major limitation of chemotherapy, and it is thus important to determine the mechanism underlying vincristine resistance in lung cancer. Survivin has been reported to be associated with the development of drug resistance and be involved in the progression of non-small cell lung cancer. In the present study, a vincristine-resistant lung cancer cell line, A549/VCR, was used to investigate the possible involvement of survivin in the acquisition of vincristine resistance. Western blot analysis demonstrated that survivin protein expression level was markedly higher in A549/VCR cells compared with in control A549 cells, whereas p53 expression level was lower in A549/VCR cells compared with in A549 cells. Thus, wild-type p53 was overexpressed in A549/VCR cells and it reversed vincristine resistance of A549/VCR cells via the inhibition of survivin expression. Furthermore, survivin was knocked down by small interfering RNA technology and the effects on viability and apoptosis of resistant cells were investigated. MTT, Annexin V-fluorescein isothiocyanate/propidium iodide and caspase-3 activity assays indicated that survivin silencing significantly inhibited cell viability and enhanced apoptosis induced by vincristine treatment in A549/VCR cells compared with non-silenced A549/VCR cells. These results suggested that survivin expression regulated by p53 may serve an important role in drug resistance in A549/VCR cells and may be a potential target for enhancing vincristine sensitivity in A549 lung cancer cells. Additionally, the present study revealed that A549/VCR cells exhibited cross resistance to methotrexate (MTX) and survivin silencing re-sensitized A549/VCR cells to MTX, indicating the crucial role of survivin in regulating A549 cells sensitivity to anticancer drugs. The results of the present study are significant for determining the underlying mechanism of vincristine resistance in lung cancer.

CCL2 influences the sensitivity of lung cancer A549 cells to docetaxel

Lung cancer is one of the most common malignant tumor types globally. Acquisition of chemoresistance in lung cancer cells is the primary cause of chemotherapy failure. Inflammatory chemokine C-C motif chemokine ligand 2 (CCL2) has been reported to be involved in the progression of cancer and drug resistance. However, its function in docetaxel (DTX) resistance of lung cancer remains unclear. In the present study, the mechanism underlying DTX-induced drug resistance was investigated. Reverse transcription-quantitative polymerase chain reaction and western blot analysis revealed that DTX treatment increased the mRNA and protein expression of CCL2 in lung cancer A549 cells. CCL2 was knocked down by small interfering RNA or was overexpressed by recombinant CCL2 lentivirus, and cell viability was determined. An MTT assay indicated that CCL2 downregulation decreased the viability of A549 cells and augmented the DTX-induced cytotoxicity, whereas CCL2 upregulation protected A549 cells from DTX-induced cytotoxicity. Additionally, it was revealed that CCL2 overexpression activated phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling and inhibited apoptosis-associated protein caspase-3 activation and B-cell lymphoma 2 (Bcl-2) phosphorylation at Ser70 induced by DTX, and enhanced DTX-induced Bcl-2-associated death promoter phosphorylation at Ser112. PI3K/AKT inhibitor LY294002 restored DTX-induced caspase-3 activation and Bcl-2 phosphorylation, reversed the effect of CCL2 on the viability of A549 cells and enhanced DTX-induced cytotoxicity. These results demonstrated that chemoresistance may be mediated by cell stress responses involving CCL2 expression, suggesting that CCL2 may be a potential target for enhancing the therapeutic effect of DTX in lung cancer.

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

Chemotherapy based on platinum compounds is the standard treatment for NSCLC patients with EGFR wild type, and is also used as second line in mutated EGFR patients. Nevertheless, this therapy presents poor clinical outcomes. ERCC1, ERCC2, XRCC1, MDM2, MTHFR, MTR, and SLC19A1 gene polymorphisms may contribute to individual variation in response and survival to platinum-based chemotherapy. The aim of this study was to investigate the influence of these polymorphisms on response and survival of NSCLC patients treated with platinum-based chemotherapy. A retrospective-prospective cohorts study was conducted, including 141 NSCLC patients. Polymorphisms were analyzed by PCR real-time with Taqman® probes. Patients with ERCC1 rs3212986-GG (p = 0.0268; OR = 2.50; CI_95% = 1.12-5.69) and XRCC1 rs25487-GG (p = 0.0161; OR = 2.99; CI_95% = 1.26-7.62) genotype showed significantly better ORR. Cox survival analysis revealed that patients carrying the MDM2 rs1690924-GG genotype (p = 0.0345; HR = 1.99; CI_95% = 1.05-3.80) presented higher risk of death. Furthermore, carriers of MTR rs1805087-A alleles (p = 0.0060; HR = 8.91; CI_95% = 1.87-42.42) and SLC19A1 rs1051266-AA genotype (p = 0.0130; HR = 1.74; CI_95% = 1.12-2.68) showed greater risk of progression. No influence of ERCC1 rs11615, ERCC2 rs13181, ERCC2 rs1799793, XRCC1 rs1799782, MDM2 rs1470383, MTHFR rs1801131, and MTHFR rs1801133 on platinum-based chemotherapy clinical outcomes was found. In conclusion, our results suggest that ERCC1 rs3212986, XRCC1 rs25487, MDM2 rs1690924, MTR rs1805087, and SLC19A1 rs1051266 gene polymorphisms may significantly act as predictive factors in NSCLC patients treated with platinum-based chemotherapy.

Pharmacogenomics of platinum-based chemotherapy response in NSCLC: a genotyping study and a pooled analysis

Published data showed inconsistent results about associations of extensively studied polymorphisms with platinum-based chemotherapy response. Our study aimed to provide reliable conclusions of these associations by detecting genotypes of the SNPs in a larger sample size and summarizing a comprehensive pooled analysis. 13 SNPs in 8 genes were genotyped in 1024 NSCLC patients by SequenomMassARRAY. 39 published studies and our study were included in meta-analysis. Patients with GA or GG genotypes of XRCC1 G1196 had better response than AA genotype carriers (Genotyping study: OR = 0.72, 95%CI: 0.53-0.96, P = 0.028; Meta-analysis: OR = 0.74, 95%CI: 0.62-0.89, P = 0.001). Patients carrying CT or TT genotypes of XRCC1 C580T could be more sensitive to platinum-based chemotherapy compared to patients with CC genotype (OR = 0.54, 95%CI: 0.37-0.80, P = 0.002). CC genotype of XRCC3 C18067T carriers showed more resistance to platinum-based chemotherapy when compared to those with CT or TT genotypes (OR = 0.69, 95%CI: 0.52-0.91, P = 0.009). Our study indicated that XRCC1 G1196A/C580T and XRCC3 C18067T should be paid attention for personalized platinum-based chemotherapy in NSCLC patients.

Combined effect of ERCC1 and ERCC2 polymorphisms on overall survival in non-squamous non-small-cell lung cancer patients treated with first-line pemetrexed/platinum

OBJECTIVES

Polymorphisms of DNA repair genes may affect DNA repair capacity and the sensitivity of platinum doublets chemotherapy in non-small-cell lung cancer (NSCLC). We prospectively evaluated whether single nucleotide polymorphisms (SNPs) of ERCC1, ERCC2, XRCC1, and XRCC3 were associated with treatment outcome in advanced non-squamous NSCLC patients receiving pemetrexed/platinum as their first-line chemotherapy.

MATERIALS AND METHODS

Genotyping of six SNPs in four DNA repair genes in 58 patients treated with first-line pemetrexed/platinum was performed using TaqMan SNP Genotyping Assays.

RESULTS

The wild-type ERCC1 8092 (C/C) was significantly associated with a better objective response compared to the variant genotypes (C/A + A/A) (48% vs 10%, P = .005). In the multivariate Cox proportional hazards model, we found that individuals with a wild-type genotype of ERCC1 Asn118Asn, ERCC1 C8092A and ERCC2 Asp312Asn had significantly better overall survival (OS) than those with a heterozygous or homozygous variant genotype. On the other hand, the heterozygous variant genotype of ERCC2 Lys751Gln was associated with better OS than that of the wild-type genotype. We further explored the combined effect of SNPs on OS, and found a significant allele/dose-dependent trend toward decreasing OS in patients with an increasing number of unfavorable alleles among four SNPs in ERCC1 and ERCC2. The median OS of patients with two or three unfavorable alleles (30.1 and 30.5 months, respectively) was significantly longer than that of patients with 4 unfavorable alleles (11.8 months, log-rank test for trend, P = .001).

CONCLUSION

A combination of ERCC1 and ERCC2 polymorphisms may predict OS among pemetrexed/platinum treated advanced non-squamous NSCLC patients.

Predictive value of inflammatory indexes on the chemotherapeutic response in patients with unresectable lung cancer: A retrospective study

Chemotherapy is widely administered to patients with advanced lung cancer; however, data regarding chemotherapeutic sensitivity are limited. The present study aimed to investigate the predictive value of inflammatory indexes for chemotherapeutic efficacy in advanced lung cancer. Patients with stage III and IV unresectable lung cancer that were treated with first-line chemotherapy between January 2007 and December 2011 were retrospectively identified, and chemotherapeutic response was evaluated following 2 or 3 chemotherapy cycles. Prior to chemotherapy, hematologic data and clinicopathological parameters were collected using electronic medical records. The associations between the main inflammatory indexes [which included the pretreatment neutrophil count (PNC), neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR)] and the chemotherapeutic efficacy, as well as the prognostic value of the indexes, were analyzed. According to the receiver operating characteristic curve, PLR failed to reach diagnostic accuracy for overall chemotherapeutic response. PNC and NLR were each classified into two groups according to the cut-off values (4.635×10⁹/l for PNC and 2.443 ×10⁹/l for NLR). The overall response rate was significantly higher in the low PNC [odds ratio, 3.261; 95% confidence interval (CI), 2.102-5.060; P<0.001, vs. high PNC] and low NLR groups (odds ratio, 1.596; 95% CI, 1.037-2.454; P=0.033, vs. high NLR). Univariate analyses showed that the high PNC (HR, 1.487) and high NLR groups (HR, 1.288) were associated with poor progression-free survival (PFS); however, NLR was considered statistically insignificant in multivariate analysis. In summary, high PNC and NLR values are associated with chemoresistance and an unfavorable prognosis, with the present study demonstrating that PNC has increased sensitivity when compared with other inflammatory indexes in predicting chemotherapeutic efficacy. Therefore, PNC has the potential to be used as a reliable and suitable predictor to stratify a high risk of chemoresistance in patients with stage III and IV unresectable lung cancer.

Chinese C allele carriers of the ERCC5 rs1047768 polymorphism are more sensitive to platinum-based chemotherapy: a meta-analysis

It is suspected that ERCC5 rs1047768 and rs17655 polymorphisms influence the response to platinum-based chemotherapy. This meta-analysis was performed to summarize the scattered evidence regarding the association between these two polymorphisms and sensitivity to platinum-based treatment. Thirteen studies were included after a comprehensive literature search. The pooled odds ratios and 95% confidence intervals suggested that the C allele of the ERCC5 rs1047768 polymorphism is associated with elevated sensitivity to platinating agents, especially for Chinese patients. However, no difference among rs17655 genotypes could be detected.

Pharmacogenomics of platinum-based chemotherapy in non-small cell lung cancer: focusing on DNA repair systems

Drug therapy for non-small cell lung cancer consists mainly of platinum-based chemotherapy regimens. However, toxicity, drug resistance, and high risk of death have been seen in the clinic, which means there is a need for optimizing the use of medications. Platinum resistance could be mediated by a series of DNA repair pathways, and therefore, these pathways should be taken into account for optimizing drug using. The goal of pharmacogenomics is to elucidate genetic factors, such as DNA repair genes, which might underlie drug efficacy and effectiveness, and to improve therapeutic effects or guide personalized therapy as well. Here, we reviewed the current knowledge of pharmacogenomic data on DNA repair systems and examined whether they could be further translated into the clinic with evidence-based perspectives.

Correlation of DNA Repair Gene Polymorphisms With Clinical Outcome in Patients With Locally Advanced Non-Small-Cell Lung Cancer Receiving Induction Chemotherapy Followed by Surgery

OBJECTIVE

The aim of this study was to evaluate whether xeroderma pigmentosum group D (XPD) and ribonucleotide reductase subunit M1 (RRM1) polymorphisms influenced clinical outcome in patients with stage IIIA-B non-small-cell lung cancer (NSCLC) treated with neoadjuvant gemcitabine/cisplatin/docetaxel followed by surgery.

MATERIALS AND METHODS

A total of 109 patients with stage IIIA and IIIB NSCLC were prospectively genotyped to examine a potential association between XPD 312 (aspartic acid [Asp]/asparagine [Asn]), XPD 751 (lysine [Lys]/glutamine [Gln]), and RRM1 (-37 C/A) polymorphisms with response and survival.

RESULTS

The median survival was 32.14 months for carriers of XPD 312 Asp/Asp and 12.04 months for those with the variant Asn allele (P = .05). In addition, event-free survival was longer for patients with the XPD 312 Asp/Asp genotype compared with patients with Asp/Asn or Asn/Asn (P = .03). A similar but nonsignificant trend was observed for the XPD 751 genotype. In a multivariate analysis, complete resection and age emerged as prognostic factors for overall survival; in patients with incomplete resection or exploratory thoracotomy, XPD 312 was the most significant prognostic factor (P = .03).

CONCLUSION

The XPD 312 single nucleotide polymorphism is a prognostic factor for survival in patients with locally advanced NSCLC receiving induction chemotherapy followed by surgery. The Asn allele is associated with unfavorable outcome and could be used for better stratification of patients.

The genetic variations in DNA repair genes ERCC2 and XRCC1 were associated with the overall survival of advanced non-small-cell lung cancer patients

It was reported that DNA repair can confer cancer cell resistance to therapeutic treatments by activating antiapoptotic cellular defense. We hypothesized that genetic variants of DNA repair genes may be associated with lung cancer prognosis. Seventeen tagging single‐nucleotide polymorphism (tagSNPs) selected from 12 DNA repair genes were genotyped in 280 advanced non‐small‐cell lung cancer (NSCLC) patients by TaqMan assay. The associations of these SNPs and overall survival of advanced NSCLC patients were investigated. Advanced NSCLC patients carrying ERCC2 rs50872 CT+TT genotypes had significantly longer median survival time (MST) and decreased death risk than patients with rs50872 CC genotype [log‐rank P = 0.031; adjusted HR(95% CI) = 0.73 (0.55–0.98), P = 0.033]. These effects were mainly seen among younger patients (≤65 years old) [HR(95% CI) = 0.57 (0.37–0.87), P = 0.010], patients without surgery [HR(95% CI) = 0.68 (0.47–0.98), P = 0.036] but with chemotherapy [HR(95% CI) = 0.64 (0.46–0.91), P = 0.012] or radiotherapy [HR(95% CI) = 0.58 (0.38–0.89), P = 0.013]. Meanwhile, compared to advanced NSCLC patients with rs25487 GG genotype, patients carrying XRCC1 rs25487 GA+AA genotypes had significantly shorter MST (MST = 11.7 vs. 16.7, log‐rank P = 0.048). In addition, advanced NSCLC patients carrying the ERCC2 rs50872 CC in combination with XRCC1 rs25487 GA+AA genotype had the shortest MST (11.2 month) and highest death risk [HR(95% CI) = 1.70 (1.15–2.52), P = 0.008] when compared with those carrying rs50872 CT+TT and rs25487 GG genotype (MST = 22.0 month). The ERCC2 rs50872 T allele was associated with favorable but XRCC1 rs25487 A allele with bad survival for advanced NSCLC in Chinese population, which may offer novel biomarkers for predicting clinical outcomes.

Targeting DNA Damage Response in the Radio(Chemo)therapy of Non-Small Cell Lung Cancer

Lung cancer is the leading cause of cancer death worldwide due to its high incidence and mortality. As the most common lung cancer, non-small cell lung cancer (NSCLC) is a terrible threat to human health. Despite improvements in diagnosis and combined treatments including surgical resection, radiotherapy and chemotherapy, the overall survival for NSCLC patients still remains poor. DNA damage is considered to be the primary cause of lung cancer development and is normally recognized and repaired by the intrinsic DNA damage response machinery. The role of DNA repair pathways in radio(chemo)therapy-resistant cancers has become an area of significant interest in the clinical setting. Meanwhile, some studies have proved that genetic and epigenetic factors can alter the DNA damage response and repair, which results in changes of the radiation and chemotherapy curative effect in NSCLC. In this review, we focus on the effect of genetic polymorphisms and epigenetic factors such as miRNA regulation and lncRNA regulation participating in DNA damage repair in response to radio(chemo)therapy in NSCLC. These may provide novel information on the radio(chemo)therapy of NSCLC based on the individual DNA damage response.

Survivin protein expression is involved in the progression of non-small cell lung cancer in Asians: a meta-analysis

Background

Surviving expression might serve as a prognostic biomarker predicting the clinical outcome of non-small cell lung cancer (NSCLC). The study was conducted to explore the potential correlation of survivin protein expression with NSCLC and its clinicopathologic characteristics.

Methods

PubMed, Medline, Cochrane Library, CNKI and Wanfang database were searched through January 2016 with a set of inclusion and exclusion criteria. Data was extracted from these articles and all statistical analysis was conducted by using Stata 12.0.

Results

A total of 28 literatures (14 studies in Chinese and 14 studies in English) were enrolled in this meta-analysis, including 3206 NSCLC patients and 816 normal controls. The result of meta-analysis demonstrated a significant difference of survivin positive expression between NSCLC patients and normal controls (RR = 7.16, 95 % CI = 4.63-11.07, P < 0.001). To investigate the relationship of survivin expression and clinicopathologic characteristics, we performed a meta-analysis in NSCLC patients. Our results indicates survivin expression was associated with histological differentiation, tumor-node-metastasis (TNM) stage and lymph node metastasis (LNM) (RR = 0.80, 95 % CI = 0.73-0.87, P < 0.001; RR = 0.75, 95 % CI = 0.67-0.84, P < 0.001; RR = 1.14, 95 % CI = 1.01-1.29, P = 0.035, respectively), but not pathological type and tumor size. (RR = 1.00, 95 % CI = 0.93-1.07, P = 0.983; RR = 0.95, 95 % CI = 0.86-1.05, P = 0.336, respectively).

Conclusion

Higher expression of survivin in NSCLC patients was found when compared to normal controls. Survivin expression was associated with the clinicopathologic characteristics of NSCLC and may serves as an important biomarker for NSCLC progression.

Association of single nucleotide polymorphisms in the MVP gene with platinum resistance and survival in patients with epithelial ovarian cancer

The human major vault protein (MVP) has been linked to the development of multidrug resistance in cancer cells, and overexpression of MVP has been observed in ovarian cancer tissues. The aim of the present study was to investigate the association between single nucleotide polymorphisms (SNPs) in the MVP gene and the tumor response to platinum-based chemotherapy and survival of patients affected by epithelial ovarian cancer (EOC), in addition to confirm whether tetra-primer amplification-refractory mutation system (ARMS)-polymerase chain reaction (PCR) is an accurate genotyping method. For this purpose, two polymorphisms in the MVP gene, namely reference SNP (rs)1057451 and rs4788186, were selected from the data obtained by the International haplotype map (HapMap) Project regarding Chinese Han population, and were evaluated by tetra-primer ARMS-PCR. Upon validation by DNA sequencing, the association of these polymorphisms with platinum resistance, progression-free survival (PFS) and overall survival (OS) in patients with EOC was assessed. The results of tetra-primer ARMS-PCR were in agreement with those derived from DNA sequencing. No significant differences were observed between platinum-sensitive and platinum-resistant cohorts in terms of allele and genotype distribution of these two polymorphisms in the MVP gene, which were not associated with PFS or OS. However, a trend toward prolonged PFS was observed in patients carrying the heterozygous AG allele at the rs4788186 locus. These results suggest that rs1057451 and rs4788186 variants in the MVP gene are not associated with favorable therapeutic response to platinum or longer survival in Chinese Han patients affected by EOC. In addition, the data of the present study confirm that tetra-primer ARMS-PCR is a trustworthy and economical genotyping method.

Different patterns of allelic imbalance in sporadic tumors and tumors associated with long-term exposure to gamma-radiation

The study aimed to reveal cancer related mutations in DNA repair and cell cycle genes associated with chronic occupational exposure to gamma-radiation in personnel of the Siberian Group of Chemical Enterprises (SGCE). Mutations were analyzed by comparing genotypes of malignant tumors and matched normal tissues of 255 cancer patients including 98 exposed to external gamma-radiation (mean dose 128.1±150.5mSv). Also a genetic association analysis was carried out in a sample of 149 cancer patients and 908 healthy controls occupationally exposed to gamma-radiation (153.2±204.6mSv and 150.5±211.2mSv, respectively). Eight SNPs of genes of DNA excision repair were genotyped (rs13181, rs1052133, rs1042522, rs2305427, rs4244285, rs1045642, rs1805419 and rs1801133). The mutation profiles in heterozygous loci for selected SNP were different between sporadic tumors and tumors in patients exposed to radiation. In sporadic tumors, heterozygous genotype Arg/Pro of the rs1042522 SNP mutated into Arg/0 in 15 cases (9.6%) and 0/Pro in 14 cases (8.9%). The genotype Lys/Gln of the rs13181 SNP mutated into Lys/0 and 0/Gln in 9 and 4 cases, respectively. In tumors of patients exposed to low-level radiation, the rs1042522 Arg/0 mutated genotype was found in 12 cases (12.1%), while in 2 cases (2%) 0/Pro mutation was observed. Finally, the rs13181 0/Gln mutated genotype was observed in 15 cases (16,5%) . Thus, our study showed the difference in patterns of allelic imbalance in tumors appeared under low-level radiation exposure and spontaneous tumors for selected SNPs. This suggests different mechanisms of inactivation of heterozygous genotypes in sporadic and radiation-induced tumors.

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.

Role of gross tumor volume in the prognosis of non-small cell lung cancer treated with 3D conformal radiotherapy: a meta-analysis

PURPOSE

Three-dimensional conformal radiotherapy (3D-CRT) has become widely applied in patients with non-small cell lung cancer (NSCLC), and gross tumor volume (GTV) is a reliable index for predicting prognosis in patients with NSCLC. This meta-analysis investigated the association between GTV and prognosis in patients with NSCLC after 3D-CRT.

METHODS

Electronic bibliographic databases were searched to identify articles related to NSCLC and 3D-CRT. The search results were carefully screened, using predetermined selection criteria, to select the most relevant studies. Newcastle-Ottawa Scale criteria were applied by 2 reviewers independently to evaluate the quality of the methodology of each included article., Based on GTV, each patient was assigned to either the study group (large GTV [≥112 cm(3)]) or the control group (small GTV [<112 cm(3)]), and the mean rates of overall survival (OS) and survival at 1, 3, and 5 years were calculated in each group. Summary hazard ratio (HR) with 95% CI was calculated.

FINDINGS

The data from 10 cohort studies were incorporated into the current meta-analysis (1473 patients; study group, 773; control group, 700). The OS in the study group was significantly less than that in the control group (HR = 1.52; 95% CI, 1.10-1.94; P < 0.01). The study and control groups also had significantly different survival rates at 1 year (HR = 1.27; 95% CI, 1.10-1.46, P = 0.01), 3 years (HR = 2.06; 95% CI, 1.63-2.61; P < 0.01), and 5 years (HR = 2.25; 95% CI, 1.63-3.10; P < 0.01). Findings from funnel plots and Egger tests of the OS and 3-year survival rate suggested no publication bias. With respect to the 1- and 5-year survival rates, however, the funnel plots and Egger tests demonstrated publication bias among the included studies.

IMPLICATIONS

The relatively small number of studies and small sample size, as well as the lack of a specific and standard method of defining small and large GTV, may have influenced the credibility and reliability of our results. The findings suggest that GTV influences prognosis in patients with NSCLC after 3D-CRT. However, further studies with larger sample sizes are needed to confirm our finding that a larger GTV is negatively associated with NSCLC prognosis after 3D-CRT.

Association between polymorphisms of BAG-1 and XPD and chemotherapy sensitivity in advanced non-small-cell lung cancer patients treated with vinorelbine combined cisplatin regimen

BCL-2 Associated athanogene 1 (BAG-1) and Xeroderma pigmentosum group D (XPD) are involved in the nucleotide excision repair pathway and DNA repair. We aimed to investigate whether polymorphisms in BAG-1 and XPD have effects on chemotherapy sensitivity and survival in patients with advanced non-small-cell lung cancer (NSCLC) treated with vinorelbine combined cisplatin (NP) regimen. A total of 142 patients with diagnosed advanced NSCLC were recruited in the current study. NP regimen was applied for all eligible patients. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used for BAG-1 (codon 324) and XPD (codons 312 and 751) genotyping. The treatment response was evaluated according to the RECIST guidelines. Progression-free survival (PFS) and overall survival (OS) were record as median and end point, respectively. As for BAG-1 codon 324, the chemotherapy sensitivity in NSCLC patients with CT genotype was 0.383 times of those with CC genotype (P < 0.05). With respect to XPD codon 751, the chemotherapy sensitivity in NSCLC patients with Lys/Gln genotype was 0.400 times of those with Lys/Lys genotype (P < 0.05). In addition, NSCLC patients carrying combined C/C genotype at codon 324 in BAG-1, Asp/Asp of XPD codon 312, and Lys/Lys of XPD codon 751 produced a higher efficacy of NP chemotherapy compared to those carrying mutation genotypes (all P < 0.05). Further, there were significant differences in PFS between patients with combined C/C genotype of BAG-1 codon 324, Lys/Lys genotype of XPD codon 751, and Asp/Asp genotype of XPD codon 312 and patients carrying BAG-1 codon 324 C/T genotype, XPD codon751 Lys/Gln genotype, and XPD codon312 Asp/Asn genotype (P < 0.05). Multivariate Cox regression analysis indicated that the combined wild-type of codon 324 XPD, codon 751 XPD, and codon 312 BAG-1 is the protective factor for OS and PFS, and clinical stages is the risk factor for OS and PFS. In conclusion, our research demonstrated the combined effects of BAG-1 and XPD polymorphisms on chemotherapy sensitivity and survival in patients with advanced NSCLC, which might be the important predictive markers for platinum-based chemotherapy efficacy.

CD30 Downregulation, MMAE Resistance, and MDR1 Upregulation Are All Associated with Resistance to Brentuximab Vedotin

Brentuximab vedotin (BV) is an antibody-drug conjugate that specifically delivers the potent cytotoxic drug monomethyl auristatin E (MMAE) to CD30-positive cells. BV is FDA approved for treatment of relapsed/refractory Hodgkin lymphoma and anaplastic large cell lymphoma (ALCL); however, many patients do not achieve complete remission and develop BV-resistant disease. We selected for BV-resistant Hodgkin lymphoma (L428) and ALCL (Karpas-299) cell lines using either constant (ALCL) or pulsatile (Hodgkin lymphoma) exposure to BV. We confirmed drug resistance by MTS assay and analyzed CD30 expression in resistant cells by flow cytometry, qRT-PCR, and Western blotting. We also measured drug exporter expression, MMAE resistance, and intracellular MMAE concentrations in BV-resistant cells. In addition, tissue biopsy samples from 10 Hodgkin lymphoma and 5 ALCL patients who had relapsed or progressed after BV treatment were analyzed by immunohistocytochemistry for CD30 expression. The resistant ALCL cell line, but not the Hodgkin lymphoma cell line, demonstrated downregulated CD30 expression compared with the parental cell line. In contrast, the Hodgkin lymphoma cell line, but not the ALCL cell line, exhibited MMAE resistance and increased expression of the MDR1 drug exporter compared with the parental line. For both Hodgkin lymphoma and ALCL, samples from patients relapsed/resistant on BV persistently expressed CD30 by immunohistocytochemistry. One Hodgkin lymphoma patient sample expressed MDR1 by immunohistocytochemistry. Although loss of CD30 expression is a possible mode of BV resistance in ALCL in vitro models, this has not been confirmed in patients. MMAE resistance and MDR1 expression are possible modes of BV resistance for Hodgkin lymphoma both in vitro and in patients.

Association of GSTP1 and XRCC1 gene polymorphisms with clinical outcome of advanced non-small cell lung cancer patients with cisplatin-based chemotherapy

We investigated the association between the clinical outcome and GSTP1 and XRCC1 gene polymorphisms in advanced NSCLC patients with cisplatin-based chemotherapy. We prospectively recruited 325 NSCLC patients between January 2010 and January 2014. Genotypes of GSTP1 A313G, XRCC1 Arg194Trp, Arg280His and Arg399Gln were conducted using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assay. AG and GG genotypes of GSTP1 A313G were correlated with a higher CR + PR when compared with AA genotype. Furthermore, GA and AA genotypes of XRCC1 Arg399Gln were associated with more CR + PR when compared with GG genotype. In the Cox proportional hazards model, GG genotype of GSTP1 A313G was significantly correlated with a longer median survival time when compared with AA genotype, and it is associated with a heavy decreased risk of death from NSCLC. Moreover, GA and AA genotypes of XRCC1 Arg399Gln had a significantly longer median survival time, and GA and AA genotypes were significantly associated with a moderate reduced risk of death from NSCLC. GSTP1 A313G and XRCC1 Arg399Gln gene polymorphisms might influence the response to cisplatin-based chemotherapy and affect the clinical outcome of advanced NSCLC.