Excision Repair Cross-complementing Research Articles

Contribution of ERCC2 rs13181 (Lys751Gln) and rs1799793 (Asp312Asn) polymorphisms to the risk of bladder cancer in Bangladesh

BackgroundHuman Excision Repair Cross-Complementation Group 2 (ERCC2) proteins play a vital role in the nucleotide excision repair pathway through ATP-dependent helicase activity. Several studies found that polymorphisms in the ERCC2 gene are associated with susceptibility to different cancers, although the outcomes were confusing. ObjectiveAs a result, in this retrospective study, we investigated the relationship between genetic polymorphisms of the ERCC2 gene at codons 312 (rs1799793) and 751 (rs13181) and bladder cancer susceptibility in Bangladesh, as well as the disease's aggressiveness. MethodsGenetic polymorphisms of ERCC2 were assayed by the polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) method with 121 bladder cancer patients and 130 healthy controls. ResultsPatients who had the Gln/Gln polymorphism of ERCC2 at codon 751 (OR=3.27; 95% CI=1.19-8.67; p<0.05) and Asp/Asn at codon 312 (OR=2.14; 95% CI=1.03-4.29; p<0.05) were significantly associated with a higher risk of developing bladder cancer. Again, Gln/Gln polymorphisms in bladder cancer (p<0.05) were more likely to be present in individuals with cancer in the family. ConclusionsThis study reveals that susceptibility and bladder cancer aggressiveness are associated with polymorphisms at codon 751 and Asp/Asn at codon 312 of the ERCC2 gene.

FTX promotes esophageal cancer progression and desensitizes esophageal cancer cells to ionizing radiation by microRNA-99a/b-3p/WEE1/ERCC1 axis

Abstract Objectives This study was conducted to uncover the underlying cellular and molecular mechanisms of FTX dysregulation in EC. Methods The gene expression in tumor tissues was detected using western blot, immunohistochemistry, and quantitative real-time polymerase chain reaction (qPCR). The dual-luciferase reporter and RNA FISH assays confirmed the interaction between miRNA and target genes. Mouse models for Xenograft and lung metastasis were used to assess EC cell tumorigenesis and metastasis. Results This study finds that up-regulated FTX in patients with esophageal cancer correlates with poor clinical outcomes. Silencing FTX inhibits esophageal cancer cell growth and migration in vitro and tumor metastasis in vivo. miR-99a/b-3p sensitizes esophageal cancer cells to ionizing radiation by WEE1 (Wee1-like protein kinase) and ERCC1 (excision repair cross-complementation group 1) in vitro. Conclusions FTX promotes the malignant biological phenotype of esophageal cancer cells. Mechanistically, FTX acts as a ceRNA to regulate the transcription of WEE1 and ERCC1 by sponging hsa-miR-99a/b-3p.

Perspectives in the investigation of Cockayne syndrome group B neurological disease: the utility of patient-derived brain organoid models.

Cockayne syndrome (CS) group B (CSB), which results from mutations in the excision repair cross-complementation group 6 (ERCC6) genes, which produce CSB protein, is an autosomal recessive disease characterized by multiple progressive disorders including growth failure, microcephaly, skin photosensitivity, and premature aging. Clinical data show that brain atrophy, demyelination, and calcification are the main neurological manifestations of CS, which progress with time. Neuronal loss and calcification occur in various brain areas, particularly the cerebellum and basal ganglia, resulting in dyskinesia, ataxia, and limb tremors in CSB patients. However, the understanding of neurodevelopmental defects in CS has been constrained by the lack of significant neurodevelopmental and functional abnormalities observed in CSB-deficient mice. In this review, we focus on elucidating the protein structure and distribution of CSB and delve into the impact of CSB mutations on the development and function of the nervous system. In addition, we provide an overview of research models that have been instrumental in exploring CS disorders, with a forward-looking perspective on the substantial contributions that brain organoids are poised to further advance this field.

Association of ERCC1 Gene Polymorphisms (rs3212986 and rs11615) With the Risk of Lung Cancer in a Population From Southeast Iran.

Polymorphisms within the excision repair cross-complementation group 1 (ERCC1), an essential component of DNA repair mechanisms, have been associated with various malignancies. This study aimed to evaluate the association of the single-nucleotide polymorphisms (SNPs) rs3212986 and rs11615 within the ERCC1 gene in non-small cell lung cancer (NSCLC) patients. Study Design: A case-control study. Genomic DNA was extracted from the peripheral blood samples of 83 NSCLC patients and 119 healthy individuals. The genetic diversity of SNPs rs3212986 and rs11615 was determined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The RFLP results were confirmed through sequencing. The TT genotype of the rs11615 SNP was associated with a higher risk of NSCLC development (odds ratio: 3.900, 95% confidence interval: 0.603, 22.866, P=0.050). Furthermore, the AA genotype of rs3212986 was related to a higher risk of NSCLC development (OR: 2.531, 95% CI: 1.017, 6.300, P=0.046). A significant association was observed between smoking and lung cancer (OR: 3.072, 95% CI: 1.715, 5.503, P<0.001). Moreover, among non-smokers, there was an association between lung cancer risk and the AA (OR: 6.825, 95% CI: 1.722, 27.044, P=0.006) and AC (OR: 2.503, 95% CI: 0.977, 6.412, P=0.056) genotypes of rs3212986. However, no correlation was found between the genotypes of these SNPs and patients' sensitivity to cisplatin and carboplatin (P ˃ 0.05). The rs11615-related TT genotype and the rs3212986-related AA genotype may be associated with a higher risk of lung cancer development.

ERCC2 mutations alter the genomic distribution pattern of somatic mutations and are independently prognostic in bladder cancer

Excision repair cross-complementation group 2 (ERCC2) encodes the DNA helicase xeroderma pigmentosum group D, which functions in transcription and nucleotide excision repair. Point mutations in ERCC2 are putative drivers in around 10% of bladder cancers (BLCAs) and a potential positive biomarker for cisplatin therapy response. Nevertheless, the prognostic significance directly attributed to ERCC2 mutations and its pathogenic role in genome instability remain poorly understood. We first demonstrated that mutant ERCC2 is an independent predictor of prognosis in BLCA. We then examined its impact on the somatic mutational landscape using a cohort of ERCC2 wild-type (n= 343) and mutant (n= 39) BLCA whole genomes. The genome-wide distribution of somatic mutations is significantly altered in ERCC2 mutants, including T[C>T]N enrichment, altered replication time correlations, and CTCF-cohesin binding site mutation hotspots. We leverage these alterations to develop a machine learning model for predicting pathogenic ERCC2 mutations, which may be useful to inform treatment of patients with BLCA.

The diagnostic value of inflammation-related genes in bronchopulmonary dysplasia

This study aims to explore the diagnostic value of inflammation-related genes in peripheral blood mononuclear cells in bronchopulmonary dysplasia (BPD). By using bioinformatics analysis, three datasets including GSE32472, GSE125873, and GSE220135, which contain whole-genome expression profile data of 251 neonates, were included. The GSE32472 dataset was used as a training dataset to detect differentially expressed genes between non-BPD and BPD neonates in peripheral blood mononuclear cells. The gene enrichment analysis (GSEA) was used to detect the pathway enrichment of up-regulated genes in BPD newborns. The main regulatory factors analysis (MRA) algorithm was used to filter the main regulatory genes in the inflammation-related pathway (GO:0006954). After obtaining the main regulatory genes, the expression of the main regulatory genes in the GSE32472, GSE125873, and GSE220135 datasets was detected. Through the logistic regression model, risk scoring was conducted for neonates, and the risk scores of non-BPD and BPD neonates were compared. Lastly, the classification performance of the model was evaluated using the area under the curve (AUC). The results showed that compared with non-BPD neonates, there were 486 up-regulated genes and 433 down-regulated genes in the peripheral blood mononuclear cells of BPD neonates. The inflammation-related pathway was highly enriched in the up-regulated genes. Ultimately, phospholipase C beta 1 (PLCB1), nidogen 1 (NID1), serum response factor binding protein 1 (SRFBP1), centrosomal protein 72 (CEP72), excision repair cross complementation group 6 like (ERCC6L), and peptidylprolyl isomerase like 1 (PPIL1) were identified as the main regulatory genes. The prediction model's calculation formula for risk score was PLCB1×0.26+NID1×0.97+SRFBP1×1.58+CEP72×(-0.36)+ERCC6L×2.14+PPIL1×0.67. The AUCs in the GSE32472 test dataset, GSE125873 dataset, and GSE220135 dataset were 0.88, 0.86, and 0.89, respectively. This prediction model could distinguish between non-BPD and BPD neonates. In conclusion, the prediction model based on inflammation-related pathway genes has a certain diagnostic value for BPD.

The chromatin remodeler ERCC6 and the histone chaperone NAP1 are involved in apurinic/apyrimidinic endonuclease-mediated DNA repair.

During base excision repair (BER), the apurinic or apyrimidinic (AP) site serves as an intermediate product following base excision. In plants, APE-redox protein (ARP) represents the major AP site of cleavage activity. Despite the well-established understanding that the nucleosomal structure acts as a barrier to various DNA-templated processes, the regulatory mechanisms underlying BER at the chromatin level remain elusive, especially in plants. In this study, we identified plant chromatin remodeler Excision Repair Cross-Complementing protein group 6 (ERCC6) and histone chaperone Nucleosome Assembly Protein 1 (NAP1) as interacting proteins with ARP. The catalytic ATPase domain of ERCC6 facilitates its interaction with both ARP and NAP1. Additionally, ERCC6 and NAP1 synergistically contribute to nucleosome sliding and exposure of hindered endonuclease cleavage sites. Loss-of-function mutations in Arabidopsis (Arabidopsis thaliana) ERCC6 or NAP1 resulted in arp-dependent plant hypersensitivity to 5-fluorouracil, a toxic agent inducing BER, and the accumulation of AP sites. Furthermore, similar protein interactions are also found in yeast cells, suggesting a conserved recruitment mechanism employed by the AP endonuclease to overcome chromatin barriers during BER progression.

Tumor microenvironment-activated hollow vanadium-based nanoplatform for precise therapy of lung cancer through synergistically reversing cisplatin resistance

The resistance and side effect of cisplatin (CDDP) were still great challenges for highly efficient therapy of lung cancer in clinic. The studies indicated that the CDDP resistance mainly involved GSH-mediated inactivation and the damaged DNA repair. Herein, a novel vanadium-based nanoplatform was designed via platelet-derived growth factor receptor-β (PDGFR-β)-recognizing cyclic peptide (PDGFB)-labeled liposomes coating onto the hollow vanadium-doped mesoporous silica nanoparticle (HVMSN) loaded Pt (IV) prodrugs (pLi-HVMSN-Pt). This nanoplatform actively targeted tumor tissue, and then effectively responded to weakly acidic and high GSH of tumor microenvironment, making Pt (IV) prodrugs and vanadium ions be precisely delivered and intelligently released. Moreover, the vanadium ions significantly downregulated the expression of glutamyl cysteine ligase (GCL) and excision repair cross-complementing 1 (ERCC1), which inhibited the synthesis of GSH in cells and the damaged DNA repair. These synergistic actions dramatically increased the sensitivity of tumor cells to Pt-based drug, and then reversed CDDP resistance. Furthermore, in vivo experiment results demonstrated highly efficient suppression of tumor growth induced by the pLi-HVMSN-Pt. Therefore, this work provided a novel strategy for reversing CDDP-resistance and the precise therapy of lung cancer.

Noise Stress Abrogates Structure-Specific Endonucleases within the Mammalian Inner Ear.

Nucleotide excision repair (NER) is a multistep biochemical process that maintains the integrity of the genome. Unlike other mechanisms that maintain genomic integrity, NER is distinguished by two irreversible nucleolytic events that are executed by the xeroderma pigmentosum group G (XPG) and xeroderma pigmentosum group F (XPF) structure-specific endonucleases. Beyond nucleolysis, XPG and XPF regulate the overall efficiency of NER through various protein-protein interactions. The current experiments evaluated whether an environmental stressor could negatively affect the expression of Xpg (Ercc5: excision repair cross-complementing 5) or Xpf (Ercc4: excision repair cross-complementing 4) in the mammalian cochlea. Ubiquitous background noise was used as an environmental stressor. Gene expression levels for Xpg and Xpf were quantified from the cochlear neurosensory epithelium after noise exposure. Further, nonlinear cochlear signal processing was investigated as a functional consequence of changes in endonuclease expression levels. Exposure to stressful background noise abrogated the expression of both Xpg and Xpf, and these effects were associated with pathological nonlinear signal processing from receptor cells within the mammalian inner ear. Given that exposure to environmental sounds (noise, music, etc.) is ubiquitous in daily life, sound-induced limitations to structure-specific endonucleases might represent an overlooked genomic threat.

Abstract A030: DNA repair gene polymorphism(s): Association with relapse of oral squamous cell carcinoma

Abstract Differences in DNA repair capacity have been linked to the risk and prognosis of cancer. In specific types of cancer, certain variations known as Single Nucleotide Polymorphisms (SNPs) within DNA repair genes can influence the effectiveness of treatments. This phenomenon has been observed in patients with Oral Squamous Cell Carcinoma (OSCC), especially in those undergoing chemotherapy and radiation therapy. One such gene, Excision Repair Cross-Complementation 5 (ERCC5), contains a SNP (rs17655) G&amp;gt;C, leading to a missense variation and a change in amino acid from D to H. This variation has been noted in various cancer types. Hence, this study aimed to investigate the presence of this DNA repair gene polymorphism (rs17655) and its association with OSCC. To achieve this goal, blood samples were collected from OSCC patients exposed to chemotherapy and radiation therapy, as well as from OSCC patients not exposed to these treatments, following approval from the relevant institutional review committees. Informed consent was obtained from 100 patients, and an equal number of age and gender-matched controls. Genomic DNA was extracted using the salting-out method and analyzed for quality and quantity through agarose gel electrophoresis and nanodrop spectrophotometry. Primers were designed using online primer designing software. Genetic variations were identified using Tetra Primers-Amplifies Refractory Mutation System Polymerase Chain Reaction (t-ARMS PCR), and the amplified products were visualized via agarose gel electrophoresis. The genotypic frequency analysis of rs17655 revealed a higher prevalence of the homozygous mutant type (CC) in the blood samples of OSCC patients, both exposed and non-exposed to chemotherapy and radiation therapy. In contrast, the homozygous wild type (GG) was more prevalent among the control group. Statistical analysis, including a chi-square test (χ 2 = 36.76, p &amp;lt; 0.001) and odds ratio (10.27), demonstrated a significant association between the rs17655 polymorphism and oral squamous cell carcinoma, indicating an increased risk of OSCC due to this genetic variation. These genomic variants have the potential to serve as biomarkers for predicting clinical outcomes in OSCC patients undergoing chemotherapy and radiotherapy. Citation Format: Umaiya Abdali, Saima Saleem. DNA repair gene polymorphism(s): Association with relapse of oral squamous cell carcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: DNA Damage Repair: From Basic Science to Future Clinical Application; 2024 Jan 9-11; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2024;84(1 Suppl):Abstract nr A030.

XPA tumor variant leads to defects in NER that sensitize cells to cisplatin.

Nucleotide excision repair (NER) reduces efficacy of treatment with platinum (Pt)-based chemotherapy by removing Pt lesions from DNA. Previous study has identified that missense mutation or loss of the NER genes Excision Repair Cross Complementation Group 1 and 2 (ERCC1 and ERCC2) leads to improved patient outcomes after treatment with Pt-based chemotherapies. Although most NER gene alterations found in patient tumors are missense mutations, the impact of mutations in the remaining nearly 20 NER genes is unknown. Towards this goal, we previously developed a machine learning strategy to predict genetic variants in an essential NER protein, Xeroderma Pigmentosum Complementation Group A (XPA), that disrupt repair. In this study, we report in-depth analyses of a subset of the predicted variants, including in vitro analyses of purified recombinant protein and cell-based assays to test Pt agent sensitivity in cells and determine mechanisms of NER dysfunction. The most NER deficient variant Y148D had reduced protein stability, weaker DNA binding, disrupted recruitment to damage, and degradation. Our findings demonstrate that tumor mutations in XPA impact cell survival after cisplatin treatment and provide valuable mechanistic insights to improve variant effect prediction. Broadly, these findings suggest XPA tumor variants should be considered when predicting chemotherapy response.

Prognostic Significance of Excision Repair Cross-Complementation Group 1 on Circulating Tumor Cells for Nasopharyngeal Carcinoma.

Liquid biopsy, including the detection of circulating tumor cells (CTCs), has emerged as a promising tool for cancer diagnosis and monitoring. However, the prognostic value of CTCs in nasopharyngeal carcinoma (NPC) remains unclear due to the lack of phenotypic characterization. The expression of Excision Repair Cross-Complementation Group 1 (ERCC1) and CTCs epithelial-mesenchymal transition (EMT) have been associated with treatment efficacy. In this study, we aimed to evaluate the prognostic significance of ERCC1 expression on CTCs and their EMT subtypes before treatment in NPC. We retrospectively analyzed 108 newly diagnosed locally advanced NPC patients who underwent CanPatrol™ CTC testing between November 2018 and November 2021. CTCs were counted and classified into epithelial, epithelial-mesenchymal hybrid, and mesenchymal subtypes. ERCC1 expression was divided into negative and positive groups. Clinical features and survival outcomes were analyzed. The positive rate of CTCs was 92.6% (100/108), with an ERCC1 positivity rate of 74% (74/100). Further analysis of the subtypes showed that positive ERCC1 on mesenchymal CTCs was associated with a later N stage (P = .01). Positive ERCC1 expression was associated with poor overall survival (OS; P = .039) and disease-free survival (DFS; P = .035). Further analysis of subtypes showed that the positive ERCC1 on mesenchymal-type CTCs was associated with poor OS (P = .012) and metastasis-free survival (MFS; P = .001). Our findings suggest that ERCC1 expression on CTCs may serve as a new prognostic marker for NPC patients. Evaluating CTCs subtypes may become an auxiliary tool for personalized and precise treatment.

Role of rs873601 Polymorphisms in Prognosis of Lung Cancer Patients Treated with Platinum-Based Chemotherapy.

Lung cancer is still the most lethal malignancy in the world, according to the report of Cancer Statistics in 2021. Platinum-based chemotherapy combined with immunotherapy is the first-line treatment in lung cancer patients. However, the 5-year survival rate is always affected by the adverse reactions and drug resistance caused by platinum-based chemotherapy. DNA damage and repair system is one of the important mechanisms that can affect the response to chemotherapy and clinical outcomes in lung cancer patients. The objective of this study is to find the relationship between the polymorphisms of DNA repair genes with the prognosis of platinum-based chemotherapy in lung cancer patients. We performed genotyping in 17 single nucleotide polymorphisms (SNPs) of Excision Repair Cross-Complementation group (ERCC) genes and X-ray Repair Cross-Complementing (XRCC) genes of 345 lung cancer patients via Sequenom MassARRAY. We used Cox proportional hazard models, state, and plink to analyze the associations between SNPs and the prognosis of lung cancer patients. We found that the ERCC5 rs873601 was associated with the overall survival time in lung cancer patients treated with platinum-based chemotherapy (p = 0.031). There were some polymorphisms that were related to the prognosis in specific subgroups of lung cancer. Rs873601 showed a great influence on the prognosis of patients more than 55 years, Small Cell Lung Cancer (SCLC), and smoking patients. Rs2444933 was associated with prognosis in age less than 55 years, SCLC, metastasis, and stage III/IV/ED patients. Rs3740051 played an important role in the prognosis of SCLC and metastasis patients. Rs1869641 was involved in the prognosis of SCLC patients. Rs1051685 was related to the prognosis in non-metastasis patients. The ERCC5 rs873601 (G>A) was a valuable biomarker for predicting the prognosis in lung cancer patients treated with platinum-based chemotherapy.

BRCA1 expression and its combined low expression with PARP1 and ERCC1 predict chemotherapeutic response in ovarian cancer

Objective: This study aimed to evaluate the associations of immunohistochemical expressions of various deoxyribonucleic acid repair proteins, either individually or combined, with the response to platinum-based chemotherapy and overall survival in epithelial ovarian cancer.Material and Methods: This retrospective cohort study included patients with epithelial ovarian cancer who were treated by primary cytoreductive surgery with adjuvant platinum-based chemotherapy at Songklanagarind Hospital between January 2008 and December 2019. Immunohistochemistry analysis of breast cancer type 1 (BRCA1), poly (ADP-ribose) polymerase 1 (PARP1), X-ray repair cross-complementing 1 (XRCC1), and excision repair cross-complementation group 1 (ERCC1) expression was performed. Logistic regression was used to evaluate factors associated with chemotherapeutic response and Cox regression was applied for survival analysis.Results: Chemotherapeutic response was achieved in 205 of 249 patients (82.3%). Low BRCA1 expression was associated with good response (odds ratio [OR] 5.01, 95% confidence interval [CI] 1.78–14.1) and favorable overall survival (hazard ratio 0.61, 95% CI 0.38–0.98). PARP1, XRCC1, and ERCC1 showed no significant predictive or prognostic roles; however, combined low expression of PARP1/BRCA1 (OR 7.62, 95% CI 1.69–34.31) and ERCC1/BRCA1 (OR 6.98, 95% CI 1.5–32.52) additively enhanced response compared to high/high expressions.Conclusion: This study provides evidence that epithelial ovarian cancer (EOC) with low BRCA1 expression is more likely to be responsive to platinum-based therapy and is associated with favorable overall survival compared to tumors with high BRCA1 expression. The study supports a potential therapeutic strategy involving co-depletion of PARP1/BRCA and ERCC1/BRCA1 expression, although additional studies are needed.

Polymorphisms in ERCC1, ERCC4 and ERCC5 genes as biomarkers of susceptibility for pesticide-induced DNA damage in North-West Indian agricultural workers

BackgroundOccupational pesticides exposure has raised health concerns due to genotoxicity and accumulation of DNA damage. Polymorphisms in genes encoding enzymes involved in nucleotide excision repair (NER) may affect the individual’s susceptibility to pesticide toxicity.MethodsThis study evaluates the association of excision repair cross complementation group 1 (ERCC1) (8092 C > A, 3’UTR, rs3212986) and ERCC1 (19007 C > T, Asn118Asn, rs11615), ERCC4 (1244 G > A, Arg415Gln, rs1800067) and ERCC5 (3507 G > C, Asp1104His, rs17655) polymorphisms with pesticide-induced DNA damage in North-West Indian agricultural workers. The study population comprised 225 agricultural workers exposed to pesticides and 225 non-exposed controls.ResultsOur study demonstrate that exposed workers carrying variant ERCC1 8092AA genotype showed higher total comet DNA migration (p = 0.015) as well as increased frequency of cells showing DNA migration (p = 0.027). Exposed agricultural workers with variant ERCC4 1244AA (415Gln/Gln) and ERCC5 3507CC (1104His/His) genotypes exhibited elevation in total comet DNA migration (p < 0.01). However, genotypes of ERCC1 19007 C > T (Asn118Asn) showed no association with total comet DNA migration (p = 0.963), frequency of cells showing DNA migration (p = 0.423) as well as mean tail length (p = 0.432).ConclusionERCC1, ERCC4 and ERCC5 polymorphisms influence DNA damage and can be used as biomarkers of susceptibility for pesticide-induced DNA damage in North-West Indian agricultural workers.

Mechanism of Astragali Radix-Curcumae Rhizoma in treating gastric cancer based on network pharmacology and experimental verification

This study aims to investigate the mechanism of Astragali Radix-Curcumae Rhizoma(HQEZ) in the treatment of gastric cancer based on network pharmacology. Further, the SGC7901 cell model of gastric cancer was employed to validate the efficacy and key targets of the herb pair. Firstly, the CCK-8 assay was employed to evaluate the direct effect of HQEZ on the proliferation of gastric cancer SGC7901 cells. Then, network pharmacology methods were employed to investigate the active ingredients, key targets, and key signaling pathways involved in the treatment of gastric cancer with HQEZ. The results showed that HQEZ contained 18 potential active ingredients, such as quercetin, naringenin, and curcumin. The results of gene ontology(GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment suggested that the main targets of HQEZ in treating gastric cancer were involved in the regulation of protein serine/threonine kinase activity, activation of mitogen-activated protein kinase(MAPK) activity, cysteine-type endopeptidase activity, and negative regulation of protein serine/threonine kinase activity. The hypoxia-inducible factor-1(HIF-1) signaling pathway, ATP-binding cassette(ABC) transporters, cytochrome P450-mediated metabolism of xenobiotics, p53 signaling pathway, and cell apoptosis were key signaling pathways of HQEZ in treating gastric cancer. The cell experiments demonstrated that HQEZ significantly downregulated the expression of ATP-binding cassette subfamily B member 1(ABCB1), epidermal growth factor receptor(EGFR), phosphorylated serine/threonine kinase(p-AKT), hypoxia inducible factor 1 subunit alpha(HIF1A), B-cell lymphoma 2(BCL2), breast cancer susceptibility protein 1(BRCA1), DNA polymerase theta(POLH), ribonucleotide reductase M1(RRM1), and excision repair cross-complementation group 1(ERCC1), and upregulated the expression of tumor protein P53(TP53) and cysteinyl aspartate-specific proteinase(CAPS3). Finally, a multivariate COX regression model was adopted to study the relationship between gene expression and clinical information data of gastric cancer patients in the TCGA database, which demonstrated that the key targets of HQEZ were associated with the poor prognosis in gastric cancer patients. Further feature selection using the LASSO algorithm showed that EGFR, HIF1A, TP53, POLH, RRM1, and ERCC1 were closely associated with the survival of gastric can-cer patients. In conclusion, HQEZ regulates the expression of genes involved in DNA repair, survival, and apoptosis in gastric cancer cells via multiple targets and pathways, assisting the treatment of gastric cancer.

Characterizing excision repair cross-complementing family genes as drug resistance biomarkers in breast cancer

BackgroundExcision repair cross-complementing (ERCC) genes are important regulators of DNA repair processes, the aberrant expression of which may lead to treatment failures of breast cancer. The prognostic significance of the ERCC genes in several cancers has been investigated, except for breast cancer; therefore, we explored the ERCC genes, including ERCC1, ERCC2, ERCC3, ERCC4, ERCC5, ERCC6, and ERCC8 in breast cancer, particularly during drug resistance processes.ResultsUsing the 2021 provisional study of The Metastatic Breast Cancer Project from cBioPortal, we identified ERCC genetic alterations in 8–36% of patients, where most alterations were considered amplifications followed by deep deletions. Pathway enrichment analyses identified Wnt signaling enrichment which contributed to cell proliferation. ERCC2 had the highest epigenetic alteration levels at 7 DNA methylation sites. Also, the mRNA levels of ERCC1, ERCC2, ERCC4, ERCC6, and ERCC8 were higher in patients with breast cancer when compared to normal breast tissues, with higher ERCC2 but lower ERCC8 levels in metastatic breast tissues. Breast cancer patients with low ERCC6 levels had better overall survival rates than the groups with higher ERCC6 levels. ERCC1, ERCC2, and ERCC4 were identified as endocrine therapy response predictors. ERCC1 was specifically an antihuman epidermal growth factor receptor therapy predictor, and ERCC1, ERCC2, ERCC6, and ERCC8 were chemotherapy response predictors.ConclusionWe used bioinformatics to investigate and identify the roles of ERCC genes in breast cancer resistant cells, in particular ERCC1, ERCC2, and ERCC6. We also showed how the Wnt pathway and DNA repair processes had a role in drug resistance in breast cancer cells, but further studies are required to validate those results.

Association of ERCC family mutations with prognosis and immune checkpoint inhibitors response in multiple cancers

The proteins encoded by the excision repair cross-complementing (ERCC) family are pivotal in DNA damage repair and maintaining genome stability. However, the precise role of the ERCC family in tumor prognosis and the effectiveness of immune checkpoint inhibitors (ICI) therapy remain uncertain. This study aimed to explore the connection between ERCC mutations and prognosis as well as the response to ICI. We observed that patients with ERCC mutations exhibited enhanced progression-free survival (PFS) and overall survival (OS) in two independent pan-cancer cohorts. Furthermore, this mutant subgroup showed higher tumor mutation burden (TMB) compared to the wild-type subgroup. Notably, ERCC mutations were associated with better OS (HR 0.54, 95% CI 0.42–0.70; P < 0.001) in pan-cancer patients who underwent ICI therapy (N = 1661). These findings were validated in a separate cohort, where patients in the ERCC mutant subgroup demonstrated improved clinical outcomes (HR 0.56, 95% CI 0.37–0.84; P = 0.03) and higher response rates (51.9% vs. 26.8%) than the wild-type subgroup. Further analysis revealed that patients with ERCC mutations displayed elevated tumor neoantigen burden (TNB) levels and increased infiltration of immune-response cells. Our study suggests that ERCC mutations are linked to enhanced immunogenicity and improved ICI efficacy, thus potentially serving as a biomarker for ICI therapy.

The Relationship between Single Nucleotide Polymorphism of ERCC1 Gene and the Response to Platinum Based Chemotherapy in Egyptian Non-Small Cell Lung Cancer Patients

Abstract Background Lung cancer (LC) is the second most common cancer diagnosed in both males and females. There are two subtypes of LC. Non-small cell lung cancer (NSCLC) is the major one. Treatment options for NSCLC depends mainly on the stage at diagnosis. The majority of the patients are diagnosed at advanced stages at time of presentation. Therefore, chemotherapy and radiotherapy play the dominant role in treatment of advanced NSCLC. The most commonly used chemotherapy is platinum-based chemotherapy as cisplatin and carboplatin and third generation drugs as vinorelbine and gemcitabine. The efficacy of platinum-based chemotherapy is limited by chemoresistance. The excision repair cross complementation group 1(ERCC1) gene is a member of nucleotide excision repair pathway that plays a critical role in the DNA repair by removing DNA covalent helix-distorting adducts. Aim of the Work In this study investigated the relationship between single nucleotide polymorphism of ERCC1 rs11615 and the response to platinum-based chemotherapy in Egyptian NSCLC patients in order to prevent the non-necessary exposure to the toxic effect of chemotherapy. Patients and Methods This is a cross-sectional study conducted on 50 NSCLC patients who were recruited from the Oncology Clinic in Ain Shams University Hospitals; twenty of them were responders to platinumbased chemotherapy and the other 30 were non-responders according to RECIST criteria. All subjects underwent full medical history focusing on tobacco smoking and family history of cancers, thorough clinical examination, histological diagnosis of NSCLC and TNM classification, radiological studies: computed tomography of chest and abdomen and laboratory investigations in the form of: complete blood picture (CBC), liver function tests and kidney function tests. Detection of the ERCC1 (T/C) polymorphism by realtime PCR was done for both the responders' and the non-responders' groups. Results There was no significant statistical difference observed between the responders’ and nonresponders’ groups regarding the genotype frequencies nor the allelic frequency (p &amp;gt; 0.05). Conclusion The present study did not confirm the presence of significant association between the genotypic frequencies nor the allelic frequencies of the ERCC1 rs 11615 among the responders' and the non-responders' groups. Further studies with higher sample size are needed to clarify the association.

Codelivery of ERCC2 small interfering RNA and cisplatin with macrophage-derived mimetic nanovesicles for enhanced bladder cancer treatment.

Cisplatin-based chemotherapy plays a vital role in the management of muscle-invasive bladder cancer (MIBC); however, off-tumor toxicity and resistance often lead to cancer recurrence and eventual treatment failure. The loss of function of the nucleotide excision repair gene excision repair cross-complementing rodent repair deficiency gene 2 ( ERCC2 ) in cancer cells correlates with sensitivity to cisplatin, while its overexpression causes cisplatin resistance. Small interfering RNA (siRNA) knockdown of ERCC2 combined with cisplatin treatment may improve therapeutic outcomes in patients with bladder cancer. Here, we aimed to develop macrophage-derived mimetic nanovesicles (MNVs) as a nanoplatform for the simultaneous delivery of cisplatin and ERCC2 siRNA for enhancing the efficacy of bladder cancer chemotherapy. The cellular uptake, gene down-regulation, tumor inhibition effects, and biosafety of the synthesized nanodrugs (MNV-Co) as a synergistic therapeutic strategy for MIBC were evaluated in vitro and in vivo . The results indicated high efficacy of MNV-Co against MIBC and low off-tumor toxicity. Furthermore, by down-regulating ERCC2 mRNA and protein levels, MNV-Co improved chemosensitivity, promoted cancer cell apoptosis, and effectively suppressed tumor growth. This study presents a potential approach for delivering cisplatin and ERCC2 siRNA concurrently to treat bladder cancer using a biomimetic nanosystem.