Significant Association Between XRCC1 Expression and Its rs25487 Polymorphism and Radiotherapy-Related Cancer Prognosis

Data Science Opportunities To Improve Radiotherapy Planning and Clinical Decision Making

Radiotherapy aims to achieve a high tumor control probability while minimizing damage to normal tissues. Personalizing radiotherapy treatments for individual patients, therefore, depends on integrating physical treatment planning with predictive models of tumor control and normal tissue complications. Predictive models could be improved using a wide range of rich data sources, including tumor and normal tissue genomics, radiomics, and dosiomics. Deep learning will drive improvements in classifying normal tissue tolerance, predicting intra-treatment tumor changes, tracking accumulated dose distributions, and quantifying the tumor response to radiotherapy based on imaging. Mechanistic patient-specific computer simulations ('digital twins') could also be used to guide adaptive radiotherapy. Overall, we are entering an era where improved modeling methods will allow the use of newly available data sources to better guide radiotherapy treatments.

Identification of novel genetic variants associated with oral squamous cell carcinoma (OSCC) in South-West coast of India using targeted exome sequencing

Oral squamous cell carcinoma (OSCC) is a subset of head and neck squamous cell carcinoma (HNSCC). This study explores the genetic landscape of oral squamous cell carcinoma (OSCC) in a cohort of 33 patients from Southern India using targeted exome sequencing. Our analysis revealed a diverse range of mutations across the cohort, with missense mutations being the most prevalent. Pathogenic mutations, as classified by ClinVar, exhibited significant individual variation, highlighting the heterogeneity of OSCC. Seventy-five genes were identified to harbor pathogenic or potentially pathogenic mutations, with notable recurrence in genes such as TP53, PDGFRA, and RAD50 among others. Comparison with high-frequency mutation genes in HNSCC from TCGA database revealed significant overlap, emphasizing the relevance of these mutations across different populations. Additionally, several novel mutations were identified, including those in CHD8, ITPKB, and HNF1A, shedding light on potential genetic risk factors specific to this population. Functional annotation and pathway analysis underscored the involvement of these mutated genes in various cancer-related pathways. Despite limitations such as sample size and the need for further validation, this study contributes to a deeper understanding of OSCC pathogenesis and highlights potential genetic markers for prognosis and targeted interventions, especially in the Indian context.

A clinician's perspective on boron neutron capture therapy: promising advances, ongoing trials, and future outlook

PURPOSE

This comprehensive review aims to provide a unique clinical perspective on the latest advances and ongoing boron neutron capture therapy (BNCT) trials for various cancers.

METHODS

We critically analyzed clinical data from BNCT trials for head and neck cancer, glioblastoma, melanoma, meningioma, breast cancer, and liver tumors. We investigated differences in tumor responses and normal tissue toxicities among trials and discussed potential contributing factors. We also identified the limitations of early BNCT trials and proposed strategies to optimize future trial design.

RESULTS

BNCT has shown promising results in treating head and neck cancer, with high response rates and improved survival in patients with recurrent disease. In glioblastoma, BNCT combined with surgery and chemotherapy has demonstrated survival benefits compared to standard treatments. BNCT has also been successfully used for recurrent high-grade meningiomas and shows potential for melanomas, extramammary Paget's disease, and liver tumors. However, differences in tumor responses and toxicities were observed among trials, potentially attributable to variations in treatment protocols, patient characteristics, and evaluation methods.

CONCLUSIONS

BNCT is a promising targeted radiotherapy for various cancers. Further optimization and well-designed randomized controlled trials are needed to establish its efficacy and safety. Future studies should focus on standardizing treatment protocols and addressing limitations to guide clinical decision-making and research priorities.

Genetic variations in DNA excision repair pathway contribute to the chemosensitivity and prognosis of acute myeloid leukemia

Acute myeloid leukemia (AML) is a hematologic malignancy with a high recurrence rate and poor long-term prognosis. DNA excision repair systems, such as base excision repair (BER) and nucleotide excision repair (NER), play a major role in maintaining genomic stability and integrity. Further intensive investigations are necessary to uncover additional AML prognosis loci. In this study, we analyzed 16 candidate SNPs within NER and BER pathways in AML patients. Our results showed the GT/GG genotype of the XPC rs2228001 polymorphism was significantly associated with WBC count in dominant models (OR = 0.41, 95 % CI = 0.18-0.96, p = 0.039). Additionally, the rs25487 and rs3213245 SNPs in the XRCC1 gene, in both co-dominant and dominant models, were significantly associated with PLT count in AML (p < 0.05). The GG genotype of rs1130409 in APEX1 was more prone to adverse cytogenetics in both the codominant and recessive models (p < 0.05). Furthermore, the GA genotypes of ERCC8 rs158572 in codominant model was significantly correlated with refractory group (p < 0.05). ERCC8 rs158572 and XRCC1 rs3213245 in both codominant and dominant models were significantly correlated with the MRD positivity (p < 0.05). Kaplan-Meier analysis revealed an link between overall survival (OS) and the co-dominant, dominant, and recessive models of rs2228001 in XPC. Additionally, patients with the GG and GT/GG genotype in the co-dominant, dominant model and recessive model in XPC rs2228001 exhibited significantly longer survival (p < 0.05). Multivariate Cox analyses indicated that rs2228001 in both co-dominant and dominant models were independent favorable factors impacting patient OS (OR < 1). Our findings suggest that genetic polymorphisms in DNA excision repair pathway genetic polymorphisms contribute to the chemosensitivity and prognosis of acute myeloid leukemia.

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.

The Incidence of the XRCC1 rs25487 and PON1 rs662 Polymorphisms in a Population from Central Brazil: Patterns in an Area with a High Level of Agricultural Activity

In Brazil, high levels of agricultural activity are reflected in the consumption of enormous amounts of pesticides. The production of grain in Brazil has been estimated at 289.8 million tons in the 2022 harvest, an expansion of 14.7% compared with 2021. These advances are likely associated with a progressive increase in the occupational exposure of a population to pesticides. The Paraoxonase 1 gene (PON1) is involved in liver detoxification; the rs662 variant of this gene modifies the activity of the enzyme. The repair of pesticide-induced genetic damage depends on the protein produced by the X-Ray Repair Cross-Complementing Group 1 gene (XRCC). Its function is impaired due to an rs25487 variant. The present study describes the frequencies of the rs662 and rs25487 and their haplotypes in a sample population from Goiás, Brazil. It compares the frequencies with other populations worldwide to verify the variation in the distribution of these SNPs, with 494 unrelated individuals in the state of Goiás. The A allele of the rs25487 variant had a frequency of 26% in the Goiás population, and the modified rs662 G allele had a frequency of 42.8%. Four haplotypes were recorded for the rs25487 (G > A) and rs662 (A > G) markers, with a frequency of 11.9% being recorded for the A-G haplotype (both modified alleles), 30.8% for the G-G haplotype, 14.3% for the A-A haplotype, and 42.8% for the G-A haplotype (both wild-type alleles). We demonstrated the distribution of important SNPs associated with pesticide exposure in an area with a high agricultural activity level, Central Brazil.

Association between XRCC1 Arg399Gln polymorphism with prognosis of head and neck squamous cell carcinomas: A meta-analysis

Objective

The X-ray repair cross complementing group 1 (XRCC1) gene is involved in DNA repair. Defects in DNA repair may lead to head and neck squamous cell carcinomas (HNSCCs). Several researches have focused on relationship between XRCC1 Arg399Gln genetic polymorphism with HNSCC's prognosis with conflicting results. So, the aim of the present meta-analysis was evaluation of relationship between XRCC1 Arg399Gln polymorphism with HNSCC's prognosis.

Methods

Published articles up to July 2022 were systematically searched through international databases like PubMed, Web of Science, Scopus, etc. I2 test was applied to assess the heterogeneity. Data were analyzed using random effects model. Funnel plots and Egger test were applied for assessing publication biases. The hazard ratios (HRs) and 95 % confidence intervals (CIs) were calculated for evaluation of relationship between the polymorphism with HNSCC's prognosis.

Results

Fifteen articles were included for the systematic review. Six of those articles were considered for inclusion in meta-analysis. The different forms of XRCC1 Arg399Gln polymorphism had not significant association with overall survival (OS) under varied genetic models (heterozygous: Ln (HR) = 0.02, 95 % CI= (-0.33,0.37), p-value = 0.90; homozygous: Ln (HR) = 0.33, 95 % CI= (-0.03,0.69), p-value = 0.07 and dominant: Ln (HR) = 0.06, 95 % CI = (-0.17,0.28), p-value = 0.62). Analysis showed that variants of the polymorphism had no significant relationship with OS in Asian and Caucasian ethnicity under dominant model (Ln (HR) = 0.14, 95 % CI= (-0.13,0.40), p-value = 0.31; Ln (HR) = -0.01, 95 % CI= (-0.41,0.38), p-value = 0.96).

Conclusion

Different forms of XRCC1 Arg399Gln polymorphism had no significant relationship with HNSCC's prognosis under varied genetic models and based on different ethnicity.

The effect of DNA repair gene variants on COVID-19 disease: susceptibility, severity, and clinical course

Oxidative stress (OS), which leads to DNA damage, plays a role in the pathogenesis of Coronavirus disease 2019 (COVID-19). We aimed to evaluate the role of DNA repair gene variants [X-ray repair cross complementing 4 (XRCC4) rs28360071, rs6869366, and X-ray cross-complementary gene 1 (XRCC1) rs25487] in susceptibility to COVID-19 in a Turkish population. We also evaluated its effect on the clinical course of the disease. A total of 300 subjects, including 200 COVID-19 patients and 100 healthy controls, were included in this study. These variants were genotyped using polymerase chain reaction (PCR) and/or PCR-restriction fragment length polymorphism (RFLP) methods. The patients were divided into three groups: those with a mild or severe infection; those who died or lived at the 28-day follow-up; those who required inpatient treatment or intensive care. There were 87 women (43.5%) and 113 men (56.5%) in the patient group. Hypertension was the most common comorbidity (26%). In the patient group, XRCC4 rs6869366 G/G genotype and G allele frequency were increased compared to controls, while XRCC4 rs6869366 G/T and T/T genotype frequencies were found to be higher in controls compared to patients. For XRCC1 rs25487, the A/A and A/G genotypes were significantly associated with COVID-19 disease. All of the patients hospitalized in the intensive care unit had the XRCC4 rs6869366 G/G genotype. In this study, we evaluated for the first time the impact of DNA repair gene variants on COVID-19 susceptibility. Results suggested that XRCC4 rs6869366 and XRCC1 rs25487 were associated with COVID-19 suspectibility and clinical course.

Biological Mechanisms to Reduce Radioresistance and Increase the Efficacy of Radiotherapy: State of the Art

Cancer treatment with ionizing radiation (IR) is a well-established and effective clinical method to fight different types of tumors and is a palliative treatment to cure metastatic stages. Approximately half of all cancer patients undergo radiotherapy (RT) according to clinical protocols that employ two types of ionizing radiation: sparsely IR (i.e., X-rays) and densely IR (i.e., protons). Most cancer cells irradiated with therapeutic doses exhibit radio-induced cytotoxicity in terms of cell proliferation arrest and cell death by apoptosis. Nevertheless, despite the more tailored advances in RT protocols in the last few years, several tumors show a relatively high percentage of RT failure and tumor relapse due to their radioresistance. To counteract this extremely complex phenomenon and improve clinical protocols, several factors associated with radioresistance, of both a molecular and cellular nature, must be considered. Tumor genetics/epigenetics, tumor microenvironment, tumor metabolism, and the presence of non-malignant cells (i.e., fibroblast-associated cancer cells, macrophage-associated cancer cells, tumor-infiltrating lymphocytes, endothelial cells, cancer stem cells) are the main factors important in determining the tumor response to IR. Here, we attempt to provide an overview of how such factors can be taken advantage of in clinical strategies targeting radioresistant tumors.

Clinical Impact of X-Ray Repair Cross-Complementary 1 (XRCC1) and the Immune Environment in Colorectal Adenoma-Carcinoma Pathway Progression

Purpose

Colorectal cancer (CRC) can develop via a hypermutagenic pathway characterized by frequent somatic DNA base-pair mutations. Alternatively, the immunogenicity of tumor cells themselves may influence the anticancer activity of the immune effector cells. Impaired DNA repair mechanisms drive mutagenicity, which then increase the neoantigen load and immunogenicity. However, no studies have analyzed immune checkpoint protein expression, particularly programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1), in adenoma–carcinoma progression and its relationship with the emergence of other DNA repair gene mutation.

Materials and Methods

We investigated mutations of 10 genes involved in DNA repair function: XRCC1, TP53, MLH1, MSH, KRAS, GSTP, UMP, MTHF, DPYD, and ABCC2. We performed sequencing to determine mutations and immunohistochemistry of immune checkpoints in clinical samples and determined changes in XRCC1 expression during progression through the adenoma–carcinoma pathway. We further investigated the prognostic associations of gene XRCC1 according to the expression, mutational profile, and immune profile using The Cancer Genome Atlas-colon adenocarcinoma (TCGA-COAD) dataset.

Results

From clinical samples, XRCC1 mutation demonstrated the strongest association with adenomas with a mutation frequency of 56.2% in adenomas and 34% in CRCs (p =0.016). XRCC1 was abnormally expressed and altered by mutations contributing to adenoma carcinogenesis. High expression of XRCC1, CD4, FOXP3, and PD-1/PD-L1 showed an overall upward trend with increased lesion severity (all p < 0.01). PD-1/PD-L1 expression and CD4+ intraepithelial lymphocytes (IELs) correlated with cytological dysplasia progression, specifically in patients with wild-type XRCC1 (all p < 0.01), whereas FOXP3 expression was independently associated with adenoma–carcinoma progression. From TCGA-COAD analysis, XRCC1 expression was associated with patients survival, tumor-infiltrating lymphocytes and immune marker expression.

Conclusion

Increased IEL density and PD-1/PD-L1 expression correlate with cytological dysplasia progression and specifically with the XRCC1 mutation status in CRC. Our findings support a stepwise dysplasia-carcinoma sequence of adenoma carcinogenesis and an XRCC1 hypermutated phenotypic mechanism of lesions.