Polymorphisms in XPC gene and risk for prostate cancer

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.

Structural modeling and analyses of genetic variations in the human XPC nucleotide excision repair protein

Xeroderma pigmentosum C (XPC) is a key initiator in the global genome nucleotide excision repair pathway in mammalian cells. Inherited mutations in the XPC gene can cause xeroderma pigmentosum (XP) cancer predisposition syndrome that dramatically increases the susceptibility to sunlight-induced cancers. Various genetic variants and mutations of the protein have been reported in cancer databases and literature. The current lack of a high-resolution 3-D structure of human XPC makes it difficult to assess the structural impact of the mutations/genetic variations. Using the available high-resolution crystal structure of its yeast ortholog, Rad4, we built a homology model of human XPC protein and compared it with a model generated by AlphaFold. The two models are largely consistent with each other in the structured domains. We have also assessed the degree of conservation for each residue using 966 sequences of XPC orthologs. Our structure- and sequence conservation-based assessments largely agree with the variant's impact on the protein's structural stability, computed by FoldX and SDM. Known XP missense mutations such as Y585C, W690S, and C771Y are consistently predicted to destabilize the protein's structure. Our analyses also reveal several highly conserved hydrophobic regions that are surface-exposed, which may indicate novel intermolecular interfaces that are yet to be characterized.Communicated by Ramaswamy H. Sarma.

Xeroderma Pigmentosum Complementation Group C (XPC): Emerging Roles in Non-Dermatologic Malignancies

Xeroderma pigmentosum complementation group C (XPC) is a DNA damage recognition protein essential for initiation of global-genomic nucleotide excision repair (GG-NER). Humans carrying germline mutations in the XPC gene exhibit strong susceptibility to skin cancer due to defective removal via GG-NER of genotoxic, solar UV-induced dipyrimidine photoproducts. However, XPC is increasingly recognized as important for protection against non-dermatologic cancers, not only through its role in GG-NER, but also by participating in other DNA repair pathways, in the DNA damage response and in transcriptional regulation. Additionally, XPC expression levels and polymorphisms likely impact development and may serve as predictive and therapeutic biomarkers in a number of these non-dermatologic cancers. Here we review the existing literature, focusing on the role of XPC in non-dermatologic cancer development, progression, and treatment response, and highlight possible future applications of XPC as a prognostic and therapeutic biomarker.

Association of genetic variants with prostate cancer in Africa: a concise review

Background

Prostate cancer (PCa) has one of the highest heritability of all major cancers, where the genetic contribution has been documented, and knowledge about the molecular genetics of the disease is increasing. However, the extent and aspects to which genetic variants explain PCa heritability in Africa are limited.

Main body

In this review, we summarize studies that highlight how identified genetic variants explain differences in PCa incidence and presentation across ethnic groups. We also present the knowledge gaps in PCa genetics in Africa and why Africa represents an untapped potential ground for genetic studies on PCa. A significant number of genome-wide association studies, linkage, and fine-mapping analyses have been conducted globally, and that explains 30–33% of PCa heritability. The African ancestry has a significant mention in PCa incidence and presentation. To date, the candidate gene approach has replicated 23 polymorphisms including dinucleotide and trinucleotide repeats in 16 genes. CYP17-rs743572, CYP3A4-rs2740574, CYP3A5-rs776746, CYP3A43-rs501275, and haplotype blocks, containing these variants, are significantly associated with PCa among some population groups but not others. With the few existing studies, the extent of genetic diversity in Africa suggests that genetic associations of PCa to African ancestry go beyond nucleotide sequence polymorphisms, to a level of environmental adaptation, which may interpret genetic risk profiles. Also, the shreds of evidence suggest that evolutionary history contributes to the high rates of PCa relative to African ancestry, and genetic associations do not always replicate across populations.

Conclusion

The genetic architecture of PCa in Africa provides important contributions to the global understanding of PCa specifically the African-ancestry hypothesis. There is a need for more prostate cancer consortiums to justify the heritable certainties of PCa among Africans, and emphasis should be placed on the genetic epidemiological model of PCa in Africa.

XPC exon15 Lys939Gln variant increase susceptibility to prostate adenocarcinoma: Evidence based on 4306 patients and 4779 controls

BACKGROUND

Previous studies have investigated the correlation between xeroderma pigmentosumcomplementation group C (XPC) variants and prostate adenocarcinoma (PA) risk. Nevertheless, research findings remain inconclusive.

METHODS

We conducted a pooled analysis to obtain a more accurate estimation of the relationship on XPC exon15 Lys939Gln polymorphism with susceptibility to PA. Moreover, in silico tools were employed to investigate the effect of XPC expression on PA patients' survival time.

RESULTS

A total of 4306 patients and 4779 control subjects were assessed. The overall results indicated that XPC Lys939Gln variant was associated with PA risk (recessive genetic model: odds ratio = 1.15, 95% confidence interval = 1.02-1.30, Pheterogeneity= .044, P = .021, I= 45.2), especially in Asian descendants. Population-based studies revealed similar results (odds ratio = 1.15, 95% confidence interval = 1.01-1.32, Pheterogeneity= .146, P = .040, I = 39.0). In silico tools showed that XPC expression in Caucasian patients was lower than in the normal group. No positive association was observed in African patients. PA subjects with high XPC expression had a longer overall survival time than low expression group.

CONCLUSION

Our findings indicated that XPC Lys939Gln variant might contribute to increased PA susceptibility, especially for Asian patients.

Effects of Xeroderma pigmentosum group C polymorphism on the likelihood of prostate cancer

Background

Numerous studies have assessed the association between xeroderma pigmentosum complementation group C (XPC) polymorphisms and susceptibility of prostate cancer (PCa); however, the findings remain inconsistent.

Methods

We performed an updated analysis utilizing data from electronic databases to obtain a more accurate estimation of the relationship between XPC rs2228001 A/C polymorphism and PCa risk. We further used in silico tools to investigate this correlation.

Results

Totally, 5,305 PCa cases and 6,499 control subjects were evaluated. When all studies pooled together, we detected no positive result (recessive genetic model: OR = 1.14, 95% CI = 0.93‐1.40, P_{heterogeneity} = 0.001, P = .212); nevertheless, the XPC rs2228001 A/C variant was associated with PCa risk in Asian descendants in the subgroup analysis (OR = 1.21, 95% CI = 1.01‐1.43, P_{heterogeneity} = 0.008, P = .034). In silico tools showed that more than 20 proteins can participate in the protein crosstalk with XPC. The expression of XPC was down‐regulated in all Gleason scores of prostate cancer.

Conclusions

The present study indicated that the XPC rs2228001 A/C variant may be associated with elevated PCa risk in Asian patients.