TP53 Arg72Pro polymorphism and endometrial cancer risk: a meta-analysis

The significance of co-mutations in EGFR-mutated non-small cell lung cancer: Optimizing the efficacy of targeted therapies?

Non-small cell lung cancer (NSCLC) is the most common cause of cancer death worldwide. In non-squamous NSCLC, the identification of oncogenic drivers and the development of target-specific molecules led to remarkable progress in therapeutic strategies and overall survival over the last decade. Nevertheless, responses are limited by systematically acquired mechanisms of resistance early on after starting a targeted therapy. Moreover, mounting evidence has demonstrated that each oncogenic-driven cluster is actually heterogeneous in terms of molecular features, clinical behaviour, and sensitivity to targeted therapy. In this review, we aimed to examine the prognostic and predictive significance of oncogene-driven co-mutations, focusing mainly on EGFR and TP53. A narrative review was performed by searching MEDLINE databases for English articles published over the last decade (from January 2012 until November 2022). The bibliographies of key references were manually reviewed to select those eligible for the topic. The genetic landscape of EGFR-mutated NSCLC is more complicated than what is known so far. In particular, the occurrence of TP53 co-mutations stratify patients carrying EGFR mutations in terms of treatment response. The study provides a deeper understanding of the mechanisms underlying the variability of the genetic landscape of EGFR-mutated NSCLC and summarizes notably the clinical importance of TP53 co-mutations for an open avenue to more properly addressing the clinical decision-making in the near future.

Risk factors for endometrial cancer: An umbrella review of the literature

Although many risk factors could have causal association with endometrial cancer, they are also prone to residual confounding or other biases which could lead to over- or underestimation. This umbrella review evaluates the strength and validity of evidence pertaining risk factors for endometrial cancer. Systematic reviews or meta-analyses of observational studies evaluating the association between non-genetic risk factors and risk of developing or dying from endometrial cancer were identified from inception to April 2018 using PubMed, the Cochrane database and manual reference screening. Evidence was graded strong, highly suggestive, suggestive or weak based on statistical significance of random-effects summary estimate, largest study included, number of cases, between-study heterogeneity, 95% prediction intervals, small study effects, excess significance bias and sensitivity analysis with credibility ceilings. We identified 171 meta-analyses investigating associations between 53 risk factors and endometrial cancer incidence and mortality. Risk factors were categorised: anthropometric indices, dietary intake, physical activity, medical conditions, hormonal therapy use, biochemical markers, gynaecological history and smoking. Of 127 meta-analyses including cohort studies, three associations were graded with strong evidence. Body mass index and waist-to-hip ratio were associated with increased cancer risk in premenopausal women (RR per 5 kg/m2 1.49; CI 1.39-1.61) and for total endometrial cancer (RR per 0.1unit 1.21; CI 1.13-1.29), respectively. Parity reduced risk of disease (RR 0.66, CI 0.60-0.74). Of many proposed risk factors, only three had strong association without hints of bias. Identification of genuine risk factors associated with endometrial cancer may assist in developing targeted prevention strategies for women at high risk.

The Expression Levels of XLF and Mutant P53 Are Inversely Correlated in Head and Neck Cancer Cells

XRCC4-like factor (XLF), also known as Cernunnos, is a protein encoded by the human NHEJ1 gene and an important repair factor for DNA double-strand breaks. In this study, we have found that XLF is over-expressed in HPV(+) versus HPV(-) head and neck squamous cell carcinoma (HNSCC) and significantly down-regulated in the HNSCC cell lines expressing high level of mutant p53 protein versus those cell lines harboring wild-type TP53 gene with low p53 protein expression. We have also demonstrated that Werner syndrome protein (WRN), a member of the NHEJ repair pathway, binds to both mutant p53 protein and NHEJ1 gene promoter, and siRNA knockdown of WRN leads to the inhibition of XLF expression in the HNSCC cells. Collectively, these findings suggest that WRN and p53 are involved in the regulation of XLF expression and the activity of WRN might be affected by mutant p53 protein in the HNSCC cells with aberrant TP53 gene mutations, due to the interaction of mutant p53 with WRN. As a result, the expression of XLF in these cancer cells is significantly suppressed. Our study also suggests that XLF is over-expressed in HPV(+) HNSCC with low expression of wild type p53, and might serve as a potential biomarker for HPV(+) HNSCC. Further studies are warranted to investigate the mechanisms underlying the interactive role of WRN and XLF in NHEJ repair pathway.

Detection of human papillomavirus (HPV) DNA prevalence and p53 codon 72 (Arg72Pro) polymorphism in prostate cancer in a Greek group of patients

Prostate cancer is the most common neoplasm found in males and the second most frequent cause of cancer-related mortality in males in Greece. Among other pathogens, the detection frequency of human papillomavirus (HPV) has been found to be significantly increased in tumor tissues among patients with sexually transmitted diseases (STDs), depending on the geographical distribution of each population studied. The present study focused on the detection of HPV and the distribution of Arg72Pro p53 polymorphism in a cohort of healthy individuals, as well as prostate cancer patients. We investigated the presence of HPV in 50 paraffin-embedded prostate cancer tissues, as well as in 30 physiological tissue samples from healthy individuals by real-time PCR. Furthermore, the same group of patients was also screened for the presence of the Arg72Pro polymorphism of the p53 gene, a p53 polymorphism related to HPV. Out of the 30 control samples, only 1 was found positive for HPV (3.33 %). On the contrary, HPV DNA was detected in 8 out of the total 50 samples (16 %) in the prostate cancer samples. The distribution of the three genotypes, Arg/Arg, Arg/Pro, and Pro/Pro, was 69.6, 21.7, and 8.7 % in the cancer patients and 75.0, 17.86, and 7.14 % in healthy controls, respectively. No statistically significant association was observed between the HPV presence and the age, stage, p53 polymorphism status at codon 72, or PSA. The increased prevalence of HPV detected in the prostate cancer tissues is in agreement with that reported in previous studies, further supporting the association of HPV infection and prostate cancer.

Assessment of the XPC (A2920C), XPF (T30028C), TP53 (Arg72Pro) and GSTP1 (Ile105Val) polymorphisms in the risk of cutaneous melanoma

PURPOSE

We examined the influence of XPC A2920C, XPF T30028C, TP53 Arg72Pro and GSTP1 Ile105Val polymorphisms in the risk of cutaneous melanoma (CM).

METHODS

DNA from 146 CM patients and 146 controls was analysed by polymerase chain reaction (PCR)--restriction fragment length polymorphism (RFLP).

RESULTS

The frequencies of XPC CC (15.1 vs. 6.9 %, P = 0.02), TP53 ArgArg (59.6 vs. 45.9 %, P = 0.02), XPC CC plus TP53 ArgArg (19.7 vs. 5.2 %, P = 0.01) and TP53 ArgArg plus GSTP1 IleIle (50.7 vs. 35.6 %, P = 0.03) genotypes were higher in patients than in controls. Carriers of the respective genotypes were under a 2.51 (95 % CI: 1.13-5.55), 1.76 (95 % CI: 1.09-2.83), 4.52 (95 % CI: 1.35-15.16), and 2.01 (95 % CI: 1.04-3.90)-fold increased risks for CM than others, respectively. An excess of TP53 ArgArg genotype was seen in patients with excessive sun exposure compared to patients with standard sun exposure (69.2 vs. 44.1 %, P = 0.02) and also compared to controls (69.2 vs. 45.9 %, P = 0.002). Individuals with TP53 ArgArg genotype and highly exposed to sunlight had 2.65 (95 % CI: 1.42-4.92)-fold increased risk for CM than others. XPC CC (27.8 vs. 10.4 %, P = 0.02) and the GSTP1 IleIle (58.3 vs. 36.8 %, P = 0.04) genotypes were more common in patients with advanced tumours than in patients with localized tumours and were also more common in these patients than in controls (27.8 vs. 6.9 %, P = 0.001; 58.3 vs. 37.0 %, P = 0.02, respectively). Individuals with the respective genotypes had 5.23 (95 % CI: 1.97-13.82)-fold and 2.38 (95 % CI: 1.13-5.01)-fold increased risks for advanced tumour than others, respectively.

CONCLUSION

Our data suggest that inherited abnormalities of XPC, XPF, TP53 and GSTP1 pathways of the DNA repair, apoptosis and metabolism of reactive oxygen species are important determinants of CM in individuals from south-eastern Brazil.

The prognostic value of miR-21 and miR-155 in non-small-cell lung cancer: a meta-analysis

OBJECTIVE

miR-21 and miR-155 have been implicated in the prognosis of non-small-cell lung cancer, but the results are controversial. To resolve this issue, we performed a meta-analysis on miR-21 and miR-155 and  non-small-cell lung cancer prognosis and lymphoid metastasis.

METHODS

Eligible data were extracted and the correlation between miR-21 and miR-155 and non-small-cell lung cancer survival was analyzed by calculating a pooled hazard ratio and sensitivity analysis. The heterogeneity was detected by Q statistic and I-squared statistic, and the publication bias was tested by funnel plots and Egger's test.

RESULTS

Nineteen studies were included. High miR-21 level (hazard ratio = 2.00, 95% confidence interval = 1.38-2.89, P = 0.000 for heterogeneity test, I(2) = 84.9%) and high miR-155 level (hazard ratio = 1.65, 95% confidence interval = 1.11-2.44, P = 0.004 for heterogeneity test, I(2) = 68.3%) were significantly associated with worse non-small-cell lung cancer survival. Furthermore, a high miR-21 level was associated with an increased risk of lymphoid infiltration for non-small-cell lung cancer (odds ratio = 1.93; 95% confidence interval = 1.31-2.85). Funnel plot and Egger's test suggested that there was no publication bias in the current meta-analysis.

CONCLUSIONS

This meta-analysis provides evidence that miR-21 and miR-155 are predicting factors for non-small-cell lung cancer prognosis and lymphoid infiltration.

Comparative study and meta-analysis of meta-analysis studies for the correlation of genomic markers with early cancer detection

A large number of common disorders, including cancer, have complex genetic traits, with multiple genetic and environmental components contributing to susceptibility. A literature search revealed that even among several meta-analyses, there were ambiguous results and conclusions. In the current study, we conducted a thorough meta-analysis gathering the published meta-analysis studies previously reported to correlate any random effect or predictive value of genome variations in certain genes for various types of cancer. The overall analysis was initially aimed to result in associations (1) among genes which when mutated lead to different types of cancer (e.g. common metabolic pathways) and (2) between groups of genes and types of cancer. We have meta-analysed 150 meta-analysis articles which included 4,474 studies, 2,452,510 cases and 3,091,626 controls (5,544,136 individuals in total) including various racial groups and other population groups (native Americans, Latinos, Aborigines, etc.). Our results were not only consistent with previously published literature but also depicted novel correlations of genes with new cancer types. Our analysis revealed a total of 17 gene-disease pairs that are affected and generated gene/disease clusters, many of which proved to be independent of the criteria used, which suggests that these clusters are biologically meaningful.

Genetic polymorphisms in the estrogen receptor-α gene and the risk of endometrial cancer: a meta-analysis

Estrogen receptor-α is a key mediator of the estrogen response in endometrial tissue. The most-studied gene variants are the PvuII and XbaI polymorphisms, which may be associated with altered sensitivity to estrogen. However, studies evaluating the associations between these polymorphisms and endometrial cancer risk have produced controversial conclusions. To explore a more robust estimate of the role of estrogen receptor-α polymorphisms in endometrial carcinogenesis, we searched all published articles indexed in PubMed, Web of Science, EBSCO, Highwire and the CNKI database from 1995 to 2010. Data were independently extracted by two reviewers using a standardized data extraction form. Overall, the meta-analysis included 1944 cases and 3075 controls for PvuII polymorphisms, and 1831 cases and 2875 controls for XbaI polymorphisms. Our results did not show any statistically significant association between endometrial cancer risk and either PvuII or XbaI polymorphisms. However, PvuII polymorphisms, both the CT and the CC genotypes, significantly increased the risk of endometrial cancer in an Asian-Australian population (pooled OR = 1.50, 95%CI 1.09-2.08 and pooled OR = 1.55, 95%CI 1.08-2.22, respectively). The CC genotype significantly decreased the risk of endometrial cancer (pooled odds ratio 0.77, 95% confidence interval 0.64-0.94) in a European population. In contrast, the stratified analysis suggested that the XbaI polymorphism was not significantly associated with endometrial cancer between different populations. This meta-analysis provides evidence that PvuII polymorphisms in the ESR1 gene, which encodes for estrogen receptor-α, could modify the susceptibility to endometrial cancer. However, the genetic effect varied between different geographical regions for unknown reasons.