Environmental exposure and HPV infection may act synergistically to induce lung tumorigenesis in nonsmokers

Infection with human cytomegalovirus, Epstein-Barr virus, and high-risk types 16 and 18 of human papillomavirus in EGFR-mutated lung adenocarcinoma

AIM

To assess the frequency of human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), and high-risk types of human papillomavirus (HPV16 and HPV18) infections in lung adenocarcinoma samples.

METHODS

Lung adenocarcinoma cytological smears and their DNA isolates were obtained from patients hospitalized at the Department for Lung Diseases Jordanovac, Zagreb, in 2016 and 2017. Overall, 67 lung adenocarcinoma samples were examined: 34 with epidermal growth factor receptor gene (EGFR) mutations and 33 without EGFR mutations. The EGFR mutation status and virus presence were assessed with a polymerase chain reaction, and random samples were additionally tested for EBV with Sanger sequencing. HCMV, EBV, HPV16, and HPV18 infections were evaluated in relation to EGFR mutation, smoking status, and sex. A meta-analysis of available data about HPV infection in non-small cell lung cancer was performed.

RESULTS

More frequent HCMV, EBV, HPV16, and HPV18 infections were observed in lung adenocarcinoma samples with EGFR mutations than in samples without these mutations. Coinfection of the investigated viruses was observed only in lung adenocarcinoma samples with mutated EGFR. In the group with EGFR mutations, smoking was significantly associated with HPV16 infection. The meta-analysis showed that non-small cell lung cancer patients with EGFR mutations had a higher odds of HPV infection.

CONCLUSION

HCMV, EBV, and high-risk HPV infections are more frequent in EGFR-mutated lung adenocarcinomas, which indicates a possible viral impact on the etiology of this lung cancer subtype.

Association between XRCC3 rs861539 Polymorphism and the Risk of Ovarian Cancer: Meta-Analysis and Trial Sequential Analysis

Background

Current studies on the relationship between XRCC3 rs861539 polymorphism and ovarian cancer risk have been inconsistent. Therefore, we performed a meta-analysis to explore their association.

Methods

Six electronic databases (PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, and China Wanfang Database) were searched for relevant studies published before December 2021. Meta-analysis, subgroup analysis, sensitivity analysis, and publication bias analysis were performed using Stata software 16.0. Trial sequential analysis (TSA) was performed using TSA 0.9.5.10 Beta software.

Results

A total of 12 studies were included in 9 literatures, comprising 4,634 cases of ovarian cancer and 7,381 controls. After Bonferroni correction, the meta-analysis showed an association between XRCC3 rs861539 polymorphism and ovarian cancer risk in the heterozygote model and the dominant model (GA vs. GG: OR = 0.88, 95%CI = 0.81-0.96, P = 0.003; GG vs. GA+AA: OR = 0.89, 95%CI = 0.82-0.96, P = 0.004). In an ethnically stratified subgroup analysis, XRCC3 rs861539 was shown to reduce the risk of ovarian cancer in Caucasian in the heterozygote model and the dominant model (GA vs. GG: OR = 0.88, 95%CI = 0.81-0.96, P = 0.004; GG vs. GA+AA: OR = 0.88, 95%CI = 0.81-0.96, P = 0.004). In the control source and detection method stratified subgroup analysis, hospital-based studies and PCR-RFLP-based studies were found to increase ovarian cancer risk (GG vs. AA: OR = 1.30, 95%CI = 1.05-1.62, P = 0.016; GG vs. AA: OR = 1.31, 95%CI = 1.06-1.62, P = 0.013).

Conclusion

This meta-analysis showed a significant association between XRCC3 rs861539 polymorphism and ovarian cancer risk, especially in Caucasians. Large-scale multicenter case-control studies in more different regions will be needed in the future.

Human Papillomavirus Selected Properties and Related Cervical Cancer Prevention Issues

High-risk human papillomavirus strains are widely known to be the causative agents responsible for cervical cancer development. Aggregated damage caused by papillomaviruses solely is estimated in at least 5% of all malignancies of the human body and 16% in cancers that affect the female genital area. Enhanced understanding of the complex issue on how the high extent of carcinogenicity is eventually formed due to the infection by the Papoviridae family would contribute to enhancing current prevention strategies not only towards cervical cancer, but also other HPV associated cancers. This review article is aimed at presenting the key points in two directions: the current cervical cancer prevention and related aspects of HPV behavior. Virtually all applied technologies related to HPV diagnostics and screening programs, such as HPV tests, colposcopy-based tests (VIA/VILI), conventional and liquid-based cytology, currently available are presented. Issues of availability, advantages, and drawbacks of the screening programs, as well as vaccination strategies, are also reviewed in the article based on the analyzed sources. The current point of view regarding HPV is discussed with emphasis on the most problematic aspect of the HPV family concerning the observed increasing number of highly carcinogenic types. Present trends in HPV infection diagnostics throughout the human fluids and tissues are also reported, including the latest novelties in this field, such as HPV assay/self-sample device combinations. Besides, a brief outline of the related prevention issues in Kazakhstan, the leading country of Central Asia, is presented. Kazakhstan, as one of the post-soviet middle-income countries, may serve as an example of the current situation in those terrains, concerning the implementation of globally accepted cervical cancer prevention strategies. Along with positive achievements, such as the development of a nationwide screening program, a range of drawbacks is also analyzed and discussed.

Possible Oncogenic Viruses Associated with Lung Cancer

Lung cancer is the most common cause of cancer death worldwide. Tobacco smoking is the most predominant etiology for lung cancer. However, only a small percentage of heavy smokers develop lung cancer, which suggests that other cofactors are required for lung carcinogenesis. Viruses have been central to modern cancer research and provide profound insights into cancer causes. Nevertheless, the role of virus in lung cancer is still unclear. In this article, we reviewed the possible oncogenic viruses associated with lung cancer.

E6/E7-P53-POU2F1-CTHRC1 axis promotes cervical cancer metastasis and activates Wnt/PCP pathway

Cervical cancer is an infectious cancer and the most common gynecologic cancer worldwide. E6/E7, the early genes of the high-risk mucosal human papillomavirus type, play key roles in the carcinogenic process of cervical cancer. However, little was known about its roles in modulating tumor microenvironment, particular extracellular matrix (ECM). In this study, we found that E6/E7 could regulate multiple ECM proteins, especially collagen triple helix repeat containing 1 (CTHRC1). CTHRC1 is highly expressed in cervical cancer tissue and serum and closely correlated with clinicopathological parameters. CTHRC1 promotes cervical cancer cell migration and invasion in vitro and metastasis in vivo. E6/E7 regulates the expression of CTHRC1 in cervical cancer by E6/E7-p53-POU2F1 (POU class 2 homeobox 1) axis. Futhermore, CTHRC1 activates Wnt/PCP signaling pathway. Take together, E6/E7-p53-POU2F1-CTHRC1 axis promotes cervical cancer cell invasion and metastasis and may act as a potential therapeutic target for interventions against cervical cancer invasion and metastasis.

Overexpression of Human Papillomavirus Type 16 Oncoproteins Enhances Epithelial-Mesenchymal Transition via STAT3 Signaling Pathway in Non-Small Cell Lung Cancer Cells

The human papillomavirus (HPV) infection may be associated with the development and progression of non-small cell lung cancer (NSCLC). However, the role of HPV-16 oncoproteins in the development and progression of NSCLC is not completely clear. Epithelial–mesenchymal transition (EMT), a crucial step for invasion and metastasis, plays a key role in the development and progression of NSCLC. Here we explored the effect of HPV-16 oncoproteins on EMT and the underlying mechanisms. NSCLC cell lines, A549 and NCI-H460, were transiently transfected with the EGFP-N1-HPV-16 E6 or E7 plasmid. Real-time PCR and Western blot analysis were performed to analyze the expression of EMT markers. A protein microarray was used to screen the involved signaling pathway. Our results showed that overexpression of HPV-16 E6 and E7 oncoproteins in NSCLC cells significantly promoted EMT-like morphologic changes, downregulated the mRNA and protein levels of EMT epithelial markers (E-cadherin and ZO-1), and upregulated the mRNA and protein levels of EMT mesenchymal markers (N-cadherin and vimentin) and transcription factors (ZEB-1 and Snail-1). Furthermore, the HPV-16 E6 oncoprotein promoted STAT3 activation. Moreover, WP1066, a specific signal transducer and activator of transcription 3 (STAT3) inhibitor, reversed the effect of HPV-16 E6 on the expression of ZO-1, vimentin, and ZEB-1 in transfected NSCLC cells. Taken together, our results suggest that overexpression of HPV-16 E6 and E7 oncoproteins enhances EMT, and the STAT3 signaling pathway may be involved in HPV-16 E6-induced EMT in NSCLC cells.