Oncogenicitiy Comparison of Human Papillomavirus Type 52 E6 Variants

Viral manipulation of cell polarity signalling

Cell polarity refers to the asymmetric distribution of biomacromolecules that enable the correct orientation of a cell in a particular direction. It is thus an essential component for appropriate tissue development and function. Viral infections can lead to dysregulation of polarity. This is associated with a poor prognosis due to viral interference with core cell polarity regulatory scaffolding proteins that often feature PDZ (PSD-95, DLG, and ZO-1) domains including Scrib, Dlg, Pals1, PatJ, Par3 and Par6. PDZ domains are also promiscuous, binding to several different partners through their C-terminal region which contain PDZ-binding motifs (PBM). Numerous viruses encode viral effector proteins that target cell polarity regulators for their benefit and include papillomaviruses, flaviviruses and coronaviruses. A better understanding of the mechanisms of action utilised by viral effector proteins to subvert host cell polarity sigalling will provide avenues for future therapeutic intervention, while at the same time enhance our understanding of cell polarity regulation and its role tissue homeostasis.

Genetic variability in the E6 and E7 oncogenes of HPV52 and its prevalence in the Taizhou area, China

Background

Human papillomavirus (HPV) 52 is one of the prevalent oncogenic HPV genotypes in East Asia. Chinese women have the highest susceptibility to the HPV52 type, but research data on HPV52 genetic variability and its carcinogenicity in China is lacking.

Methods

The present study aimed to investigate the genetic variability of HPV52 currently circulating among Chinese women by PCR sequencing the entire E6 and E7 oncogenes. HPV52 sequence alignment, genetic heterogeneity analyses and maximum-likelihood phylogenetic tree construction were performed by BioEdit software and MEGA X software.

Results

Between 2016 and 2018, the overall HPV infection rate was 21.3%, of which HPV52 was the most prevalent high-risk type (17.2%) in the Taizhou area, China. A total of 339 single HPV52-positive samples were included in this study. We obtained 27 distinct variation patterns of HPV52 with the accession GenBank numbers ON529577-ON529603. Phylogenetic analysis showed that 96.6% of HPV52 variants belonged to lineage B, which seemed to be uniquely defined by G350T, A379G (K93R) in the E6 gene and C751T, A801G in the E7 gene. Due to the dominance of lineage B in our study population, the results could not be used to assess the association of the HPV52 (sub)lineage with the risk of cervical lesions. In addition, no significant trends were observed between the nucleotide substitutions of HPV52 variants and the risk of cervical carcinogenesis.

Conclusion

Our data showed that HPV52 variants were strongly biased towards lineage B. These results confirmed that cervical lesions in the Taizhou area are highly attributable to HPV52, which may be due to the high infection rate of lineage B in the population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-022-01929-5.

Prevalence and distribution of human papillomavirus (HPV) in Luoyang city of Henan province during 2015-2021 and the genetic variability of HPV16 and 52

Background

Persistent high-risk Human papillomavirus (HPV) subtypes infection has been implicated as a causative of cervical cancer. Distribution and genotypes of HPV infection among females and their variations would assist in the formulation of preventive strategy for cervical cancer. The purpose of the present study is to investigate the prevalence of HPV among females in central China.

Methods

The distribution and genotypes of HPV among 9943 females attending the gynecological examinations in central of China during 2015–2021 were investigated. HPV genotypes were detected using a commercial kit. Nucleotides sequences of L1, E6 and E7 genes in HPV16 or HPV52 positive samples collected in 2021 were amplified by polymerase chain reaction (PCR). Variations of L1, E6 and E7 in HPV16 and HPV52 were gained by sequencing and compared with the reference sequence. Sublineages of HPV16 and HPV52 were determined by the construction of phylogenetic tree based on L1 gene.

Results

The overall prevalence of HPV infection was 22.81%, with the infection rate of high-risk human papillomavirus (HR-HPV) was 19.02% and low-risk human papillomavirus (LR-HPV) was 6.40%. The most top five genotypes of HPV infection were HPV16 (7.49%), HPV52 (3.04%), HPV58 (2.36%), HPV18 (1.65%) and HPV51 (1.61%). Plots of the age-infection rate showed that the single HPV, multiple HPV, HR-HPV, LR-HPV infection revealed the same tendency with two peaks of HPV infection were observed among females aged ≤ 20 year-old and 60–65 year-old. The predominant sublineage of HPV16 was A1 and B2 for HPV52. For HPV16, The most prevalent mutations were T266A (27/27) and N181T (7/27) for L1, D32E for E6 and S63F for E7 in HPV16. For HPV52, all of the nucleotide changes were synonymous mutation in L1 (except L5S) and E7 genes. The K93R mutation was observed in most HPV52 E6 protein.

Conclusions

The present study provides basic information about the distribution, genotypes and variations of HPV among females population in Henan province, which would assist in the formulation of preventive strategies and improvements of diagnostic probe and vaccine for HPV in this region.

Analysing the HERV-K env, np9, rec and gag expression in cervical tissues

Cervical cancer is considered to be the fourth common cancer. It is assumed that numerous risk factors, especially infectious ones, can have a detrimental effect on cervical cancer. In this study, we evaluated the expression of Herv-K env, np9, rec and gag in cervical tissues. After RNA extraction and cDNA sensitizing of 12 cervical cancer tissues and CIN3, 51 CIN1,2 and 18 normal ones, Herv-K env, np9, rec and gag were assessed using quantitative real-time PCR analysis. There was a decrease in the level of HERV-K env expression in cervical cancer and CIN 1-3 in compression with normal tissues. Cervical cancer and CIN3 indicated the most increase in expression. Meanwhile, we observed an increase in gag and rec expression in CIN 1,2; although cervical cancer and CIN 3 had a decrease in rec and gag expression, we did not report any changes in np expression. In conclusion, given the relationship between HERV-associated genes and cervical cancer, our study suggests that these genes can be useful for cancer diagnosis. However, further investigations are needed to provide a better perspective about the effectiveness of these genes in the diagnostic strategies of gastrointestinal cancer. These results are just an observation that could open a wider investigation to test the correlation between the expression of these genes and cervical cancer.

Saikosaponin-A induces apoptosis of cervical cancer through mitochondria- and endoplasmic reticulum stress-dependent pathway in vitro and in vivo: involvement of PI3K/AKT signaling pathway

Cervical cancer causes considerable mortality in women worldwide. Saikosaponin-A, a triterpenoid glycoside isolated from Bupleurum falcatum, has been proven to exert anti-cancer property. In this study, we evaluated the possibility of saikosaponin-A on cervical cancer in vitro and in vivo. The results showed that saikosaponin-A induced cell death and altered cellular morphology dose-dependently. Saikosaponin-A significantly induced apoptosis in HeLa cells, confirmed by Hoechst 33,342 staining and flow cytometry. Sequentially, saikosaponin-A triggered the mitochondrial-mediated apoptosis demonstrated by deficiency of MMP, induction of Bax/Bcl-2 ratio, leakage of cytochrome c to cytoplasm, and activation of caspase-3. Moreover, ER stress also participated in the apoptosis induced by saikosaponin-A in HeLa cells as indicated by the upregulation of GPR78, CHOP and caspase-12 expression. Furthermore, HeLa cells showed increased expressions of p-PI3K and p-AKT in response to saikosaponin-A treatment. Additionally, saikosaponin-A could inhibit HeLa tumor growth in nude mice and induce apoptosis, reflected by the induction of TUNEL and the expression of cytochrome c, caspase-3 and CHOP confirmed by immunohistochemistry. These findings at least to a certain extent suggested that saikosaponin-A triggered apoptosis through both mitochondrial pathway and ER stress pathway and inhibiting PI3K/Akt signaling, thereby contributing to against cervical cancer. This work provides a new understanding of saikosaponin-A on therapeutic application in treatment of cancer, which has the potential to be a promising candidate therapeutic agent for cervical cancer patients.

Current Updates on Cancer-Causing Types of Human Papillomaviruses (HPVs) in East, Southeast, and South Asia

Simple Summary

Among the over 200 human papillomavirus (HPV) genotypes identified, approximately 15 of them can cause human cancers. In this review, we provided an updated overview of the distribution of cancer-causing HPV genotypes by countries in East, Southeast and South Asia. Besides the standard screening and treatment methods employed in these regions, we unravel HPV detection methods and therapeutics utilised in certain countries that differ from other part of the world. The discrepancies may be partly due to health infrastructure, socio-economy and cultural diversities. Additionally, we highlighted the area lack of study, particularly on the oncogenicity of HPV genotype variants of high prevalence in these regions.

Abstract

Human papillomavirus (HPV) infection remains one of the most prominent cancer-causing DNA viruses, contributing to approximately 5% of human cancers. While association between HPV and cervical cancers has been well-established, evidence on the attribution of head and neck cancers (HNC) to HPV have been increasing in recent years. Among the cancer-causing HPV genotypes, HPV16 and 18 remain the major contributors to cancers across the globe. Nonetheless, the distribution of HPV genotypes in ethnically, geographically, and socio-economically diverse East, Southeast, and South Asia may differ from other parts of the world. In this review, we garner and provide updated insight into various aspects of HPV reported in recent years (2015–2021) in these regions. We included: (i) the HPV genotypes detected in normal cancers of the uterine cervix and head and neck, as well as the distribution of the HPV genotypes by geography and age groups; (ii) the laboratory diagnostic methods and treatment regimens used within these regions; and (iii) the oncogenic properties of HPV prototypes and their variants contributing to carcinogenesis. More importantly, we also unveil the similarities and discrepancies between these aspects, the areas lacking study, and the challenges faced in HPV studies.

Transcriptional Regulation of Epithelial to Mesenchymal Transition Related Genes by Lipopolysaccharide in Human Cervical Cancer Cell Line HeLa

Objective:

Cancer is one of the common diseases in the world, and cervical cancer is the fourth one. In this type of cancer, many risk factors, especially infectious diseases, such as human papilloma virus (HPV) and gram-negative bacteria can have important effects on the expression of epithelial to mesenchymal transition related genes like Snail,E-cadherin, and ZEB-1, responsible for connecting cell tissues. In this study, we have investigated the effect of Escherichia coli O111:B4 Lipopolysaccharide (LPS) on HPV positive cell line (HeLa), the expression level of the (Snail, E-cadherin, and ZEB-1), HPV oncogenes (E6, E7) and also microRNA-9, 192.

Materials and Methods:

HeLa cell line was treated with LPS to analyze Snail, E-cadherin, ZEB-1, E6, E7 and also microRNA-9, 192 expression by quantitative real-time PCR in 24, 48 and 72 hours.

Results:

Quantitative real-time PCR revealed a significant reduction in E-cadherin mRNA level at 10ug/L of LPS in three time-points and after 24 hours at 5ug/L of LPS; however, ZEB-1 at 10ug/L of LPS and Snail at 5, 10ug/L of LPS are up-regulated. E7 also illustrated a slight increase, but we did not find any relationship between E7 and LPS treatment. Additionally, there are upward trends in microRNA-9, 192 levels.

Conclusion:

The result of this study, LPS is able to reduce E-cadherin expression, caused by increase in repressor E-cadherin protein expression and some microRNAs, probably. Since bacterial infection can be in cervical site, it is likely to be effective in reducing the E-cadherin expression in the EMT and enhance cancer process, therefore; removing these infections by using the appropriate antibiotics may result in slowing down this process, which requires more research.