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

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

Role of polycyclic aromatic hydrocarbons as a co-factor in human papillomavirus-mediated carcinogenesis

Abstract Background Human papillomavirus (HPV) is an etiological agent of cervical cancer. Yet co-factors are believed to be involved in HPV-mediated carcinogenesis. Polycyclic aromatic hydrocarbons (PAHs) are considered as one of these co-factors. Epidemiologic studies have associated high PAH exposure with increased risk for cancer development. To date, many studies focus on benzo[a]pyrene, however, the role of other PAHs should not be neglected. This study aimed to compare the potential of different PAHs as a co-factor in HPV-mediated carcinogenesis, and to investigate the possible mechanisms involved. Methods The effect of 17 PAHs on high-risk HPV (HPV16) were examined in this study. HPV16 E7 oncogene was expressed in primary cells extracted from baby rat kidney and treated with PAHs. The co-transforming ability of PAHs were measured by colony formation index according to the number and size of transformed colonies. Effects of PAHs on proliferation of HPV-null (C33A) and –infected (CaSki) were examined using CCK-8 assay. Wound healing assay and matrigel invasion chambers were used to investigate effects of PAHs on cell motility and invasivion of HPV-null (MCF7, C33A) and –infected (SiHa) cells. Results Benzo[a]pyrene (BaP), dibenz[a,h]anthracene (DBA) and indeno[1,2,3-cd]pyrene (IDP) showed the greatest co-transforming potential in the baby rat kidney cell system. Short-term exposure to BaP, DBA, IDP and pyrene (PR) did not affect proliferation of C33A or CaSki cells, however, long-term exposure of these four PAHs led to dramatic increase in growth rate of CaSki cells by 120–140%. Besides, exposure of PAHs has an effect on cell motility and invasiveness of C33A and SiHa cells, but not for MCF7 cells. Exposure of BaP and DBA enhanced migration (1.26 to 1.40-fold) and invasion (1.68 to 1.94-fold) capacity of C33A cells. Intriguingly, exposure of all four types of PAHs boosted the migration (1.12 to 1.28-fold) and invasion (1.26 to 1.40-fold) capacity of SiHa cells. Conclusions Our results indicate that exposure to PAHs can be a key co-factor in HPV-related cancer development. They could act on all three stages, namely initiation, promotion and progression. Further study is needed to unveil the mechanisms by which PAHs interact with HPV to cause malignancy

Acceptance of the COVID-19 vaccine based on the health belief model: A population-based survey in Hong Kong

BACKGROUND: Vaccines for COVID-19 are anticipated to be available by 2021. Vaccine uptake rate is a crucial determinant for herd immunity. We examined factors associated with acceptance of vaccine based on (1). constructs of the Health Belief Model (HBM), (2). trust in the healthcare system, new vaccine platforms and manufacturers, and (3). self-reported health outcomes. METHODS: A population-based, random telephone survey was performed during the peak of the third wave of COVID-19 outbreak (27/07/2020 to 27/08/2020) in Hong Kong. All adults aged ≥ 18 years were eligible. The survey included sociodemographic details; self-report health conditions; trust scales; and self-reported health outcomes. Multivariable regression analyses were applied to examine independent associations. The primary outcome is the acceptance of the COVID-19 vaccine.RESULTS: We conducted 1200 successful telephone interviews (response rate 55%). The overall vaccine acceptance rate after adjustment for population distribution was 37.2% (95% C.I. 34.5–39.9%). The projected acceptance rates exhibited a “J-shaped” pattern with age, with higher rates among young adults (18–24 years), then increased linearly with age. Multivariable regression analyses revealed that perceived severity, perceived benefits of the vaccine, cues to action, self-reported health outcomes, and trust in healthcare system or vaccine manufacturers were positive correlates of acceptance; whilst perceived access barriers and harm were negative correlates. Remarkably, perceived susceptibility to infection carried no significant association, whereas recommendation from Government (aOR = 10.2, 95% C.I. 6.54 to 15.9, p < 0.001) was as the strongest driving factor for acceptance. Other key obstacles of acceptance included lack of confidence on newer vaccine platforms (43.4%) and manufacturers without track record (52.2%), which are of particular relevance to the current context.CONCLUSIONS: Governmental recommendation is an important driver, whereas perceived susceptibility is not associated with acceptance of COVID-19 vaccine. These HBM constructs and independent predictors inform evidence-based formulation and implementation of vaccination strategies

Diabetic (db/db) mice promoted CUP-1 xenograft growth.

<p>CUP-1 cells were injected subcutaneously into the scruff of diabetic db/db mice and non-diabetic control littermates (m+/db) of 10 weeks age. Tumor size was monitored every other day for 2 weeks and tumor volume was calculated as in nude mice. <b>(A)</b> CUP-1 tumor growth in db/db and m+/db mice. Each point represents mean ± S.E.M (n = 10). <b>(B</b>) Representative photographs show db/db (right) and m+/db mice (left) with respective representative excised tumors on day 27 after CUP-1 inoculation. Arrows indicate the site with CUP-1 inoculation. <b>(C)</b> Representative photomicrographs of H&E-stained CUP-1 tumor tissues from db/db (left) and m+/db mice (right) excised on day 27 after CUP-1 inoculation, X400. Atypical cells with large irregular nuclei (stars) and mitotic figures (arrows) were present in CUP-1 tumor tissues. <b>(D)</b> Western blotting confirmed E7 expression in CUP-1 excised xenograft from both db/db and m+/db mice.</p

CUP-1 was an immortalized epithelial cell line with functional E7 protein.

<p><b>(A)</b> Phase-contrast micrograph of CUP-1 cells, (i) x40 (ii) x200. <b>(B)</b> Proliferation profile of CUP-1. CUP-1 was plated at a density of 2 × 10⁵ cells in a T25 flask. When they reached 80% confluency, cell number was determined and cells were subcultured. Each sub-culture was counted as one passage. This process was repeated up to 200 days with over 60 passages. Cumulative population doublings was calculated using the equation: 3.32 x [log(the number of cell harvested)–log(the initial number of cells plated) + S, where S is the initial population doubling. Cumulative population doubling was then plotted against days in culture. Each point represents the mean of triplicate determinations. CUP-1 grew in a steady rate without any sign of senescence, indicating that it was immortalized. <b>(C)</b> Cell type of CUP-1 at passage 28 (P28) and 60 (P60) was characterized via (i) Western blotting and (ii) immunofluorescence using keratinocyte marker pan-keratin (green) and fibroblast marker S100A. HaCaT (keratinocytes) and NIH 3T3 (fibroblasts) were included as cell type controls. CUP-1 nuclei was counterstained by DAPI (blue) in immunofluorescence. <b>(D)</b> Western blot analysis of pRb levels in CUP-1. Total cell lysate was collected from non-transfected primary baby mouse kidney (BMK) cells and CUP-1 cells at P28 and P60. CUP-1 expressed E7 and readily degraded pRb in both P28 and P60. β-actin was included as the loading control.</p

CUP-1 cells were tumorigenic in athymic (nu/nu) mice.

<p>Ten million CUP-1 cells were injected subcutaneously into the scruff of 10-week-old nude mice and tumour development was monitored for 12 weeks. <b>(A)</b> Representative image of a nude mouse with significant tumor mass growth (arrow) at week 12 upon CUP-1 inoculation. <b>(B)</b> Representative excised tumors at 12 weeks after inoculation. <b>(C)</b> CUP-1 xenograft growth in nude mice. Tumor volumes were monitored every other day over the study period by caliper measurement of the largest dimension of the tumor, “a” and the perpendicular diameter, “b”. Tumor volumes were calculated using the formula (a×b²) × 0.5236. Each point represents mean ± S.E.M (n = 10). <b>(D)</b> (i) and (ii) Representative photomicrographs of H&E-stained CUP-1 tumor tissues excised from nude mice, X200. Tissue sections showed presence of cells with enlarged and pleomorphic nucleus (black arrowhead), mitotic figures (black circle) and infiltration of red blood cells (black arrow).</p