Human papillomavirus genotype distribution in Ethiopia: an updated systematic review

Background Cervical cancer is caused by infection with high-risk human papillomaviruses (HR-HPVs). It is one of the leading causes of cancer-related deaths in Ethiopia and globally. To develop efficient vaccination and HPV-based cervical cancer screening approaches, data on genotype distribution of HPVs is crucial. Hence, the study was aimed to review HPV genotype distribution in Ethiopia. Methods Research articles were systematically searched using comprehensive search strings from PubMed/Medline and SCOPUS. Besides, Google Scholar was searched manually for grey literature. The last search was conducted on 18 August 2021. The first two authors independently appraised the studies for scientific quality and extracted the data using Excel sheet. The pooled HPV genotype distribution was presented with descriptive statistics. Results We have included ten studies that were reported from different parts of the country during 2005 and 2019. These studies included 3633 women presented with different kinds of cervical abnormalities, from whom 29 different HPV genotypes with a sum of 1926 sequences were reported. The proportion of high-risk, possible/probable high-risk and low-risk HPVs were at 1493 (77.5%), 182 (9.4%) and 195 (10.1%), respectively. Of the reported genotypes, the top five were HPV 16 (37.3%; 95% CI 35.2.1–39.5%), HPV 52 (6.8%; 95% CI 5.8–8.0%), HPV 35 (4.8%; 95% CI 3.9–5.8%), HPV 18 (4.4%; 95% CI 3.5–5.3%) and HPV 56 (3.9%: 95% CI 3.1–4.9%). Some of other HR-HPV groups include HPV 31 (3.8%), HPV 45 (3.5%), HPV 58 (3.1%), HPV 59(2.3%), and HPV 68 (2.3%). Among the high-risk types, the combined prevalence of HPV 16/18 was at 53.7% (95% CI 51.2–56.3%). HPV 11 (2.7%: 95% CI 2.1–3.5%), HPV 42 (2.1%: 95% CI 1.5–2.8%) and HPV 6 (2.1%: 95% CI 1.4–2.7%) were the most common low-risk HPV types. Conclusions We noted that the proportion of HR-HPV types was higher and HPV 16 in particular, but also HPV 52, HPV 35 and HPV 18, warrant special attention in Ethiopian’s vaccination and HPV based cervical screening program. Additional data from other parts of the country where there is no previous HPV genotype report are needed to better map the national HPV genotypes distribution of Ethiopia.

Incidence and clearance of anal high-risk Human Papillomavirus infection and their risk factors in men who have sex with men living with HIV

HIV-infected men who have sex with men (MSM) display the highest prevalence of anal infection by high-risk Human Papillomaviruses (hrHPVs) and incidence of anal carcinoma. Anal specimens were genotyped by the Linear Array. Incidence and clearance of anal infection by hrHPVs, hrHPVs other than HPV16, low-risk HPVs, and four individual types (6,11,16,18) were estimated using a two-state Markov model. Determinants for incidence and clearance were assessed by logistic regression. Overall, 204 individuals were included (median age 42 years, IQR = 34–49). For hrHPVs, incidence and clearance rates were 36.1 × 1000 person-months (p-m) (95% CI 23.3–56.5) and 15.6 × 1000 p-m (95% CI 10.7–23.3), respectively. HPV16 showed a higher incidence than HPV18 (10.2 vs. 7.2 × 1000 p-m). Its clearance was more than twofold lower than that of HPV18 (30.1 vs. 78.2 × 1000 p-m). MSM receiving cART displayed a 68% to 88% decrease in risk of acquiring hrHPVs, hrHPVs other than HPV16, HPV16, and HPV18 (adjusted Hazard Ratio [aHR] 0.13, 95% CI 0.02–0.67; aHR 0.22, 95% CI 0.06–0.78; aHR 0.32, 95% CI 0.12–0.90; aHR 0.12, 95% CI 0.04–0.31, respectively) than patients not treated. A nadir CD4 + count < 200 cells/mm3 significantly reduced the clearance of hrHPVs other than HPV16 (aHR 0.39, 95% CI 0.17–0.90). cART use reduces the risk of acquiring anal infection by hrHPVs.

Development and testing of procedures for detecting HPV 6 and HPV 16 DNA in water samples

The present study aims to develop and test procedures for detecting the DNA of dangerous human papillomaviruses (HPV) types 6 and 16 in water samples. The conserved segments of HPV 6 L1 and HPV 16 L1 nucleic acid sequences were studied using bioinformatic methods with the help of the NCBI (National Center for Biotechnology Information) database and the BioEdit program. A total of 135 nucleic acid sequences of HPV6 L1 and 945 nucleic acid sequences of HPV16 L1 were examined. Five pairs of specific primers were developed for the identified conserved segments of nucleic acid sequences using specialized programs (PerlPrimer v.1.1.21, FastPCR 6.6, and Primer3Plus). In addition, several procedures for collecting samples from various water bodies located near Listvyanka settlement (Lake Baikal) were tested. The samples were subjected to comprehensive purification from insoluble particles and bacterial contamination to be tested for the presence of HPV DNA via PCR analysis using primers complementary to the nucleic acid sequences of HPV6 L1 and HPV16 L1. The conducted studies revealed HPV 6 and HPV 16 DNA in the water samples. Due to the use of the developed and tested procedures for collecting and examining samples from various water sources in the Baikal Natural Territory followed by a PCR analysis, it was possible to detect the presence of dangerous viruses. The proposed procedure of testing water samples for the presence of HPV can be useful in developing effective monitoring of water bodies and wastewater both in Baikal and other regions.

Targeted Disruption of E6/p53 Binding Exerts Broad Activity and Synergism with Paclitaxel and Topotecan against HPV-Transformed Cancer Cells

High-risk human papillomaviruses (HR-HPV) are the etiological agents of almost all cervical cancer cases and a high percentage of head-and-neck malignancies. Although HPV vaccination can reduce cancer incidence, its coverage significantly differs among countries, and, therefore, in the next decades HPV-related tumors will not likely be eradicated worldwide. Thus, the need of specific treatments persists, since no anti-HPV drug is yet available. We recently discovered a small molecule (Cpd12) able to inhibit the E6-mediated degradation of p53 through the disruption of E6/p53 binding in HPV16- and HPV18-positive cervical cancer cells. By employing several biochemical and cellular assays, here we show that Cpd12 is also active against cervical cancer cells transformed by other HR-HPV strains, such as HPV68 and HPV45, and against a HPV16-transformed head-and-neck cancer cell line, suggesting the possibility to employ Cpd12 as a targeted drug against a broad range of HPV-induced cancers. In these cancer cell lines, the antitumoral mechanism of action of Cpd12 involves p53-dependent cell cycle arrest, a senescent response, and inhibition of cancer cell migration. Finally, we show that Cpd12 can strongly synergize with taxanes and topoisomerase inhibitors, encouraging the evaluation of Cpd12 in preclinical studies for the targeted treatment of HPV-related carcinomas.

Infection by High-Risk Human Papillomaviruses, Epithelial-to-Mesenchymal Transition and Squamous Pre-Malignant or Malignant Lesions of the Uterine Cervix: A Series of Chained Events?

Wound healing requires static epithelial cells to gradually assume a mobile phenotype through a multi-step process termed epithelial-to-mesenchymal transition (EMT). Although it is inherently transient and reversible, EMT perdures and is abnormally activated when the epithelium is chronically exposed to pathogens: this event deeply alters the tissue and eventually contributes to the development of diseases. Among the many of them is uterine cervical squamous cell carcinoma (SCC), the most frequent malignancy of the female genital system. SCC, whose onset is associated with the persistent infection of the uterine cervix by high-risk human papillomaviruses (HR-HPVs), often relapses and/or metastasizes, being resistant to conventional chemo- or radiotherapy. Given that these fearsome clinical features may stem, at least in part, from the exacerbated and long-lasting EMT occurring in the HPV-infected cervix; here we have reviewed published studies concerning the impact that HPV oncoproteins, cellular tumor suppressors, regulators of gene expression, inflammatory cytokines or growth factors, and the interactions among these effectors have on EMT induction and cervical carcinogenesis. It is predictable and desirable that a broader comprehension of the role that EMT inducers play in SCC pathogenesis will provide indications to flourish new strategies directed against this aggressive tumor.

Diagnostic Test Accuracy of First-Void Urine Human Papillomaviruses for Presence Cervical HPV in Women: Systematic Review and Meta-Analysis

First-void urine usually contains exfoliated cells of the debris and mucus from the female genital organs and cervix, i.e., high concentration of human papillomavirus deoxyribonucleic acid (HPV DNA). We conducted a meta-analysis of published data and determined an accuracy of HPV detection in first-void urine compared to the women’s cervix. According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we carried out a comprehensive literature search. Eligible articles published from 2011 until 2021 were gathered by searching Embase, PubMed and Cochrane Library Central databases. The patient selection, index test, standard test, and patient flow were the factors involved in quality evaluation. A meta-analysis of 15 studies (3412 women) based on 5054 potential records was conducted. Pooled sensitivity for high-risk HPV detection in urine of 78% (70–84%) and specificity of 89% (81–94%) were calculated. Any HPV detection in urine of 87% (74–94%) and 91% (83–96%) were pooled sensitivity and specificity, respectively. HPV 16 and 18 had a pooled sensitivity of 77% (76–77%) and specificity of 98% (98–98%). Meta-analysis indicated variations between the pooled specificities and sensitivities. In meta-regression analysis, a heterogeneity in accuracy by using covariates (bias in patient selection, purpose, sample timing, storage temperature and HPV detection method) were not detected. Our meta-analysis demonstrates the accuracy of detection of HPV in urine for the presence of cervical HPV. Although progress is continuously made in urinary HPV detection, further studies are needed to evaluate and to improve the accuracy of the first-void urine test in order to be comparable with other screening methods.

Identification of microRNAs that stabilize p53 in HPV-positive cancer cells

Etiologically, 5% of all cancers worldwide are caused by the high-risk human papillomaviruses (hrHPVs). These viruses encode two oncoproteins (E6 and E7) whose expression is required for cancer initiation and maintenance. Among their cellular targets are the p53 and the retinoblastoma tumor suppressor proteins. Inhibition of the hrHPV E6-mediated ubiquitylation of p53 through the E6AP ubiquitin ligase results in the stabilization of p53, leading to cellular apoptosis. We utilized a live cell high throughput screen to determine whether exogenous microRNA (miRNA) transfection had the ability to stabilize p53 in hrHPV-positive cervical cancer cells expressing a p53-fluorescent protein as an in vivo reporter of p53 stability. Among the miRNAs whose transfection resulted in the greatest p53 stabilization was 375-3p that has previously been reported to stabilize p53 in HeLa cells, providing validation of the screen. The top 32 miRNAs in addition to 375-3p were further assessed using a second cell-based p53 stability reporter system as well as in non-reporter HeLa cells to examine their effects on endogenous p53 protein levels, resulting in the identification of 23 miRNAs whose transfection increased p53 levels in HeLa cells. While a few miRNAs that stabilized p53 led to decreases in E6AP protein levels, all targeted HPV oncoprotein expression. We further examined subsets of these miRNAs for their abilities to induce apoptosis and determined whether it was p53-mediated. The introduction of specific miRNAs revealed surprisingly heterogeneous responses in different cell lines. Nonetheless, some of the miRNAs described here have potential as therapeutics for treating HPV-positive cancers. Importance Human papillomaviruses cause approximately 5% of all cancers worldwide and encode genes that contribute to both the initiation and maintenance of these cancers. The viral oncoprotein E6 is expressed in all HPV-positive cancers and functions by targeting the degradation of p53 through the engagement of the cellular ubiquitin ligase E6AP. Inhibiting the degradation of p53 leads to apoptosis in HPV-positive cancer cells. Using a high throughput live cell assay we identified several miRNAs whose transfection stabilize p53 in HPV-positive cells. These miRNAs have the potential to be used in the treatment of HPV-positive cancers.

HPV16 Entry into Epithelial Cells: Running a Gauntlet

During initial infection, human papillomaviruses (HPV) take an unusual trafficking pathway through their host cell. It begins with a long period on the cell surface, during which the capsid is primed and a virus entry platform is formed. A specific type of clathrin-independent endocytosis and subsequent retrograde trafficking to the trans-Golgi network follow this. Cellular reorganization processes, which take place during mitosis, enable further virus transport and the establishment of infection while evading intrinsic cellular immune defenses. First, the fragmentation of the Golgi allows the release of membrane-encased virions, which are partially protected from cytoplasmic restriction factors. Second, the nuclear envelope breakdown opens the gate for these virus–vesicles to the cell nucleus. Third, the dis- and re-assembly of the PML nuclear bodies leads to the formation of modified virus-associated PML subnuclear structures, enabling viral transcription and replication. While remnants of the major capsid protein L1 and the viral DNA remain in a transport vesicle, the viral capsid protein L2 plays a crucial role during virus entry, as it adopts a membrane-spanning conformation for interaction with various cellular proteins to establish a successful infection. In this review, we follow the oncogenic HPV type 16 during its long journey into the nucleus, and contrast pro- and antiviral processes.

Special Issue “HPV in the Head and Neck Region”

Previously, human papillomaviruses were best known for causing diseases in the genital tract, where high-risk types may cause, e.g., cancer of the cervix uteri, while low risk types could cause condylomas [...]