Genetic variations of human papillomavirus type 16: implications for cervical carcinogenesis

Kernel Bayesian nonlinear matrix factorization based on variational inference for human-virus protein-protein interaction prediction

Identification of potential human-virus protein-protein interactions (PPIs) contributes to the understanding of the mechanisms of viral infection and to the development of antiviral drugs. Existing computational models often have more hyperparameters that need to be adjusted manually, which limits their computational efficiency and generalization ability. Based on this, this study proposes a kernel Bayesian logistic matrix decomposition model with automatic rank determination, VKBNMF, for the prediction of human-virus PPIs. VKBNMF introduces auxiliary information into the logistic matrix decomposition and sets the prior probabilities of the latent variables to build a Bayesian framework for automatic parameter search. In addition, we construct the variational inference framework of VKBNMF to ensure the solution efficiency. The experimental results show that for the scenarios of paired PPIs, VKBNMF achieves an average AUPR of 0.9101, 0.9316, 0.8727, and 0.9517 on the four benchmark datasets, respectively, and for the scenarios of new human (viral) proteins, VKBNMF still achieves a higher hit rate. The case study also further demonstrated that VKBNMF can be used as an effective tool for the prediction of human-virus PPIs.

Impact of HPV-16 Lineages Infection in Response to Radio-Chemotherapy in Cervical Cancer

BACKGROUND

HPV is strongly related to cervical cancer. HPV lineages can contribute to a response to cervical cancer therapy. The aim of this research was to estimate the frequency of human papillomavirus (HPV)-16 lineages in specimens of cervical cancer, relate the pathological factors in these variants, and assess their response to treatment with radical chemoradiotherapy.

METHODS

Samples of cervical cancer were collected from women who were referred to a reference cancer hospital to test the presence of human papillomavirus-type DNA. The standard protocol of this service consisted of cisplatin-based chemotherapy of 40 mg/m², plus conventional pelvic irradiation in doses of 45-50.4 Gy and high dose-rate brachytherapy of 28-30 Gy to Point A. The response to chemotherapy was evaluated after three months in patients with the HPV-16 lineage.

RESULTS

HPV DNA was detected in 104 (88.1%) of the 118 patients. HPV-16 was present in 63 patients (53%). Lineages of HPV-16 were identified in 57 patients and comprised 33 instances of (57.8%) lineage A, 2 instances of lineage B (3.5%), 2 instances of lineage C (3.5%), and 20 instances of (35.0%) lineage D. The median age of the patients was 48.4 years (range 25-85 years). Squamous cell carcinoma was detected 48 times (84.2%). Adenocarcinoma was more likely to occur in lineage D, as three of the four cases occurred in this lineage. A total of 11 patients with the HPV-16 variant were treated with chemoradiotherapy. After three months, it was observed that nine of the eleven patients (81.8%) achieved a complete response, five with the lineage A type, two with the lineage C type, and two with the lineage D type. The two cases of partial response and disease progression, one of each, occurred in lineage A.

CONCLUSIONS

In addition to the small number of patients and HPV variants, we noticed a better response in patients with the HPV-16 lineage A. Increasing the sample size could be helpful to better assess the impact of HPV variants on cervical cancer treatment.

Frequency of human papilomavirus and associated factors in gypsy and quilombola women : Human papillomavirus in gypsy and quilombola women

BACKGROUND

The prevalence of Human Papillomavirus (HPV) infection in the general population is widely known, however, there are still few studies related to this infection in minority groups, Thus, the objective is to analyze the frequency of human papillomavirus and associated factors in quilombola and gypsy women.

METHODS

Cross-sectional research with 145 quilombola and gypsy women from Caxias, Maranhão. Two Pap smear collections were performed and a questionnaire with 46 questions was applied between January, 2020 and March, 2021. Descriptive analysis and Odds Ratio with 95% confidence interval were performed. The research was approved by the ethics committee.

RESULTS

There were 09 cases of atypia. The frequency of human papillomavirus was 41.37%, with a higher risk in quilombolas 55 (91.70%). Multiple infections were prevalent (53%) with high-risk genotypes 21 (35%). Types 16 and 18 together accounted for 42.85% of cases.

CONCLUSIONS

The frequency of human papillomavirus infection was higher than those recorded in the Northeast and Brazil, and therefore type 16 predominated. Due to limitations, the virus lineages and sublineages were not evaluated. Quilombola women had a higher rate of infection than gypsies.

Genetic diversity of E6, E7 and the long control region in human papillomavirus type 16 variants in Beijing, China

Background

High-risk human papillomavirus type 16 (HPV16) is a risk factor for cervical cancer. The progression from initial infection to cervical cancer has been linked to properties of the viral sequences. However, the distribution of HPV16 variants among Chinese women has not been extensively addressed and the role of HPV16 variants in the risk of cervical carcinogenesis remains poorly understood.

Methods

HPV16 positive cervical exfoliated cell samples were collected from 249 women living in Beijing, China. PCR products from two fragments of E6-E7 and LCR of HPV16 in these samples were sequenced and analyzed.

Results

Lineage A was found in the subjects, including A1, A2, A3 and A4 sublineages. Based on the HPV16 reference sequences, 26 nucleotide mutations of A4 sublineage and 39 nucleotide mutations of A1-3 sublineages were found in the E6, E7 and LCR of HPV16 isolates. Point mutations T843C, A7287C and A7872G of A4 sublineage were significantly associated with high-grade cervical lesions. The high-frequency sites in HPV16 LCR located at regions that can bind to multiple transcription factors.

Conclusions

This study contributes to the identification of unique variants in the E6, E7 and LCR of HPV16 isolates infected in Chinese women. Mutations of T843C, A7287C and A7872G in A4 sublineages were significantly associated with high-grade cervical lesions, suggesting that mutations in the E7 and LCR region have potential effects on viral replication and progression of cervical cancer.

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Lineage A is the predominant HPV16 variant in Chinese women.

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Based on the HPV16 prototype, 25 nucleotide mutations in E6 and E7 were found and 41 nucleotide mutations in LCR were found.

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The mutations of C843T, A7287C and A7872G were significantly correlated with the cervical lesions.

Epidemiology and Molecular Biology of HPV Variants in Cervical Cancer: The State of the Art in Mexico

Cervical cancer (CC) continues to be a major public health problem in Mexico, ranking second among cancers in women. A persistent infection with human papillomaviruses (HPV) is the main risk factor for CC development. In addition, a significant fraction of other cancers including those of the anus, oropharynx, and penis are also related to HPV infection. In CC, HPV-16 is the most prevalent high-risk HPV type, followed by HPV-18, both being responsible for 70% of cases. HPV intratype variant lineages differ in nucleotide sequences by 1–10%, while sublineages differ by 0.5–1%. Several studies have postulated that the nucleotide changes that occur between HPV intratype variants are reflected in functional differences and in pathogenicity. Moreover, it has been demonstrated that HPV-16 and -18 intratype variants differentially affect molecular processes in infected cells, changing their biological behavior that finally impacts in the clinical outcome of patients. Mexico has participated in providing knowledge on the geographical distribution of intratype variants of the most prevalent HPVs in premalignant lesions of the cervix and cervical cancer, as well as in other HPV-related tumors. In addition, functional studies have been carried out to assess the cellular effects of intratype variations in HPV proteins. This review addresses the state of the art on the epidemiology of HPV-16 and HPV-18 intratype variants in the Mexican population, as well as their association with persistence, precancer and cervical cancer, and functional aspects related to their biological behavior.

The polymorphism analysis and epitope predicted of Alphapapillomavirus 9 E6 in Sichuan, China

Background

The Alphapapillomavirus 9 (α-9 HPV) is a member of the Alphapapillomavirus genus and Papillomaviridae family. These viruses are almost all carcinogenic HPV, which is closely related to 75% of invasive cervical cancer worldwide, and has a high prevalence in Sichuan. The carcinogenic function is mainly realized by its E6 oncoprotein.

Methods

Cell samples were collected by cervical scraped for HPV detecting and typing. HPV-16, HPV-31, HPV-33, HPV-52, HPV-58 5 α-9 genus HPV subtype positive samples were selected, their E6 gene was sequenced and analyzed. The positive selection sites of HPV E6 genes were estimated by PAML 4.8 server. The secondary and tertiary structure of E6 protein were predicted by PSIPred and Swiss-model. The T-cell antigen epitopes of E6 protein were predicted by IEDB.

Results

α-9 HPV has a high prevalence in Sichuan, China. From 2012 to 2017, 18,067 cell cervical samples were collected, and 3135 were detected with α-9 HPV infection. Among which, 250 cases HPV-16 E6, 96 cases HPV-31 E6, 216 cases HPV-33 E6, 288 cases HPV-52 E6 and 405 cases HPV-58 E6 were successfully amplified, 17, 6, 6, 13, and 4 non-synonymous nucleotide mutations were respectively detected in HPV-16, 31, 33, 52, and 58 E6, 7 positive selection sites of α-9 HPV E6 were selected out (D32E of HPV-16 E6, K35N, K93N and R145I of HPV-33 E6, K93R of HPV-52 E6, K93N and R145K of HPV-58 E6). The structure and antigen epitopes of E6 protein with amino acid substitution differ from those of wild-type E6 protein, especially for the mutation located in the E6 positive selection site.

Conclusions

HPV E6 nucleotide non-synonymous mutation in the positive selection site influence the protein structure and decrease the antigen epitopes affinity of the E6 protein overall, making it more difficult for the HPV-infected cells to be detected by the immune system, and enhancing the HPV adaptability to the environment. Mutations influence the validity of HPV clinical diagnostic probes, the polymorphism analysis of α-9 HPV E6 enrich the data of HR-risk HPV in Sichuan China, and the detection probes designed with the polymorphism data in mind can improve the efficiency of clinical detection; Mutations influence epitopes affinity, the association of E6 polymorphism and epitope affinity can improve the design of therapeutic vaccine with good immunity and high generality antigen epitope; The above study all provide a good theoretical basis for the prevention and treatment of HPV-related diseases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-021-01728-4.

Association of cervical carcinogenesis risk with HPV16 E6 and E7 variants in the Taizhou area, China

Background

Human papillomavirus (HPV) type 16 accounts for a larger share of cervical cancer and has been a major health problem worldwide for decades. The progression of initial infection to cervical cancer has been linked to viral sequence properties; however, the role of HPV16 variants in the risk of cervical carcinogenesis, especially with longitudinal follow-up, is not fully understood in China.

Methods

We aimed to investigate the genetic variability of HPV16 E6 and E7 oncogenes in isolates from cervical exfoliated cells. Between December 2012 and December 2014, a total of 310 single HPV16-positive samples were selected from women living in the Taizhou area, China. Sequences of all E6 and E7 oncogenes were analysed by PCR-sequencing assay. Detailed sequence comparison, genetic heterogeneity analyses and maximum-likelihood phylogenetic tree construction were performed with BioEdit Sequence Alignment Editor and MEGA X software. Data for cytology tests and histological diagnoses were obtained from our Taizhou Area Study with longitudinal follow-up for at least 5 years. The relationship between HPV16 variants and cervical carcinogenesis risk was analysed by the chi-square test or Fisher’s exact test.

Results

In this study, we obtained 64 distinct variation patterns with the accession GenBank numbers MT681266-MT681329. Phylogenetic analysis revealed that 98.3% of HPV16 variants belong to lineage A, in which the A4 (Asian) sublineage was dominant (64.8%), followed by A2 (12.1%), A1 (11.4%), and A3 (10.0%). The A4 (Asian) sublineage had a higher risk of CIN2+ than the A1–3 (European) sublineages (OR = 2.69, 95% CI = 1.04–6.97, P < 0.05). Furthermore, nucleotide variation in HPV16 E6 T178G is associated with the development of cervical cancer.

Conclusion

These data could provide novel insights into the role of HPV16 variants in cervical carcinogenesis risk in China.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08531-y.

MicroRNA-Based Fingerprinting of Cervical Lesions and Cancer

The regulatory functions of microRNA (miRNA) are involved in all processes contributing to carcinogenesis and response to viral infections. Cervical cancer in most cases is caused by the persistence of high-risk human papillomavirus (HR-HPV) infection. While oncogenic human papillomaviruses induce aberrant expression of many cellular miRNAs, this dysregulation could be harnessed as a marker in early diagnosis of HR-HPV infection, cervical squamous intraepithelial lesions, and cancer. In recent years, growing data indicate that miRNAs show specific patterns at various stages of cervical pathology. The aim of this review is to systematize current reports on miRNA capacity that can be utilized in personalized diagnostics of cervical precancerous and cancerous lesions. The analysis of the resources available in online databases (National Center for Biotechnology Information—NCBI, PubMed, ScienceDirect, Scopus) was performed. To date, no standardized diagnostic algorithm using the miRNA pattern in cervical pathology has been defined. However, the high sensitivity and specificity of the reported assays gives hope for the development of non-invasive diagnostic tests that take into account the heterogeneity of tumor-related changes. Due to this variability resulting in difficult to predict clinical outcomes, precise molecular tools are needed to improve the diagnostic and therapeutic process.

Mutational landscape and intra-host diversity of human papillomavirus type 16 long control region and E6 variants in cervical samples

Human papillomavirus genotype 16 (HPV16) is the most frequent high-risk HPV (HR-HPV) identified in cervical precursor lesions and cervical cancer (CC) worldwide. The oncogenic potential of HPV16 is partly dependent on the lineage involved in the infection and the presence of clinically relevant mutations. In this report, we present the distribution of HR-HPV and the mutational profile and intra-host variability of HPV16 lineages, based on analysis of the long control region (LCR) and the E6 gene in samples with normal cytology (n = 39), squamous intraepithelial lesions (n = 25), and CC (n = 39). HR-HPV genotyping was performed using multiplex real-time PCR. HPV16 lineage assignments and mutation frequencies were determined by conventional PCR and Sanger DNA sequencing, and intra-patient viral populations were analyzed using next-generation sequencing (NGS). The most frequent HR-HPV type was HPV16, followed by HPV31 and HPV18. The frequency of HPV16 sublineages was A1/A2 > D2 > D3 and B1. Moreover, the most frequent mutations, both in samples from this study and in the available sequences from Mexican isolates in the GenBank database were LCR-G7518A, which is involved in carcinogenesis, and E6-T350G (producing L83V), associated with persistence of infection. Otherwise, deep sequencing revealed high conservation of viral lineages and mutations, independently of the stages studied. In conclusion, the high frequency and stability of these molecular markers, as well as the circulating viral lineages, could be related to the incidence of CC associated with HPV16. Hence, they deserve a broader analysis to determine the risk of specific populations for progression of the disease.

Human Papillomavirus Genotypes and HPV16 E6/E7 Variants among Patients with Genital Cancers in Vietnam

We previously reported human papillomavirus type 52 (HPV52) as the most prevalent high-risk genotype in non-cancer individuals in Vietnam. This study aimed to evaluate HPV genotypes and HPV16 E6 and E7 (E6/E7) gene variations in Vietnamese patients with genital cancers. Biopsy samples were collected from 124 Vietnamese patients with genital cancers (20 with vaginal, 50 with vulvar, and 54 with penile cancer). The HPV-DNA was amplified and genotyped, and HPV16 E6/E7 genes were compared with those previously reported for women with normal cervical cytology (N = 23). HPV-DNA was detected in 80.6% (100/124) of the cancer patients (80.0% of vaginal, 82.0% of vulvar, and 79.6% of penile), with HPV16/18 in 86.0% (86/100) and HPV52 in 7.0% (7/100) of the HPV-positive samples. The HPV-DNA prevalence and HPV genotype distribution did not significantly differ among the genital cancer patients (both P = 0.95). Significantly fewer instances of the HPV16 A4 sublineage (34.8% vs. 82.6%, P < 0.0001) and HPV16 E7 29S (36.4% vs. 87.0%, P = 0.0002) occurred in the cancer patients than in the women with normal cytology. Our results indicate that HPV16/18 accounts for more than 85% of genital cancers in Vietnam, and the HPV16 sublineage A4 containing E7 29S may be less oncogenic.

Findings of multiple HPV genotypes in cervical carcinoma are associated with poor cancer-specific survival in a Swedish cohort of cervical cancer primarily treated with radiotherapy

Cervical cancer (CC) is one of the most common cancers in women and virtually all cases of CC are a result of a persistent infection of human papillomavirus (HPV). For disease detected in early stages there is curing treatment but when diagnosed late with recurring disease and metastasis there are limited possibilities. Here we evaluate HPV impact on treatment resistance and metastatic disease progression. Prevalence and distribution of HPV genotypes and HPV16 variants in a Swedish CC patient cohort (n=209) was evaluated, as well as HPV influence on patient prognosis. Tumor samples suitable for analysis (n=204) were genotyped using two different real-time PCR methods. HPV16 variant analysis was made using pyrosequencing. Results showed that HPV prevalence in the total series was 93%. Of the HPV-positive samples, 13% contained multiple infections, typically with two high-risk HPV together. Primary cure rate for the complete series was 95%. Recurrence rate of the complete series was 28% and distant recurrences were most frequent (20%). Patients with tumors containing multiple HPV-strains and particularly HPV genotypes belonging to the alpha 7 and 9 species together had a significantly higher rate of distant tumor recurrences and worse cancer-specific survival rate.

Utility of high-throughput DNA sequencing in the study of the human papillomaviruses

The Papillomaviridae family is probably the most diverse group of viruses that affect vertebrates. The study of the relationship between infection by certain types of human papillomavirus (HPV) and the development of neoplastic epithelial lesions is of particular interest because of the high prevalence of HPV-related carcinomas in populations of developing countries. To understand the mechanisms of infection and their association with different clinical manifestations, molecular tools play an important role in the description of new types of HPV, the characterization of effector properties of the viral factors, the specific diagnosis and monitoring of HPV types, and the alteration patterns at genetic level in the host. Technological advances in the field of DNA sequencing have led to the development of different next-generation sequencing systems, allowing obtaining a large amount of data and broadening the applications to study viral diseases. In this review, we summarize the main approaches and their perspectives where the use of massively parallel sequencing has been proved as a useful tool in the research of the HPV infection.

Heat Increases the Editing Efficiency of Human Papillomavirus E2 Gene by Inducing Upregulation of APOBEC3A and 3G

Apolipoprotein B mRNA-editing catalytic polypeptide (APOBEC) 3 proteins have been identified as potent viral DNA mutators and have broad antiviral activity. In this study, we demonstrated that apolipoprotein B mRNA-editing catalytic polypeptide 3A (A3A) and A3G expression levels were significantly upregulated in human papillomavirus (HPV)-infected cell lines and tissues. Heat treatment resulted in elevated expression of A3A and A3G in a temperature-dependent manner in HPV-infected cells. Correspondingly, HPV-infected cells heat-treated at 44 °C showed accumulated G-to-A or C-to-T mutation in HPV E2 gene. Knockdown of A3A or A3G could promote cell viability, along with the lower frequency of A/T in HPV E2 gene. In addition, regressing genital viral warts also harbored high G-to-A or C-to-T mutation in HPV E2 gene. Taken together, we demonstrate that apolipoprotein B mRNA-editing catalytic polypeptide 3 expression and editing function was heat sensitive to a certain degree, partly explaining the mechanism of action of local hyperthermia to treat viral warts.