Different Association of Human Papillomavirus 16 Variants with Early and Late Presentation of Cervical Cancer

RIPOR2 Expression Decreased by HPV-16 E6 and E7 Oncoproteins: An Opportunity in the Search for Prognostic Biomarkers in Cervical Cancer

High-risk human papillomavirus (HPV) infection is the main risk factor for cervical cancer (CC) development, where the continuous expression of E6 and E7 oncoproteins maintain the malignant phenotype. In Mexico, around 70% of CC cases are diagnosed in advanced stages, impacting the survival of patients. The aim of this work was to identify biomarkers affected by HPV-16 E6 and E7 oncoproteins that impact the prognosis of CC patients. Expression profiles dependent on E6 and E7 oncoproteins, as well as their relationship with biological processes and cellular signaling pathways, were analyzed in CC cells. A comparison among expression profiles of E6- and E7-expressing cells and that from a CC cohort obtained from The Cancer Genome Atlas (TCGA) demonstrated that the expression of 13 genes impacts the overall survival (OS). A multivariate analysis revealed that the downregulated expression of RIPOR2 was strongly associated with a worse OS. RIPOR2, including its transcriptional variants, were overwhelmingly depleted in E6- and E7-expressing cells. Finally, in a Mexican cohort, it was found that in premalignant cervical lesions, RIPOR2 expression decreases as the lesions progress; meanwhile, decreased RIPOR2 expression was also associated with a worse OS in CC patients.

Characterization of the Human Papillomavirus 16 Oncogenes in K14HPV16 Mice: Sublineage A1 Drives Multi-Organ Carcinogenesis

The study of human papillomavirus (HPV)-induced carcinogenesis uses multiple in vivo mouse models, one of which relies on the cytokeratin 14 gene promoter to drive the expression of all HPV early oncogenes. This study aimed to determine the HPV16 variant and sublineage present in the K14HPV16 mouse model. This information can be considered of great importance to further enhance this K14HPV16 model as an essential research tool and optimize its use for basic and translational studies. Our study evaluated HPV DNA from 17 samples isolated from 4 animals, both wild-type (n = 2) and HPV16-transgenic mice (n = 2). Total DNA was extracted from tissues and the detection of HPV16 was performed using a qPCR multiplex. HPV16-positive samples were subsequently whole-genome sequenced by next-generation sequencing techniques. The phylogenetic positioning clearly shows K14HPV16 samples clustering together in the sub-lineage A1 (NC001526.4). A comparative genome analysis of K14HPV16 samples revealed three mutations to the human papillomaviruses type 16 sublineage A1 representative strain. Knowledge of the HPV 16 variant is fundamental, and these findings will allow the rational use of this animal model to explore the role of the A1 sublineage in HPV-driven cancer.

Infection status and survival impact of high-risk human papillomavirus in cervical adenocarcinomas: A systematic review and meta-analysis

OBJECTIVE

Cervical adenocarcinoma (CAC) comprises a heterogeneous group of tumors that are not universally associated with HPV infection. As has been shown in other organs, it is becoming increasingly apparent that HPV status significantly affects the prognosis of adenocarcinoma. We conducted a systematic review and meta-analysis to investigate the infection status of high-risk Human papillomavirus (hrHPV) in CAC and evaluate its impact on the survival of patients.

METHODS

PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), International Clinical Trials Registry Platform (ICTRP), and Clinical Trials.gov were searched from inception to May 1st, 2022. Data on HPV infection status and survival outcomes were evaluated using STATA 16.0.

RESULTS

Seventy-one studies with 11,278 participants were included in HPV infection analysis and eight studies with 1099 participants were included in prognosis analysis. The HPV infection rate (including high-risk and low-risk) and hrHPV infection rate in CAC were 75% (95% CI 0.70-0.80, 6978 participants) and 75% (95% CI 0.70-0.81, 4906 participants), respectively. HPV-16 and -18 were the most common HPVs in CAC, with pooled infection rates of 37% (95% CI 0.33-0.41, 7848 participants) and 34% (95% CI 0.30-0.38, 7730 participants), respectively. hrHPV infection was associated with better overall survival (HR 0.23, 95% CI 0.11-0.47, 1013 participants), better disease-free survival (HR 0.18, 95% CI 0.07-0.43, 292 participants), better progression-free survival (HR 0.20, 95% CI 0.08-0.47, 271 participants) and less recurrence (RR 0.30, 95% CI 0.07-0.43, 181 participants).

CONCLUSION

HPV infection rates were high in CAC. HPV-16 and -18 had the highest infection rates in CAC. However, hrHPV infection was associated with better survival and less recurrence. Future studies should clarify the relationship between hrHPV infection and other prognostic factors and make reasonable treatment strategies for CAC with different HPV status.

PROTOCOL REGISTRATION

CRD42022319390.

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.

Phylogeny and In Silico Structure Analysis of Major Capsid Protein (L1) Human Papillomavirus 45 from Indonesian Isolates

BACKGROUND

Human papillomavirus (HPV)-45 genotype circulates in high percentage in Bandung area - Indonesia, after HPV-16 and HPV-18. The aim of this study was to analyse variations of major capsid (L1) HPV-45 and its phylogeny. Furthermore in silico protein structure and epitope prediction was explored.

METHODS

L1 gene of HPV-45 was amplified, sequenced and aligned. Phylogenetic tree had been built and compared with a complete L1 HPV-45 sequence. Structure and epitope prediction of L1 protein were then developed in silico.

RESULTS

Of 5 L1 HPV-45 sequences collected, we have detected one variant of sub lineage A2 which was considered as a new variant, and two variants of B2. Superimposition of structure of these two variants with reference showed very similar structure. Furthermore, seven amino acid substitutions were found within these L1 variants of which two substitutions might change the polarity of corresponding amino acid I329T and S383G. The S383G occurred in surface loop (HI-Loop) of new L1 HPV-45 variant.

CONCLUSION

Similar structure of Indonesian variants indicates that amino acids variations do not affect the L1 structure. However, one substitution with altered amino acid polarity found within the area of surface loop suggests a potential impact in antibody recognition and neutralization.

Role of HPV 16 variants among cervical carcinoma samples from Northeastern Brazil

BACKGROUND

Cervical cancer is the fourth most common type of cancer affecting women globally. In Brazil, it is the third most frequent type of cancer in women and HPV is present in approximately 90% of cases. Evidence suggests that variants of HPV 16 can interfere biologically and etiologically during the development of cervical cancer.

METHODS

Cervix tumor fragments were collected, their DNA was extracted, and nested PCR was used to detect HPV. Positive samples were sequenced to determine the viral genotype. To characterize the HPV 16 strains, positive samples PCR was used to amplify the LCR and E6 regions of the HPV 16 virus.

RESULTS

Data from 120 patients with cervical cancer were analyzed. Most women were between 41 and 54 years of age, had schooling until primary school, a family income between 1 and 2 times the minimum wage and were married/in a consensual union. There was no statistically significant association between HPV or socio-demographic variables and risk factors for cervical cancer (P <  0.05). HPV was present in 88 women (73%). The most prevalent types were HPV 16 (53.4%), HPV 18 (13.8%), HPV 35 (6.9%) and HPV 45 (5.7%). Of the 47 HPV 16 positive cases, variant A (49%) was present in 23 samples, followed by variant D in 20 cases (43%), and variants B and C in 2 cases each (4%). The most prevalent histological type of HPV 16 tumors was squamous cell carcinoma, followed by adenocarcinoma. There was a statistically significant association between HPV 16 variants and the tumors' histological types (P <  0.001).

CONCLUSIONS

Knowledge of HPV 16 variants will provide data on their influence on the pathological and oncogenic aspects of cervical lesions.

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.

High frequency of HPV16 European variant E350G among Mexican women from Sinaloa

Background & objectives:

Human papillomavirus (HPV) infections play a crucial role in the aetiology of cervical cancer (CC), and HPV16 is the primary viral genotype associated with CC. A number of variants of the HPV16 E6 gene are involved in the progression of CC, differing in their prevalence and biological and biochemical properties. This study was designed to determine the frequency of HPV types 16/18 and to identify the presence of HPV16 E6-variants in asymptomatic Mexican women.

Methods:

A total of 189 cervical Pap smears were collected from women attending public health services in three different cities in Sinaloa, Mexico. Viral DNA was identified by amplification of E6 viral gene fragments using polymerase chain reaction (PCR). Identification of variants was done by sequencing a DNA fragment (321bp) of the HPV16 E6 gene.

Results:

More than half of the women tested were HPV-positive (52.38%), with HPV16 being the most frequent genotype (21.16%), followed by HPV18 (8.99%). Sequence analysis of the E6-HPV16 PCR products showed that in all cases, the viruses corresponded to European variants. It was further observed that the E350G intra-variant was the most common (>76%).

Interpretation & conclusions:

This study showed a predominance of European lineage variants of HPV16 among asymptomatic women from Sinaloa, Mexico, predominantly with of the E350G variant. This variant has been shown to be associated with an increased risk of early development of CC. The use of molecular identification of carcinogenic HPV and Pap test screening may be a good strategy for monitoring women to prevent CC.