Unique LCR variations among lineages of HPV16, 18 and 45 isolates from women with normal cervical cytology in Ghana

Expression of "Hallmarks of Cancer" Genes in Cervical Carcinoma Is Differentially Affected by GPER1 Overexpression Depending on Histologic Entity

BACKGROUND/AIM

Cervical cancer (CC) remains the fourth most common malignancy in women worldwide. Current treatments primarily consist of surgery and combined radiochemotherapy, while targeted therapies, as seen in other malignancies, remain underdeveloped. The G-protein-coupled estrogen receptor (GPER1) is implicated in various cancers and can differentially influence tumor behavior, though its precise role in CC remains unclear, with both tumor-promoting and tumor-suppressive effects reported. We previously explored the impact of stable GPER1 overexpression (OE) in CC cell lines, SiHa (cervical squamous cell carcinoma, CSCC) and HeLa (cervical adenocarcinoma, CAC), analyzing proliferation, migration, invasion, apoptosis, and stem cell properties. GPER1-OE enhanced tumorigenic properties in CSCC cells but demonstrated tumor-suppressive effects in CAC cells. To investigate the underlying mechanisms, we conducted next-generation sequencing (NGS) analyses, which supported our earlier findings.

MATERIALS AND METHODS

SiHa CSCC and HeLa CAC cells with stable GPER1-OE were generated. The effects of GPER1-OE on gene expression were then examined using next-generation sequencing (NGS) analyses.

RESULTS

In CSCC cells, GPER1-OE upregulated genes involved in tumorigenic pathways, including epithelial-to-mesenchymal transition (EMT), mTOR-C1, Myc, p53, hypoxia, and angiogenesis signaling. In CAC cells, however, GPER1-OE downregulated these pathways, along with additional pathways such as KRAS, Hedgehog, TNFα (via NFκB), and Wnt/Beta-Catenin signaling.

CONCLUSION

The results highlight the divergent roles of GPER1-OE in CC cells, promoting oncogenesis in CSCC while exerting tumor-suppressive effects in CAC by modulating oncogenic signaling pathways.

HPV18 L1 and long control region sequences variation and E6/E7 differential expression in nasopharyngeal and cervical cancers: a comparative study

BACKGROUND

The role of high-risk human papillomaviruses (hr-HPVs) in cervical cancer (CC) pathogenesis has long been established. Knowledge about the involvement of hr-HPVs in the etiology of nasopharyngeal cancers (NPC) was not well appreciated until the early 2000s when a clear link began to emerge. However, it is not clear whether HPV oncogenesis in the different epithelial cancers is associated with L1 gene and long-control region (LCR) sequences variation. This study aimed to investigate the HPV18 L1 gene and LCR sequences variation in cervical and nasopharyngeal biopsies, and assessed E6 and E7 genes expression level in both cancers.

METHOD

Four-hundred and three (403) formalin-fixed paraffin-embedded tissues originating from nasopharyngeal (NPC) (279) and cervical (CC) (124) sites were collected from a pathology laboratory, Pathologist Without Borders, Accra, Ghana. Haematoxylin and eosin staining was carried out to confirm the presence of cancer on prepared biopsy sections. DNA was extracted from the confirmed cancer biopsies, followed by PCR using MY09/GP5+ /6+ primers to detect the presence of HPV and specific primers for the amplification of L1 gene and LCR. Sanger sequencing was carried out to determine HPV genotypes, and L1 and LCR sequences variant of HPV18s in CC and NPC biopsies. The HPV18 E6/E7 mRNA expression pattern in both cancers was determined using RT-qPCR.

RESULTS

Most of the NPC (45%) and CC (55%) biopsies were HPV18 positive. Comparison of HPV18 L1 sequences obtained from cervical and nasopharyngeal cancer tissues, the L1 sequences from the NPC were highly dissimilar with a 59-100% variation among themselves, and in relation to the reference strains. However, the L1 sequences from the CC were more similar with a 91.0-100% variation among the amplified sequences. Also, the LCR sequences from CC were quite different relative to that of NPC. Results for the differential expression of E6/E7 in the two cancers showed a higher fold change in E6 expression in the CC tissues than the NPC tissues while a reverse expression pattern was found for E7 gene.

CONCLUSION

The current study reports for the first-time variations in HPV18 L1 and LCR sequences, and differential expression of E6/E7 genes in NPC compared to CC, suggesting a possible adaptation mechanism of the virus at different cancer sites.

Diversity of cervicovaginal human papillomavirus (HPV) genotypes and naturally occurring E6/E7 DNA polymorphisms of HPV-16 in Ghana

Human papillomavirus (HPV) E6 and E7 oncogene expression is essential for cervical carcinogenesis. Evidence exists that E6/E7 variants may have different transforming activities while the risk of HPV-16 variants (A/D) differs by race/ethnicity. We determined the type-specific diversity of HPV infection in women with high grade cervical disease or cervical cancer in Ghana and investigated naturally occurring E6/E7 DNA variants in this population. HPV genotyping was carried out on 207 cervical swab samples collected from women referred to a gynaecology clinic at two teaching hospitals in Ghana. HPV-16, HPV-18 and HPV-45 were detected in 41.9%, 23.3% and 16.3% of cases respectively. HPV-16 E6/E7 DNA sequencing was performed in 36 samples. Thirty samples contained E6/E7 variants of the HPV-16-B/C lineage. 21/36 samples were of the HPV-16C1 sublineage variant and all contained the E7 A647G(N29S) single nucleotide polymorphism (SNP). This study reveals the diversity of E6/E7 DNA and the dominance of HPV16 B/C variants in cervicovaginal HPV infection in Ghana. Type-specific HPV diversity analysis indicates that most Ghanaian cervical disease cases are vaccine preventable. The study provides an important baseline from which for the impact of vaccine and antivirals on clinically relevant HPV infection and associated disease can be measured.

Genetic diversity and functional implication of the long control region in human papillomavirus types 52, 58, and 16 from Central China

OBJECT

High-risk human papillomavirus (HR-HPV) is a main reason for cervical cancer. The long control region (LCR) of the genome plays a variety of roles in the transcription of the virus.

METHODS

LCR sequences were amplified by polymerase chain reaction (PCR) and confirmed by DNA sequencing. MEGA 11.0 software and NCBI blast were used to analyze the sequences and construct the Neighbor-Joining tree. In addition, the JASPAR database was used to predict the potential transcription factor binding sites (TFBS).

RESULTS

For HPV-52 LCR, 68 single nucleotide polymorphisms (SNPs), 8 deletions, and 1 insertion were found, 17 of which were novel variations. Most of the variants were clustered in B2 sub-lineage (96.22%). For HPV-58 LCR, 25.43% of samples were prototype. 49 SNPs, 2 deletions, and 1 insertion were observed in the remaining samples. A1 sub-lineage was the most frequent (64.16%). For HPV-16 LCR, 75 SNPs and 2 deletions were identified, 13 of which were newly identified. A total of 55.68% of the variants were distributed in A4 sub-lineage. The JASPAR results suggested that multiple variations occurred in TFBSs, which might affect the function of transcription factors.

CONCLUSIONS

This study provides experimental data for further studies on the epidemiology and biological function of LCR. Various LCR mutational data may prove useful for exploring the carcinogenic mechanism of HPV.

Characterization of Human Papillomavirus 16 from Kinshasa (Democratic Republic of the Congo)-Implications for Pathogenicity and Vaccine Effectiveness

Human Papillomavirus (HPV) type 16 is the main etiological agent of cervical cancer worldwide. Mutations within the virus genome may lead to an increased risk of cancer development and decreased vaccine response, but there is a lack of information about strains circulating in Sub-Saharan Africa. Endocervical cytology samples were collected from 480 women attending a voluntary cervical cancer screening program at Monkole Hospital and four outpatient centers in Kinshasa, Democratic Republic of the Congo (DRC). The prevalence of HPV infection was 18.8% and the most prevalent high-risk types were HPV16 (12.2%) followed by HPV52 (8.8%) and HPV33/HPV35 (7.8% each). HPV16 strains were characterized: 57.1% were classified as C lineage; two samples (28.6%) as A1 and one sample belonged to B1 lineage. HPV33, HPV35, HPV16, and HPV58 were the most frequent types associated with low-grade intraepithelial lesion while high-grade squamous intraepithelial lesions were predominantly associated with HPV16. Several L1 mutations (T266A, S282P, T353P, and N181T) were common in Kinshasa, and their potential effect on vaccine-induced neutralization, especially the presence of S282P, should be further investigated. Long control region (LCR) variability was high with frequent mutations like G7193T, G7521A, and G145T that could promote malignancy of these HPV16 strains. This study provides a helpful basis for understanding HPV16 variants circulating in Kinshasa and the potential association between mutations of LCR region and malignancy and of L1 and vaccine activity.

Epidemiology and Burden of Human Papillomavirus and Related Diseases, Molecular Pathogenesis, and Vaccine Evaluation

Diagnosed in more than 90% of cervical cancers, the fourth deadliest cancer in women, human papillomavirus (HPV) is currently the most common pathogen responsible for female cancers. Moreover, HPV infection is associated with many other diseases, including cutaneous and anogenital warts, and genital and upper aerodigestive tract cancers. The incidence and prevalence of these pathologies vary considerably depending on factors including HPV genotype, regional conditions, the study population, and the anatomical site sampled. Recently, features of the cervicovaginal microbiota are found to be associated with the incidence of HPV-related diseases, presenting a novel approach to identify high-risk women through both blood and cervical samples. Overall, the HPV repartition data show that HPV infection and related diseases are more prevalent in developing countries. Moreover, the available (2-, 4-, and 9-valent) vaccines based on virus-like particles, despite their proven effectiveness and safety, present some limitations in terms of system development cost, transport cold chain, and oncogenic HPV variants. In addition, vaccination programs face some challenges, leading to a considerable burden of HPV infection and related diseases. Therefore, even though the new (9-valent) vaccine seems promising, next-generation vaccines as well as awareness programs associated with HPV vaccination and budget reinforcements for immunization are needed.

Genetic variability and functional implication of HPV16 from cervical intraepithelial neoplasia in Shanghai women

Human papillomavirus (HPV)16 gene mutation is usually associated with persistent HPV infection and cervical intraepithelial neoplasia (CIN). However, the functional implications of HPV16 mutations remain poorly understood.145 LCR/E6/E7 of the HPV16 isolates were amplified and sequenced, and HPV16 integration status was detected. In total, 89 SNPs (68 in the LCR, 13 in E6, 8 in E7) were discovered, 11 of which were nonsynonymous mutations (8 in E6, 3 in E7). The H85Y and E120D variants in E6 were significantly reduced in the high-grade squamous intraepithelial lesion (HSIL) group compared to the <HSIL group (P = .046 and .005), conversely the N29S in E7(P = .01). Amino acid substitutions (D32N/E, E36Q, H85Y, and E120D in E6 and N29H/S and R77C in E7) were predicted to have an effect on conserved structural and functional residues, and five amino acid substitutions (H85Y, E36Q, I34L, and D32E in E6; R77C in E7) would potentially change the secondary structure. "6329G>T," a potential binding site for TATA-binding protein, is the most common in LCR variants. A4 (Asian) was associated with an increased risk of HSIL compared to A1-3(P = .009). The H85/E120 in E6 and N29 in HPV16 E7 might play a critical role in carcinogenesis by disrupting p53 and Rb degradation due to affecting their interaction, respectively. In a word, the findings in this study provide preventative and therapeutic interventions of HPV16 -related cervical lesions/cancer.

Designing of CD8+ and CD8+-overlapped CD4+ epitope vaccine by targeting late and early proteins of human papillomavirus

BACKGROUND AND AIM

Human papillomavirus (HPV) is an oncogenic agent that causes over 90% of cases of cervical cancer in the world. Currently available prophylactic vaccines are type specific and have less therapeutic efficiency. Therefore, we aimed to predict the potential species-specific and therapeutic epitopes from the protein sequences of HPV45 by using different immunoinformatics tools.

METHODS

Initially, we determined the antigenic potential of late (L1 and L2) and early (E1, E2, E4, E5, E6, and E7) proteins. Then, major histocompatibility complex class I-restricted CD8+ T-cell epitopes were selected based on their immunogenicity. In addition, epitope conservancy, population coverage (PC), and target receptor-binding affinity of the immunogenic epitopes were determined. Moreover, we predicted the possible CD8+, nested interferon gamma (IFN-γ)-producing CD4+, and linear B-cell epitopes. Further, antigenicity, allergenicity, immunogenicity, and system biology-based virtual pathway associated with cervical cancer were predicted to confirm the therapeutic efficiency of overlapped epitopes.

RESULTS

Twenty-seven immunogenic epitopes were found to exhibit cross-protection (≥55%) against the 15 high-risk HPV strains (16, 18, 31, 33, 35, 39, 51, 52, 56, 58, 59, 68, 69, 73, and 82). The highest PC was observed in Europe (96.30%), North America (93.98%), West Indies (90.34%), North Africa (90.14%), and East Asia (89.47%). Binding affinities of 79 docked complexes observed as global energy ranged from -10.80 to -86.71 kcal/mol. In addition, CD8+ epitope-overlapped segments in CD4+ and B-cell epitopes demonstrated that immunogenicity and IFN-γ-producing efficiency ranged from 0.0483 to 0.5941 and 0.046 to 18, respectively. Further, time core simulation revealed the overlapped epitopes involved in pRb, p53, COX-2, NF-X1, and HPV45 infection signaling pathways.

CONCLUSION

Even though the results of this study need to be confirmed by further experimental peptide sensitization studies, the findings on immunogenic and IFN-γ-producing CD8+ and overlapped epitopes provide new insights into HPV vaccine development.