Microfluid biosensor for detection of hpv in patient scraping samples: Determining E6 and E7 oncogenes.

E6 and E7 oncogenes are pivotal in the carcinogenic transformation in HPV infections and efficient diagnostic methods can ensure the detection and differentiation of HPV genotype. This study describes the development and validation of an electrochemical, label-free genosensor coupled with a microfluidic system for detecting the E6 and E7 oncogenes in cervical scraping samples. The nanostructuring employed was based on a cysteine and graphene quantum dots layer that provides functional groups, surface area, and interesting electrochemical properties. Biorecognition tests with cervical scraping samples showed differentiation in the voltammetric response. Low-risk HPV exhibited a lower biorecognition response, reflected in ΔI% values of 82.33 % ± 0.29 for HPV06 and 80.65 % ± 0.68 for HPV11 at a dilution of 1:100. Meanwhile, high-risk, HPV16 and HPV18, demonstrated ΔI% values of 96.65 % ± 1.27 and 93 % ± 0.026, respectively, at the same dilution. Therefore, the biorecognition intensity followed the order: HPV16 >HPV18 >HPV06 >HPV11. The limit of detection and the limit of quantification of E6E7 microfluidic LOC-Genosensor was 26 fM, and 79.6 fM. Consequently, the E6E7 biosensor is a valuable alternative for clinical HPV diagnosis, capable of detecting the potential for oncogenic progression even in the early stages of infection.

Novel Gammapapillomavirus type in the nasal cavity of a wild red colobus (Piliocolobus tephrosceles).

Papillomaviruses (PVs) are double-stranded, circular, epitheliotropic DNA viruses causing benign warts (papillomas) or inducing dysplasia that can progress to cancer. Although they have been identified in all vertebrate taxa, most classified types are human PVs (HPVs); relatively little is known about PVs in other species. Here we characterize a novel Gammapapillomavirus type, PtepPV1, from a nasal swab of a wild red colobus (Piliocolobus tephrosceles) in Kibale National Park, Uganda. The virus has a genome of 6576 bases, encoding the seven canonical early (E) ORFs (E6, E7, E1, E2, E4, E1^E4 and E8^E2) and two late (L) ORFs (L1 and L2) of the gammapapillomaviruses, and is 81.0% similar to HPV-mSK_118, detected in a cutaneous wart from an immunocompromised human patient, in the L1 gene at the amino acid level. Alphapapillomaviruses (genus Alphapapillomavirus) cause anogenital carcinomas such as cervical cancer and have been described previously in several nonhuman primates. However, the first gammapapillomavirus (genus Gammapapillomavirus), which cause transient cutaneous infections, was not described until 2019 in a healthy rhesus macaque (Macaca mulatta) genital swab. The new virus from red colobus, PtepPV1, has many genomic features encoded by high-risk oncogenic PVs, such as the E7 gene LXSXE and CXXC motifs, suggesting potential for pRb and zinc-finger binding, respectively. To our knowledge, PtepPV1 is also the first reported nonhuman primate PV found in the nasal cavity. PtepPV1 expands the known host range, geographical distribution, tissue tropism and biological characteristics of nonhuman primate PVs.

Genome composition-based deep learning predicts oncogenic potential of HPVs.

Human papillomaviruses (HPVs) account for more than 30% of cancer cases, with definite identification of the oncogenic role of viral E6 and E7 genes. However, the identification of high-risk HPV genotypes has largely relied on lagged biological exploration and clinical observation, with types unclassified and oncogenicity unknown for many HPVs. In the present study, we retrieved and cleaned HPV sequence records with high quality and analyzed their genomic compositional traits of dinucleotide (DNT) and DNT representation (DCR) to overview the distribution difference among various types of HPVs. Then, a deep learning model was built to predict the oncogenic potential of all HPVs based on E6 and E7 genes. Our results showed that the main three groups of Alpha, Beta, and Gamma HPVs were clearly separated between/among types in the DCR trait for either E6 or E7 coding sequence (CDS) and were clustered within the same group. Moreover, the DCR data of either E6 or E7 were learnable with a convolutional neural network (CNN) model. Either CNN classifier predicted accurately the oncogenicity label of high and low oncogenic HPVs. In summary, the compositional traits of HPV oncogenicity-related genes E6 and E7 were much different between the high and low oncogenic HPVs, and the compositional trait of the DCR-based deep learning classifier predicted the oncogenic phenotype accurately of HPVs. The trained predictor in this study will facilitate the identification of HPV oncogenicity, particularly for those HPVs without clear genotype or phenotype.

HPV18 E6/E7 activates Ca2+ influx to promote the malignant progression of cervical cancer by inhibiting Ca2+ binding protein 1 expression.

Mounting studies have shown that the oncoproteins E6 and E7 encoded by the human papillomavirus (HPV) genome are essential in HPV-induced cervical cancer (CC). Ca2+ binding protein 1 (CABP1), a downstream target of HPV18-positive HeLa cells that interferes with E6/E7 expression, was identified through screening the GEO Database (GSE6926). It was confirmed to be down-regulated in CC through TCGA prediction and in vitro detection. Subsequent in vitro experiments revealed that knocking down E6/E7 inhibited cell proliferation, migration, and invasion, whereas knocking down CABP1 promoted these processes. Simultaneously knocking down CABP1 reversed these effects. Additionally, the results were validated in vivo. Previous studies have indicated that CABP1 can regulate Ca2+ channels, influencing Ca2+ influx and tumor progression. In this study, it was observed that knocking down CABP1 enhanced Ca2+ inflow, as demonstrated by flow cytometry and confocal microscopy. Knocking down E6/E7 inhibited these processes, whereas simultaneously knocking down E6/E7 and CABP1 restored the inhibitory effect of knocking down E6/E7 on Ca2+ inflow. To further elucidate that E6/E7 promotes CC progression by inhibiting CABP1 expression and activating Ca2+ influx, BAPTA/AM treatment was administered during CABP1 knockdown. It was discovered that Ca2+ chelation could reverse the effect of CABP1 knockdown on CC cells. In conclusion, our results offer a novel target for the diagnosis and treatment of HPV-induced CC.

Comparison of preclinical efficacy of immunotherapies against HPV-induced cancers.

INTRODUCTION: Persistent infections with the human papilloma viruses, HPV16 and HPV18, are associated with multiple cancers. Although prophylactic vaccines that induce HPV-neutralizing antibodies are effective against primary infections, they have no effect on HPV-mediated malignancies against which there is no approved immuno-therapy. Active research is ongoing on immunotherapy of these cancers. AREAS COVERED: In this review, we compared the preclinical efficacy of vaccine platforms used to treat HPV-induced tumors in the standard model of mice grafted with TC-1 cells, which express the HPV16 E6 and E7 oncoproteins. We searched for the key words, 'HPV,' 'vaccine,' 'therapy,' 'E7,' 'tumor,' 'T cells' and 'mice' for the period from 2005 to 2023 in PubMed and found 330 publications. Among them, we selected the most relevant to extract preclinical antitumor results to enable cross-sectional comparison of their efficacy. EXPERT OPINION SECTION: We compared these studies for HPV antigen design, immunization regimen, immunogenicity, and antitumor effect, considering their drawbacks and advantages. Among all strategies used in murine models, certain adjuvanted proteins and viral vectors showed the strongest antitumor effects, with the use of lentiviral vectors being the only approach to result in complete tumor eradication in 100% of experimental individuals while providing the longest-lasting memory.

Persistent infections with the human papilloma virus HPV16 and HPV18 gentoypes can cause multiple cancers.Prophylactic anti-HPV vaccines show no efficacy against persistent HPV infections or already malignant tissues.No immunotherapy against HPV-induced cancers has been thus far approved for use in humans.Active research is ongoing on immunotherapy of HPV-induced malignancies.We compared the efficacy of the immunotherapy strategies developed against HPV-induced cancers in the standard murine TC-1 tumor model since 2005.Certain adjuvanted proteins and viral vectors induce the strongest effects against HPV-induced tumors.Lentiviral vectors, able to induce the longest-lasting T-cell immune memory, give rise to full eradication of large solid tumors in 100% of mice.

Genetic variability of human papillomavirus type 18 based on E6, E7 and L1 genes in central China.

BACKGROUND: High-risk human papillomavirus (HR-HPV) infection is an important factor for the development of cervical cancer. HPV18 is the second most common HR-HPV after HPV16. METHODS: In this study, MEGA11 software was used to analyze the variation and phylogenetic tree of HPV18 E6-E7 and L1 genes. The selective pressure to E6, E7 and L1 genes was estimated using pamlX. In addition, the B cell epitopes of L1 amino acid sequences and T cell epitopes of E6-E7 amino acid sequences in HPV18 were predicted by ABCpred server and IEDB website, respectively. RESULTS: A total of 9 single nucleotide variants were found in E6-E7 sequences, of which 2 were nonsynonymous variants and 7 were synonymous variants. Twenty single nucleotide variants were identified in L1 sequence, including 11 nonsynonymous variants and 9 synonymous variants. Phylogenetic analysis showed that E6-E7 and L1 sequences were all distributed in A lineage. In HPV18 E6, E7 and L1 sequences, no positively selected site was found. The nonconservative substitution R545C in L1 affected hypothetical B cell epitope. Two nonconservative substitutions, S82A in E6, and R53Q in E7, impacted multiple hypothetical T cell epitopes. CONCLUSION: The sequence variation data of HPV18 may lay a foundation for the virus diagnosis, further study of cervical cancer and vaccine design in central China.

Correlation analysis of human papillomavirus E6/E7 mRNA detection with diagnosis, prognosis and recurrence risk in patients with cervical epithelioma.

BACKGROUND: Cervical intraepithelial neoplasia (CIN) is an important precursor of cervical cancer. Early detection and treatment can reduce the incidence of cervical cancer. AIM: To investigate the detection rate of human papillomavirus (HPV) E6/E7 mRNA in cervical tissue of patients with different types of epithelial cell neoplasia (CIN) and its relationship with CIN progression and diagnosis. METHODS: One hundred women with HPV infection detected by cervical exfoliation cytology between January 2022 and January 2023 were retrospectively selected. These patients were graded CIN based on colposcopy and cervical pathology. The positive expression rates of HPV E6/E7 mRNA and HPV [polymerase chain reaction (PCR)-reverse dot crossing] were compared among all groups. Patients with HPV E6/E7 mRNA expression in the grade 1 CIN group were followed up for 1 yr. The relationship between atypical squamous epithelium and high malignant epithelial neoplasia was investigated by univariate and multivariate analysis. RESULTS: The diagnostic sensitivity, specificity, and sensitivity of PCR-reverse point hybridization technology for secondary CIN were 70.41%, 70.66%, and 0.714, respectively. Sensitivity and specificity for secondary CIN were 752% and 7853%, respectively, the area under the curve value was 0.789. Logistic Multifactorial model analysis revealed that the HPV positive rates and the HPV E6/E7 mRNA positive rates were independent risk factors of CIN grade I (P < 0.05). In CIN grade I patients with positive for HPV E6/E7 mRNA, in its orientation to grade CIN patients, in its orientation to grade CIN patients, at 69.2%, compared with patients negative for HPV E6/E7 mRNA (30.8%), significant difference (P < 0.05). CONCLUSION: HPV E6/E7 mRNA and HPV (PCR-reverse dot hybrid) positive expression have a close relationship with CIN-grade disease progression and is an independent risk factor for high-grade CIN lesions.

Enhancing Cervical Cancer Screening with 7-Type HPV mRNA E6/E7 Testing on Self-Collected Samples: Multicentric Insights from Mexico.

Cervical cancer remains a significant public health issue, particularly in regions with low screening uptake. This study evaluates the effectiveness of self-sampling and the 7-type HPV mRNA E6/E7 test in improving cervical cancer screening outcomes among a referral population in Mexico. A cohort of 418 Mexican women aged 25 to 65, referred for colposcopy and biopsy due to abnormal cytology results (ASC-US+), participated in this study. Self-samples were analyzed using both the 14-type HPV DNA test and the 7-type HPV mRNA E6/E7 test. The study assessed the sensitivity, specificity, positive predictive value (PPV), and the necessity of colposcopies to detect CIN3+ lesions. Participant acceptability of self-sampling was also evaluated through a questionnaire. The 7-type HPV mRNA E6/E7 test demonstrated equivalent sensitivity but significantly higher specificity (77.0%) and PPV for CIN3+ detection compared to the 14-type HPV DNA test (specificity: 45.8%, p < 0.001). The use of the HPV mRNA test as a triage tool reduced the number of colposcopies needed per CIN3+ case detected from 16.6 to 7.6 (p < 0.001). Self-sampling was highly accepted among participants, with the majority reporting confidence in performing the procedure, minimal discomfort, and willingness to undertake self-sampling at home. Self-sampling combined with the 7-type HPV mRNA E6/E7 testing offers a promising strategy to enhance cervical cancer screening by improving accessibility and ensuring precise diagnostics. Implementing these app roaches could lead to a significant reduction in cervical cancer morbidity and mortality, especially in underserved populations. Future research should focus on the long-term impact of integrating these methods into national screening programs and explore the cost-effectiveness of widespread implementation.

The RP11-417E7.1/THBS2 signaling pathway promotes colorectal cancer metastasis by activating the Wnt/ß-catenin pathway and facilitating exosome-mediated M2 macrophage polarization.

BACKGROUND: Metastasis is the major cause of colorectal cancer (CRC) mortality. Emerging evidence suggests that long noncoding RNAs (lncRNAs) drive cancer metastasis and that their regulatory pathways could be targeted for preventing metastasis. However, the underlying mechanisms of lncRNAs in CRC metastasis remain poorly understood. METHODS: Microarray analysis was used to screen for differentially expressed lncRNAs. Transwell assays, fibronectin cell adhesion assays, and mouse metastasis models were utilized to evaluate the metastatic capacities of CRC in vitro and in vivo. Chromatin isolation by RNA purification, chromatin immunoprecipitation and chromosome conformation capture were applied to investigate the underlying mechanism involved. qRT‒PCR and transmission electron microscopy were performed to confirm macrophage polarization and the presence of cancer-derived exosomes. RESULTS: The lncRNA RP11-417E7.1 was screened and identified as a novel metastasis-associated lncRNA that was correlated with a poor prognosis. RP11-417E7.1 enhances the metastatic capacity of CRC cells in vivo and in vitro. Mechanistically, RP11-417E7.1 binding with High mobility group A1 (HMGA1) promotes neighboring thrombospondin 2 (THBS2) transcription via chromatin loop formation between its promoter and enhancer, which activates the Wnt/ß-catenin signaling pathway and facilitates CRC metastasis. Furthermore, exosomes derived from CRC cells transport THBS2 into macrophages, thereby inducing the M2 polarization of macrophages to sustain the prometastatic microenvironment. Notably, netropsin, a DNA-binding drug, suppresses chromatin loop formation mediated by RP11-417E7.1 at the THBS2 locus and significantly inhibits CRC metastasis in vitro and in vivo. CONCLUSIONS: This study revealed the novel prometastatic function and mechanism of the lncRNA RP11-417E7.1, which provides a potential prognostic indicator and therapeutic target in CRC.

The association between human papillomavirus and lung cancer: A Mendelian randomization study.

BACKGROUND: To investigate the causal relationship between human papillomavirus (HPV) and lung cancer, we conducted a study using the two-sample Mendelian randomization (TSMR). METHOD: Data from genome-wide association studies (GWAS) were analyzed with HPV E7 Type 16 and HPV E7 Type 18 as exposure factors. The outcome variables included lung cancer, small cell lung cancer, adenocarcinoma and squamous cell lung cancer. Causality was estimated using inverse variance weighted (IVW), MR-Egger and weighted median methods. Heterogeneity testing, sensitivity analysis, and multiple validity analysis were also performed.. RESULTS: The results showed that HPV E7 Type 16 infection was associated with a higher risk of squamous cell lung cancer (OR = 7.69; 95% CI:1.98-29.85; p = 0.0149). HPV E7 Type 18 infection significantly increased the risk of lung adenocarcinoma (OR = 0.71; 95% CI: 0.38-1.31; p = 0.0079) and lung cancer (OR = 7.69; 95% CI:1.98-29.85; p = 0.0292). No significant causal relationship was found between HPV E7 Type 16 and lung adenocarcinoma, lung cancer, or small cell lung carcinoma, and between HPV E7 Type 18 and squamous cell lung cancer or small cell lung carcinoma. CONCLUSIONS: This study has revealed a causal relationship between HPV and lung cancers. Our findings provide valuable insights for further mechanistic and clinical studies on HPV-mediated cancer.

Time to take HPV infection in colorectal cancer patients more seriously.

Background: The association between viral infections and colorectal cancer (CRC) remains an enigma in cancer research. Certain types of Human Papillomaviruses (hr-HPVs), known for their oncogenic properties, have been observed in particular CRC biopsies, further adding to the enigma surrounding this association. Materials and methods: This cross-sectional study was conducted on 40 confirmed cases of CRC adenocarcinoma. The presence and genotyping of HPV DNA in colorectal fresh tissue and urine samples was assessed using an HPV DNA hybridization kit. A subset of serum samples from both CRC cases and healthy volunteers was randomly chosen and subjected to western blot to investigate the presence of HPV16 E6/E7 oncoproteins carried by exosomes. Results: It was observed that 26/40 HPV-positive CRC patients demonstrated 7 times more chance to develop colorectal cancer when compared to those 8/40 normal tissue (odds ratio [OR] = 7.4; confidence interval [CI] 95% = 0.483156-0.793718; p < 0.001). Of 26 HPV-positive CRC patients, 14 urine samples were also showed HPV DNA positivity (p = 0.013). High-risk HPV16 was the most prevalent genotype detected in both 24/40 tumor and 12/40 urine samples (p < 0.001). The tumor sample of a male was HPV45, while another male's urine sample was HPV31. A female CRC patient had HPV83 in tumor and HPV56 in urine. Here, was the first detection of HPV83 in a CRC patient. Notably among 20 randomly selected serum exosome samples, one serum sample concurrently tested positive for both HPV16 E6 and E7 oncoproteins, and one sample tested positive for HPV16 E7 oncoprotein. Conclusion: High risk HPV DNA detection in CRC urine samples supports non-invasive screening tools. Detection of HPV16 E6 and E7 oncoproteins in exosomes from serum samples shows potential for non-invasive diagnostics. HPV's potential role in CRC development is also underscored. HPV vaccination should be implemented in low- and middle-income countries to prevent cancer.

HPV integration and cervical cancer: a failed evolutionary viral trait.

Countless efforts have been made to eradicate cervical cancer worldwide, including improving disease screening and human papillomavirus (HPV) vaccination programs. Nevertheless, cervical cancer still claims the lives of more than 300 000 women every year. Persistent infections with high-risk HPV genotypes 16 and 18 are the main cause of cancer and may result in HPV integration into the host genome. The central dogma is that HPV integration is an important step in oncogenesis, but in fact, it impedes the virus from replicating and spreading. HPV causing cervical cancer can therefore be perceived as a failed evolutionary viral trait. Here we outline the occurrence and mechanisms of HPV integration and how this process results in oncogenic transformation.

HPV-driven oncogenesis-much more than the E6 and E7 oncoproteins.

High-risk human papillomaviruses are well-established drivers of several cancer types including cervical, head and neck, penile as well as anal cancers. While the E6 and E7 viral oncoproteins have proven to be critical for malignant transformation, evidence is also beginning to emerge suggesting that both host pathways and additional viral genes may also be pivotal for malignant transformation. Here, we focus on the role of host APOBEC genes, which have an important role in molecular editing including in the response to the viral DNA and their role in HPV-driven carcinogenesis. Further, we also discuss data developed suggesting the existence of HPV-derived miRNAs in HPV + tumors and their potential role in regulating the host transcriptome. Collectively, while recent advances in these two areas have added complexity to the working model of papillomavirus-induced oncogenesis, these discoveries have also shed a light onto new areas of research that will be required to fully understand the process.

The emerging role of human papillomavirus in lung cancer.

Lung cancer stands as one of the most lethal diseases and is the foremost cause of cancer-related mortalities worldwide. The pathophysiology of lung cancer is multifaceted, and it includes multiple cell signaling pathways and other complex factors such as oxidative stress and genetics. The association of HPV with lung carcinogenesis was first proposed in 1979, and since then, scientists worldwide have been putting forward several hypotheses to establish a relationship between this virus and lung cancer. Although studies have reported the presence of HPV in lung cancer, the exact mechanism of entry and the route of transmission have not been elucidated clearly till date. Numerous studies across the globe have detected differentially expressed HPV oncoproteins in lung cancer patients and found their association with the critical cell signaling pathways that leads to the development and progression of lung cancer. Many reports have also provided evidence stating the involvement of HPV in determining the survival status of lung cancer patients. The present review recapitulates the studies evincing the association of HPV and lung cancer, its route of transmission and mechanism of action; the detection of the virus and treatment opportunities for HPV-positive lung cancer; and the severity associated with this disease. Therefore, this will provide an explicit idea and would help to develop preventive measures and specific as well as effective treatment for HPV-associated lung carcinogenesis.

Quantification of HPV16 E7 Oncoproteins in Urine Specimens from Women with Cervical Intraepithelial Neoplasia.

We present the validity of using an ultrasensitive enzyme-linked immunosorbent assay (ELISA) for quantifying high-risk human papillomavirus (HPV) 16 E7 oncoproteins in urine specimens as a noninvasive method of analyzing the oncogenic activity of HPV. Some reports claim that the oncogenic activity of HPV is a more relevant clinical indicator than the presence of HPV DNA for estimating malignant potential. In the present study, urine containing HPV16 and related types were selected by uniplex E6/E7 polymerase chain reaction and classified according to the pathologic diagnosis of cervical intraepithelial neoplasia (CIN) in cervical biopsy specimens. Our ultrasensitive ELISA was able to detect attomole levels of HPV16 E7 oncoproteins, and it detected HPV16-positive SiHa cells at >500 cells/mL without detecting HPV18-positive cells. Our ELISA results showed E7 oncoproteins in 80% (4/5) of urine specimens from women with HPV16-positive CIN1, 71% (5/7) of urine specimens from CIN2 patients, and 38% (3/8) of urine specimens from CIN3 patients. Some urine specimens with undetectable E7 oncoproteins were thought to be negative for live HPV 16-positive cells or in an inactivated state of infection. These results provide the basis for assessing oncogenic activity by quantifying E7 oncoproteins in patient urine.

Enhancement of Tumor Antigen-specific T-cell Responses by Immune Checkpoint Blockade in Human Papillomavirus-related Head and Neck Squamous Cell Carcinoma.

BACKGROUND/AIM: Human papillomavirus (HPV)-positive head and neck squamous cell carcinoma (HNSCC) is clinically and immunologically distinct from HPV-negative HNSCC. Herein, we investigated the presence of tumor antigens HPV E6/E7 and wild-type p53-specific T-cell responses, and the impact of immune checkpoint blockade in patients with HPV-positive HNSCC. MATERIALS AND METHODS: Peripheral blood mononuclear cells (PBMCs) from patients with HPV-positive HNSCC were stimulated with HPV E6/E7 or wild-type p53-derived peptide mixture and evaluated using the interferon-γ enzyme-linked immunosorbent spot assay. Flow cytometry was performed to analyze the proportion of T-cell subsets and T cells expressing immune checkpoint molecules. RESULTS: HPV E6/E7-specific T cells were detected in 22 (95.7%) of 23 patients, whereas wild-type p53-specific T cells were detected in 3 (15.0%) of 20 patients. Seven (43.8%) of 16 patients exhibited wild-type p53-specific T-cell responses, as determined using whole proteins instead of peptides. Immune checkpoint blockade enhanced wild-type p53-specific T-cell responses in 9 (45.0%) of 20 patients. Flow cytometric analysis of PBMCs revealed that responders exhibiting enhanced wild-type p53-specific T-cell responses following immune checkpoint blockade had a significantly higher proportion of Ki-67+CD4+ T cells, Ki-67+CD8+ T cells, regulatory T cells, PD-1+CD4+ T cells, and TIM-3+CD4+ T cells than non-responders. CONCLUSION: Our findings indicate that tumor antigen-specific T cells are present in the peripheral blood of patients with HPV-positive HNSCC. Blockade of checkpoint pathways can enhance T-cell responses in certain patients, probably via activated T cells, Tregs, and/or exhausted CD4+ T cells.

Bioinformatics Analysis Reveals E6 and E7 of HPV 16 Regulate Metabolic Reprogramming in Cervical Cancer, Head and Neck Cancer, and Colorectal Cancer through the PHD2-VHL-CUL2-ELOC-HIF-1α Axis.

Human papillomavirus 16 (HPV 16) infection is associated with several types of cancer, such as head and neck, cervical, anal, and penile cancer. Its oncogenic potential is due to the ability of the E6 and E7 oncoproteins to promote alterations associated with cell transformation. HPV 16 E6 and E7 oncoproteins increase metabolic reprogramming, one of the hallmarks of cancer, by increasing the stability of hypoxia-induced factor 1 α (HIF-1α) and consequently increasing the expression levels of their target genes. In this report, by bioinformatic analysis, we show the possible effect of HPV 16 oncoproteins E6 and E7 on metabolic reprogramming in cancer through the E6-E7-PHD2-VHL-CUL2-ELOC-HIF-1α axis. We proposed that E6 and E7 interact with VHL, CUL2, and ELOC in forming the E3 ubiquitin ligase complex that ubiquitinates HIF-1α for degradation via the proteasome. Based on the information found in the databases, it is proposed that E6 interacts with VHL by blocking its interaction with HIF-1α. On the other hand, E7 interacts with CUL2 and ELOC, preventing their binding to VHL and RBX1, respectively. Consequently, HIF-1α is stabilized and binds with HIF-1ß to form the active HIF1 complex that binds to hypoxia response elements (HREs), allowing the expression of genes related to energy metabolism. In addition, we suggest an effect of E6 and E7 at the level of PHD2, VHL, CUL2, and ELOC gene expression. Here, we propose some miRNAs targeting PHD2, VHL, CUL2, and ELOC mRNAs. The effect of E6 and E7 may be the non-hydroxylation and non-ubiquitination of HIF-1α, which may regulate metabolic processes involved in metabolic reprogramming in cancer upon stabilization, non-degradation, and translocation to the nucleus.

Genetically engineered mouse model of HPV16 E6-E7 with vaginal-cervical intraepithelial neoplasia and decreased immunity.

Objective: To construct models of high-risk human papillomavirus (HPV) infection with precancerous lesions or cervical cancer and explore the immune function. Methods: Using CRISPR/Cas9, the expression vector HPV16-E6-E7-Rosa26 was microinjected into fertilized eggs of C57BL/6 N mice using homologous recombination, and the F0 generation was obtained for reproduction. Then, the formation of precancerous lesions was promoted via intramuscular injection of estradiol. Presence of precancerous cervical-vaginal intraepithelial lesions, Ki67 and p16 expression levels, and CD8+ T cell proportions in the spleen were evaluated. Results: Two F0 generation mice exhibited correct the homologous recombination. Seven positive mice were identified in the F1 generation. After breeding and mating, 25 homozygous and 11 heterozygous HPV16-E6-E7-engineered mice were obtained from the F2 generation. After estradiol benzoate treatment, the cervical-vaginal epithelium appeared as precancerous lesions with positive Ki67 and p16 expression. The percentage of CD8+ T cells decreased. Conclusion: HPV16-E6-E7-Rosa26 induced low immune function in mice, and provides a good model for the basic research of the mechanisms of action of HPV infection-associated precancerous lesions or cervical cancer.

An E7-retinoblastoma protein pathway mechanism may account for the higher carcinogenic ability of HPV16 over HPV58 in cervical cancer.

Background: Among human papillomavirus (HPV) type, HPV16 displays the strongest carcinogenic capacity for cervical cancer, but the mechanism underlying this phenomenon remains unclear. We investigated the effect and the underlying mechanism of HPV16 on higher carcinogenic capacity than HPV58. Methods: We collected 4,030 cervical exfoliated cell samples for genotyping HPV using HybriBio's proprietary flow-through hybridization technique, liquid-based cytology (LBC), colposcopy, and biopsies if indicated. Four plasmids containing E6 and E7 of HPV16 and 58 were constructed and transfected into 293T and U2OS cells. We detected the cell phenotype using Cell Counting Kit 8 (CCK8) assay, Transwell assay, flow cytometry, and apoptosis assay; the expression of retinoblastoma protein (Rb) and phosphorylated Rb (pRb) was determined via Western blot; and the cell activity was determined via a zebrafish model treated with or without roscovitine. Results: The positive rates of HPV16 and 58 were, respectively, 18.9% and 19.7% in the ≤ low-grade squamous intraepithelial lesion (LSIL) group, 49.5% and 19.6% (P<0.001) in the high-grade squamous intraepithelial lesion (HSIL) group, 65.3% and 9.0% (P<0.001) in the cancer group. In vitro, both 293T and U2OS cells with overexpressed HPV16 E6 and E7 displayed significantly higher cell proliferation, faster cell invasion, decreased cell apoptosis, and accelerated cell cycle from G1 phase to S phase compared to those with overexpressed HPV58 E6 and E7 (all P values <0.05). Rb loss of function was observed in cells with HPV16 E7 overexpression, while a greater level of phosphorylated Rb was observed in cells with HPV58 E7 overexpression. Roscovitine restored Rb expression and decreased the cell activity in zebrafish. Conclusions: HPV16 possesses a stronger carcinogenic ability than does HPV 58, and the mechanism underlying this effect may be the impairment of the E7-Rb pathway.

Exosomal EGFR and miR-381-3P Mediate HPV-16 E7 Oncoprotein-Induced Angiogenesis of Non-Small Cell Lung Cancer.

BACKGROUND: It has been demonstrated that exosomes derived from HPV-16 E7-over-expressiong non-small cell lung cancer (NSCLC) cells (E7 Exo) trigger increased levels of epidermal growth factor receptor (EGFR) and miR-381-3p. The purpose of this investigation was to examine the role of E7 Exo in NSCLC angiogenesis, and to analyze the contribution of exosomal EGFR and miR-381-3p to it. METHODS: The influence of E7 Exo on the proliferation and migration of human umbilical vein endothelial cells (HUVECs) was assessed using colony formation and transwell migration assays. Experiments on both cells and animal models were conducted to evaluate the angiogenic effect of E7 Exo treatment. The involvement of exosomal EGFR and miR-381-3p in NSCLC angiogenesis was further investigated through suppressing exosome release or EGFR activation, or by over-expressing miR-381-3p. RESULTS: Treatment with E7 Exo increased the proliferation, migration, and tube formation capacities of HUVECs, as well as angiogenesis in animal models. The suppression of exosome release or EGFR activation in NSCLC cells decreased the E7-induced enhancements in HUVEC migration and tube formation, and notably reduced vascular endothelial growth factor A (VEGFA) and Ang-1 levels. HUVECs that combined miR-381-3p mimic transfection and E7 Exo treatment exhibited a more significant tube-forming capacity than E7 Exo-treated HUVECs alone, but were reversed by the miR-381-3p inhibitor. CONCLUSION: The angiogenesis induced by HPV-16 E7 in NSCLC is mediated through exosomal EGFR and miR-381-3p.