HPV16 E7 Research Articles

Antibodies against high-risk human papillomavirus proteins as markers for noncervical HPV-related cancers in a Black South African population, according to HIV status.

Human papillomavirus (HPV) proteins may elicit antibody responses in the process toward HPV-related malignancy. However, HPV seroepidemiology in noncervical HPV-related cancers remains poorly understood, particularly in populations with a high prevalence of human immunodeficiency virus (HIV). Using a glutathione S-transferase-based multiplex serology assay, antibodies against E6, E7 and L1 proteins of HPV16 and HPV18 were measured in sera of 535 cases of noncervical HPV-related cancers (anal (n = 104), vulval (n = 211), vaginal (n = 49), penile (n = 37) and oropharyngeal (n = 134)) and 6651 non-infection-related cancer controls, from the Johannesburg Cancer Study that recruited Black South African with newly diagnosed cancer between 1995 and 2016. Logistic and Poisson regression models were used to calculate adjusted odds ratios (aOR) and prevalence ratios (aPR) and 95% confidence intervals (CI) in cases versus controls. HPV16 E6 was more strongly associated with noncervical HPV-related cancers than HPV16 L1 or E7, or HPV18 proteins: anal (females (HPV16 E6 aOR = 11.50;95%CI:6.0-22.2), males (aOR = 10.12;95%CI:4.9-20.8), vulval (aOR = 11.69;95%CI:7.9-17.2), vaginal (aOR = 10.26;95%CI:5.0-21), penile (aOR = 18.95;95%CI:8.9-40), and oropharyngeal (females (aOR = 8.95;95%CI:2.9-27.5), males (aOR = 3.49;95%CI:1.8-7.0)) cancers. HPV16-E6 seropositivity ranged from 24.0% to 35.1% in anal, vulval, vaginal and penile cancer but was significantly lower (11.2%) in oropharyngeal cancer. After adjustment for HIV, prevalence of which increased from 22.2% in 1995-2005 to 54.1% in 2010-2016, HPV16 E6 seropositivity increased by period of diagnosis (aPR for 2010-2016 vs. 1995-2006 = 1.84;95%CI:1.1-3.0). Assuming HPV16 E6 seroprevalence reflects HPV attributable fraction, the proportion of certain noncervical-HPV-related cancers caused by HPV is increasing over time in South Africa. This is expected to be driven by the increasing influence of HIV.

Abstract LB353: Repurposing varicella zoster virus and human papillomavirus vaccines for local immunotherapy against solid tumors

Abstract Local immunotherapy against solid tumors is considered a viable approach to stimulate the tumor microenvironment (TME) and anti-tumor immunity. We assessed in situ vaccination with licensed subunit vaccines to leverage preexisting anti-vaccine immunity in the TC-1 tumor model expressing HPV16 viral oncogenes E6 and E7. We chose Shingrix, a VZV vaccine containing the glycoprotein E (gE), and Gardasil-9, an HPV vaccine containing L1 virus-like particles (VLP), to preferentially induce CD4 and CD8 T cell responses, respectively. Intratumoral (IT) injection of Shingrix in Shingrix prevaccinated mice led to complete regression in 20% to 50% of treated mice and elicited CD8 T cell responses against the viral oncoprotein E7. IT injection of an MHC-II-restricted gE peptide with polyI:C also led to durable remission, suggesting that gE-specific CD4 T cells played a significant role in tumor control. In contrast, IT injection of Gardasil-9 in Gardasi-9 prevaccinated animals did not delay tumor growth. However, IT injection of an MHC-I-restricted L1 peptide with Shingrix consistently led to complete remissions perhaps by overcoming preexisting antibodies against native HPV VLP which appeared to inhibit the cross-presentation of VLP derived antigens. TME analysis showed that IT injection of Shingrix with Gardasil-derived peptide induced IFN-gamma, TNF-alpha and CXCL9. This treatment also dramatically reshaped the immune cell infiltrate causing the recruitment of T cells and neutrophils and the decrease of tumor-associated macrophage and eosinophils. We are investigating now how these changes may contribute to tumor clearance and epitope spreading against tumor-derived antigens. Finally, IT injection of Shingrix and a E7 viral neoantigen peptide led to the eradication of all primary injected and abscopal tumors. Our results indicate that the ability of Shingrix to induce exceptionally strong Th1 responses makes it a versatile component for in-situ vaccination which can be combined with peptides derived from licensed vaccines or tumor antigens. Because this approach relies on relatively low cost existing vaccines and inexpensively manufactured minimal CD8 restricted peptides, it has the potential for a broadly applicable cancer immunotherapy strategy for use in resource-constrained settings. The approach is currently being evaluated in a phase I clinical trial in companion dogs with spontaneously arising cancers. Citation Format: Nicolas Cuburu, Shiv K. Sethi, Claire E. Bradley, Lukas Bialkowski, Cynthia D. Thompson, Douglas R. Lowy, John T. Schiller. Repurposing varicella zoster virus and human papillomavirus vaccines for local immunotherapy against solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB353.

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

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. 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. 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. 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.

Alterations of UHRF family Expression and was regulated by High Risk Type HPV16 in Uterine Cervical Cancer

The altered protein expression of inverted CCAAT box-binding protein of 90 kDa/ubiquitin-like with PHD and RING finger domains 1 (ICBP90/UHRF1), and Np95-like ring finger protein (NIRF)/UHRF2, which belong to the ubiquitin-like with PHD and RING finger domains (UHRF) family, is linked to tumor malignancy and the progression of various cancers. In this study, we analyzed the UHRF family expression in cervical cancers, and it's regulation by human papillomavirus (HPV). Western blotting was performed to analyze protein expression in cervical cancer cell lines. Immunohistochemical analysis were used to investigate the expression of UHRF family and MIB-1 in cervical cancer tissues. Transfection were done for analyze the relationship between UHRF family and HPVs. We showed that NIRF expression was decreased and ICBP90 expression was increased in cervical cancers compared to normal counterparts. Western blotting also showed that NIRF expression was quite low levels, but ICBP90 was high in human cervical cancer cell lines. Interestingly, ICBP90 was up regulated by high risk type HPV16 E6 and E7, but not low-risk type HPV11. On the other hand, NIRF was down regulated by high risk type HPV16 E6 but not by E7. Low risk type HPV11 E6 did not affect the NIRF expression at all. We propose that ICBP90 overexpression, and reduced NIRF expression, found in cervical cancers, is an important event of a cervical carcinogenesis, and especially ICBP90 may offer a proliferating marker and therapeutic target for treating uterine cervical cancers.

Biochemical and toxicity evaluation of Retama sphaerocarpa extracts and in-silico investigation of phenolic compounds as potential inhibitors against HPV16 E6 oncoprotein

Cervical cancer is a type of cancer which affects the cervix cells. The conventional treatments for cervical cancer including surgery, chemotherapy, and radiotherapy are only effective in premature stages and less effective in late stages of this tumor. Therefore, the therapeutic strategies based on biologically active substances from plants are needed to develop for the treatment of cervical cancer. The aim of the present study was to assess in vivo toxicity, hematological and biochemical blood parameters in Wistar rats fed Retama sphaerocarpa aqueous leaf extract (RS-AE), as well as to perform in silico molecular docking studies and dynamic simulation of phenolic compounds against HPV16 oncoprotein E6 in order to identify potential inhibitors. RS-AE was found not to induce acute or sub-acute oral toxicity or significant alterations in hematological and biochemical blood parameters in Wistar rats. A total of 11 phenolic compounds were identified in RS-AE, including dihydrodaidzein glucuronide, chrysoperiol pentoside, genistin and vitexin, which turned out to have the highest binding affinity to HPV16 oncoprotein E6. Based on these results, these RS-AE phenolic compounds could be used as natural drugs against the HPV16 E6 oncoprotein.

Decoding the Enigma: Harnessing HPV Testing for the Precision Care in Carcinoma Unknown Primary with Secondary Metastasis to the Neck in North Indian Population Undergoing TORS for Primary Identification.

To assess the exact role of high-risk HPV testing in patients of carcinoma unknown primary with secondary metastasis to the neck who underwent TORS and neck dissection for identification of the primary site. A prospective study was carried out at a tertiary care centre over one year. Patients with unilateral neck swelling, which was cytologically proven squamous cell carcinoma neck metastasis, were included in the study. After clinicopathological evaluation, they underwent TORS-assisted ipsilateral radical tonsillectomy, tongue base mucosal wedge biopsy for primary site identification, and ipsilateral neck dissection. They underwent HPV RNA ISH from the tonsil, the base of the tongue and blood. They also underwent HPV DNA testing from the blood. P16 was done in the base of tongue, tonsil, and lymph node specimens. In the study cohort of 18 patients who underwent ipsilateral radical tonsillectomy, mucosal tongue base wedge biopsy and neck dissection, p16 positivity was isolated in 5.56%, 0% and 2.78% of patients, respectively. (n = 1/18, 0/18, 5/18). Interestingly, HPV E7 mRNA expression was absent in the tonsil /base of tongue specimens, but metastatic lymph nodes displayed expression in 11.11%. HPV DNA was undetected in all analysed tissues and patients' blood. In the Indian subcontinent, it is not essential to do detailed high-risk HPV analysis in cases of carcinoma unknown primary with secondary metastasis to the neck.

Abstract 2875: Resistance to conventional chemo and radiotherapy associated with increased DNA repair and stem cell-like phenotype in head and neck squamous cell carcinoma expressing HPV E5

Abstract Human papillomavirus-associated head and neck squamous cell carcinoma (HPV+ HNSCC) is one of the fastest-rising cancers in the US. While HPV+ HNSCC patients exhibit better responses to chemoradiation compared to HPV- HNSCC patients, a subset of HPV+ patients do not respond as well and develop recurrent/refractory disease. In this study, we investigated the potential role of HPV E5 in promoting resistance to conventional chemo- and radiotherapy, and the underlying molecular mechanisms. HPV E5 is a small hydrophobic viral oncoprotein with multiple functions including regulation of tumor cell differentiation and apoptosis, modulation of H+ ATPase responsible for acidification of late endosomes, and immune modulation. To test the impact of HPV E5 on therapeutic resistance, we generated HNSCC cell lines and normal keratinocytes expressing HPV16 E5. Upon treatment with radiation (2Gy, 4Gy, 8Gy) and/or cisplatin, HNSCC cells and keratinocytes expressing HPV 16 E5 had increased cell viability, decreased apoptosis, and increased colony-forming capacity compared to empty vector (EV) control lines. Specifically, treatment with 4Gy radiation, 4µM cisplatin, or the combination led to a ~2-fold decrease in % of apoptotic cells in HPV16 E5-expressing HNSCC cells compared to EV and HPV16 E6/E7 HNSCC cells (p &amp;lt;0.05). Examination of DNA damage response and repair pathways indicated that while HPV16 E5 HNSCC cells initially had increased phosphorylation of H2AX 6 hours post treatment, at 24 hours post treatment H2AX phosphorylation in HPV16 E5 cells was significantly decreased compared to EV or HPV16 E6/E7 HNSCC cells. These findings indicate increased DNA repair capacity of HPV16 E5 HNSCC cells. To identify mechanisms underlying this phenotype, we performed RNA-seq and observed enhanced signaling pathways associated with epithelial development and increased expression of stem cell markers in HPV16 E5 HNSCC cells compared to EV control lines. Functionally, we observed a ~2.5-fold increase in sphere-forming capacity and increased expression of markers associated with stem cell phenotype in HPV16 E5 HNSCC cells compared to EV and HPV E6/E7 HNSCC cells. To determine whether these findings translated clinically, 18 HPV+ HNSCC patients from the GSE74927 dataset were grouped according to median expression level of HPV E5 (High vs Low). In support of our hypothesis, HPV E5-High patients exhibited enrichment of pathways associated with extrinsic apoptotic signaling, pluripotency of stem cells, and positive regulation of DNA repair. Taken together these results identify HPV E5 as a potential mediator of resistance to conventional radiation and chemotherapy in HNSCC and suggest that patient tumors expressing HPV E5 may have increased DNA repair capacity and cell survival after cytotoxic therapies. Citation Format: Souvick Roy, Sayuri Miyauchi, Riley Jones, Sangwoo Kim, Andrew B. Sharabi. Resistance to conventional chemo and radiotherapy associated with increased DNA repair and stem cell-like phenotype in head and neck squamous cell carcinoma expressing HPV E5 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2875.

Abstract 2955: HPV E6* and senescence-related gene expression in cervical cancer

Abstract Previous work in our lab found that increased expression of the E6* variant of the HPV E6 viral protein was significantly correlated with worse response to standard-of-care chemoradiation (CRT) and progression-free survival, independently of HPV genotype. In vitro validation showed that overexpression of E6* induces senescence in an HPV 16-positive cervical cancer cell line. Given these findings, we hypothesized that increased E6* expression mediates resistance to CRT by inducing a reversible state of tumor cell senescence. We created a senescence score using ten genes that have been consistently reported in the literature as associated with senescence. Using an institutional cohort of 68 patients with cervical cancer with prospectively collected clinical outcome data, we performed bulk RNA sequencing to assess senescence scores before CRT and determine whether there is an association between senescence scores and E6* expression. Using a second institutional cohort of 35 patients with cervical cancer treated with CRT with pre and posttreatment tumor biopsies, we performed bulk RNA sequencing to evaluate the same relationship and determine whether expression of senescence-related genes was affected by CRT. Nine cervical cancer cell lines stratified into low- and high-E6* expression groups will be assessed regarding their senescence score, beta-galactosidase staining, and SASP expression before and after CRT. In our first cohort, there was no correlation between E6*:E6 expression ratio and senescence score, regardless of HPV genotype. In our second cohort, CRT increased senescence score in CRT-treated samples (p &amp;lt; 0.01), but p16INK4a expression significantly decreased compared to pre-treatment samples (p &amp;lt; 0.01). Increased senescence score was not associated with cancer recurrence. There was no significant difference in senescence scores between different HPV genotypes before therapy. Tumors that were positive for HPV 16 or HPV 18 had significantly lower senescence scores compared to HPV negative tumors (p = 0.037 and p = 0.038, respectively) after CRT. Among HPV 16-positive tumors (n = 12), there was no correlation between E6*:E6 expression ratio and senescence score before or after CRT. We found no association between senescence score and E6* expression, and between senescence score and cancer recurrence after CRT in our dataset. Additionally, our results suggest that p16INK4a might not be an appropriate senescence marker in tumors that have intrinsically high p16INK4a expression, such as in cervical cancer, reinforcing the need for a cervical cancer-specific senescence signature. We are currently testing beta-galactosidase and SASP expression in vitro and in vivo before and after CRT. Citation Format: Louise Medina Bengtsson, Matthew Inkman, Naoshad Muhammad, Leahan Castillo, Naomi Msengi, Tyler McKinnish, Nishanth Gabriel, Jin Zhang, Julie Schwarz. HPV E6* and senescence-related gene expression in cervical cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2955.

Abstract 2280: HPV integration identifies emerging oncogenes and carcinogenic mechanisms, potentially indicating tumor recurrences

Abstract HPV integration events in Head and neck squamous cell carcinomas (HNSCC) are strongly associated with carcinogenesis and tumor progression. Previous studies have elucidated the mechanisms and structures of HPV-human fusion events, pinpointing potential integration “hotspots” (i.e. genes with nearby HPV integration in recurrent patients). However, none has comprehensively investigated the effects of HPV integration on both HPV and human gene expression, nor assessed the clinical implications of these bidirectional expression changes. In this study, we conducted bulk RNA sequencing on 67 Formalin-Fixed Paraffin-Embedded Oropharyngeal Squamous Cell Carcinoma (OPSCC) tumor samples from the University of Michigan hospital, and analyzed them in conjunction with bulk and single cell RNA-seq from another &amp;gt;200 HPV(+) HNSCC patients from four previous studies. Among the 117 samples confidently identified as HPV integration positive, we recaptured all previously known integration “hotspot” genes as well as several novel ones that have altered expression in the integrated samples. Exploring the impact of HPV integration on the expression of human and HPV genes, we found that HPV integration in HNSCC is strongly associated with keratinization, immune response, and the development of HPV(+) HNSCC subtypes. Upon HPV integration, expression of non-oncogenic HPV genes is often lost. We hypothesized that the expression ratio of these potentially HPV immunogenic genes (E1-E5, L1,L2) to the HPV oncogenic genes E6 and E7 (termed the ImmunOnco Score) would predict clinical outcomes. Survival analysis of 70 University of Michigan patients showed low ImmunOnco Score is associated with tumor recurrence. Citation Format: Shiting Li, Shaomiao Xia, Maria Lawas, Tingting Qin, Bailey Grab, Nisha D'Silva, Laura Rozek, Maureen Sartor. HPV integration identifies emerging oncogenes and carcinogenic mechanisms, potentially indicating tumor recurrences [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2280.

Abstract 3683: Prognostic value and biological correlates of LINE1 hypomethylation in oropharyngeal cancer

Abstract Background. We have recently demonstrated that LINE-1 hypomethylation is a negative prognostic factor in oropharyngeal squamous cell carcinoma (OPSCC). HPV-positive patients with LINE-1 methylation &amp;lt;55% showed an almost 5-fold higher risk of death than hypermethylated once, with an overall survival as poor as HPV-negative patients. Somatic TP53 mutations are a common feature in HPV-negative OPSCC, whereas their presence has been reported in only a small subset of HPV-related OPSCC. At present, little is known about the correlation between LINE-1 methylation and p53 expression status and/or TP53 mutation in OPSCC. Methods. Since 2019, an ongoing prospective study has been enrolling patients with OPSCC in nine cancer centers in Northern Italy. HPV16 E6 DNA was quantified using real-time quantitative PCR (qPCR). LINE-1 methylation was evaluated by methylation-specific qPCR. p53 expression was detected by immunohistochemical staining. TP53 exon mutations were analyzed by Next Generation Sequencing. Results. Up to date, 134 OPSCC patients have been enrolled, including cancer of the tonsil (n=74; 55.2%), base of tongue (n=47; 35.1%), and other subsites (n=13; 9.7%). HPV16 DNA was found in 54.3% of cases: 65.7% in base of tongue, 57.1% in tonsil, and 16.7% in other subsites (p&amp;lt;0.001). LINE-1 methylation was higher in HPV16-positive patients (median: 55.8%, interquartile rage [IQR]: 42.5-68.5) than HPV16-negative ones (median: 40.7; IQR: 23.9-59.1; p=0.003). Nevertheless, the median LINE-1 methylation was lower (50.7%) among HPV-16 OPSCC patients who relapsed than those who did not (56.0%), thus confirming the findings previously reported. However, data from the present investigation are presently not mature to purse the study aims (median follow-up: 12.3 months). The correlation between LINE-1 hypomethylation and p53 expression has also been evaluated in OPSCC patients. p53 expression was categorized into three groups (0%, 1-49%, and ≥50%) based on the overall intensity of nuclear staining of the tumor cells. p53 was considered null, overexpressed, or wild type when its nuclear staining was 0 %, ≥50%, or ranged between 1% and 49%, respectively. Of note, the highest level of LINE-1 methylation was observed in OPSCC tissues with nuclear p53 staining between 1% and 49% (57.8%), whereas OPSCC patients with p53 expression ≥50% showed a decline of LINE-1 methylation levels (40.6; p=0.026). Interestingly, LINE-1 methylation was lower in OPSCC patients harboring TP53 mutations in both HPV16-negative (24.8%) and HPV16-positive (24.0%) OPSCC patients, even if statistical significance was reached only in the HPV-negative group (p=0.015). Conclusion. Preliminary results confirm the potential of LINE-1 methylation to identify HPV16-positive patients with poor prognosis. In addition, this study suggest that TP53 mutations might influence LINE-1 methylation, irrespective of HPV status. Citation Format: Mariateresa Casarotto, Roberto Guerrieri, Paolo Boscolo-Rizzo, Monica Schiappacassi, Sara D'Andrea, Valentina Lupato, Susanna Chiocca, Marta Tagliabue, Rita De Berardinis, Anna Menegaldo, Alice Piccinato, Paola Stritoni, Mohssen Ansarin, Doriano Politi, Giuseppe Fanetti, Giorgio Giurato, Jerry Polesel, Elisabetta Fratta. Prognostic value and biological correlates of LINE1 hypomethylation in oropharyngeal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3683.

Assessing the Potential of HPV16 E6 Seroprevalence as a Biomarker for Anal Dysplasia and Cancer Screening-A Systematic Review and Meta-Analysis.

Elevated rates of human papillomavirus (HPV)-related anal high-grade squamous intraepithelial lesions (HSIL) and anal cancer (AC) in populations like men who have sex with men (MSM) living with HIV underscore the need for effective screening. While high-resolution anoscopy-guided biopsy is the gold standard, limited provider availability poses a challenge. This has spurred interest in identifying biomarkers for improved AC prevention. Antibodies against HPV16 oncoprotein E6, known as markers for cervical and oropharyngeal cancers, are the focus of the current study. The systematic review and meta-analysis included six studies meeting inclusion criteria, assessing HPV16 E6 seroprevalence in individuals with anal HSIL or AC. A two-step meta-analysis estimated pooled odds ratios and 95% confidence intervals (CI) for HPV16 E6 seroprevalence and HSIL or AC. Pooled prevalence, sensitivity, specificity, and diagnostic odds ratios were also calculated. This meta-analysis revealed a 3.6-fold increased risk of HSIL for HPV16 E6 seropositive individuals, escalating to a 26.1-fold risk increase for AC. Pooled specificity and sensitivity indicated a high specificity (0.99; 95%CI: 0.99, 0.99) but lower sensitivity (0.19; 95%CI: 0.10, 0.34) for HPV16 E6 serostatus as an AC biomarker. In conclusion, while HPV16 E6 seroprevalence demonstrates specificity as a potential biomarker for HPV-related AC, its utility as a standalone screening tool may be limited. Instead, it could serve effectively as a confirmation test, particularly in high-risk populations, alongside other diagnostic methods. Further research is imperative to explore HPV16 E6 seroconversion dynamics and alternative screening algorithms.

Adenosine Increases the Immunosuppressive Capacity of Cervical Cancer Cells by Increasing PD-L1 Expression and TGF-β Production through Its Interaction with A2AR/A2BR.

The present study provides evidence showing that adenosine (Ado) increases the expression of programmed death ligand 1 (PD-L1) in cervical cancer (CeCa) cells by interacting with A2AR/A2BR and that TGF-β1 acts in an autocrine manner to induce PD-L1 expression, enhancing the immunosuppressive effects of CeCa cells on activated T lymphocytes (ATLs) and CD8+ cytotoxic T lymphocytes (CTLs) specific for antigenic peptides derived from E6 and E7 proteins of HPV-16. Interestingly, the addition of the antagonists ZM241385 and MRS1754, which are specific for A2AR and A2BR, respectively, or SB-505124, which is a selective TGF-β1 receptor inhibitor, to CeCa cell cultures significantly inhibited PD-L1 expression. In addition, supernatants from CeCa cells that were treated with Ado (CeCa-Ado Sup) increased the expression of PD-1, TGF-β1, and IL-10 and decreased the expression of IFN-γ in ATLs. Interestingly, the addition of an anti-TGF-β neutralizing antibody strongly reversed the effect of CeCa-Ado Sup on PD-1 expression in ATLs. These results strongly suggest the presence of a feedback mechanism that involves the adenosinergic pathway, the production of TGF-β1, and the upregulation of PD-L1 expression in CeCa cells that suppresses the antitumor response of CTLs. The findings of this study suggest that this pathway may be clinically important and may be a therapeutic target.

HPV16 E7 modulates the cell surface expression of MET and CD109 via the AP2 complex

Multiple cellular pathways are affected by HPV E6 and E7 oncoproteins, including endocytic and cellular trafficking. HPV-16 E7 can target the adaptor protein (AP) complex, which contains proteins important during endocytosis transport. To further investigate the role of HPV E7 during this process, we analysed the expression of cell surface proteins in NIKS cells expressing HPV-16 E7. We show that different cell surface proteins are regulated by HPV-16 E7 via interaction with AP2. We observed that the expression of MET and CD109 membrane protein seems to be upregulated in cells expressing E7. Moreover, the interaction of MET and CD109 with AP2 proteins is disrupted by HPV-16 E7. In addition, in the absence of HPV-16 E7, there is a downregulation of the cell membrane expression of MET and CD109 in HPV-positive cell lines. These results expand our knowledge of the functions of E7 and open new potential cellular pathways affected by this oncoprotein.

Bioinformatics analysis of photoexcited natural flavonoid glycosides as the inhibitors for oropharyngeal HPV oncoproteins

The presence of oropharyngeal human papillomavirus (HPV)-18 E6 and E7 oncoproteins is highly significant in the progression of oropharyngeal cancer. Natural flavonoid compounds have potential as photosensitizers for light-activated antimicrobial therapy against HPV-associated oropharyngeal cancer. This study evaluated five natural flavonoid glycosides including Fisetin, Kaempferol, Morin, Myricetin, and Quercetin as photosensitizers against HPV-18 E6 and E7 oncoproteins using computational methods. After obtaining the amino acid sequences of HPV-18 E6 and E7, various tools were used to predict and verify their properties. The PubChem database was then examined to identify potential natural flavonoid glycosides, followed by predictions of their drug-likeness and ADMET properties. Subsequently, molecular docking was conducted to enhance the screening accuracy and to gain insights into the interactions between the natural compounds and the active sites of HPV-18 E6 and E7 oncoproteins. The protein structures of E6 and E7 were predicted and validated to be reliable. The results of molecular docking demonstrated that Kaempferol exhibited the highest binding affinity to both E6 and E7. All compounds satisfied Lipinski's rules of drug-likeness, except Myricetin. They showed high absorption, distribution volume and similar ADMET profiles with no toxicity. In summary, natural flavonoid glycosides, especially Kaempferol, show potential as photosensitizers for antimicrobial photodynamic therapy against HPV-associated oropharyngeal cancer through inhibition of E6 and E7 oncoproteins. These findings provide insights into the development of novel therapeutic strategies based on antimicrobial photodynamic therapy.

Human papillomavirus-16 E6 activates the pentose phosphate pathway to promote cervical cancer cell proliferation by inhibiting G6PD lactylation

High-risk human papillomaviruses (HPVs) are the causative agents of cervical cancer. Here, we report that HPV16 E6E7 promotes cervical cancer cell proliferation by activating the pentose phosphate pathway (PPP). We found that HPV16 E6 activates the PPP primarily by increasing glucose-6-phosphate dehydrogenase (G6PD) enzyme activity. Mechanistically, HPV16 E6 promoted G6PD dimer formation by inhibiting its lactylation. Importantly, we suggest that G6PD K45 was lactylated during G6PD-mediated antioxidant stress. In primary human keratinocytes and an HPV-negative cervical cancer C33A cells line ectopically expressing HPV16 E6, the transduction of G6PD K45A (unable to be lactylated) increased GSH and NADPH levels and, correspondingly, decreasing ROS levels. Conversely, the re-expression of G6PD K45T (mimicking constitutive lactylation) in HPV16-positive SiHa cells line inhibited cell proliferation. In vivo, the inhibition of G6PD enzyme activity with 6-aminonicotinamide (6-An) or the re-expression of G6PD K45T inhibited tumor proliferation. In conclusion, we have revealed a novel mechanism of HPV oncoprotein-mediated malignant transformation. These findings might provide effective strategies for treating cervical and HPV-associated cancers.

Structural analysis of PTPN21 reveals a dominant-negative effect of the FERM domain on its phosphatase activity.

PTPN21 belongs to the four-point-one, ezrin, radixin, moesin (FERM) domain-containing protein tyrosine phosphatases (PTP) and plays important roles in cytoskeleton-associated cellular processes like cell adhesion, motility, and cargo transport. Because of the presence of a WPE loop instead of a WPD loop in the phosphatase domain, it is often considered to lack phosphatase activity. However, many of PTPN21's biological functions require its catalytic activity. To reconcile these findings, we have determined the structures of individual PTPN21 FERM, PTP domains, and a complex between FERM-PTP. Combined with biochemical analysis, we have found that PTPN21 PTP is weakly active and is autoinhibited by association with its FERM domain. Disruption of FERM-PTP interaction results in enhanced ERK activation. The oncogenic HPV18 E7 protein binds to PTP at the same location as PTPN21 FERM, indicating that it may act by displacing the FERM domain from PTP. Our results provide mechanistic insight into PTPN21 and benefit functional studies of PTPN21-mediated processes.

Evaluation of HPV 16 and HPV 18 Oncoprotein Expression as Alternative Diagnostic Tools in Cervical Lesion.

The study aimed to evaluate E6 and E7 oncoproteins of HPV16 and HPV18 expression in formalin - fixed paraffin embedded (FFPE) tissue in different grades of the cervical lesion and evaluate the potential use of E6 and E7 oncoproteins derived from HPV 16 and 18 as diagnostic protein biomarkers for triaging cervical lesions. A total of 102 FFPE cervical tissues were collected from 2 tertiary hospitals and immunohistochemical reactivity staining of E6 and E7 oncoproteins of HPV16 and HPV18 were evaluated using immunoreactive scoring (IRS) system and analysed statistically. The result showed an increased oncoprotein expression with the progression of cervical lesions. There is a statistically significant association between histology grade and HPV16/18-E6 expression (p = 0.028). However, there are no significant association of histological grade to HPV16-E7 immunoreactivity score (p = 0.264) and HPV18-E7 (p=0.080). The immunohistochemical expression of HPV oncoproteins is a potential alternative diagnostic tool applicable in a low-resource laboratory setting. The advantage of the histochemical evaluation is that this method is simpler to apply and less expensive in comparison to in situ mRNA hybridization. Nevertheless, our study also found that antibodies against HPV that are commercially available suffer quite substantial specificity issues such as background staining and inconsistency between different batches. Hence, the utilization of antibody-based staining warrants stringent quality control.

A novel method for colposcopic shunting in HPV-positive women: Quantitative detection of HPV E7 oncoprotein

The objective of the study was to evaluate the clinical application potential of quantitatively detecting human papillomavirus (HPV) E7 oncoprotein in HPV-positive women, with the goal of detecting potential high-grade cervical squamous intraepithelial lesions (HSIL) and cervical cancer improving the accuracy of colposcopic shunting in these patients.HPV-positive women (N = 611) were selected for quantitatively detecting HPV E7 protein levels by magnetic particle-based chemiluminescence immunoassay before colposcopy. Receiver operating characteristic (ROC) curve analysis was performed (n = 400) to determine diagnostic detection thresholds for HPV E7 oncoprotein. ThinPrep cytology test (TCT) and Aptima HPV E6/E7 mRNA analysis were also performed (n = 211). The diagnostic performance of these three diagnostic methods in detecting HSIL and cervical cancer was compared with the gold standard of pathological diagnosis. The area under the ROC curve was 0.724. The diagnostic detection threshold of HPV E7 oncoprotein was ≥10.88 ng/mL. The sensitivity (SEN), specificity (SPE), positive predictive value (PPV), negative predictive value (NPV), and Youden index of HPV E7 oncoprotein for the identification of HSIL and cervical cancer were 78.7 %, 77.9 %, 72.2 %, 83.3 %, and 56.6 %, respectively, which were higher than those of TCT and HPV E6/E7 mRNA.The results indicate that quantitative detection of HPV E7 oncoprotein can effectively shunt HPV-positive women and reduce unnecessary colposcopy and biopsy. It can detect potential HSIL and cervical cancer in a timely manner and prevent high-risk patients from missing diagnosis.

Lymph Node-Targeted Vaccine Boosting of TCR T-cell Therapy Enhances Antitumor Function and Eradicates Solid Tumors.

T-cell receptor (TCR)-modified T-cell therapies have shown promise against solid tumors, but overall therapeutic benefits have been modest due in part to suboptimal T-cell persistence and activation in vivo, alongside potential tumor antigen escape. In this study, we demonstrate an approach to enhance the in vivo persistence and function of TCR T cells through combination with Amphiphile (AMP) vaccination including cognate TCR T peptides. AMP modification improves lymph node targeting of conjugated tumor immunogens and adjuvants, thereby coordinating a robust T cell-activating endogenous immune response. AMP vaccine combination with TCR T-cell therapy led to complete eradication and durable responses against established murine solid tumors refractory to TCR T-cell monotherapy. Enhanced antitumor efficacy was correlated with simultaneous in vivo invigoration of adoptively transferred TCR T cells and in situ expansion of the endogenous antitumor T-cell repertoire. Long-term protection against tumor recurrence in AMP-vaccinated mice was associated with antigen spreading to additional tumor-associated antigens not targeted by vaccination. AMP vaccination further correlated with pro-inflammatory lymph node transcriptional reprogramming and increased antigen presenting-cell maturation, resulting in TCR T-cell expansion and functional enhancement in lymph nodes and solid tumor parenchyma without lymphodepletion. In vitro evaluation of AMP peptides with matched human TCR T cells targeting NY-ESO-1, mutant KRAS, and HPV16 E7 illustrated the clinical potential of AMP vaccination to enhance human TCR T-cell proliferation, activation, and antitumor activity. Taken together, these studies provide rationale and evidence to support clinical evaluation of combining AMP vaccination with TCR T-cell therapies to augment antitumor activity.

The difference of transcriptome of HPV-infected patients contributes more to the occurrence of cervical cancer than the mutations of E6 and E7 genes in HPV16.

Human papillomavirus (HPV) E6 and E7 genes are biomarkers and drivers of the progression of cervical cancer (CxCa). The aim of this study was to investigate the relationship between HPV16 E6, E7 gene mutations and the occurrence and development of CxCa. Cervical exfoliated cells and clinical data of patients with cervical diseases were collected. Sample DNA was extracted, the E6 and E7 gene fragments were amplified by PCR, and the mutations were detected by Sanger sequencing and compared with standard sequences. Microarray was used to sequence the transcriptome of cells. Data of transcriptome analyzed and visualized using R software and its packages. Analysis of clinical characteristics demonstrated the association of HPV16 infection with CxCa (P < .05). Sanger sequencing results showed that the mutation sites of E6 gene included T178G/A, T350G, A131C, and T241G; among these, A131C and T241G were synonymous mutations. The mutation sites of E7 gene included A647G, T846C, G666A, T843C, and T760C, and all of them were synonymous mutations except A647G. There was no significant difference in the distribution of HPV16 E6, E7 mutations among CxCa, cervical intraepithelial neoplasia, and infection groups (P > .05). Compared with the non- CxCa group, gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis of differentially expressed genes (DEGs) showed more significant enrichment of DEGs in the biological processes, pathways, and diseases closely related to cancer. Compared with the non-mutation group, the DEGs in the E6, E7 gene mutation group were significantly enriched in the events related to infection and immunity. To summarize, HPV16 may be associated with the occurrence and development of CxCa, but HPV16 E6 and E7 gene mutations have little effect on the occurrence and development of CxCa. Individual differences may have a greater effect on the progression of CxCa.