HPV16 E6 promotes cervical cancer cell migration and invasion by downregulation of NHERF1

PCK1-mediated glycogenolysis facilitates ROS clearance and chemotherapy resistance in cervical cancer stem cells

Cervical cancer, one of the most common gynecological cancers, is primarily caused by human papillomavirus (HPV) infection. The development of resistance to chemotherapy is a significant hurdle in treatment. In this study, we investigated the mechanisms underlying chemoresistance in cervical cancer by focusing on the roles of glycogen metabolism and the pentose phosphate pathway (PPP). We employed the cervical cancer cell lines HCC94 and CaSki by manipulating the expression of key enzymes PCK1, PYGL, and GYS1, which are involved in glycogen metabolism, through siRNA transfection. Our analysis included measuring glycogen levels, intermediates of PPP, NADPH/NADP+ ratio, and the ability of cells to clear reactive oxygen species (ROS) using biochemical assays and liquid chromatography-mass spectrometry (LC-MS). Furthermore, we assessed chemoresistance by evaluating cell viability and tumor growth in NSG mice. Our findings revealed that in drug-resistant tumor stem cells, the enzyme PCK1 enhances the phosphorylation of PYGL, leading to increased glycogen breakdown. This process shifts glucose metabolism towards PPP, generating NADPH. This, in turn, facilitates ROS clearance, promotes cell survival, and contributes to the development of chemoresistance. These insights suggest that targeting aberrant glycogen metabolism or PPP could be a promising strategy for overcoming chemoresistance in cervical cancer. Understanding these molecular mechanisms opens new avenues for the development of more effective treatments for this challenging malignancy.

Exploring MiR-484 Regulation by Polyalthia longifolia: A Promising Biomarker and Therapeutic Target in Cervical Cancer through Integrated Bioinformatics and an In Vitro Analysis

BACKGROUND

MiR-484, implicated in various carcinomas, holds promise as a prognostic marker, yet its relevance to cervical cancer (CC) remains unclear. Our prior study demonstrated the Polyalthia longifolia downregulation of miR-484, inhibiting HeLa cells. This study investigates miR-484's potential as a biomarker and therapeutic target in CC through integrated bioinformatics and an in vitro analysis.

METHODS

MiR-484 levels were analyzed across cancers, including CC, from The Cancer Genome Atlas. The limma R package identified differentially expressed genes (DEGs) between high- and low-miR-484 CC cohorts. We assessed biological functions, tumor microenvironment (TME), immunotherapy, stemness, hypoxia, RNA methylation, and chemosensitivity differences. Prognostic genes relevant to miR-484 were identified through Cox regression and Kaplan-Meier analyses, and a prognostic model was captured via multivariate Cox regression. Single-cell RNA sequencing determined cell populations related to prognostic genes. qRT-PCR validated key genes, and the miR-484 effect on CC proliferation was assessed via an MTT assay.

RESULTS

MiR-484 was upregulated in most tumors, including CC, with DEGs enriched in skin development, PI3K signaling, and immune processes. High miR-484 expression correlated with specific immune cell infiltration, hypoxia, and drug sensitivity. Prognostic genes identified were predominantly epidermal and stratified patients with CC into risk groups, with the low-risk group showing enhanced survival and immunotherapeutic responses. qRT-PCR confirmed FGFR3 upregulation in CC cells, and an miR-484 mimic reversed the P. longifolia inhibitory effect on HeLa proliferation.

CONCLUSION

MiR-484 plays a crucial role in the CC progression and prognosis, suggesting its potential as a biomarker for targeted therapy.

Mechanisms and Potential Clinical Implications of Oral Microbiome in Oral Squamous Cell Carcinoma

Microorganisms in the oral cavity are abundant in the human body. At present, more than 700 species of oral microorganisms have been identified. Recently, a lot of literature has indicated that the oral microbiota plays an important role in the occurrence, development, and prognosis of oral squamous cell carcinoma (OSCC) through various mechanisms. And researchers are now trying to utilize oral microbiota in cancer diagnosis and treatment. However, few articles systematically summarize the effects of oral microbes in the diagnosis, treatment, and disease outcomes of oral cancer. Herein, we made a summary of the microbial changes at cancerous sites and placed more emphasis on the mechanisms by which the oral microbiome promotes cancerization. Moreover, we aimed to find out the clinical value of the oral microbiome in OSCC.

Human papillomavirus associated cervical lesion: pathogenesis and therapeutic interventions

Human papillomavirus (HPV) is the most prevalent sexually transmitted virus globally. Persistent high-risk HPV infection can result in cervical precancerous lesions and cervical cancer, with 70% of cervical cancer cases associated with high-risk types HPV16 and 18. HPV infection imposes a significant financial and psychological burden. Therefore, studying methods to eradicate HPV infection and halt the progression of precancerous lesions remains crucial. This review comprehensively explores the mechanisms underlying HPV-related cervical lesions, including the viral life cycle, immune factors, epithelial cell malignant transformation, and host and environmental contributing factors. Additionally, we provide a comprehensive overview of treatment methods for HPV-related cervical precancerous lesions and cervical cancer. Our focus is on immunotherapy, encompassing HPV therapeutic vaccines, immune checkpoint inhibitors, and advanced adoptive T cell therapy. Furthermore, we summarize the commonly employed drugs and other nonsurgical treatments currently utilized in clinical practice for managing HPV infection and associated cervical lesions. Gene editing technology is currently undergoing clinical research and, although not yet employed officially in clinical treatment of cervical lesions, numerous preclinical studies have substantiated its efficacy. Therefore, it holds promise as a precise treatment strategy for HPV-related cervical lesions.

Genetic variation of E6 and E7 genes of human papillomavirus type 16 from central China

BACKGROUND

Persistent high-risk human papillomavirus (HR-HPV) infection is an important factor in the development of cervical cancer, and human papillomavirus type 16 (HPV-16) is the most common HR-HPV type worldwide. The oncogenic potential of HPV-16 is closely related to viral sequence variation.

METHODS

In order to clarify the variant characteristics of HPV-16 E6 and E7 genes in central China, E6 and E7 sequences of 205 HPV-16 positive samples were amplified by polymerase chain reaction. PCR products of E6 and E7 genes were further sequenced and subjected to variation analysis, phylogenetic analysis, selective pressure analysis and B-cell epitope prediction.

RESULTS

Twenty-six single nucleotide variants were observed in E6 sequence, including 21 non-synonymous and 5 synonymous variants. Twelve single nucleotide variants were identified in E7 sequence, including 6 non-synonymous and 6 synonymous variants. Four new variants were found. Furthermore, nucleotide variation A647G (N29S) in E7 was significantly related to the higher risk of HSIL and cervical cancer. Phylogenetic analysis showed that the E6 and E7 sequences were all distributed in A lineage. No positively selected site was found in HPV-16 E6 and E7 sequences. Non-conservative substitutions in E6, H31Y, D32N, D32E, I34M, L35V, E36Q, L45P, N65S and K75T, affected multiple B-cell epitopes. However, the variation of E7 gene had little impact on the corresponding B-cell epitopes (score < 0.85).

CONCLUSION

HPV-16 E6 and E7 sequences variation data may contribute to HR-HPV prevention and vaccine development in Jingzhou, central China.

HPV-positive murine oral squamous cell carcinoma: development and characterization of a new mouse tumor model for immunological studies

BACKGROUND

Infection with high-risk human papillomavirus (HPV) strains is one of the risk factors for the development of oral squamous cell carcinoma (OSCC). Some patients with HPV-positive OSCC have a better prognosis and respond better to various treatment modalities, including radiotherapy or immunotherapy. However, since HPV can only infect human cells, there are only a few immunocompetent mouse models available that enable immunological studies. Therefore, the aim of our study was to develop a transplantable immunocompetent mouse model of HPV-positive OSCC and characterize it in vitro and in vivo.

METHODS

Two monoclonal HPV-positive OSCC mouse cell lines were established by inducing the expression of HPV-16 oncogenes E6 and E7 in the MOC1 OSCC cell line using retroviral transduction. After confirming stable expression of HPV-16 E6 and E7 with quantitative real-time PCR and immunofluorescence staining, the cell lines were further characterized in vitro using proliferation assay, wound healing assay, clonogenic assay and RNA sequencing. In addition, tumor models were characterized in vivo in C57Bl/6NCrl mice in terms of their histological properties, tumor growth kinetics, and radiosensitivity. Furthermore, immunofluorescence staining of blood vessels, hypoxic areas, proliferating cells and immune cells was performed to characterize the tumor microenvironment of all three tumor models.

RESULTS

Characterization of the resulting MOC1-HPV cell lines and tumor models confirmed stable expression of HPV-16 oncogenes and differences in cell morphology, in vitro migration capacity, and tumor microenvironment characteristics. Although the cell lines did not differ in their intrinsic radiosensitivity, one of the HPV-positive tumor models, MOC1-HPV K1, showed a significantly longer growth delay after irradiation with a single dose of 15 Gy compared to parental MOC1 tumors. Consistent with this, MOC1-HPV K1 tumors had a lower percentage of hypoxic tumor area and a higher percentage of proliferating cells. Characteristics of the newly developed HPV-positive OSCC tumor models correlate with the transcriptomic profile of MOC1-HPV cell lines.

CONCLUSIONS

In conclusion, we developed and characterized a novel immunocompetent mouse model of HPV-positive OSCC that exhibits increased radiosensitivity and enables studies of immune-based treatment approaches in HPV-positive OSCC.

hnRNP K induces HPV16 oncogene expression and promotes cervical cancerization

PURPOSE

This study aims to explore the expression of hnRNP K in cervical carcinogenesis and to investigate the regulatory role of hnRNP K on HPV16 oncogene expression as well as biological changes in cervical cancer cells.

METHODS

In total 1042 subjects, including 573 with the normal cervix and 469 with different grades of cervical lesions were enrolled in this study to explore the association between hnRNP K and HPV16 oncogene expression in cervical carcinogenesis. Additionally, the Gene Omnibus (GEO) database was used to analyze hnRNP K mRNA expression in cervical cancerization. Meanwhile, the effects of hnRNP K on cell biological functions and HPV16 oncogene expression were investigated in Siha cells. Moreover, Function analyses were conducted using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases after ChIP-seq.

RESULTS

hnRNP K was highly expressed in cervical cancer and precancerous lesions, and positively correlated with HPV16 E6, but negatively correlated with HPV16 E2 and HPV16 E2/E6 ratio. hnRNP K induced cell proliferation, inhibited apoptosis and caused cell cycle arrest in the S phase, and particularly increased HPV16 E6 protein expression.

CONCLUSION

This study revealed that hnRNP K overexpression has important warning significance for the malignant transformation of cervical lesions, and could be used as a potential therapeutic target for inhibiting the carcinogenicity of HPV16 and prevention of cervical carcinogenesis.

Effects of CpG sites methylation modification of HPV16 integration essential gene on the proliferation of cervical cancer cells

PURPOSE

The mechanism of methylation of HPV CpG sites in the occurrence and prognosis of cervical carcinogenesis remains unclear. We investigated the effects of demethylation of the CpG sites of E2 and E6, essential genes of HPV16 integration, on cervical cancer cell expression, integration, and proliferation.

MATERIALS AND METHODS

HPV16-positive (Caski) cells were treated with different concentrations of the demethylation compound 5-aza-dc (0, 5, 10, 20 μmol/l) in vitro. After the intervention, the methylation statuses of HPV16 E2 and E6 were detected by TBS, the expression levels of E2 and E6 mRNA and protein were detected by real-time PCR and western blot, cell proliferation activity was detected by CCK8, and cell cycle and apoptosis were determined by FCM. GraphPad Prism version 8.4.2 and R version 4.2.3 were used for relevant data analyses.

RESULTS

The methylation levels of HPV16 E2 and E6 CpG sites decreased gradually with increasing 5-aza-dc intervention concentrations. With decreasing E2 and E6 methylation rates, E2 expression increased, the E2/E6 ratio increased, E6 expression decreased, and the growth inhibition rate of Caski cells increased. E2 and E6 expression were negatively and positively correlated with their degrees of methylation respectively, while the E2/E6 mRNA to protein ratio was negatively correlated with the methylation degrees of E2 and E6.

CONCLUSION

Demethylation can be used as a prospective treatment to affect HPV expression and persistent infection, providing a new theoretical basis for the clinical treatment of viral infections.

siRNA-E6 sensitizes HPV-16-related cervical cancer through Oxaliplatin: an in vitro study on anti-cancer combination therapy

BACKGROUND

Persistent infection with high-risk Human papillomaviruses (HPV), such as hr-HPV-16 and hr-HPV-18, lead to cervical cancer, the fourth most common cancer in the world. In the present study, we investigated the alteration of E6 oncogene expression by E6-specific short interfering RNA (siRNA) combined with Oxaliplatin.

METHODS

The cervical cancer cell line, CaSki, was transfected with E6-siRNA, then treated with Oxaliplatin. The cellular genes, such as p53, MMP9, Nanog, and caspases expression, were assessed by quantitative real-time PCR. The cell death rate, cell cycle, and cell viability were assessed by Annexin V/PI staining, DAPI staining, and MTT test, respectively. Furthermore, colony formation assay and scratch test determined the stemness ability and cell metastasis, respectively.

RESULTS

Combination therapy increased the re-expression of genes involved in the p53-dependent apoptosis pathway (increase in apoptosis to 44.2%), and reduced stemness and metastasis ability compared to either siRNA or Oxaliplatin monotherapy. Together, our results demonstrate that E6-siRNA and Oxaliplatin combination increased the cervical cancer cells' sensitivity to Oxaliplatin and decreased the survival rate, proliferation, and metastasis, and consequently escalated apoptosis rate, induced cell cycle arrest in the sub-G1 stage, and reduced the chemotherapy drug dosage.

CONCLUSION

Inhibition of E6 oncogene expression and subsequent E6-siRNA with Oxaliplatin combination therapy could be a novel strategy for cervical cancer treatment.

Alteration of Na/H exchange regulatory factor-1 protein levels in anogenital lesions positive for mucosal high-risk human papillomavirus type 16

Mucosal high-risk (HR) human papillomaviruses (HPV) are associated with anogenital carcinogenesis. The products of two early genes, E6 and E7, act as major viral oncoproteins. Functional studies in experimental models showed that HPV16 E6 induces degradation of the PDZ protein, the Na+/H+ exchanger regulatory factor-1 (NHERF-1). Here, we determined NHERF-1 protein levels by immunohistochemistry (IHC) in (i) benign anogenital warts (n = 8) (ii) premalignant lesions (L-SIL and H-SIL) (n = 43) and (iii) invasive cervical squamous cell carcinomas (SCC) (n = 17). A decrease of NHERF-1 protein level was not observed in genital warts in comparison to healthy epithelium. Conversely, a clearly decrease in NHERF-1 protein levels was observed in HPV16-positive pre-malignant and malignant lesions, while the phenomenon was much attenuated in lesions induced by other HR HPV types. In conclusion, these findings show that mucosal HPV types differently impact on NHERF-1 protein level in benign and malignant anogenital lesions.

hnRNP E1 Regulates HPV16 Oncogene Expression and Inhibits Cervical Cancerization

hnRNP E1 (heterogeneous nuclear ribonucleoprotein E1) is an important RNA-binding protein (RBPs) that plays a vital role in tumor development. Human papillomavirus 16 (HPV16) contains numerous sites that can bind to RNA/DNA and may be modified by multiple RBPs, which contribute to HPV gene expression and HPV-associated cancer development. However, the effects of hnRNP E1 on HPV16 oncogenes in the development of cervical lesions remain unclear. A total of 816 participants with different grades of cervical lesions were enrolled in a community-based cohort established in Shanxi Province, China. The Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases were used to analyze the association between hnRNP E1 mRNA expression and cervical lesions. Cells with up_ and down_regulated hnRNP E1 were established. hnRNP E1 functions were evaluated using cell counting kit-8, flow cytometry analyses, and chromatin immunoprecipitation sequencing. Our results showed that hnRNP E1 expression was linearly dependent on the severity of the cervical lesions. Low expression of HPV16 E2, high expression of E6, and a low ratio of E2 to E6 could increase the risk of cervical lesions. hnRNP E1 expression was correlated with HPV16 oncogene expression. hnRNP E1-relevant genes were involved in the dopaminergic synapses, Wnt signaling pathway, gnRH secretion, and mTOR signaling pathway. hnRNP E1 significantly inhibited cell proliferation, induced apoptosis, arrested the cell cycle at the G0/G1 stage, and decreased HPV16 E6 expression. Our results indicate that hnRNP E1 could downregulate HPV16 E6 oncogene expression and inhibit cervical cancerization, which sheds new light on preventing the carcinogenicity of HPV across a range of diseases by regulating RNA-binding proteins.

Oral Microbiota-Driven Cell Migration in Carcinogenesis and Metastasis

The oral cavity harbors approximately 1,000 microbial species, and both pathogenic and commensal strains are involved in the development of carcinogenesis by stimulating chronic inflammation, affecting cell proliferation, and inhibiting cell apoptosis. Moreover, some substances produced by oral bacteria can also act in a carcinogenic manner. The link between oral microbiota and chronic inflammation as well as cell proliferation has been well established. Recently, increasing evidence has indicated the association of the oral microbiota with cell migration, which is crucial in regulating devastating diseases such as cancer. For instance, increased cell migration induced the spread of highly malignant cancer cells. Due to advanced technologies, the mechanistic understanding of cell migration in carcinogenesis and cancer metastasis is undergoing rapid progress. Thus, this review addressed the complexities of cell migration in carcinogenesis and cancer metastasis. We also integrate recent findings on the molecular mechanisms by which the oral microbiota regulates cell migration, with emphasis on the effect of the oral microbiota on adhesion, polarization, and guidance. Finally, we also highlight critical techniques, such as intravital microscopy and superresolution microscopy, for studies in this field.

Period circadian regulator 2 suppresses drug resistance to cisplatin by PI3K/AKT pathway and improves chronochemotherapeutic efficacy in cervical cancer

OBJECTIVE

Chronotherapy, a promising therapy, may build up the chemotherapy efficacy through thinking about timing of therapy. Here, we observed the roles of period circadian regulator 2 (PER2) on cervical cancer progression and the therapeutic efficacy of cisplatin (DDP) based on the circadian rhythm of PER2.

METHODS

When Hela/DDP and SiHa/DDP transfected with pcDNA3.1-PER2 and/or treated with human epidermal growth factor (hEGF), viability, apoptosis, migration, and nuclear translocation of NF-κB p65 were detected by CCK-8, flow cytometry, transwell, immunofluorescence and western blot. Furthermore, the expression of circadian rhythm regulators, multidrug resistance, and epithelial-mesenchymal transition (EMT) proteins was detected by western blot. Hela/DDP cells-induced tumor formation in nude mice was constructed. The expression of PER2 was measured at different time point by RT-qPCR. Cisplatin was separately injected into mice with cervical cancer at the highest and lowest expression of PER2. After 5 weeks, tumor volume was measured and tumor proliferation was assessed by immunohistochemistry.

RESULTS

Overexpression of PER2 significantly reduced proliferative and migrated capacities and nuclear translocation of NF-κB p65 as well as enhanced apoptosis in Hela/DDP and SiHa/DDP cells. Meanwhile, its overexpression elevated the expression of circadian rhythm regulators as well as lowered the expression of multidrug resistance proteins and EMT pathway activation by suppressing PI3K/AKT pathway. PER2 was rhythmically expressed in cervical cancer tissues. Compared to cisplatin treatment at the lowest expression of PER2, tumor growth and proliferation of tumor cells were distinctly suppressed in mice treated with cisplatin at the highest expression of PER2.

CONCLUSION

Our findings confirmed the circadian rhythm of PER2 in cervical cancer and its overexpression restrained the resistance to cisplatin in cervical cancer by PI3K/AKT pathway. It may improve cisplatin efficacy through considering the circadian rhythm of PER2.

Rab31 promotes the invasion and metastasis of cervical cancer cells by inhibiting MAPK6 degradation

Persistent infection with high-risk human papillomavirus (HPV) is the main risk factor for cervical cancer. Our mass spectrometry data showed that the Ras-associated binding protein Rab31 was upregulated by HPV; however, little is known regarding the role of Rab31 in the metastasis of cervical cancer cells. In this study, we showed that Rab31 was highly expressed in cervical cancer tissues and cells, and both HPV E6 and E7 promoted the expression of Rab31. Rab31 knockdown inhibited while Rab31 overexpression promoted the migration and invasion capabilities of cervical cancer cells. Additionally, Rab31 knockdown inhibited the epithelial-mesenchymal transition (EMT) and cytoskeletal rearrangement in cervical cancer cells. Furthermore, Rab31 interacted with mitogen-activated protein kinase 6 (MAPK6), and Rab31 knockdown inhibited the expression of MAPK6, which was mainly localized in the cytoplasm. More importantly, Rab31 knockdown promoted and Rab31 overexpression inhibited MAPK6 degradation. Accordingly, MAPK6 overexpression restored the decreased migration potential caused by Rab31 knockdown. Finally, a xenograft mouse model showed that Rab31 knockdown in cervical cancer cells led to reduced tumor growth and impaired lung and liver metastasis in vivo. In conclusion, Rab31 plays a crucial role in cervical cancer metastasis by inhibiting MAPK6 degradation. Thus, Rab31 may serve as a novel therapeutic target to manage cervical cancer.

Autophagy Modulation by Viral Infections Influences Tumor Development

Autophagy is a self-degradative process important for balancing cellular homeostasis at critical times in development and/or in response to nutrient stress. This is particularly relevant in tumor model in which autophagy has been demonstrated to have an important impact on tumor behavior. In one hand, autophagy limits tumor transformation of precancerous cells in early stage, and in the other hand, it favors the survival, proliferation, metastasis, and resistance to antitumor therapies in more advanced tumors. This catabolic machinery can be induced by an important variety of extra- and intracellular stimuli. For instance, viral infection has often been associated to autophagic modulation, and the role of autophagy in virus replication differs according to the virus studied. In the context of tumor development, virus-modulated autophagy can have an important impact on tumor cells' fate. Extensive analyses have shed light on the molecular and/or functional complex mechanisms by which virus-modulated autophagy influences precancerous or tumor cell development. This review includes an overview of discoveries describing the repercussions of an autophagy perturbation during viral infections on tumor behavior.

High-Risk HPV16 E6 Activates the cGMP/PKG Pathway Through Glycosyltransferase ST6GAL1 in Cervical Cancer Cells

Alterations in glycosylation regulate fundamental molecular and cellular processes of cancer, serving as important biomarkers and therapeutic targets. However, the potential association and regulatory mechanisms of E6 oncoprotein on glycosylation of cervical cancer cells are still unclear. Here, we evaluated the glycomic changes via using Lectin microarray and determined the corresponding enzymes associated with endogenous high-risk HPV16 E6 expression in cervical cancer cells. α-2,6 sialic acids and the corresponding glycosyltransferase ST6GAL1 were significantly increased in E6 stable-expressing HPV- cervical cancer C33A cells. Clinical validation further showed that the expression of ST6GAL1 was significantly increased in patients infected with high-risk HPV subtypes and showed a positive association with E6 in cervical scraping samples. Interfering ST6GAL1 expression markedly blocked the oncogenic effects of E6 on colony formulation, proliferation, and metastasis. Importantly, ST6GAL1 overexpression enhanced tumorigenic activities of both E6-positive and E6-negative cells. Mechanistical investigations revealed that E6 depended on activating YAP1 to stimulate ST6GAL1 expression, as verteporfin (inhibitor of YAP1) significantly suppressed the E6-induced ST6GAL1 upregulation. E6/ST6GAL1 triggered the activation of downstream cGMP/PKG signaling pathway and ODQ (inhibitor of GMP production) simultaneously suppressed the oncogenic activities of both E6 and ST6GAL1 in cervical cancer cells. Taken together, these findings indicate that ST6GAL1 is an important mediator for oncogenic E6 protein to activate the downstream cGMP/PKG signaling pathway, which represents a novel molecular mechanism and potential therapeutic targets for cervical cancer.

Reduced MAGI3 level by HPV18E6 contributes to Wnt/β-catenin signaling activation and cervical cancer progression

Human papillomavirus type 18 (HPV18) has high carcinogenic power in invasive cervical cancer (ICC) development. However, the underlying mechanism remains elusive. The carcinogenic properties of HPV18 require the PDZ‐binding motif of its E6 oncoprotein (HPV18 E6) to degrade its target PSD95/Dlg/ZO‐1 (PDZ) proteins. In this study, we demonstrated that the PDZ protein membrane‐associated guanylate kinase, WW and PDZ domain containing 3 (MAGI3) inhibited the Wnt/β‐catenin pathway, and subsequently cervical cancer (CC) cell migration and invasion, via decreasing β‐catenin levels. By reducing MAGI3 protein levels, HPV18 E6 promoted CC cell migration and invasion through activation of Wnt/β‐catenin signaling. Furthermore, HPV18 rather than HPV16 was preferentially associated with the downregulation of MAGI3 and activation of the Wnt/β‐catenin pathway in CC. These findings shed light on the mechanism that gives HPV18 its high carcinogenic potential in CC progression.

TRIP13 exerts a cancer-promoting role in cervical cancer by enhancing Wnt/β-catenin signaling via ACTN4

Increasing evidence has indicated that thyroid hormone receptor interacting protein 13 (TRIP13) exerts a cancer-promoting role in a broad spectrum of cancers. However, the detailed relevance and function of TRIP13 in cervical cancer remain undefined. The goal of this work was to evaluate the functional significance and mechanism of TRIP13 in cervical cancer. Our data demonstrated that TRIP13 expression was markedly increased in cervical cancer tissue, and high expression of TRIP13 predicted a low survival rate in cervical cancer patients. Knockdown of TRIP13 caused a significant reduction in the proliferation and invasion of cervical cancer cells. By contrast, over-expression of TRIP13 accelerated the proliferation and invasion of cervical cancer cells. Further data revealed that TRIP13 enhanced the activation of Wnt/β-catenin signaling associated with modulation of α-Actinin-4 (ACTN4). Knockdown of ACTN4 markedly reversed TRIP13-mediated activation of Wnt/β-catenin signaling. In addition, inhibition of Wnt/β-catenin signaling reversed TRIP13-induced cancer-promoting effects in cervical cancer cells. Knockdown of TRIP13 markedly retarded the tumor formation and growth of cervical cells in vivo in nude mice. Taken together, the data of this work indicate that TRIP13 accelerates the proliferation and invasion of cervical cancer by enhancing Wnt/β-catenin signaling via regulation of ACTN4. These findings underscore a relevance of the TRIP13/ACTN4/Wnt/β-catenin signaling axis in the progression of cervical cancer and suggest TRIP13 as a potential target for treatment of cervical cancer.

E6/E7 Functional Differences among Two Natural Human Papillomavirus 18 Variants in Human Keratinocytes

It is suggested that HPV-18 variants from the A lineage have higher oncogenic potential compared to B variants. Some studies show uneven distribution of HPV-18 variants in cervical adenocarcinomas and squamous cell carcinomas. Regarding HPV-18 variants’ functions, the few studies reported focus on E6, and none were performed using natural host cells. Here, we immortalized primary human keratinocytes (PHKs) with E6/E7 of HPV-18 A1 and B1 sublineages and functionally characterized these cells. PHK18A1 reached immortalization significantly faster than PHK18B1 and formed a higher number of colonies in monolayer and 3D cultures. Moreover, PHK18A1 showed greater invasion ability and higher resistance to apoptosis induced by actinomycin-D. Nevertheless, no differences were observed regarding morphology, proliferation after immortalization, migration, or epithelial development in raft cultures. Noteworthy, our study highlights qualitative differences among HPV-18 A1 and B1 immortalized PHKs: in contrast to PHK18A1, which formed more compact colonies and spheroids of firmly grouped cells and tended to invade and migrate as clustered cells, morphologically, PHK18B1 colonies and spheroids were looser, and migration and invasion of single cells were observed. Although these observations may be relevant for the association of these variants with cervical cancer of different histological subtypes, further studies are warranted to elucidate the mechanisms behind these findings.

EGFR Protein Expression Relates with Tumor Histology, Methylation Status of EGFR and HPV16 E6 Viral Load in Oropharyngeal Carcinoma

The epidermal growth factor receptor (EGFR) pathway is important in tumorigenesis of oropharyngeal carcinoma (OPC). However, the molecular mechanisms contributing to EGFR expression in OPC are not well-known. To detect relating factors and clinicopathological impact of EGFR protein expression in OPC, gene amplification/loss, point mutations including synonymous mutations, and promoter methylation of EGFR, and the viral genome load of human papillomavirus type 16 (HPV16)-E5, -E6, and -E7, after extracting HPV16-related OPCs with qPCR of HPV16-E6 and E7, were investigated in 74 OPC surgical cases, including 52 HPV-related (HPV-OPC) and 22 HPV-unrelated (nHPV-OPC). Immunohistochemical (IHC) data of EGFR expression (high, weak, and negative), validated by the qPCR of EGFR mRNA, were compared with molecular, viral, and clinicopathological data of patients. All nHPV-OPC cases were EGFR-IHC-high, whereas 21.2%, 65.4%, and 13.5% of HPV-OPC cases showed EGFR-IHC-high, -weak, -negative (p < 0.01), respectively. In HPV-OPC cases, EGFR-IHC-weak/negative status was related to promoter methylation of EGFR (p = 0.009), but not with gene amplification/loss or the point mutation of EGFR and was more often seen in HPV16-OPC cases (p = 0.049). Among HPV16-OPC cases, EGFR-IHC-weak/negative was related to high E6 expression. EGFR protein-loss was related to the tumor histology of non-keratinizing squamous cell carcinoma (SCC) (p = 0.035) but not with patient prognosis. In conclusion, decreased EGFR protein expression was more frequent in HPV-OPC than in nHPV-OPC and was related to EGFR methylation, infection of HPV16, and the viral genome load of HPV16-E6. Clinicopathologically, it was related to the tumor histology of non-keratinizing SCC.

Immunodiagnosis and Immunotherapeutics Based on Human Papillomavirus for HPV-Induced Cancers

Infection with human papillomavirus (HPV) is one of the main causes of malignant neoplasms, especially cervical, anogenital, and oropharyngeal cancers. Although we have developed preventive vaccines that can protect from HPV infection, there are still many new cases of HPV-related cancers worldwide. Early diagnosis and therapy are therefore important for the treatment of these diseases. As HPVs are the major contributors to these cancers, it is reasonable to develop reagents, kits, or devices to detect and eliminate HPVs for early diagnosis and therapeutics. Immunological methods are precise strategies that are promising for the accurate detection and blockade of HPVs. During the last decades, the mechanism of how HPVs induce neoplasms has been extensively elucidated, and several oncogenic HPV early proteins, including E5, E6, and E7, have been shown to be positively related to the oncogenesis and malignancy of HPV-induced cancers. These oncoproteins are promising biomarkers for diagnosis and as targets for the therapeutics of HPV-related cancers. Importantly, many specific monoclonal antibodies (mAbs), or newly designed antibody mimics, as well as new immunological kits, devices, and reagents have been developed for both the immunodiagnosis and immunotherapeutics of HPV-induced cancers. In the current review, we summarize the research progress in the immunodiagnosis and immunotherapeutics based on HPV for HPV-induced cancers. In particular, we depict the most promising serological methods for the detection of HPV infection and several therapeutical immunotherapeutics based on HPV, using immunological tools, including native mAbs, radio-labelled mAbs, affitoxins (affibody-linked toxins), intracellular single-chain antibodies (scFvs), nanobodies, therapeutical vaccines, and T-cell-based therapies. Our review aims to provide new clues for researchers to develop novel strategies and methods for the diagnosis and treatment of HPV-induced tumors.

HPV16 E6 regulates the proliferation, invasion, and apoptosis of cervical cancer cells by downregulating miR-504

BACKGROUND

Human papillomavirus (HPV) 16 infection is a necessary condition for the pathogenesis and development of cervical cancer. The E6 protein is expressed by the HPV16 E6 gene and promotes malignant phenotype transformation, which is an important mechanism for the occurrence and development of cervical cancer. MicroRNA-504 (miR-504) has been reported as an oncogene or tumor suppressor gene; the expression of miR-504 in cervical cancer has been found to be negatively correlated with HPV infection. However, the relationship between HPV16 E6 and miR-504 and the role of miR-504 in cervical cancer are not clear. In the current study, we observed the effect of HPV16 E6 on the expression of miR-504 in cervical cancer cells, and analyzed whether HPV16 E6 affects proliferation, invasion, and apoptosis in cervical cancer cells by regulating the expression of miR-504.

METHODS

Cervical cancer cells (SiHa) were divided into four groups: the empty vector group, E6 overexpression group, E6 overexpression + miR-NC group, and E6 overexpression+miR-504 group. The expressions levels of HPV16 E6 mRNA and miR-504 were detected by real-time polymerase chain reaction (PCR), and the expression level of HPV16 E6 protein was detected by Western blot. Cell proliferation, invasion, and apoptosis were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Tastelessly, and flow cytometry, respectively.

RESULTS

The expression level of miR-504 was significantly decreased in E6 overexpression cells compared to the control cells (P<0.05); the overexpression of miR-504 with miR-504 mimic significantly reversed the downregulation of miR-504 in E6 overexpression SiHa cells (P<0.05). MTT and Transwell assays showed that the overexpression of E6 significantly increased proliferation and invasion of SiHa cells (P<0.05). The overexpression of miR-504 reversed the role of HPV16 E6 on the proliferation and invasion in E6 overexpression SiHa cells, and the difference was statistically significant (P<0.05). Further analysis showed that the overexpression of E6 significantly reduced apoptosis of SiHa cells (P<0.05). The overexpression of miR-504 reversed the role of HPV16 E6 on apoptosis in E6 overexpression SiHa cells, and the difference was statistically significant (P<0.05).

CONCLUSIONS

HPV16 E6 may promote the proliferation and invasion, and inhibit the apoptosis, of cervical cancer SiHa cells by downregulating miR-504 expression.

Extracellular vesicular Wnt7b mediates HPV E6-induced cervical cancer angiogenesis by activating the β-catenin signaling pathway

Background

The E6 oncoproteins of human papillomavirus (HPV) 16/18 are the critical drivers of cervical cancer (CC) progression. Extracellular vesicles (EVs) are emerging as critical mediators of cancer-tumor microenvironment (TME) communication. However, whether EVs contribute to HPV 16/18 E6-mediated impacts on CC progression remains unclear.

Methods

A series of in vitro and in vivo assays were performed to elucidate the roles and mechanism of EV-Wnt7b in HPV E6-induced CC angiogenesis. The prognostic value of serum EV-Wnt7b was determined and a predictive nomogram model was established.

Results

HPV 16/18 E6 upregulated Wnt7b mRNA expression in four HPV 16/18-positive CC cell lines and their EVs. In vitro and in vivo experiments demonstrated that EV-Wnt7b mRNA was transferred to and modulated human umbilical vein endothelial cells (HUVECs) toward more proliferative and proangiogenic behaviors by impacting β-catenin signaling. Clinically, serum EV-Wnt7b levels were elevated in CC patients and significantly correlated with an aggressive phenotype. Serum EV-Wnt7b was determined to be an independent prognostic factor for CC overall survival (OS) and recurrence-free survival (RFS). Notably, we successfully established a novel predictive nomogram model using serum EV-Wnt7b, which showed good prediction of 1- and 3-year OS and RFS.

Conclusions

Our results illustrate a potential crosstalk between HPV 16/18-positive CC cells and HUVECs via EVs in the TME and highlight the potential of circulating EV-Wnt7b as a novel predictive biomarker for CC prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-020-01745-1.

Combined Detection of ACTN4 and SCC-Ag is a Promising Serological Biomarker for Cervical Intraepithelial Neoplasia 3 or Worse: A Case-Control Study

Purpose

Cervical cancer (CC) is a common malignancy in women. Squamous cell carcinoma antigen (SCC-Ag) and cancer antigen (CA)-125 are widely used to help diagnose CC, but novel tumour markers with superior sensitivity and specificity are needed. α-Actinin 4(ACTN4) is overexpressed in CC, though its diagnostic value for CC is unclear. This study examined the diagnostic value of ACTN4 and SCC-Ag as biomarkers for cervical intraepithelial neoplasia (CIN) 3 or worse.

Methods

Women screened for CC at Fujian Medical University Union Hospital were recruited from 2017.1 to 2018.5. Cervical tissues and blood were collected at the same time. Patients pathologically diagnosed as CIN3+ or NILM/CIN1/CIN2 were classified into the case and control groups, respectively. ACTN4 mRNA and protein levels were detected through quantitative PCR and immunohistochemistry, respectively, and ACTN4 and SCC-Ag concentrations were analysed by ELISA. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood rate (PLR), negative likelihood rate (NLR), and Youden index (YI) of ACTN4 and SCC-Ag were evaluated. The optimum cut-off points for ACTN4 and SCC-Ag were determined by receiver operating characteristic (ROC) curve analysis, and accuracy was evaluated by the area under the ROC curve.

Results

In total, 105 patients were classified as CIN3+ cases and 106 as controls. The median ACTN4 levels in case and control tissues were 10.6 and 4.15, respectively. The ACTN4 and SCC-Ag concentrations were significantly higher in cases than controls (P_ACTN4=0.0007; P_SCC-Ag=0.0067). The sensitivity, specificity, PPV, NPV, PLR, NLR and YI of ACTN4 were 68.6%, 76.3%, 76.3%, 72.5%, 2.89, 0.41 and 44.9, respectively; SCC-Ag had a similar diagnostic value (P>0.05), and ACTN4 combined with SCC-Ag had a superior diagnostic value (75.6%, 87.5%, 88.6%, 73.7%, 6.05, 0.28, and 63.1, respectively).

Conclusion

Combined ACTN4 and SCC-Ag detection is a promising serological biomarker for patients with CIN3 or worse.

Effects of HPV16 E6 protein on Daxx-induced apoptosis in C33A cells

Aims

Daxx is a highly conserved nuclear protein with an important role in transcription, apoptosis and other cell processes. We investigated the role of HPV16 E6 in Daxx-induced apoptosis through their interactions in C33A cells.

Methods

The binding of HPV16 E6 and Daxx was confirmed in C33A cells using co-immunoprecipitation and indirect immunofluorescence assays. Quantitative PCR and western blotting were performed to determine the RNA and protein expressions of Daxx, respectively. Automatic cell count and MTT assays were performed to investigate the proliferation of C33A cells. The apoptosis rate of C33A cells was determined via flow cytometry using Annexin V-FITC/PI staining. The relative activity of caspase-8 was tested using ELISA.

Results

HPV16 E6 can bind with Daxx and cause its translocation in C33A cells. The transfected HPV16 E6 can cause a decrease in relative quantification for Daxx in Daxx-overexpressing cells. After Daxx transfection, cell proliferation was found to decrease sharply and cell apoptosis to increase sharply. However, when HPV16 E6 was co-transfected with Daxx, this decrease and increase both became gentle. Similarly, HPV16 E6 made the Daxx-induced increase in caspase-8 activity milder.

Conclusions

HPV16 E6 is involved in inhibiting apoptosis through deregulation of Daxx-induced caspase-8 activities.