1
|
Human Papillomavirus in Breast Carcinogenesis: A Passenger, a Cofactor, or a Causal Agent? BIOLOGY 2021; 10:biology10080804. [PMID: 34440036 PMCID: PMC8389583 DOI: 10.3390/biology10080804] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 08/05/2021] [Accepted: 08/06/2021] [Indexed: 12/16/2022]
Abstract
Simple Summary Breast cancer (BC) is the most frequent tumor in women worldwide. A minority of BC patients have a family history of the disease, suggesting the importance of environmental and lifestyle factors. Human papillomavirus (HPV) infection has been detected in a subset of tumors, suggesting a potential role in BC. In this review, we summarized relevant information in respect to this topic and we propose a model of HPV-mediated breast carcinogenesis. Evidence suggests that breast tissue is accessible to HPV, which may be a causal agent of BC in a subset of cases. Abstract Breast cancer (BC) is the most commonly diagnosed malignancy in women worldwide as well as the leading cause of cancer-related death in this gender. Studies have identified that human papillomavirus (HPV) is a potential risk factor for BC development. While vaccines that protect against oncogenic HPVs infection have been commercially available, global disparities persist due to their high cost. Interestingly, numerous authors have detected an increased high risk (HR)-HPV infection in BC specimens when compared with non-tumor tissues. Therefore, it was suggested that HR-HPV infection could play a role in breast carcinogenesis in a subset of cases. Additional epidemiological and experimental evidence is still needed regarding the role of HR-HPV infection in the development and progression of BC.
Collapse
|
2
|
Viral Manipulation of the Host Epigenome as a Driver of Virus-Induced Oncogenesis. Microorganisms 2021; 9:microorganisms9061179. [PMID: 34070716 PMCID: PMC8227491 DOI: 10.3390/microorganisms9061179] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/24/2021] [Accepted: 05/26/2021] [Indexed: 12/13/2022] Open
Abstract
Tumorigenesis due to viral infection accounts for a high fraction of the total global cancer burden (15–20%) of all human cancers. A comprehensive understanding of the mechanisms by which viral infection leads to tumor development is extremely important. One of the main mechanisms by which viruses induce host cell proliferation programs is through controlling the host’s epigenetic machinery. In this review, we dissect the epigenetic pathways through which oncogenic viruses can integrate their genome into host cell chromosomes and lead to tumor progression. In addition, we highlight the potential use of drugs based on histone modifiers in reducing the global impact of cancer development due to viral infection.
Collapse
|
3
|
Hier J, Vachon O, Bernstein A, Ibrahim I, Mlynarek A, Hier M, Alaoui-Jamali MA, Maschietto M, da Silva SD. Portrait of DNA methylated genes predictive of poor prognosis in head and neck cancer and the implication for targeted therapy. Sci Rep 2021; 11:10012. [PMID: 33976322 PMCID: PMC8113272 DOI: 10.1038/s41598-021-89476-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 04/23/2021] [Indexed: 12/31/2022] Open
Abstract
In addition to chronic infection with human papilloma virus (HPV) and exposure to environmental carcinogens, genetic and epigenetic factors act as major risk factors for head and neck cancer (HNC) development and progression. Here, we conducted a systematic review in order to assess whether DNA hypermethylated genes are predictive of high risk of developing HNC and/or impact on survival and outcomes in non-HPV/non-tobacco/non-alcohol associated HNC. We identified 85 studies covering 32,187 subjects where the relationship between DNA methylation, risk factors and survival outcomes were addressed. Changes in DNA hypermethylation were identified for 120 genes. Interactome analysis revealed enrichment in complex regulatory pathways that coordinate cell cycle progression (CCNA1, SFN, ATM, GADD45A, CDK2NA, TP53, RB1 and RASSF1). However, not all these genes showed significant statistical association with alcohol consumption, tobacco and/or HPV infection in the multivariate analysis. Genes with the most robust HNC risk association included TIMP3, DCC, DAPK, CDH1, CCNA1, MGMT, P16, MINT31, CD44, RARβ. From these candidates, we further validated CD44 at translational level in an independent cohort of 100 patients with tongue cancer followed-up beyond 10 years. CD44 expression was associated with high-risk of tumor recurrence and metastasis (P = 0.01) in HPV-cases. In summary, genes regulated by methylation play a modulatory function in HNC susceptibility and it represent a critical therapeutic target to manage patients with advanced disease.
Collapse
Affiliation(s)
- Jessica Hier
- Department of Otolaryngology-Head and Neck Surgery, Lady Davis Institute for Medical Research and Segal Cancer Centre, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, 3755 Côte Ste-Catherine Road, Montreal, QC, H3T 1E2, Canada
| | - Olivia Vachon
- Department of Otolaryngology-Head and Neck Surgery, Lady Davis Institute for Medical Research and Segal Cancer Centre, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, 3755 Côte Ste-Catherine Road, Montreal, QC, H3T 1E2, Canada
| | - Allison Bernstein
- Department of Otolaryngology-Head and Neck Surgery, Lady Davis Institute for Medical Research and Segal Cancer Centre, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, 3755 Côte Ste-Catherine Road, Montreal, QC, H3T 1E2, Canada
| | - Iman Ibrahim
- Department of Otolaryngology-Head and Neck Surgery, Lady Davis Institute for Medical Research and Segal Cancer Centre, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, 3755 Côte Ste-Catherine Road, Montreal, QC, H3T 1E2, Canada
| | - Alex Mlynarek
- Department of Otolaryngology-Head and Neck Surgery, Lady Davis Institute for Medical Research and Segal Cancer Centre, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, 3755 Côte Ste-Catherine Road, Montreal, QC, H3T 1E2, Canada
| | - Michael Hier
- Department of Otolaryngology-Head and Neck Surgery, Lady Davis Institute for Medical Research and Segal Cancer Centre, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, 3755 Côte Ste-Catherine Road, Montreal, QC, H3T 1E2, Canada
| | - Moulay A Alaoui-Jamali
- Segal Cancer Centre of the Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, QC, Canada
| | - Mariana Maschietto
- Department of Structural and Functional Biology, Institute of Biology, Universidade Estadual de Campinas (UNICAMP) and Boldrini Children's Center, Campinas, Sao Paulo, Brazil
| | - Sabrina Daniela da Silva
- Department of Otolaryngology-Head and Neck Surgery, Lady Davis Institute for Medical Research and Segal Cancer Centre, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, 3755 Côte Ste-Catherine Road, Montreal, QC, H3T 1E2, Canada. .,Segal Cancer Centre of the Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, QC, Canada.
| |
Collapse
|
4
|
High-Risk Human Papillomavirus and Tobacco Smoke Interactions in Epithelial Carcinogenesis. Cancers (Basel) 2020; 12:cancers12082201. [PMID: 32781676 PMCID: PMC7465661 DOI: 10.3390/cancers12082201] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/04/2020] [Accepted: 08/04/2020] [Indexed: 02/06/2023] Open
Abstract
Cervical, anogenital, and some head and neck cancers (HNC) are etiologically associated with high-risk human papillomavirus (HR-HPV) infection, even though additional cofactors are necessary. Epidemiological studies have established that tobacco smoke (TS) is a cofactor for cervical carcinogenesis because women who smoke are more susceptible to cervical cancer when compared to non-smokers. Even though such a relationship has not been established in HPV-related HNC, a group of HPV positive patients with this malignancy are smokers. TS is a complex mixture of more than 4500 chemical compounds and approximately 60 of them show oncogenic properties such as benzo[α]pyrene (BaP) and nitrosamines, among others. Some of these compounds have been evaluated for carcinogenesis through experimental settings in collaboration with HR-HPV. Here, we conducted a comprehensive review of the suggested molecular mechanisms involved in cooperation with both HR-HPV and TS for epithelial carcinogenesis. Furthermore, we propose interaction models in which TS collaborates with HR-HPV to promote epithelial cancer initiation, promotion, and progression. More studies are warranted to clarify interactions between oncogenic viruses and chemical or physical environmental factors for epithelial carcinogenesis.
Collapse
|
5
|
DNA Methylation Changes in Human Papillomavirus-Driven Head and Neck Cancers. Cells 2020; 9:cells9061359. [PMID: 32486347 PMCID: PMC7348958 DOI: 10.3390/cells9061359] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/25/2020] [Accepted: 05/28/2020] [Indexed: 12/12/2022] Open
Abstract
Disruption of DNA methylation patterns is one of the hallmarks of cancer. Similar to other cancer types, human papillomavirus (HPV)-driven head and neck cancer (HNC) also reveals alterations in its methylation profile. The intrinsic ability of HPV oncoproteins E6 and E7 to interfere with DNA methyltransferase activity contributes to these methylation changes. There are many genes that have been reported to be differentially methylated in HPV-driven HNC. Some of these genes are involved in major cellular pathways, indicating that DNA methylation, at least in certain instances, may contribute to the development and progression of HPV-driven HNC. Furthermore, the HPV genome itself becomes a target of the cellular DNA methylation machinery. Some of these methylation changes appearing in the viral long control region (LCR) may contribute to uncontrolled oncoprotein expression, leading to carcinogenesis. Consistent with these observations, demethylation therapy appears to have significant effects on HPV-driven HNC. This review article comprehensively summarizes DNA methylation changes and their diagnostic and therapeutic indications in HPV-driven HNC.
Collapse
|
6
|
Perrard J, Morel A, Meznad K, Paget-Bailly P, Dalstein V, Guenat D, Mourareau C, Clavel C, Fauconnet S, Baguet A, Mougin C, Pretet JL. DNA demethylation agent 5azadC downregulates HPV16 E6 expression in cervical cancer cell lines independently of TBX2 expression. Oncol Lett 2019; 19:1074-1081. [PMID: 31897221 DOI: 10.3892/ol.2019.11158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 09/09/2019] [Indexed: 12/18/2022] Open
Abstract
HPV16 is the most carcinogenic human papillomavirus and causes >50% of cervical cancers, the majority of anal cancers and 30% of oropharyngeal squamous cell carcinomas. HPV carcinogenesis relies on the continuous expression of the two main viral oncoproteins E6 and E7 that target >150 cellular proteins. Among them, epigenetic modifiers, including DNA Methyl Transferases (DNMT), are dysregulated, promoting an aberrant methylation pattern in HPV-positive cancer cells. It has been previously reported that the treatment of HPV-positive cervical cancer cells with DNMT inhibitor 5-aza-2'-deoxycytidine (5azadC) caused the downregulation of E6 expression due to mRNA destabilization that was mediated by miR-375. Recently, the T-box transcription factor 2 (TBX2) has been demonstrated to repress HPV LCR activity. In the current study, the role of TBX2 in E6 repression was investigated in HPV16 cervical cancer cell lines following 5azadC treatment. A decrease of E6 expression was accompanied by p53 and p21 restoration. While TBX2 mRNA was upregulated in 5azadC-treated SiHa and Ca Ski cells, TBX2 protein was not detectable. Furthermore, the overexpression of TBX2 protein in cervical cancer cells did not allow the repression of E6 expression. The TBX2 transcription factor is therefore unlikely to be associated with the repression of E6 following 5azadC treatment of SiHa and Ca Ski cells.
Collapse
Affiliation(s)
- Jerome Perrard
- Équipe d'Accueil 3181, University of Bourgogne Franche-Comté, Laboratoire d'Excellence Lipoprotéines et Santé, Prévention et Traitement des Maladies Inflammatoires et du Cancer, 25000 Besançon, France
| | - Adrien Morel
- Center For Research in Genetics and Genomics-CIGGUR, GENIUROS Research Group, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 112041, Colombia
| | - Koceila Meznad
- Équipe d'Accueil 3181, University of Bourgogne Franche-Comté, Laboratoire d'Excellence Lipoprotéines et Santé, Prévention et Traitement des Maladies Inflammatoires et du Cancer, 25000 Besançon, France
| | - Philippe Paget-Bailly
- Équipe d'Accueil 3181, University of Bourgogne Franche-Comté, Laboratoire d'Excellence Lipoprotéines et Santé, Prévention et Traitement des Maladies Inflammatoires et du Cancer, 25000 Besançon, France
| | - Veronique Dalstein
- Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche-S 1250 Pathologies Pulmonaires et Plasticité Cellulaire, Université de Reims Champagne-Ardenne, Faculté de Médecine, 51000 Reims, France.,Centre Hospitalier Universitaire Reims, Laboratoire Biopathologie, 51000 Reims, France
| | - David Guenat
- Équipe d'Accueil 3181, University of Bourgogne Franche-Comté, Laboratoire d'Excellence Lipoprotéines et Santé, Prévention et Traitement des Maladies Inflammatoires et du Cancer, 25000 Besançon, France.,Centre National de Référence Papillomavirus, CHU Besançon, Boulevard Alexandre Fleming, 25000 Besançon, France
| | - Celine Mourareau
- Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche-S 1250 Pathologies Pulmonaires et Plasticité Cellulaire, Université de Reims Champagne-Ardenne, Faculté de Médecine, 51000 Reims, France.,Centre Hospitalier Universitaire Reims, Laboratoire Biopathologie, 51000 Reims, France
| | - Christine Clavel
- Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche-S 1250 Pathologies Pulmonaires et Plasticité Cellulaire, Université de Reims Champagne-Ardenne, Faculté de Médecine, 51000 Reims, France.,Centre Hospitalier Universitaire Reims, Laboratoire Biopathologie, 51000 Reims, France
| | - Sylvie Fauconnet
- Équipe d'Accueil 3181, University of Bourgogne Franche-Comté, Laboratoire d'Excellence Lipoprotéines et Santé, Prévention et Traitement des Maladies Inflammatoires et du Cancer, 25000 Besançon, France
| | - Aurelie Baguet
- Équipe d'Accueil 3181, University of Bourgogne Franche-Comté, Laboratoire d'Excellence Lipoprotéines et Santé, Prévention et Traitement des Maladies Inflammatoires et du Cancer, 25000 Besançon, France
| | - Christiane Mougin
- Équipe d'Accueil 3181, University of Bourgogne Franche-Comté, Laboratoire d'Excellence Lipoprotéines et Santé, Prévention et Traitement des Maladies Inflammatoires et du Cancer, 25000 Besançon, France.,Centre National de Référence Papillomavirus, CHU Besançon, Boulevard Alexandre Fleming, 25000 Besançon, France
| | - Jean-Luc Pretet
- Équipe d'Accueil 3181, University of Bourgogne Franche-Comté, Laboratoire d'Excellence Lipoprotéines et Santé, Prévention et Traitement des Maladies Inflammatoires et du Cancer, 25000 Besançon, France.,Centre National de Référence Papillomavirus, CHU Besançon, Boulevard Alexandre Fleming, 25000 Besançon, France
| |
Collapse
|
7
|
Abstract
Since their discovery as the etiologic agents of cervical cancer in the mid-1970s, human papillomaviruses (HPVs) have been linked with a growing number of epithelial-derived tumors, including head and neck squamous cell carcinomas. HPV demonstrates a particular predilection for causing tumors of the oropharynx, with the majority of cases involving infection with high-oncogenic risk HPV-16. People living with HIV are at increased risk of infection with HPV- and HPV-related oral complications even with adequate control of their HIV infection with antiretroviral therapy. In this chapter, we discuss the molecular mechanisms that underlie HPV-mediated oncogenesis in the oropharynx. We also describe the progress that has been made in understanding the epidemiology of oral HPV infection and the determinants of oral HPV-related pathology. Finally, we examine what can be done to treat and prevent oral HPV infection, benign lesions, and cancer, particularly in the context of the HIV-positive patient.
Collapse
|
8
|
Khanal S, Shumway BS, Zahin M, Redman RA, Strickley JD, Trainor PJ, Rai SN, Ghim SJ, Jenson AB, Joh J. Viral DNA integration and methylation of human papillomavirus type 16 in high-grade oral epithelial dysplasia and head and neck squamous cell carcinoma. Oncotarget 2018; 9:30419-30433. [PMID: 30100997 PMCID: PMC6084396 DOI: 10.18632/oncotarget.25754] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/25/2018] [Indexed: 12/19/2022] Open
Abstract
This study evaluated the integration and methlyation of human papillomavirus type 16 (HPV16) in head and neck squamous cell carcinoma (HNSCC) and its oral precursor, high-grade oral epithelial dysplasia (hgOED). Archival samples of HPV16-positive hgOED (N = 19) and HNSCC (N = 15) were evaluated, along with three HNSCC (UMSCC-1, -47 and -104) and two cervical cancer (SiHa and CaSki) cell lines. HgOED cases were stratified into three groups with increasing degrees of cytologic changes (mitosis, karyorrhexis and apoptosis). The viral load was higher and the E2/E6 ratio lower (indicating a greater tendency toward viral integration) in group 3 than in groups 1 or 2 (p = 0.002, 0.03). Methylation was not observed in hgOED cases and occurred variably in only three HNSCC cases (26.67%, 60.0% and 93.3%). In HNSCC cell lines, lower E7 expression correlated with higher levels of methylation. HgOED with increased cytologic change, now termed HPV-associated oral epithelial dysplasia (HPV-OED), exhibited an increased viral load and a tendency toward DNA integration, suggesting a potentially increased risk for malignant transformation. More detailed characterization and clinical follow-up of HPV-OED patients is needed to determine whether HPV-OED is a true precursor to HPV-associated HNSCC and to clarify the involvement of HPV in HNSCC carcinogenesis.
Collapse
Affiliation(s)
- Sujita Khanal
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Brian S Shumway
- Department of Surgical and Hospital Dentistry, University of Louisville School of Dentistry, Louisville, KY, USA
| | - Maryam Zahin
- James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA
| | - Rebecca A Redman
- James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA.,Department of Medicine, School of Medicine, University of Louisville, Louisville, KY, USA
| | - John D Strickley
- James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA.,Department of Medicine, School of Medicine, University of Louisville, Louisville, KY, USA
| | - Patrick J Trainor
- James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA
| | - Shesh N Rai
- James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA
| | - Shin-Je Ghim
- James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA
| | | | - Joongho Joh
- James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA.,Department of Medicine, School of Medicine, University of Louisville, Louisville, KY, USA.,Center for Predictive Medicine, University of Louisville, Louisville, KY, USA
| |
Collapse
|
9
|
Boscolo-Rizzo P, Furlan C, Lupato V, Polesel J, Fratta E. Novel insights into epigenetic drivers of oropharyngeal squamous cell carcinoma: role of HPV and lifestyle factors. Clin Epigenetics 2017; 9:124. [PMID: 29209433 PMCID: PMC5704592 DOI: 10.1186/s13148-017-0424-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 11/18/2017] [Indexed: 12/22/2022] Open
Abstract
In the last years, the explosion of high throughput sequencing technologies has enabled epigenome-wide analyses, allowing a more comprehensive overview of the oropharyngeal squamous cell carcinoma (OPSCC) epigenetic landscape. In this setting, the cellular pathways contributing to the neoplastic phenotype, including cell cycle regulation, cell signaling, DNA repair, and apoptosis have been demonstrated to be potential targets of epigenetic alterations in OPSCC. Of note, it has becoming increasingly clear that HPV infection and OPSCC lifestyle risk factors differently drive the epigenetic machinery in cancer cells. Epigenetic changes, including DNA methylation, histone modifications, and non-coding RNA expression, can be used as powerful and reliable tools for early diagnosis of OPSCC patients and improve prognostication. Since epigenetic changes are dynamic and reversible, epigenetic enzymes may also represent suitable targets for the development of more effective OPSCC therapeutic strategies. Thus, this review will focus on the main known epigenetic modifications that can occur in OPSCC and their exploitation as potential biomarkers and therapeutic targets. Furthermore, we will address epigenetic alterations to OPSCC risk factors, with a particular focus on HPV infection, tobacco exposure, and heavy alcohol consumption.
Collapse
Affiliation(s)
- Paolo Boscolo-Rizzo
- Department of Neurosciences, ENT Clinic and Regional Center for Head and Neck Cancer, Treviso Regional Hospital, University of Padova, Treviso, Italy
| | - Carlo Furlan
- Division of Radiotherapy, Centro di Riferimento Oncologico, IRCCS-National Cancer Institute, Aviano, PN Italy
| | - Valentina Lupato
- Unit of Otolaryngology, General Hospital “S. Maria degli Angeli”, Pordenone, Italy
| | - Jerry Polesel
- Unit of Cancer Epidemiology, Centro di Riferimento Oncologico, IRCCS-National Cancer Institute, Aviano, PN Italy
| | - Elisabetta Fratta
- Immunopathology and Cancer Biomarkers, Centro di Riferimento Oncologico, IRCCS-National Cancer Institute, Aviano, PN Italy
| |
Collapse
|
10
|
Chen GD, Qian DY, Li ZG, Fan GY, You KL, Wu YL. Down-regulation of p16 and MGMT promotes the anti-proliferative and pro-apoptotic effects of 5-Aza-dC and radiation on cervical cancer cells. Cell Biochem Funct 2017; 35:488-496. [PMID: 29143344 DOI: 10.1002/cbf.3282] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 07/05/2017] [Accepted: 07/05/2017] [Indexed: 12/19/2022]
Abstract
Cervical cancer is one of the most common malignancies of the female reproductive system. Therefore, it is critical to investigate the molecular mechanisms involved in the development and progression of cervical cancer. In this study, we stimulated cervical cancer cells with 5-aza-2'-deoxycytidine (5-Aza-dC) and found that this treatment inhibited cell proliferation and induced apoptosis; additionally, methylation of p16 and O-6-methylguanine-DNA methyltransferase (MGMT) was reversed, although their expression was suppressed. 5-Aza-dC inhibited E6 and E7 expression and up-regulated p53, p21, and Rb expression. Cells transfected with siRNAs targeting p16 and MGMT as well as cells stimulated with 5-Aza-dC were arrested in S phase, and the expression of p53, p21, and Rb was up-regulated more significantly. However, when cells were stimulated with 5-Aza-dC after transfection with siRNAs targeting p16 and MGMT, proliferation decreased significantly, and the percentage of cells in the sub-G1 peak and in S phase was significantly increased, suggesting a marked increase in apoptosis. But E6 and E7 overexpression could rescue the observed effects in proliferation. Furthermore, X-ray radiation caused cells to arrest in G2/M phase, but cells transfected with p16- and MGMT-targeted siRNAs followed by X-ray radiation exhibited a significant decrease in proliferation and were shifted toward the sub-G1 peak, also indicating enhanced apoptosis. In addition, the effects of 5-Aza-dC and X-ray radiation were most pronounced when MGMT expression was down-regulated. Therefore, down-regulation of p16 and MGMT expression enhances the anti-proliferative effects of 5-Aza-dC and X-ray radiation. This discovery may provide novel ideas for the treatment of cervical cancer.
Collapse
Affiliation(s)
- Guan-di Chen
- Southern Medical University, Guangzhou, Guangdong, China
| | - De-Ying Qian
- Department of Gynecology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Zhi-Gang Li
- Department of Gynecology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Ge-Ying Fan
- Department of Gynecology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Ke-Li You
- Department of Gynecology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Yi-Long Wu
- Southern Medical University, Guangzhou, Guangdong, China.,Medical Research Centre, Guangdong Lung Cancer Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| |
Collapse
|
11
|
Yao S, Hart DJ, An Y. Recent advances in universal TA cloning methods for use in function studies. Protein Eng Des Sel 2016; 29:551-556. [PMID: 27578885 DOI: 10.1093/protein/gzw047] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/28/2016] [Accepted: 08/05/2016] [Indexed: 01/08/2023] Open
Abstract
As one of the simplest and most efficient cloning methods, T-vector-based TA cloning has been widely used for cloning of single genes and construction of DNA libraries. This approach is especially suitable for high-throughput cloning of diverse DNA fragments since inserts can be cloned without knowledge of their sequence; it is therefore an ideal tool for high-throughput analysis of protein structure and function. Although most of the currently available T-vectors can only be used for cloning purposes, some novel variants with improved functions have be developed. This review focuses on recent developments of universal TA cloning methods and T-vectors constructed for function studies.
Collapse
Affiliation(s)
- Shuo Yao
- College of Biosciences and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Darren J Hart
- Institut de Biologie Structurale (IBS), CEA, CNRS, University Grenoble Alpes, Grenoble38044, France
| | - Yingfeng An
- College of Biosciences and Biotechnology, Shenyang Agricultural University, Shenyang, China
| |
Collapse
|
12
|
5-aza-2'-deoxycytidine (DAC) treatment downregulates the HPV E6 and E7 oncogene expression and blocks neoplastic growth of HPV-associated cancer cells. Oncotarget 2016; 8:52104-52117. [PMID: 28881717 PMCID: PMC5581016 DOI: 10.18632/oncotarget.10631] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 06/03/2016] [Indexed: 11/25/2022] Open
Abstract
High-risk human papillomaviruses (hr HPVs) may cause various human cancers and associated premalignant lesions. Transformation of the host cells is triggered by overexpression of the viral oncogenes E6 and E7 that deregulate the cell cycle and induce chromosomal instability. This process is accompanied by hypermethylation of distinct CpG sites resulting in silencing of tumor suppressor genes, inhibition of the viral E2 mediated control of E6 and E7 transcription as well as deregulated expression of host cell microRNAs. Therefore, we hypothesized that treatment with demethylating agents might restore those regulatory mechanisms. Here we show that treatment with 5-aza-2′-deoxycytidine (DAC) strongly decreases the expression of E6 and E7 in a panel of HPV-transformed cervical cancer and head and neck squamous cell carcinoma cell lines. Reduction of E6 and E7 further resulted in increased target protein levels including p53 and p21 reducing the proliferation rates and colony formation abilities of the treated cell lines. Moreover, DAC treatment led to enhanced expression of tumor the suppressive miRNA-375 that targets and degrades E6 and E7 transcripts. Therefore, we suggest that DAC treatment of HPV-associated cancers and respective precursor lesions may constitute a targeted approach to subvert HPV oncogene functions that deserves testing in clinical trials.
Collapse
|