E6 and E7 oncoproteins: Potential targets of cervical cancer

2020 ◽  
Vol 27 ◽  
Author(s):  
Ramarao Malla ◽  
Mohammad Amjad Kamal
Keyword(s):  
Cervical Cancer ◽  
Drug Resistance ◽  
Host Cell ◽  
Molecular Mechanisms ◽  
Immune Therapy ◽  
Cervical Lesions ◽  
Diagnostic Strategies ◽  
E6 And E7 Oncoproteins ◽  
E6 And E7

: Cervical cancer (CC) is the fourth leading cancer in women in the age group 15-44 globally. Experimental as well as epidemiological studies identified that type16 and 18 HPV cause 70% of precancerous cervical lesions as well as cervical cancer worldwide by bringing about genetic as well as epigenetic changes in the host genome. The insertion of the HPV genome triggers various defense mechanisms including the silencing of tumor suppressor genes as well as activation of oncogenes associated with cancer metastatic pathway. E6 and E7 are small oncoproteins consisting of 150 and 100 amino acids respectively. These oncoproteins affect the regulation of the host cell cycle by interfering with p53 and pRb. Further these oncoproteins adversely affect the normal functions of the host cell by binding to their signaling proteins. Recent studies demonstrated that E6 and E7 oncoproteins are potential targets for CC. Therefore, this review discusses the role of E6 and E7 oncoproteins in metastasis and drug resistance as well as their regulation, early oncogene mediated signaling pathways. This review also uncovers the recent updates on molecular mechanisms of E6 and E7 mediated phytotherapy, gene therapy, immune therapy, and vaccine strategies as well as diagnosis through precision testing. Therefore, understanding the potential role of E6/E7 in metastasis and drug resistance along with targeted treatment, vaccine, and precision diagnostic strategies could be useful for the prevention and treatment of cervical cancer.

scholarly journals Association of cervical carcinogenesis risk with HPV16 E6 and E7 variants in the Taizhou area, China

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mei-Zhen Dai ◽  
Yi Qiu ◽  
Xing-Hong Di ◽  
Wei-Wu Shi ◽  
Hui-Hui Xu
Keyword(s):  
Cervical Cancer ◽  
Cervical Carcinogenesis ◽  
Chi Square ◽  
Major Health Problem ◽  
Hpv16 E6 ◽  
Exact Test ◽  
Chi Square Test ◽  
E6 And E7

Abstract Background Human papillomavirus (HPV) type 16 accounts for a larger share of cervical cancer and has been a major health problem worldwide for decades. The progression of initial infection to cervical cancer has been linked to viral sequence properties; however, the role of HPV16 variants in the risk of cervical carcinogenesis, especially with longitudinal follow-up, is not fully understood in China. Methods We aimed to investigate the genetic variability of HPV16 E6 and E7 oncogenes in isolates from cervical exfoliated cells. Between December 2012 and December 2014, a total of 310 single HPV16-positive samples were selected from women living in the Taizhou area, China. Sequences of all E6 and E7 oncogenes were analysed by PCR-sequencing assay. Detailed sequence comparison, genetic heterogeneity analyses and maximum-likelihood phylogenetic tree construction were performed with BioEdit Sequence Alignment Editor and MEGA X software. Data for cytology tests and histological diagnoses were obtained from our Taizhou Area Study with longitudinal follow-up for at least 5 years. The relationship between HPV16 variants and cervical carcinogenesis risk was analysed by the chi-square test or Fisher’s exact test. Results In this study, we obtained 64 distinct variation patterns with the accession GenBank numbers MT681266-MT681329. Phylogenetic analysis revealed that 98.3% of HPV16 variants belong to lineage A, in which the A4 (Asian) sublineage was dominant (64.8%), followed by A2 (12.1%), A1 (11.4%), and A3 (10.0%). The A4 (Asian) sublineage had a higher risk of CIN2+ than the A1–3 (European) sublineages (OR = 2.69, 95% CI = 1.04–6.97, P < 0.05). Furthermore, nucleotide variation in HPV16 E6 T178G is associated with the development of cervical cancer. Conclusion These data could provide novel insights into the role of HPV16 variants in cervical carcinogenesis risk in China.

scholarly journals Multiple ASF/SF2 Sites in the Human Papillomavirus Type 16 (HPV-16) E4-Coding Region Promote Splicing to the Most Commonly Used 3′-Splice Site on the HPV-16 Genome

2010 ◽  
Vol 84 (16) ◽  
pp. 8219-8230 ◽  
Author(s):  
Monika Somberg ◽  
Stefan Schwartz
Keyword(s):  
Cervical Cancer ◽  
Human Papillomavirus ◽  
Splice Site ◽  
Binding Sites ◽  
Mrna Levels ◽  
Coding Region ◽  
Cervical Lesions ◽  
Hpv 16 ◽  
Human Papillomavirus Type 16 ◽  
E6 And E7

ABSTRACT Our results presented here demonstrate that the most abundant human papillomavirus type 16 (HPV-16) mRNAs expressing the viral oncogenes E6 and E7 are regulated by cellular ASF/SF2, itself defined as a proto-oncogene and overexpressed in cervical cancer cells. We show that the most frequently used 3′-splice site on the HPV-16 genome, site SA3358, which is used to produce primarily E4, E6, and E7 mRNAs, is regulated by ASF/SF2. Splice site SA3358 is immediately followed by 15 potential binding sites for the splicing factor ASF/SF2. Recombinant ASF/SF2 binds to the cluster of ASF/SF2 sites. Mutational inactivation of all 15 sites abolished splicing to SA3358 and redirected splicing to the downstream-located, late 3′-splice site SA5639. Overexpression of a mutant ASF/SF2 protein that lacks the RS domain, also totally inhibited the usage of SA3358 and redirected splicing to the late 3′-splice site SA5639. The 15 ASF/SF2 binding sites could be replaced by an ASF/SF2-dependent, HIV-1-derived splicing enhancer named GAR. This enhancer was also inhibited by the mutant ASF/SF2 protein that lacks the RS domain. Finally, silencer RNA (siRNA)-mediated knockdown of ASF/SF2 caused a reduction in spliced HPV-16 mRNA levels. Taken together, our results demonstrate that the major HPV-16 3′-splice site SA3358 is dependent on ASF/SF2. SA3358 is used by the most abundantly expressed HPV-16 mRNAs, including those encoding E6 and E7. High levels of ASF/SF2 may therefore be a requirement for progression to cervical cancer. This is supported by our earlier findings that ASF/SF2 is overexpressed in high-grade cervical lesions and cervical cancer.

scholarly journals Nucleolin Promotes Cisplatin Resistance in Cervical Cancer by the YB1-MDR1 Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jing Ke ◽  
Chunming Gu ◽  
Heyan Zhang ◽  
Yang Liu ◽  
Wenhao Zhang ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Drug Resistance ◽  
Hela Cells ◽  
Protein Level ◽  
Molecular Mechanisms ◽  
Cisplatin Resistance ◽  
Mdr1 Gene ◽  
Luciferase Reporter ◽  
Drug Efflux ◽  
Cell Line Hela

Purpose. Cervical cancer is the fourth most common cancer in women worldwide and is the main cause of cancer-related deaths in women. Cisplatin (DDP) is one of the major chemotherapeutic drugs for cervical cancer patients. But, drug resistance limits the effectiveness of cancer therapy. Nucleolin (NCL) is a nucleocytoplasmic multifunctional protein involved in the development of cancer. It has been reported that NCL may be a potential target for modulation of drug resistance. However, the precise molecular mechanisms are poorly understood. Materials and Methods. Human cervical cancer Hela cells and their cisplatin-resistant cell line Hela/DDP were used in this study. The protein level of NCL in cervical cancer cells was measured by western blot analysis. Hela cells and Hela/DDP cells were transfected with NCL overexpression plasmid or NCL siRNA separately. MTT and EdU assay were performed to evaluate the cell viability and sensitivity to cisplatin. The drug efflux function of MDR1 protein was assessed by intracellular rhodamine-123 accumulation assay.The promoter activity of MDR1 was assessed by using a dual-luciferase reporter assay. Results. We found that the protein level of NCL was elevated in Hela/DDP cells. Overexpression of NCL increased cervical cancer cell proliferation and attenuated the sensitivity to cisplatin. Overexpression of NCL increased Multidrug resistance (MDR1) gene expression and drug efflux. Our results demonstrated that NCL was highly related with cisplatin resistance in cervical cancer. NCL played an important role in MDR1 gene transcription through regulation of the transcription factor YB1. Conclusion. Our findings revealed the novel role of NCL in cisplatin-resistant cervical cancer and NCL may be a potential therapeutic target for chemoresistance.

scholarly journals Vitamin D-Induced Molecular Mechanisms to Potentiate Cancer Therapy and to Reverse Drug-Resistance in Cancer Cells

Nutrients ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1798 ◽  
Author(s):  
Mariarosaria Negri ◽  
Annalisa Gentile ◽  
Cristina de Angelis ◽  
Tatiana Montò ◽  
Roberta Patalano ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Vitamin D ◽  
Drug Resistance ◽  
Cancer Therapy ◽  
Cancer Stem Cells ◽  
Crucial Role ◽  
Molecular Mechanisms ◽  
Vitamin D Supplementation

Increasing interest in studying the role of vitamin D in cancer has been provided by the scientific literature during the last years, although mixed results have been reported. Vitamin D deficiency has been largely associated with various types of solid and non-solid human cancers, and the almost ubiquitous expression of vitamin D receptor (VDR) has always led to suppose a crucial role of vitamin D in cancer. However, the association between vitamin D levels and the risk of solid cancers, such as colorectal, prostate and breast cancer, shows several conflicting results that raise questions about the use of vitamin D supplements in cancer patients. Moreover, studies on vitamin D supplementation do not always show improvements in tumor progression and mortality risk, particularly for prostate and breast cancer. Conversely, several molecular studies are in agreement about the role of vitamin D in inhibiting tumor cell proliferation, growth and invasiveness, cell cycle arrest and inflammatory signaling, through which vitamin D may also regulate cancer microenvironment through the activation of different molecular pathways. More recently, a role in the regulation of cancer stem cells proliferation and short non-coding microRNA (miRNAs) expression has emerged, conferring to vitamin D a more crucial role in cancer development and progression. Interestingly, it has been shown that vitamin D is able not only to potentiate the effects of traditional cancer therapy but can even contribute to overcome the molecular mechanisms of drug resistance—often triggering tumor-spreading. At this regard, vitamin D can act at various levels through the regulation of growth of cancer stem cells and the epithelial–mesenchymal transition (EMT), as well as through the modulation of miRNA gene expression. The current review reconsiders epidemiological and molecular literature concerning the role of vitamin D in cancer risk and tumor development and progression, as well as the action of vitamin D supplementation in potentiating the effects of drug therapy and overcoming the mechanisms of resistance often triggered during cancer therapies, by critically addressing strengths and weaknesses of available data from 2010 to 2020.

scholarly journals Deregulation of the miRNAs Expression in Cervical Cancer: Human Papillomavirus Implications

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Yazmín Gómez-Gómez ◽  
Jorge Organista-Nava ◽  
Patricio Gariglio
Keyword(s):  
Cervical Cancer ◽  
Mirna Expression ◽  
Mirna Expression Profile ◽  
Human Papillomaviruses ◽  
Prognostic Biomarkers ◽  
Non Coding Rnas ◽  
E6 And E7 ◽  
Mirnas Expression ◽  
Tumor Suppressive Mirnas

MicroRNAs (miRNAs) are a class of small non coding RNAs of 18–25 nucleotides in length. The temporal or short-lived expression of the miRNAs modulates gene expression post transcriptionally. Studies have revealed that miRNAs deregulation correlates and is involved with the initiation and progression of human tumors. Cervical cancer (CC) displays notably increased or decreased expression of a large number of cellular oncogenic or tumor suppressive miRNAs, respectively. However, understanding the potential role of miRNAs in CC is still limited. In CC, the high-risk human papillomaviruses (HR-HPVs) infection can affect the miRNAs expression through oncoprotein E6 and E7 that contribute to viral pathogenesis, although other viral proteins might also be involved. This deregulation in the miRNAs expression has an important role in the hallmarks of CC. Interestingly, the miRNA expression profile in CC can discriminate between normal and tumor tissue and the extraordinary stability of miRNAs makes it suitable to serve as diagnostic and prognostic biomarkers of cancer. In this review, we will summarize the role of the HR-HPVs in miRNA expression, the role of miRNAs in the hallmarks of CC, and the use of miRNAs as potential prognostic biomarkers in CC.

scholarly journals High levels of p105 (NFKB1) and p100 (NFKB2) proteins in HPV16-transformed keratinocytes: role of E6 and E7 oncoproteins

Virology ◽  
2005 ◽  
Vol 331 (2) ◽  
pp. 357-366 ◽  
Author(s):  
L. Havard ◽  
S. Rahmouni ◽  
J. Boniver ◽  
P. Delvenne
Keyword(s):  
E6 And E7 Oncoproteins ◽  
E6 And E7

scholarly journals Signaling Pathways in Cervical Cancer Chemoresistance: Are microRNAs and Long-Noncoding RNAs the Main Culprits?

2020 ◽  
Author(s):  
Seyyed Reza Mousavi ◽  
Nima Hemmat ◽  
Hossein Bannazadeh Baghi ◽  
Afshin Derakhshani ◽  
Stefania Tommasi ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Drug Resistance ◽  
Signaling Pathways ◽  
Molecular Mechanisms ◽  
Bioinformatic Analysis ◽  
Aberrant Expression ◽  
Recurrent Cervical Cancer ◽  
Response To Chemotherapy ◽  
Wide Range ◽  
Non Coding Rnas

Cervical cancer is known as one of the most important cancers in women worldwide. Chemotherapy is a standard treatment for advanced/recurrent cervical cancer in which the prognosis of the disease is really poor and the 1-year survival chance in these patients is maximally 20%. However, resistance to anticancer drugs is a major problem in treating cancer. Cervical cancer stem cells are considered as a fundamental cause of chemo and radio-resistance and also relapse after primary successful treatment. Signaling pathways include a wide range of molecular mechanisms contribute to drug resistance. Recently, microRNAs (miRNAs) are announced as a group of molecular biomarkers involving in response to chemotherapy in cancer patients. As the miRNAs, there are some long non-coding RNAs (LncRNAs) which their aberrant expression is considered as a biomarker for monitoring chemoresistance. In this review, we summarized current reports about the involvement of signaling pathways during chemoresistance in cervical cancer. Then, genes that have been demonstrated their involvement during drug resistance in cervical cancer were tabulated. Further, miRNAs that have been reported as biomarkers during treatment are listed. By bioinformatic analysis, we predictedmiR-335-5p and miR-16-5p as the most potential biomarkers for monitoring resistance to chemotherapy. Finally, long non-coding RNAs that have been introduced in recent studies as novel biomarkers during the response to chemotherapy were mentioned.

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