scholarly journals Selection of Indonesian Medicinal Plant Active Compounds as Inhibitor Candidates of Oncoproteins E6 and E7 Human Papillomavirus Type 16 by Molecular Docking

Author(s):  
Riyanti Weni Syafitri ◽  
Azzania Fibriani ◽  
Reza Aditama

Cervical cancer cases caused by infection with Human Papillomavirus (HPV), especially HPV 16 (60.5% of cases) continue to increase every year with a high mortality rate. The current anti-cancer drugs were not only specifically targeting cancer cells, but healthy cells and can cause serious side effects. Therefore, it is necessary to find safer alternative therapies, e.g., using active compounds from natural products. The purpose of this study was to find the active compounds of Indonesian medicinal plants potentially as an inhibitor of oncoprotein E6 and E7 HPV 16, the main protein causing cervical cancer by in silico method. In this study, 711 active compounds from 187 medicinal plant species were selected based on molecular weight, solubility, gastrointestinal absorption index, and drug-likeness. Compounds that meet the criteria were tested for their affinity and interaction profile with E6 and E7 proteins through the molecular docking method. The results of this study showed 164 compounds that met the criteria. The molecular docking analysis showed nine of the most potent compounds as E6 inhibitors on the E6AP binding site and six compounds on the p53 binding site. Besides that, there were eleven most potent compounds as E7 inhibitors.  The results of this study indicate that there are natural compounds that can inhibit E6 and E7 proteins and have further potential to be used as anti-HPV drugs. However, further research is needed to test these compounds in vitro and in vivo.

2010 ◽  
Vol 84 (16) ◽  
pp. 8219-8230 ◽  
Author(s):  
Monika Somberg ◽  
Stefan Schwartz

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.


2009 ◽  
Vol 30 (12) ◽  
pp. 2999-3005 ◽  
Author(s):  
Joo-Ho Kim ◽  
Il-Hoon Cho ◽  
Sung-Min Seo ◽  
Ji-Sook Kim ◽  
Kyu-Ha Oh ◽  
...  

2007 ◽  
Vol 81 (6) ◽  
pp. 2869-2879 ◽  
Author(s):  
Dai-Wei Liu ◽  
Yuh-Cheng Yang ◽  
Ho-Fan Lin ◽  
Mei-Fang Lin ◽  
Ya-Wen Cheng ◽  
...  

ABSTRACT Previously, we found that human papillomavirus type 16 (HPV-16) E5 protein is a tumor rejection antigen and can induce cytotoxic T-lymphocyte (CTL) activity. Therefore, in this study, human leukocyte antigen A*0201 (HLA-A*0201)-restricted human CTL epitopes of HPV-16 E5 protein were identified using a bioinformatics approach, and the abilities of these predicted peptides to induce an immune response in HLA-A*0201 transgenic mice were confirmed by assaying E5-specific CTLs and in vitro-generated CTLs from normal peripheral blood T lymphocytes of HLA-A2-positive human donors. Second, the CTL responses to HLA-A*0201 CTL epitopes (E5 63-71 and E7 11-20) were examined in HPV-16-infected patients with HLA-A2. Third, the effect of HLA-A-type alleles on CTL activities in response to the entire E5 and E7 proteins was examined in cervical cancer patients. E5 and E7 peptides (but not the whole proteins) stimulated E5- and E7-specific CTL recall responses in HPV-16- and HLA-A2-positive cervical cancer patients, and HPV-16 E5 and E7 proteins stimulated naïve T cells in HPV-16-negative cervical cancer patients with HLA-A11 and -A24 haplotypes. In summary, this is the first demonstration that E5 63-71 is an HLA-A*0201-restricted T-cell epitope of HPV-16 E5.


2003 ◽  
Vol 77 (2) ◽  
pp. 1551-1563 ◽  
Author(s):  
Rosa Anna DeFilippis ◽  
Edward C. Goodwin ◽  
Lingling Wu ◽  
Daniel DiMaio

ABSTRACT Cervical cancer cells express high-risk human papillomavirus (HPV) E6 and E7 proteins, and repression of HPV gene expression causes the cells to cease proliferation and undergo senescence. However, it is not known whether both HPV proteins are required to maintain the proliferative state of cervical cancer cells, or whether mutations that accumulate during carcinogenesis eliminate the need for one or the other of them. To address these questions, we used the bovine papillomavirus E2 protein to repress the expression of either the E6 protein or the E7 protein encoded by integrated HPV18 DNA in HeLa cervical carcinoma cells. Repression of the E7 protein activated the Rb pathway but not the p53 pathway and triggered senescence, whereas repression of the E6 protein activated the p53 pathway but not the Rb pathway and triggered both senescence and apoptosis. Telomerase activity, cyclin-dependent kinase activity, and expression of c-myc were markedly inhibited by repression of either E6 or E7. These results demonstrate that continuous expression of both the E6 and the E7 protein is required for optimal proliferation of cervical carcinoma cells and that the two viral proteins exert distinct effects on cell survival and proliferation. Therefore, strategies that inhibit the expression or activity of either viral protein are likely to inhibit the growth of HPV-associated cancers.


2020 ◽  
Vol 23 (3) ◽  
pp. 374-385
Author(s):  
Tahere Azimi ◽  
◽  
Malihe Bagheri ◽  
Mahdi Pariyan ◽  
Behzad Khansarinejad ◽  
...  

Background and Aim: Cervical Cancer (CC) is the third most common malignancy in the women, the main cause of which is human papillomavirus (HPV). Both E6 and E7 oncogenes of the virus play an important role in its tumorigenesis. Today, methods available for screening CC are not capable of detecting the disease at an early stage. Therefore, it is important to identify new biomarkers for early detection of this cancer. For this purpose, in the present study, miRNAs targeting the two oncogenes E6 and E7 of human papillomavirus (types 16 and 18) were studied in CC by bioinformatics. Methods & Materials: First, using the NCBI database, the E6 and E7 gene sequences were obtained for both human papillomavirus types 16 and 18. Then, using the miRBase and RNA22 bioinformatics databases, the most appropriate targeting miRNAs for these genes were selected. Ethical Considerations: This study was approved by Ethics Committee of Arak University of Medical Sciences. Results: Based on the P obtained from bioinformatics databases, miRNA including miR-92a-5p (P=7.51e-2), miR-195-3p (P=2.24e-1), miR-34a-5p (P=2.73e-1) and miR-155-5p (P=4.95e-2) were introduced for the two genes E6 and E7. Conclusion: Results from bioinformatics studies revealed that of the four miRNAs identified, miR-155-5p and miR-92a-5p are probably the targeting miRNAs specific for the E6 and E7 genes, respectively. Therefore, it seems that these miRNAs can be a suitable candidate for in vitro studies in CC patients.


2019 ◽  
Vol 20 (9) ◽  
pp. 926-934 ◽  
Author(s):  
Eskandar Taghizadeh ◽  
Sepideh Jahangiri ◽  
Daryoush Rostami ◽  
Forough Taheri ◽  
Pedram Ghorbani Renani ◽  
...  

Human papillomavirus (HPV) cancers are expected to be major global health concerns in the upcoming decades. The growth of HPV-positive cancer cells depends on the consistent expression of oncoprotein which has been poorly taken into account in the cellular communication. Among them, E6/E7 oncoproteins are attractive therapeutic targets as their inhibition rapidly leads to the onset of aging in HPV-positive cancer cells. This cellular response is associated with the regeneration of p53, pRb anti-proliferative proteins as well as the mTOR signaling pathway; hence, the identification of involved and application of E6/E7 inhibitors can lead to new therapeutic strategies. In the present review, we focused on the pathogenicity of E6/E7 Proteins of human papillomavirus and their roles associated with the cervical cancer.


2008 ◽  
Vol 82 (19) ◽  
pp. 9600-9614 ◽  
Author(s):  
Sandy S. Tungteakkhun ◽  
Maria Filippova ◽  
Jonathan W. Neidigh ◽  
Nadja Fodor ◽  
Penelope J. Duerksen-Hughes

ABSTRACT High-risk strains of human papillomavirus, such as types 16 and 18, have been etiologically linked to cervical cancer. Most cervical cancer tissues are positive for both the E6 and E7 oncoproteins, since it is their cooperation that results in successful transformation and immortalization of infected cells. We have reported that E6 binds to tumor necrosis factor receptor 1 and to Fas-associated death domain (FADD) and, in doing so, prevents E6-expressing cells from responding to apoptotic stimuli. The binding site of E6 to FADD localizes to the first 23 amino acids of FADD and has now been further characterized by the use of deletion and site-directed mutants of FADD in pull-down and functional assays. The results from these experiments revealed that mutations of serine 16, serine 18, and leucine 20 obstruct FADD binding to E6, suggesting that these residues are part of the E6 binding domain on FADD. Because FADD does not contain the two previously identified E6 binding motifs, the LxxφLsh motif, and the PDZ motif, a novel binding domain for E6 has been identified on FADD. Furthermore, peptides that correspond to this region can block E6/FADD binding in vitro and can resensitize E6-expressing cells to apoptotic stimuli in vivo. These results demonstrate the existence of a novel E6 binding domain.


2019 ◽  
Vol 98 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Jimena Hochmann ◽  
Silvaneide Ferreira ◽  
João Sobrinho ◽  
Laura Sichero

The roles of E6 and E7 oncoproteins of Human Papillomavirus type 16 (HPV-16) in the progression of immortalized epithelial cells to invasive tumors are not fully understood. Here, we establish a novel link between E6 and E7 of two molecular variants of HPV-16 (AA and E-350G), and c-MYC, regarding the cooperation in promoting malignant transformation of primary human foreskin keratinocytes (PHK). We aimed to study the synergistic effects of E6/E7 and c-MYC upon proliferation, and the in vitro transformation potential of PHK. We evaluated cellular proliferation through the expression of the Proliferating Cell Nuclear Antigen (PCNA) protein and colony formation abilities using soft agar and low attachment plates. We observed that E-350G-c-MYC PHKs exhibited discrete higher PCNA levels and formed significantly more colonies in both soft-agar and when growth in low-adhesion culture plates. Overall, we concluded that the E-350G variant co-transfected with c-MYC might promote malignant cellular transformation with a better efficiency than the AA-c-MYC counterpart. The enhanced oncogenic properties exhibited by the E-350G-c-MYC variant offer insights into mechanisms that may operate in human cervical neoplasia, given the higher frequency of its occurrence in the progression of high-grade precursor lesions to invasive carcinomas.


2009 ◽  
Vol 83 (13) ◽  
pp. 6779-6789 ◽  
Author(s):  
Stefania Bellone ◽  
Karim El-Sahwi ◽  
Emiliano Cocco ◽  
Francesca Casagrande ◽  
Marilisa Cargnelutti ◽  
...  

ABSTRACT Papillomavirus-like particles (VLPs) based on L1 capsid protein represent a promising prophylactic vaccine against human papillomavirus (HPV) infections. However, cell-mediated immune responses against this antigen are believed to be of limited therapeutic value in established HPV-infected cervical lesions and, for this reason, have not been intensively investigated in cervical cancer patients. In this study we analyzed and quantified by real-time PCR (RT-PCR) the RNA expression levels of E6, E7, and L1 genes in flash-frozen HPV-16 cervical carcinomas. In addition, the kinetics of expression of E6, E7, and L1 in HPV-16-infected primary cell lines established as long-term cultures in vitro was also evaluated at RNA and protein levels. Finally, in order to evaluate the therapeutic potential of L1-specific CD4+ and CD8+ T lymphocytes responses in cervical cancer patients, L1 VLP-loaded dendritic cells (DCs) were used to stimulate peripheral blood lymphocytes from cervical cancer patients and such responses were compared to those elicited by the E7 oncoprotein. We show that 22 of 22 (100%) flash-frozen cervical biopsy samples collected from HPV-16-positive cervical cancer patients harbor L1, in addition to E6 and E7 RNA, as detected by RT-PCR. E7 RNA copy number (mean, 176.2) was significantly higher in HPV-16-positive cervical cancers compared to the E6 RNA copy number (mean, 47.3) and the L1 copy number (mean, 58.3) (P < 0.0001 and P < 0.001, respectively). However, no significant differences in expression levels between E6 and L1 were found. Kinetic studies of E6, E7, and L1 RNA and protein expression levels in primary tumors showed a sharp reduction in L1 expression after multiple in vitro passages compared to E6 and E7. Autologous DCs pulsed with HPV-16 VLPs or recombinant full-length E7 elicited strong type 1 L1- and E7-specific responses in CD4+ and CD8+ T cells from cervical cancer patients. Importantly, L1 VLP-specific CD8+ T lymphocytes expressed strong cytolytic activity against autologous tumor cells and were as effective as E7-specific cytotoxic T lymphocytes in lysing naturally HPV-16-infected autologous tumor cells. Taken together, these data demonstrate a consistent expression of L1 in primary cervical tumors and the possibility of inducing effective L1/tumor-specific CD4+ and CD8+ T-lymphocyte responses in patients harboring HPV-infected cervical cancer. These results may have important implications for the treatment of patients harboring established HPV-infected lesions with L1 VLPs or combined E7/L1 DC-based vaccinations.


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