scholarly journals Microwaves can reverse the tumour phenotype of human papillomavirus type 16 (HPV16)-positive keratinocytes in 3D cell culture models: a novel therapy for HPV-associated disease?

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Ilaria Epifano ◽  
Michaela J. Conley ◽  
Andrew Stevenson ◽  
John Doorbar ◽  
Sheila V. Graham
Keyword(s):  
Cell Proliferation ◽  
Human Papillomavirus ◽  
Tumour Progression ◽  
Microwave Treatment ◽  
Adjacent Area ◽  
Novel Therapy ◽  
Hpv16 E6 ◽  
Cancerous Lesions ◽  
E6 And E7

High-risk human papillomavirus (HPV) is the causative agent of benign, precancerous and cancerous lesions, in both anogenital and oropharyngeal sites. Increased expression of the viral oncoproteins E6 and E7 are responsible for tumour progression. The treatment of these precancerous and cancerous lesions is invasive, painful and with long-term side effects. Localised microwaves have been used successfully in the clinic for the treatment of verrucas, which are caused by low-risk HPV genotypes (>75% success rate versus >33% for cryotherapy). Moreover, local hyperthermia is known to have anti-tumour effects. Ten-second microwave treatment of 3D in vitro-grown cervical tumour tissues (HPV16-positive SiHa cell) resulted in cell death in the treated zone while the tissue integrity was disrupted in the adjacent area. Microwaves induced apoptosis (induction of cleaved caspase 3) and autophagy (induction of LC3) and inhibited cell proliferation (loss of Ki67 and MCM2) in the entire tissue. Furthermore, HPV16 E6 and E7 expression was reduced in cells in the treated and transition zones, with subsequent induction of expression of the apoptosis-regulator, p53 over a 24 hour period following microwave treatment. Thermal stress, identified with the Heat Shock Protein 70 (HSP70) and translational stress identified by G3BP expression, was observed in the transition zone. In conclusion, we demonstrate that the microwave treatment induces cell stress pathways and inhibits HPV oncoprotein expression that causes tumour progression. Induction of apoptosis and reduced cell proliferation suggest a reversal of the cervical tumour phenotype in the 3D tissues.

scholarly journals Comparative Proteomic Study of the Antiproliferative Activity of Frog Host-Defence Peptide Caerin 1.9 and Its Additive Effect with Caerin 1.1 on TC-1 Cells Transformed with HPV16 E6 and E7

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Guoying Ni ◽  
Di Liang ◽  
Scott F. Cummins ◽  
Shelley F. Walton ◽  
Shu Chen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Tumour Microenvironment ◽  
Additive Effect ◽  
Host Defence ◽  
Signalling Pathways ◽  
Hpv16 E6 ◽  
Cytokines And Chemokines ◽  
Glandular Secretion ◽  
E6 And E7

Caerin is a family of peptides isolated from the glandular secretion of Australian tree frogs, the genusLitoria, and has been previously shown to have anticancer activity against several cancer cells. In this work, we used two host-defence peptides, caerin 1.1 and caerin 1.9, to investigate their ability to inhibit a murine derived TC-1 cell transformed with human papillomavirus 16 E6 and E7 growthin vitro. Caerin 1.9 inhibits TC-1 cell proliferation, although inhibition is more pronounced when applied in conjunction with caerin 1.1. To gain further insights into the antiproliferative mechanisms of caerin 1.9 and its additive effect with caerin 1.1, we used a proteomics strategy to quantitatively examine (i) the changes in the protein profiles of TC-1 cells and (ii) the excretory-secretory products of TC-1 cells following caerin peptides treatment. Caerin 1.9 treatment significantly altered the abundance of several immune-related proteins and related pathways, such as the Tec kinase and ILK signalling pathways, as well as the levels of proinflammatory cytokines and chemokines. In conclusion, caerin peptides inhibit TC-1 cell proliferation, associated with modification in signalling pathways that would change the tumour microenvironment which is normally immune suppressive.

scholarly journals Positive and negative regulation of cell proliferation by E2F-1: influence of protein level and human papillomavirus oncoproteins.

1994 ◽  
Vol 14 (12) ◽  
pp. 8241-8249 ◽  
Author(s):  
R M Melillo ◽  
K Helin ◽  
D R Lowy ◽  
J T Schiller
Keyword(s):  
Human Papillomavirus ◽  
Biological Activities ◽  
Wild Type ◽  
Positive Role ◽  
Hpv16 E6 ◽  
Data Support ◽  
Binding Function ◽  
Growth Inhibitory Activity ◽  
E6 And E7

E2F-1 is a member of a family of transcription factors implicated in the activation of genes required for the progression through the S phase of the cell cycle. We have examined the biological activities of E2F-1 with short-term colony-forming assays and long-term immortalization assays. High levels of E2F-1, produced by transfection of the E2F-1 cDNA under the control of a strong promoter, reduced colony formation in normal human foreskin keratinocytes (NHFKs). This inhibition could not be overcome by wild-type human papillomavirus type 16 (HPV16) E6 and E7, two proteins which cooperate to immortalize NHFKs, or by a transdominant p53 mutant. High levels of E2F-1 also inhibited growth of primary and established fibroblasts. The growth-inhibitory activity required the DNA binding function of E2F-1 but not its transactivation or pRB binding activities. A positive role for lower levels of E2F-1 in NHFK immortalization was established by examining the ability of E2F-1 to complement HPV16 E7 mutants that were unable to cooperate with HPV16 E6 to immortalize NHFKs. Although E2F-1 was unable by itself to cooperate with E6, it did, in conjunction with E6, complement a p24GLY mutant of E7 that is defective for immortalization and binding of pRB and pRB-related proteins. By contrast, E2F-1 was unable to complement two other E7 mutants, p2PRO and p31/32ARG/PRO, which are also defective in the immortalization assay, although their proteins display wild-type binding of pRB in vitro. Since the binding of E7 to pRB results in disruption of pRB-E2F interaction and release of transcriptionally active E2F, the data support the hypothesis that binding of pRB by E7 and the consequence increase in E2F, the data support the hypothesis that binding of pRB by E7 and the consequence increase in E3F activity are important but not sufficient for E7-induced keratinocyte immortalization.

Effects of 17β-estradiol and progesterone on transcription of human papillomavirus 16 E6/E7 oncogenes in CaSki and SiHa cell lines

2006 ◽  
Vol 16 (3) ◽  
pp. 1261-1268
Author(s):  
M. Ruutu ◽  
N. Wahlroos ◽  
K. Syrjänen ◽  
B. Johansson ◽  
S. Syrjänen
Keyword(s):  
Cell Proliferation ◽  
Human Papillomavirus ◽  
Cell Lines ◽  
Messenger Rna ◽  
Hormone Receptors ◽  
Colorimetric Assay ◽  
Siha Cell ◽  
Tetrazolium Salt ◽  
Hpv16 E6

Several in vitro studies have addressed the interactions between estrogen/progesterone and human papillomavirus (HPV), but the results are controversial. We evaluated the effects of estrogen and progesterone and their antagonists on messenger RNA expression of HPV16 E6/E7 in HPV16-positive cell lines CaSki and SiHa with real-time reverse-transciptase polymerase chain reaction method. Colorimetric assay with tetrazolium salt (WST-1) and flow cytometry were used for testing proliferation and apoptosis. No statistically significant changes were found after hormone treatment in the expression of HPV16 E6/E7 or hormone receptors in CaSki and SiHa cell lines. Progesterone increased cell proliferation in both the cells, while estrogen increased proliferation of SiHa cells only. Estrogen seemed to protect the CaSki cells from apoptosis, and tamoxifen did not abrogate this effect. Progesterone slightly increased apoptosis of CaSki cells, and this effect was neutralized with RU486. In this study, estrogen and progesterone did not change either the transcription levels of HPV16 E6/E7 or estrogen receptor or progesterone receptor levels. Hormone receptor antagonists had no effect on transcription. Both hormones might have a permissive effect for the growth of cervical cancer, by promoting cell proliferation and making the cells vulnerable to mutations. In addition, estrogen acts as an antiapoptotic agent allowing growth advance of the cells infected with oncogenic HPV.

Positive and negative regulation of cell proliferation by E2F-1: influence of protein level and human papillomavirus oncoproteins

1994 ◽  
Vol 14 (12) ◽  
pp. 8241-8249
Author(s):  
R M Melillo ◽  
K Helin ◽  
D R Lowy ◽  
J T Schiller
Keyword(s):  
Human Papillomavirus ◽  
Biological Activities ◽  
Wild Type ◽  
Positive Role ◽  
Hpv16 E6 ◽  
Data Support ◽  
Binding Function ◽  
Growth Inhibitory Activity ◽  
E6 And E7

E2F-1 is a member of a family of transcription factors implicated in the activation of genes required for the progression through the S phase of the cell cycle. We have examined the biological activities of E2F-1 with short-term colony-forming assays and long-term immortalization assays. High levels of E2F-1, produced by transfection of the E2F-1 cDNA under the control of a strong promoter, reduced colony formation in normal human foreskin keratinocytes (NHFKs). This inhibition could not be overcome by wild-type human papillomavirus type 16 (HPV16) E6 and E7, two proteins which cooperate to immortalize NHFKs, or by a transdominant p53 mutant. High levels of E2F-1 also inhibited growth of primary and established fibroblasts. The growth-inhibitory activity required the DNA binding function of E2F-1 but not its transactivation or pRB binding activities. A positive role for lower levels of E2F-1 in NHFK immortalization was established by examining the ability of E2F-1 to complement HPV16 E7 mutants that were unable to cooperate with HPV16 E6 to immortalize NHFKs. Although E2F-1 was unable by itself to cooperate with E6, it did, in conjunction with E6, complement a p24GLY mutant of E7 that is defective for immortalization and binding of pRB and pRB-related proteins. By contrast, E2F-1 was unable to complement two other E7 mutants, p2PRO and p31/32ARG/PRO, which are also defective in the immortalization assay, although their proteins display wild-type binding of pRB in vitro. Since the binding of E7 to pRB results in disruption of pRB-E2F interaction and release of transcriptionally active E2F, the data support the hypothesis that binding of pRB by E7 and the consequence increase in E2F, the data support the hypothesis that binding of pRB by E7 and the consequence increase in E3F activity are important but not sufficient for E7-induced keratinocyte immortalization.

scholarly journals Intrabodies targeting human papillomavirus 16 E6 and E7 oncoproteins for therapy of established HPV-associated tumors

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Francesca Paolini ◽  
Carla Amici ◽  
Mariantonia Carosi ◽  
Claudia Bonomo ◽  
Paola Di Bonito ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Antitumor Activity ◽  
Tumor Growth ◽  
Tumor Progression ◽  
Cellular Transformation ◽  
Neoplastic Progression ◽  
Single Chain ◽  
Hpv16 E6 ◽  
Associated Lesions ◽  
E6 And E7

Abstract Background The oncogenic activity of the high risk human papillomavirus type 16 (HPV16) is fully dependent on the E6 and E7 viral oncoproteins produced during viral infection. The oncoproteins interfere with cellular homeostasis by promoting proliferation, inhibiting apoptosis and blocking epithelial differentiation, driving the infected cells towards neoplastic progression. The causal relationship between expression of E6/E7 and cellular transformation allows inhibiting the oncogenic process by hindering the activity of the two oncoproteins. We previously developed and characterized some antibodies in single-chain format (scFvs) against the HPV16 E6 and E7 proteins, and demonstrated both in vitro and in vivo their antitumor activity consisting of protective efficacy against tumor progression of HPV16-positive cells. Methods Envisioning clinical application of the best characterized anti-HPV16 E6 and –HPV16 E7 scFvs, we verified their activity in the therapeutic setting, on already implanted tumors. Recombinant plasmids expressing the anti-HPV16 E6 scFvI7 with nuclear targeting sequence, or the anti-HPV16 E7 scFv43M2 with endoplasmic reticulum targeting sequence were delivered by injection followed by electroporation to three different preclinical models using C57/BL6 mice, and their effect on tumor growth was investigated. In the first model, the HPV16+ TC-1 Luc cells were used to implant tumors in mice, and tumor growth was measured by luciferase activity; in the second model, a fourfold number of TC-1 cells was used to obtain more aggressively growing tumors; in the third model, the HPV16+ C3 cells where used to rise tumors in mice. To highlight the scFv possible mechanism of action, H&E and caspase-3 staining of tumor section were performed. Results We showed that both the anti-HPV16 E6 and HPV16 E7 scFvs tested were efficacious in delaying tumor progression in the three experimental models and that their antitumor activity seems to rely on driving tumor cells towards the apoptotic pathway. Conclusion Based on our study, two scFvs have been identified that could represent a safe and effective treatment for the therapy of HPV16-associated lesions. The mechanism underlying the scFv effectiveness appears to be leading cells towards death by apoptosis. Furthermore, the validity of electroporation, a methodology allowed for human treatment, to deliver scFvs to tumors was confirmed.

scholarly journals Phylogenetic analysis and predicted functional effect of protein mutations of E6 and E7 HPV16 strains isolated in Indonesia

2015 ◽  
Vol 24 (4) ◽  
pp. 197-205
Author(s):  
Dwi Wulandari ◽  
Lisnawati Rachmadi ◽  
Tjahjani M. Sudiro
Keyword(s):  
Amino Acids ◽  
Phylogenetic Analysis ◽  
Amino Acid ◽  
Asian American ◽  
Protein Function ◽  
Single Amino Acid ◽  
Hpv16 E6 ◽  
E6 And E7 ◽  
Neutral Mutations

Background: E6 and E7 are oncoproteins of HPV16. Natural amino acid variation in HPV16 E6 can alter its carcinogenic potential. The aim of this study was to analyze phylogenetically E6 and E7 genes and proteins of HPV16 from Indonesia and predict the effects of single amino acid substitution on protein function. This analysis could be used to reduce time, effort, and research cost as initial screening in selection of protein or isolates to be tested in vitro or in vivo.Methods: In this study, E6 and E7 gene sequences were obtained from 12 samples of  Indonesian isolates, which  were compared with HPV16R (prototype) and 6 standard isolates in the category of European (E), Asian (As), Asian-American (AA), African-1 (Af-1), African-2 (Af-2), and North American (NA) branch from Genbank. Bioedit v.7.0.0 was used to analyze the composition and substitution of single amino acids. Phylogenetic analysis of E6 and E7 genes and proteins was performed using Clustal X (1.81) and NJPLOT softwares. Effects of single amino acid substitutions on protein function of E6 and E7 were analysed by SNAP.Results: Java variants and isolate ui66* belonged to European branch, while the others belonged to Asian and African branches. Twelve changes of amino acids were found in E6 and one in E7 proteins. SNAP analysis showed two non neutral mutations, i.e. R10I and C63G in E6 proteins. R10I mutations were found in Af-2 genotype (AF472509) and Indonesian isolates (Af2*), while C63G mutation was found only in Af2*.Conclusion: E6 proteins of HPV16 variants were more variable than E7. SNAP analysis showed that only E6 protein of African-2 branch had functional differences compared to HPV16R.

scholarly journals HPV-18 E6 Oncoprotein and Its Spliced Isoform E6*I Regulate the Wnt/β-Catenin Cell Signaling Pathway through the TCF-4 Transcriptional Factor

2018 ◽  
Vol 19 (10) ◽  
pp. 3153 ◽  
Author(s):  
J. Muñoz-Bello ◽  
Leslie Olmedo-Nieva ◽  
Leonardo Castro-Muñoz ◽  
Joaquín Manzo-Merino ◽  
Adriana Contreras-Paredes ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cell Proliferation ◽  
Signaling Pathway ◽  
Transcriptional Activation ◽  
Target Genes ◽  
Promote Cell Proliferation ◽  
E6 And E7 ◽  
Hpv 18

The Wnt/β-catenin signaling pathway regulates cell proliferation and differentiation and its aberrant activation in cervical cancer has been described. Persistent infection with high risk human papillomavirus (HR-HPV) is the most important factor for the development of this neoplasia, since E6 and E7 viral oncoproteins alter cellular processes, promoting cervical cancer development. A role of HPV-16 E6 in Wnt/β-catenin signaling has been proposed, although the participation of HPV-18 E6 has not been previously studied. The aim of this work was to investigate the participation of HPV-18 E6 and E6*I, in the regulation of the Wnt/β-catenin signaling pathway. Here, we show that E6 proteins up-regulate TCF-4 transcriptional activity and promote overexpression of Wnt target genes. In addition, it was demonstrated that E6 and E6*I bind to the TCF-4 (T cell factor 4) and β-catenin, impacting TCF-4 stabilization. We found that both E6 and E6*I proteins interact with the promoter of Sp5, in vitro and in vivo. Moreover, although differences in TCF-4 transcriptional activation were found among E6 intratype variants, no changes were observed in the levels of regulated genes. Furthermore, our data support that E6 proteins cooperate with β-catenin to promote cell proliferation.

scholarly journals RNA Interference of Human Papillomavirus Type 18 E6 and E7 Induces Senescence in HeLa Cells

2003 ◽  
Vol 77 (10) ◽  
pp. 6066-6069 ◽  
Author(s):  
Allison H. S. Hall ◽  
Kenneth A. Alexander
Keyword(s):  
Cell Proliferation ◽  
Human Papillomavirus ◽  
Rna Interference ◽  
Hela Cells ◽  
Tumor Suppressors ◽  
Small Interfering Rna ◽  
Promote Cell Proliferation ◽  
E6 And E7 ◽  
Cellular Dna ◽  
Interfering Rna

ABSTRACT The human papillomavirus oncoproteins E6 and E7 promote cell proliferation and contribute to carcinogenesis by interfering with the activities of cellular tumor suppressors. We used a small interfering RNA molecule targeting the E7 region of the bicistronic E6 and E7 mRNA to induce RNA interference, thereby reducing expression of E6 and E7 in HeLa cells. RNA interference of E6 and E7 also inhibited cellular DNA synthesis and induced morphological and biochemical changes characteristic of cellular senescence. These results demonstrate that reducing E6 and E7 expression is sufficient to cause HeLa cells to become senescent.

scholarly journals NFX1-123 Increases hTERT Expression and Telomerase Activity Posttranscriptionally in Human Papillomavirus Type 16 E6 Keratinocytes

2009 ◽  
Vol 83 (13) ◽  
pp. 6446-6456 ◽  
Author(s):  
Rachel A. Katzenellenbogen ◽  
Portia Vliet-Gregg ◽  
Mei Xu ◽  
Denise A. Galloway
Keyword(s):  
Human Papillomavirus ◽  
Transcriptional Activation ◽  
Telomerase Activity ◽  
Mrna Levels ◽  
Htert Mrna ◽  
Cytoplasmic Protein ◽  
Nucleic Acid Binding ◽  
Htert Expression ◽  
Hpv16 E6

ABSTRACT High-risk human papillomavirus (HPV) E6 protein induces telomerase activity through transcriptional activation of hTERT, the catalytic subunit of telomerase. HPV type 16 (HPV16) E6 interacts with two splice variants of NFX1 to increase hTERT expression. NFX1-91 is a transcriptional repressor of hTERT that is polyubiquitinated and targeted for degradation by HPV16 E6 in concert with E6-associated protein. We previously showed that NFX1-123 augments hTERT expression through binding to cytoplasmic poly(A) binding proteins (PABPCs). In this study, we determined that unlike NFX1-91, NFX1-123 is a cytoplasmic protein that colocalized with PABPCs but does not shuttle with PABPCs between the nucleus and cytoplasm. NFX1-123 requires both its PAM2 motif, with which it binds PABPCs, and its R3H domain, which has putative nucleic acid binding capabilities, to increase hTERT mRNA levels and telomerase activity in keratinocytes expressing HPV16 E6. In keratinocytes expressing HPV16 E6 and overexpressing NFX1-123, there was increased protein expression from in vitro-transcribed RNA fused with the 5′ untranslated region (5′ UTR) of hTERT. This posttranscriptional increase in expression required the PAM2 motif and R3H domain of NFX1-123 as well as the coexpression of HPV16 E6. NFX1-123 bound endogenous hTERT mRNA and increased its stability in HPV16 E6-expressing human foreskin keratinocytes, and NFX1-123 increased the stability of in vitro-transcribed RNA fused with the 5′ UTR of hTERT. Together, these studies describe the first evidence of posttranscriptional regulation of hTERT, through the direct interaction of the cytoplasmic protein NFX1-123 with hTERT mRNA, in HPV16 E6-expressing keratinocytes.

scholarly journals Influence of Physiologic Folate Deficiency on Human Papillomavirus Type 16 (HPV16)-harboring Human Keratinocytes in Vitro and in Vivo

2012 ◽  
Vol 287 (15) ◽  
pp. 12559-12577 ◽  
Author(s):  
Suhong Xiao ◽  
Ying-Sheng Tang ◽  
Rehana A. Khan ◽  
Yonghua Zhang ◽  
Praveen Kusumanchi ◽  
...  
Keyword(s):  
Human Keratinocytes ◽  
Folate Deficiency ◽  
Hpv16 E6 ◽  
Immunodeficient Mice ◽  
E6 And E7 ◽  
Nutrition Sensitive ◽  
Hnrnp E1 ◽  
L1 And L2

Although HPV16 transforms infected epithelial tissues to cancer in the presence of several co-factors, there is insufficient molecular evidence that poor nutrition has any such role. Because physiological folate deficiency led to the intracellular homocysteinylation of heterogeneous nuclear ribonucleoprotein E1 (hnRNP-E1) and activated a nutrition-sensitive (homocysteine-responsive) posttranscriptional RNA operon that included interaction with HPV16 L2 mRNA, we investigated the functional consequences of folate deficiency on HPV16 in immortalized HPV16-harboring human (BC-1-Ep/SL) keratinocytes and HPV16-organotypic rafts. Although homocysteinylated hnRNP-E1 interacted with HPV16 L2 mRNA cis-element, it also specifically bound another HPV16 57-nucleotide poly(U)-rich cis-element in the early polyadenylation element (upstream of L2̂L1 genes) with greater affinity. Together, these interactions led to a profound reduction of both L1 and L2 mRNA and proteins without effects on HPV16 E6 and E7 in vitro, and in cultured keratinocyte monolayers and HPV16-low folate-organotypic rafts developed in physiological low folate medium. In addition, HPV16-low folate-organotypic rafts contained fewer HPV16 viral particles, a similar HPV16 DNA viral load, and a much greater extent of integration of HPV16 DNA into genomic DNA when compared with HPV16-high folate-organotypic rafts. Subcutaneous implantation of 18-day old HPV16-low folate-organotypic rafts into folate-replete immunodeficient mice transformed this benign keratinocyte-derived raft tissue into an aggressive HPV16-induced cancer within 12 weeks. Collectively, these studies establish a likely molecular linkage between poor folate nutrition and HPV16 and predict that nutritional folate and/or vitamin-B12 deficiency, which are both common worldwide, will alter the natural history of HPV16 infections and also warrant serious consideration as reversible co-factors in oncogenic transformation of HPV16-infected tissues to cancer.

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