Small T Oncoprotein of Merkel Cell Polyomavirus Attenuates Cisplatin-Induced Apoptosis and Enhances E1, E6/E7, MMP-1, and Ki-67 Expression in HeLa Cervical Cancer Cells

Purpose: Cervical cancer (CxCa) is primarily caused by high-risk human papillomaviruses (hrHPV), which disrupt p53 and pRb regulation, leading to uncontrolled growth and progression. Co-infection with polyomaviruses like MCPyV in some HPV-positive cases suggests a potential combined effect on tumor...

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Main Authors: Fatemeh Pakdel, Seyed Masoud Hosseini, Neda Soleimani, Ali Farhadi
Format: Article
Language:English
Published: Tabriz University of Medical Sciences 2025-04-01
Series:Advanced Pharmaceutical Bulletin
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Online Access:https://apb.tbzmed.ac.ir/PDF/apb-15-194.pdf
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author Fatemeh Pakdel
Seyed Masoud Hosseini
Neda Soleimani
Ali Farhadi
author_facet Fatemeh Pakdel
Seyed Masoud Hosseini
Neda Soleimani
Ali Farhadi
author_sort Fatemeh Pakdel
collection DOAJ
description Purpose: Cervical cancer (CxCa) is primarily caused by high-risk human papillomaviruses (hrHPV), which disrupt p53 and pRb regulation, leading to uncontrolled growth and progression. Co-infection with polyomaviruses like MCPyV in some HPV-positive cases suggests a potential combined effect on tumor development. Cisplatin is commonly used for advanced CxCa, but resistance remains a challenge. This study examines whether MCPyV sT oncoprotein and HPV-18 oncoproteins affect key gene transcription, influencing proliferation and cisplatin resistance in CxCa. Methods: The sT gene was cloned into the pCMV6 vector, and HeLa cells were transfected with pCMV6-sT using Lipofectamine 3000. Transfection efficiency was assessed via fluorescence microscopy and flow cytometry. Protein expression was analyzed using SDS-PAGE and Western blotting. Cytotoxicity was measured with the MTT assay, gene expression was analyzed by RT-qPCR, Ki-67 staining was performed on cell blocks, and cisplatin-induced effects on proliferation and apoptosis were examined. Results: Cytotoxicity assays showed a significant increase in cell viability at 0.2 μg of sT plasmid after 72 hours (13.76%, P<0.05). MCPyV sT expression significantly upregulated E1 (4.22-fold), E6/E7 (3.80-fold), and MMP1 (6-fold) mRNA levels (P<0.001). Increased Ki-67 positivity indicated enhanced proliferation. Additionally, sT expression reduced cisplatin-induced apoptosis, with fewer apoptotic cells observed in the sT+cisplatin group than in the cisplatin-only group (25.9% vs. 38.3%, P<0.05). Conclusion: The presence of MCPyV sT and HPV oncoproteins together enhances resistance to cisplatin-induced apoptosis in CxCa cells, highlighting the need for further investigation into viral oncoprotein interactions to overcome therapeutic resistance.
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spelling doaj-art-d78b7db2f99f4d0ebc17e27296fc5c2e2025-08-20T03:17:42ZengTabriz University of Medical SciencesAdvanced Pharmaceutical Bulletin2228-58812251-73082025-04-0115119420510.34172/apb.43882apb-43882Small T Oncoprotein of Merkel Cell Polyomavirus Attenuates Cisplatin-Induced Apoptosis and Enhances E1, E6/E7, MMP-1, and Ki-67 Expression in HeLa Cervical Cancer CellsFatemeh Pakdel0Seyed Masoud Hosseini1Neda Soleimani2Ali Farhadi3Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran.Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran.Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran.Division of Medical Biotechnology, Department of Medical Laboratory Sciences, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran.Purpose: Cervical cancer (CxCa) is primarily caused by high-risk human papillomaviruses (hrHPV), which disrupt p53 and pRb regulation, leading to uncontrolled growth and progression. Co-infection with polyomaviruses like MCPyV in some HPV-positive cases suggests a potential combined effect on tumor development. Cisplatin is commonly used for advanced CxCa, but resistance remains a challenge. This study examines whether MCPyV sT oncoprotein and HPV-18 oncoproteins affect key gene transcription, influencing proliferation and cisplatin resistance in CxCa. Methods: The sT gene was cloned into the pCMV6 vector, and HeLa cells were transfected with pCMV6-sT using Lipofectamine 3000. Transfection efficiency was assessed via fluorescence microscopy and flow cytometry. Protein expression was analyzed using SDS-PAGE and Western blotting. Cytotoxicity was measured with the MTT assay, gene expression was analyzed by RT-qPCR, Ki-67 staining was performed on cell blocks, and cisplatin-induced effects on proliferation and apoptosis were examined. Results: Cytotoxicity assays showed a significant increase in cell viability at 0.2 μg of sT plasmid after 72 hours (13.76%, P<0.05). MCPyV sT expression significantly upregulated E1 (4.22-fold), E6/E7 (3.80-fold), and MMP1 (6-fold) mRNA levels (P<0.001). Increased Ki-67 positivity indicated enhanced proliferation. Additionally, sT expression reduced cisplatin-induced apoptosis, with fewer apoptotic cells observed in the sT+cisplatin group than in the cisplatin-only group (25.9% vs. 38.3%, P<0.05). Conclusion: The presence of MCPyV sT and HPV oncoproteins together enhances resistance to cisplatin-induced apoptosis in CxCa cells, highlighting the need for further investigation into viral oncoprotein interactions to overcome therapeutic resistance.https://apb.tbzmed.ac.ir/PDF/apb-15-194.pdfcervical cancercisplatinstagmcpyvhpv-18hela
spellingShingle Fatemeh Pakdel
Seyed Masoud Hosseini
Neda Soleimani
Ali Farhadi
Small T Oncoprotein of Merkel Cell Polyomavirus Attenuates Cisplatin-Induced Apoptosis and Enhances E1, E6/E7, MMP-1, and Ki-67 Expression in HeLa Cervical Cancer Cells
Advanced Pharmaceutical Bulletin
cervical cancer
cisplatin
stag
mcpyv
hpv-18
hela
title Small T Oncoprotein of Merkel Cell Polyomavirus Attenuates Cisplatin-Induced Apoptosis and Enhances E1, E6/E7, MMP-1, and Ki-67 Expression in HeLa Cervical Cancer Cells
title_full Small T Oncoprotein of Merkel Cell Polyomavirus Attenuates Cisplatin-Induced Apoptosis and Enhances E1, E6/E7, MMP-1, and Ki-67 Expression in HeLa Cervical Cancer Cells
title_fullStr Small T Oncoprotein of Merkel Cell Polyomavirus Attenuates Cisplatin-Induced Apoptosis and Enhances E1, E6/E7, MMP-1, and Ki-67 Expression in HeLa Cervical Cancer Cells
title_full_unstemmed Small T Oncoprotein of Merkel Cell Polyomavirus Attenuates Cisplatin-Induced Apoptosis and Enhances E1, E6/E7, MMP-1, and Ki-67 Expression in HeLa Cervical Cancer Cells
title_short Small T Oncoprotein of Merkel Cell Polyomavirus Attenuates Cisplatin-Induced Apoptosis and Enhances E1, E6/E7, MMP-1, and Ki-67 Expression in HeLa Cervical Cancer Cells
title_sort small t oncoprotein of merkel cell polyomavirus attenuates cisplatin induced apoptosis and enhances e1 e6 e7 mmp 1 and ki 67 expression in hela cervical cancer cells
topic cervical cancer
cisplatin
stag
mcpyv
hpv-18
hela
url https://apb.tbzmed.ac.ir/PDF/apb-15-194.pdf
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