Studies on the role of NS3 and NS5A non-structural genes of hepatitis C virus genotype 3a local isolates in apoptosis.
BACKGROUND
Hepatitis C virus (HCV) is the causative agent of chronic liver diseases, which usually lead to liver fibrosis, liver cirrhosis, and hepatocellular carcinoma (HCC). Among the non-structural genes of HCV, NS3 and NS5A play important roles in apoptosis. The NS3 and NS5A genes of HCV interact with the p53 tumor suppressor gene differentially. The objective of this study was to analyze the interaction of NS3 and NS5A genes of HCV genotype 3a with the p53 gene, subgenomic HCV replicons harboring NS3 and NS5A genes.


METHODS
Huh-7 cell lines stably expressing NS3 and NS5A genes were generated. The stable cell lines were confirmed by Western blot, reverse transcriptase PCR, and immunofluorescence assay. HCV NS3- and NS5A-expressing cell lines were transfected with p53-expressing clone.


RESULTS
NS3 and NS5A both interact with p53 by down-regulating the expression of the p53 gene. In HCV subgenomic harboring cells, the interaction of NS3 and NS5A with p53 was observed consistently. The suppression of p53 gene expression by NS3 and NS5A was observed significantly as compared with NS3- and NS5A-negative control Huh-7 cells.


CONCLUSIONS
It is concluded that both of the non-structural genes, NS3 and NS5A, of HCV play important roles in the hepatocarcinogenesis of HCV by interacting directly or indirectly in different manners with the p53 gene.
Department of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan.
Sabeen
S
Sabri
National Center of Excellence in Molecular Biology, University of the Punjab, 87 West Canal Bank Road, Thokar Niaz Baig, Lahore 53700, Pakistan. Electronic address: Idrees.khan96@yahoo.com.
Muhammad
M
Idrees
Center of Applied Molecular Biology, Ministry of Science and Technology, Govt. of Punjab, Lahore, Pakistan.
Shazia
S
Rafique
Department of Biotechnology, University of Malakand, Chakdra Dir (lower), Khyber Pakhtunkhwa, Pakistan.
Amjad
A
Ali
Center of Applied Molecular Biology, Ministry of Science and Technology, Govt. of Punjab, Lahore, Pakistan.
Muhammad
M
Iqbal
D017209:Apoptosis; D002460:Cell Line; D002478:Cells, Cultured; D015870:Gene Expression; D023061:Gene Order; D005822:Genetic Vectors / Q000235:genetics; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics*; D019698:Hepatitis C, Chronic / Q000821:virology; D006801:Humans; D011485:Protein Binding; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D017361:Viral Nonstructural Proteins / Q000235:genetics* / Q000378:metabolism; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; D012324:RNA-Dependent RNA Polymerase
D012333:RNA, Messenger; D012367:RNA, Viral; D016159:Tumor Suppressor Protein p53; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase
HCC; Hepatitis C virus; Huh-7 cell lines; Liver cirrhoses; Non-structural proteins; p53 gene