Hepatitis C virus nonstructural protein NS3 and telomerase activity

To study the effect of hepatitis C virus nonstructural protein NS 3 (HCV NS3) on telomerase activity and carcinogenesis Methods Streptavidin peroxidase (SP) conjugated method was used to detect the expressio n of HCV NS 3 protein in NIH3T3 cells transfected with plasmid pRcHCNS 3 5' and pRcHCNS 3 3' Telomerase activity was detected by an in situ telomerase a ctivity labeling method, telomeric repeat amplification protocol polymerase chai n reaction (TRAP PCR) and telomerase PCR enzyme linked immunosorbent assay (ELI SA) technology in the transfected and non transfected NIH3T3 cells Results HCV NS 3 protein was expressed in the NIH3T3 cells transfected with plasmid pR cHCNS 3 5' expressing HCV NS 3 C terminal deleted protein or with plasmid pR cHCNS 3 3' expressing HCV NS 3 N terminal deleted protein The positive sig nal of HCV NS 3 protein was localized in the cytoplasm of NIH3T3 cells, and th e signal intensity of the former was stronger Telomerase activity in NIH3T3 c ells transfected with plasmid pRcHCNS 3 5' was stronger than that in NIH3T3 c ells transfected with plasmid pRcHCNS 3 3' ( P <0 01), whereas telomerase a ctivity in NIH3T3 cells transfected with plasmid pRcCMV or untreated NIH3T3 ce lls was weaker than that in NIH3T3 cells transfected with plasmid pRcHCNS 3 3 ' ( P <0 05) The expression level of HCV NS 3 protein was significantly co rrelated with the strength of telomerase activity ( P <0 05) The results ob tained by in situ telomerase activity labeling corresponded to the results by te lomerase PCR ELISA technology Conclusions HCV NS 3 protein may activate telomerase through endogenous mechanism to induce host cell transformation The effect of HCV NS 3 C terminal deleted protein on telomerase activity in the host cell may be stronger than that of HCV NS 3 N terminal deleted protein In situ telomerase activity labeling was a reliabl e technology for studying pathological morphology and telomerase activity in tis sues and cells