BACKGROUND & AIMS: Cdc42 is a Rho family GTPase protein and was recently implicated in mediating hepatitis C virus (HCV) infectivity. This study examines the association between Cdc42-related gene and interferon (IFN) therapy in HCV patients. METHODS: We analyzed the associations between the outcome of IFN therapy and 17 tagging single nucleotide polymorphisms (SNPs) within two genes involved in Cdc42 signaling (CDC42 and ACK1). A total of 295 out of the 409 study subjects were sustained responders (SR) and 114 were non-responders (NR). Replication was performed using an independent set of 794 IFN-treated patients. RESULTS: SNP rs2278034 [A/G] in intron 11 of activated Cdc42 associated tyrosine kinase (ACK) 1 was associated with the outcome of IFN therapy (p=6.4 × 10(-4)). Replication analysis confirmed the association (p=2.2 × 10(-3)) for patients treated with IFN monotherapy, but the association was not significant for pegylated-IFN-plus ribavirin therapy. Analysis using published HapMap expression data revealed that ACK1 expression correlates with IFN-stimulated gene (ISG) expression independently of ethnicity, but the relationship between rs2278034 and ACK1 expression was observed only within Asian populations. Over-expression of ACK1, but not the kinase-inactive mutant, increased ISG transcription in Huh7 cells. ACK1 expression enhanced the IFN-stimulated response element (ISRE) and interferon-γ-activated site (GAS) promoter activity through tyrosine phosphorylation of signal transducers and activators of transcription (STAT) 1. Furthermore, ACK1 over-expression in HCV-N replicon cells inhibited HCV replication. CONCLUSIONS: SNP rs2278034 in ACK1 is associated with IFN therapy outcome in patients with HCV. ACK1 may play a role in innate and IFN-induced antiviral action against HCV.
BACKGROUND & AIMS:Cdc42 is a Rho family GTPase protein and was recently implicated in mediating hepatitis C virus (HCV) infectivity. This study examines the association between Cdc42-related gene and interferon (IFN) therapy in HCVpatients. METHODS: We analyzed the associations between the outcome of IFN therapy and 17 tagging single nucleotide polymorphisms (SNPs) within two genes involved in Cdc42 signaling (CDC42 and ACK1). A total of 295 out of the 409 study subjects were sustained responders (SR) and 114 were non-responders (NR). Replication was performed using an independent set of 794 IFN-treated patients. RESULTS: SNP rs2278034 [A/G] in intron 11 of activated Cdc42 associated tyrosine kinase (ACK) 1 was associated with the outcome of IFN therapy (p=6.4 × 10(-4)). Replication analysis confirmed the association (p=2.2 × 10(-3)) for patients treated with IFN monotherapy, but the association was not significant for pegylated-IFN-plus ribavirin therapy. Analysis using published HapMap expression data revealed that ACK1 expression correlates with IFN-stimulated gene (ISG) expression independently of ethnicity, but the relationship between rs2278034 and ACK1 expression was observed only within Asian populations. Over-expression of ACK1, but not the kinase-inactive mutant, increased ISG transcription in Huh7 cells. ACK1 expression enhanced the IFN-stimulated response element (ISRE) and interferon-γ-activated site (GAS) promoter activity through tyrosine phosphorylation of signal transducers and activators of transcription (STAT) 1. Furthermore, ACK1 over-expression in HCV-N replicon cells inhibited HCV replication. CONCLUSIONS: SNP rs2278034 in ACK1 is associated with IFN therapy outcome in patients with HCV. ACK1 may play a role in innate and IFN-induced antiviral action against HCV.
Authors: Xiang Zhou; Jennifer J Michal; Lifan Zhang; Bo Ding; Joan K Lunney; Bang Liu; Zhihua Jiang Journal: Int J Biol Sci Date: 2013-02-11 Impact factor: 6.580