We demonstrate that HCV-mediated Ca(2+) signaling, elevation of reactive oxygen species, and activation of cellular kinases such as p38 MAPK, JNK, PI3K, and MEK1/2 are involved in OPN activation.
Given the prevalence of beta-catenin mutations in many human tumors, especially colon and hepatocellular carcinomas, these data implicate NS5A-mediated PI3K activation as a contributory factor in the increasingly common association between HCV infection and the development of hepatocellular carcinoma.
In this regard, we showed previously that the HCV NS5A protein bound to the p85 regulatory subunit of phosphoinositide-3 kinase (PI3K), thereby stimulating the activity of the p110 catalytic subunit of the enzyme.
In contrast to the reported crucial function of EGFR-downstream signaling for the entry of hepatitis C virus (HCV), blockade of EGFR-downstream signaling proteins, including mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K), and signal transducer and activator of transcription (STAT), had no or only minor effects on HBV infection.
Moreover, miR-199a-5p may facilitate HCV replication by regulating pro-survival pathways through PI3K/Akt, Ras/ERK and Wnt/β-catenin. miR-199a-5p might be a potential drug target for developing a novel strategy to combat HCV infection.
Here we demonstrate that the β isoform of class II PI3K (PI3K-C2β) plays an indispensable role in hepatitis C virus (HCV) propagation in human hepatocellular carcinoma cells.
These findings provide evidence for a possible pathogenetic role played by HCV core protein in HCV-related lymphomagenesis; it could occur through the deregulation of PI3K activity, consequent activation of Akt and overexpression of DNp63.