Hypoxia-inducible factor 1, hepatocellular carcinoma and angiogenesis

Effect and Molecular Mechanisms of Jiedu Recipe on Hypoxia-Induced Angiogenesis after Transcatheter Arterial Chemoembolization in Hepatocellular Carcinoma

Transcatheter arterial chemoembolization (TACE) is one of the effective treatment methods for hepatocellular carcinoma (HCC) in middle and late phases. However, TACE-induced hypoxia may promote the angiogenesis and section of some cytokines, such as IL-8, and, thereby, lead to tumor metastasis. Therefore, we investigated the effect of Jiedu Recipe (JR), which has been demonstrated as an effective Traditional Chinese Medicine (TCM) recipe on HCC, on TACE-induced cytokines upregulation and hypoxia-induced angiogenesis. A total of 88 hepatocellular carcinoma (HCC) patients treated with TACE were enrolled and divided into a JR group or control group. TACE induced significant increases of neutrophil lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR), IL-1β, IL-2R, IL-6, and IL-8. JR treatment significantly inhibited the elevation of IL-8 compared with control. In vitro, JR significantly inhibited the hypoxia-induced overexpression of IL-8, HIF-1α, and VEGF mRNA in Huh 7 cells. ELISA assay demonstrated the effect of JR on IL-8 expression. Both hypoxia and IL-8 may promote angiogenesis which was suppressed by JR. Western blot showed that IL-8 upregulated the expression of phosphorylation of AKT, ERK, NF-κB, and VEGFR, which were inhibited by JR. On the other hand, effects of IL-8 on the increase of p-AKT and p-ERK were also blocked by LY294002 and U0126, respectively. In conclusion, our results indicated that JR may inhibit hypoxia-induced angiogenesis through suppressing IL-8/HIF-1α/PI3K and MAPK/ERK pathways after TACE in HCC patients.

Hypoxia-inducible factors as molecular targets for liver diseases

Liver disease is a growing global health problem, as deaths from end-stage liver cirrhosis and cancer are rising across the world. At present, pharmacologic approaches to effectively treat or prevent liver disease are extremely limited. Hypoxia-inducible factor (HIF) is a transcription factor that regulates diverse signaling pathways enabling adaptive cellular responses to perturbations of the tissue microenvironment. HIF activation through hypoxia-dependent and hypoxia-independent signals have been reported in liver disease of diverse etiologies, from ischemia-reperfusion-induced acute liver injury to chronic liver diseases caused by viral infection, excessive alcohol consumption, or metabolic disorders. This review summarizes the evidence for HIF stabilization in liver disease, discusses the mechanistic involvement of HIFs in disease development, and explores the potential of pharmacological HIF modifiers in the treatment of liver disease.

The role of hypoxia inducible factor-1 in hepatocellular carcinoma

Hypoxia is a common feature of many solid tumors, including hepatocellular carcinoma (HCC). Hypoxia can promote tumor progression and induce radiation and chemotherapy resistance. As one of the major mediators of hypoxic response, hypoxia inducible factor-1 (HIF-1) has been shown to activate hypoxia-responsive genes, which are involved in multiple aspects of tumorigenesis and cancer progression, including proliferation, metabolism, angiogenesis, invasion, metastasis and therapy resistance. It has been demonstrated that a high level of HIF-1 in the HCC microenvironment leads to enhanced proliferation and survival of HCC cells. Accordingly, overexpression, of HIF-1 is associated with poor prognosis in HCC. In this review, we described the mechanism by which HIF-1 is regulated and how HIF-1 mediates the biological effects of hypoxia in tissues. We also summarized the latest findings concerning the role of HIF-1 in the development of HCC, which could shed light on new therapeutic approaches for the treatment of HCC.