ABSTRACT
OBJECTIVE: Precancerous lesion, a well-established histopathologically premalignant tissue with the highest risk for tumourigenesis, develops preferentially from activation of DNA damage checkpoint and persistent inflammation. However, little is known about the mechanisms by which precancerous lesions are initiated and their physiological significance. DESIGN: Laser capture microdissection was used to acquire matched normal liver, precancerous lesion and tumour tissues. miR-484(-/-), Ifnar1(-/-) and Tgfbr2(â³hep) mice were employed to determine the critical role of the interferon (IFN)-microRNA pathway in precancerous lesion formation and tumourigenesis. RNA immunoprecipitation (RIP), pull-down and chromatin immunoprecipitation (ChIP) assays were applied to explore the underlying mechanisms. RESULTS: miR-484 is highly expressed in over 88% liver samples clinically. DEN-induced precancerous lesions and hepatocellular carcinoma were dramatically impaired in miR-484(-/-) mice. Mechanistically, ectopic expression of miR-484 initiates tumourigenesis and cell malignant transformation through synergistic activation of the transforming growth factor-ß/Gli and nuclear factor-κB/type I IFN pathways. Specific acetylation of H3K27 is indispensable for basal IFN-induced continuous transcription of miR-484 and cell transformation. Convincingly, formation of precancerous lesions were significantly attenuated in both Tgfbr2(â³hep) and Ifnar1(-/-) mice. CONCLUSIONS: These findings demonstrate a new protumourigenic axis involving type I IFN-microRNA signalling, providing a potential therapeutic strategy to manipulate or reverse liver precancerous lesions and tumourigenesis.
Subject(s)
Carcinoma, Hepatocellular/genetics , Cell Transformation, Neoplastic/genetics , Liver Neoplasms/genetics , MicroRNAs/genetics , Precancerous Conditions/genetics , Signal Transduction , Acetylation , Animals , Carcinoma, Hepatocellular/chemistry , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Cell Transformation, Neoplastic/chemistry , Cell Transformation, Neoplastic/metabolism , Cell Transformation, Neoplastic/pathology , Hepatocytes , Humans , Interferon Type I/metabolism , Liver/chemistry , Liver Neoplasms/chemistry , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , Mice , Mice, Knockout , MicroRNAs/analysis , NF-kappa B/metabolism , NIH 3T3 Cells , Pentanones , Precancerous Conditions/chemically induced , Precancerous Conditions/metabolism , Precancerous Conditions/pathology , Promoter Regions, Genetic , Protein Serine-Threonine Kinases/genetics , Receptor, Interferon alpha-beta/genetics , Receptor, Transforming Growth Factor-beta Type II , Receptors, Transforming Growth Factor beta/genetics , Transforming Growth Factor beta/metabolism , Zinc Finger Protein GLI1/metabolismABSTRACT
BACKGROUND & AIMS: We have previously reported that Shp2, a tyrosine phosphatase previously known as a pro-leukemogenic molecule, suppresses the initiation of hepatocellular carcinoma (HCC). However, the role of Shp2 in HCC progression remains obscure. METHODS: Shp2 expression was determined in human HCC using real-time PCR, immunoblotting and immunohistochemistry. Clinical significance of Shp2 expression was analyzed in 301 HCC tissues with clinico-pathological characteristics and follow-up information. Short hairpin RNA was utilized to investigate the function of Shp2 in hepatoma cell behavior. Role of Shp2 in HCC progression was monitored through nude mice xenograft assay. Kinase activity assay and co-immunoprecipitation were used for mechanism analysis. RESULTS: Elevated expression of Shp2 was detected in 65.9% (394/598) of human HCCs, and its levels were even higher in metastasized foci. Overexpression of Shp2 correlated well with the malignant clinico-pathological characteristics of HCC and predicted the poor prognosis of patients. Interference of Shp2 expression suppressed the proliferation of hepatoma cells in vitro and inhibited the growth of HCC xenografts in vivo. Down-regulation of Shp2 attenuated the adhesion and migration of hepatoma cells and diminished metastasized HCC formation in mice. Our data demonstrated that Shp2 promotes HCC growth and metastasis by coordinately activating Ras/Raf/Erk pathway and PI3-K/Akt/mTOR cascade. Moreover, down-regulation of Shp2 enhanced the sensitivity of hepatoma cells upon sorafenib treatment, and patients with low Shp2 expression exhibited superior prognosis to sorafenib. CONCLUSIONS: Shp2 promotes the progression of HCC and may serve as a prognostic biomarker for patients.
Subject(s)
Carcinoma, Hepatocellular/etiology , Liver Neoplasms/etiology , Protein Tyrosine Phosphatase, Non-Receptor Type 11/physiology , Animals , Carcinoma, Hepatocellular/mortality , Cell Line, Tumor , Cell Proliferation , Disease Progression , Humans , Liver Neoplasms/mortality , MAP Kinase Signaling System , Mice , Niacinamide/analogs & derivatives , Niacinamide/pharmacology , Phenylurea Compounds/pharmacology , Phosphatidylinositol 3-Kinases/physiology , Prognosis , Sorafenib , raf Kinases/physiologyABSTRACT
CD133 on cancer stem cells is a potential therapeutic target. In this study, CD133 antibody (CD133mAb) treatment resulted in cell death in hepatoma LM3, HepG2, Hep3B and Huh-7 cells, especially under low glucose condition. The treatment also inhibited formation of spheroids, colonies, and xenograft tumors. Ectopic CD133 enabled hepatocyte L02 to be suppressed by CD133mAb and increased spheroid formation. CD133mAb caused cell death in primary HCC cells and sensitized them to Doxorubicin and Cisplatin. The antibody effect was attributed to suppressing autophagy and promoting necrotic cell death. Therefore, targeting CD133 under low glucose condition is a potential therapeutic approach for hepatocarcinomas.
