الفهرس 
Hepatocellular carcinomaOnly 14 pages are availabe for public view
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Abstract
Hepatocellular carcinoma (HCC) is the most common form of primary hepatic tumor and is the fifth most common cancer worldwide and the third most common cause of death from cancer .
HCC usually develops in patients with cirrhosis. Cirrhosis may be caused by viral hepatitis (primarily hepatitis B and C), alcohol, high dietary exposure to fungal aflatoxins, hereditary haemochromatosis, autoimmune liver diseases and actually any disease that results in chronic inflammation of the liver .
Despite significant improvements in our understanding of the pathogenesis of HCC over the past few decades; we still do not have a comprehensive understanding of the major molecular pathogenic processes involved in liver carcinogenesis .
The development and progression of HCC are caused by the accumulation of genetic changes resulting in altered expression of cancer related genes, such as oncogenes, tumor suppressor genes, and genes involved in different regulatory pathways. Therefore, identification of new molecular parameters is important for cancer research and treatment .
Conceptually, hepatocarcinogenesis is based on two main principles: (1) the activation of genes such as oncogenes (c-myc, ß-catenin), growth factor (IGF-I & TGF-α) and telomerase enzyme inducing cellular immortalization and (2) the inactivation of genes called tumor suppressor genes (for example p53 and Rb) their expression can be affected by different modifications such as mutations, promoter methylation, biallelic loss and loss of heterozygosity (LOH) .
Several intracellular signaling pathways have been closely associated with HCC: p35 pathway and DNA alternation, retinoblastoma (Rb) pathway and regulation of cell cycle, transforming growth factor-beta (TGF-ß) and inhibition of cellular growth, and Wnt/beta-catenin pathway and cellular adhesion and signal transduction. Deregulation in these different pathways favors the development of liver tumor. Comprehensive understanding of the functions of these tumor suppressors is a prerequisite to devise innovative treatments of HCC .