الفهرس 
Hepatitis C viral infection
MicroRNAsOnly 14 pages are availabe for public view
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Abstract
Hepatocellular carcinoma (HCC) is the 6th most common cancer and the 4th cause of cancer-related mortality worldwide. More than 600,000 people die from HCC each year (Brar et al., 2019). Approximately 20% of chronic HCV-infected individuals develop liver cirrhosis within 20–30 years and once cirrhosis is established, the rate of HCC development is 1–4% annually. HCC development due to HCV is a stepwise process spanning over 20 to 40 years. HCV-induced development of HCC is affected by the duration of disease and viral genotype(Axley et al., 2018).
In Egypt, liver cancer forms 11.75% of the malignancies of all digestive organs and 1.68% of the total malignancies. HCC constitutes 70.48% of all liver tumors among Egyptians (Holah et al., 2015).
The methods for surveillance and early detection of HCC in high risk groups are abdominal ultrasound imaging and alpha- fetoprotein (AFP). However, the diagnostic accuracy of both modalities is unsatisfactory, especially for the detection of early and small stage tumor. Only 30% to 40% of patients with HCC are candidate for curative management due to late detection of HCC and diagnosis at advanced stage (Zhou et al., 2011).
MicroRNAs (miRNAs) are short noncoding RNAs of 19–22 nucleotides which regulate posttranscriptional gene expression of their target genes through binding to the 3′-untranslated regions of target messenger RNAs (mRNAs) which resulted in translational or
Chapter I Introduction and aim of the work
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post translational inhibition of a protein synthesis either by mRNA suppression or degradation (Sohel et al., 2020).
Upregulation of some miRNAs as well as downexpression of others associated with carcinogenesis and correlates with the development of cancer associated phenotypes (Di Leva et al., 2014).
The involvement of miRNAs in hepatocarcinogenesis and the development of clinical applications of miRNAs as diagnostic, prognostic and therapeutic tools in different types of cancer represents an important area of clinical investigations (Sohel et al., 2020).
MiRNA-500 (MiR-500) is an oncofetal miRNA, which is highly expressed in hepatocellular carcinoma tissue. Also, previous studies have shown that miR-500 is of great interest in cancer therapies due to its association with various types of cancer, including gastric cancer and prostate cancer. The dynamic miR-500 regulation is an important feature as an oncofetal non-coding small RNA relevant to the diagnosis of human liver cancer (Bao et al., 2018).