Expression of c<i>-myc</i> mRNA in Hepatocellular Carcinomas, Noncancerous Livers, and Normal Livers

Abstract

Objectives: c-myc is a transcription factor that regulates cell proliferation, differentiation, and apoptosis. However, little is known about the clinical importance of c-myc mRNA expression in a primary hepatocellular carcinoma (HCC). In this study, we investigated whether a correlation existed between the level of c-myc mRNA expression and the occurrence of apoptosis or proliferative activity in an HCC. Methods: The levels of c-myc mRNA expression were quantified by real-time reverse transcriptase polymerase chain reaction (RT-PCR) and compared with immunohistochemical detection of the occurrence of spontaneous apoptosis and proliferative activity of cancer cells in 59 surgically resected HCCs. Results: The mean level of c-myc mRNA expression in 59 HCCs (1.19) was significantly suppressed compared with that in 59 noncancerous liver tissues (1.44, p < 0.0001). The level of c-myc mRNA expression was not correlated with tumor differentiation, tumor progression, proliferative activity of cancer cells, or patient survival. However, there was a significant positive correlation between the levels of c-myc mRNA expression and the occurrence of apoptosis in 59 HCCs (p < 0.001). Conclusions: Inhibition of c-myc mRNA expression may obstruct the induction of apoptosis of HCC cells and lead to uncontrolled cell growth.

Expression of C‐Myc mRNA in squamous cell carcinoma of the tongue

“…A study on hepatocellular carcinoma demonstrated suppression of Cmyc mRNA in cancerous tissues than non-cancerous liver tissues [28]. Further, a significant positive correlation was observed between the levels of C-myc mRNA and occurrence of apoptosis [28]. Contrary to our findings, Johnson et al [29] showed that chemotherapy-treated cell lines with C-myc gene amplification survived significantly shorter time than patients without C-myc gene amplification.…”

“…In breast cancer, Lockett et al have noted high (100%) positivity of C-myc mRNA in stage I patients than in stage IIIB patients (50%) [11]. A study on hepatocellular carcinoma demonstrated suppression of Cmyc mRNA in cancerous tissues than non-cancerous liver tissues [28]. Further, a significant positive correlation was observed between the levels of C-myc mRNA and occurrence of apoptosis [28].…”

HDAC inhibitor treatment of hepatoma cells induces both TRAIL-independent apoptosis and restoration of sensitivity to TRAIL

“…It is tempting to speculate that a complex regulation pattern after HDAC inhibition mediates apoptosis via upregulation of c-myc, which has been found to be suppressed in hepatoma cells. 41,42 This complex regulation pattern in hepatoma cells is currently addressed in a separate study.…”

Immunohistochemical expression of CD95 (Fas), c‐myc and epidermal growth factor receptor in hepatitis C virus infection, cirrhotic liver disease and hepatocellular carcinoma

“…Immunohistochemical data revealed overexpression of c‐myc in HCC, consistent with altered function of tumor hepatocytes (11). This may play a role in tumor development and/or progression (9), as it targets several genes that are negative regulators of cell cycle progression, such as p21 and p27, and thus is strongly implicated in control of cellular proliferation, apoptosis and differentiation (12).…”