DNA Methylation of TGFß Target Genes: Epigenetic Control of TGFß Functional Duality in Liver Cancer.

Transforming growth factor beta (TGFß) plays a key role in liver carcinogenesis. However, its action is complex, since TGFß exhibits tumor-suppressive or oncogenic properties, depending on the tumor stage. At an early stage TGFß exhibits cytostatic features, but at a later stage it promotes cell growth and metastasis, as a potent inducer of epithelial to mesenchymal transition (EMT). Here, we evaluated DNA methylation as a possible molecular mechanism switching TGFß activity toward tumor progression in hepatocellular carcinoma (HCC). We report that decitabine, a demethylating agent already used in the clinic for the treatment of several cancers, greatly impairs the transcriptional response of SNU449 HCC cells to TGFß. Importantly, decitabine was shown to induce the expression of EMT-related transcription factors (e.g., SNAI1/2, ZEB1/2). We also report that the promoter of SNAI1 was hypomethylated in poor-prognosis human HCC, i.e., associated with high grade, high AFP level, metastasis and recurrence. Altogether, the data highlight an epigenetic control of several effectors of the TGFß pathway in human HCC possibly involved in switching its action toward EMT and tumor progression. Thus, we conclude that epidrugs should be carefully evaluated for the treatment of HCC, as they may activate tumor promoting pathways.

Cyclooxygenase-2 expression is associated with elevated aspartate aminotransferase level in hepatocellular carcinoma.

BACKGROUND: Cyclooxygenase-2 (COX-2), the inducible rate-limiting enzyme of prostaglandins biosynthesis, is involved in the pathogenesis of many chronic inflammation-related human malignancies including hepatocellular carcinoma (HCC). However, its clinical significance in HCC remains obscure. The aim of our study was to evaluate COX-2 expression in HCC and correlate its expression to both clinicopathological parameters and patients survival. MATERIALS AND METHODS: The present study was conducted on 17 HCC and 21 adjacent nontumor liver tissues obtained from 22 HCC patients underwent hepatectomy. Eight normal liver tissues taken from normal donors and HepG2 cells were used as controls. Total RNA was extracted and COX-2 mRNA was detected by reverse transcription polymerase chain reaction and correlated to the clinicopathological criteria and to patient's survival. RESULTS: COX-2 mRNA was detected in 58.8% of the HCC tissues and in 28.6% of the adjacent nontumor liver tissues. COX-2 expression was significantly associated with elevated levels of serum aspartate aminotransferase (AST) with high specificity for disease detection. There was no significance between COX-2 expression and any of the histopathological criteria. CONCLUSIONS: COX-2 expression may be involved in HCC carcinogenesis with high specificity for disease detection. COX-2 expression is significantly associated with elevated AST levels indicating a mechanism that may correlate both markers. However COX-2 expression seems to be an independent factor with no correlation to any of the histopathological data or patient's survival.

Expression of pro- and anti-inflammatory cytokines in relation to apoptotic genes in Egyptian liver disease patients associated with HCV-genotype-4.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common tumors worldwide strongly linked to hepatitis C virus (HCV) infection. However, the exact pathogenetic mechanisms are still unclear. METHODS: We assessed the expression of apoptosis genes (GSK3-B, AKT-1, Bcl-2), inflammatory cytokines (TNFalpha, TNF-RI, TNF-RII, IL-6, IL-6R), anti-inflammatory IL-10, CRP and alphaFP by reverse transcription-polymerase chain reaction (RT-PCR) in 33 HCC, 25 chronic hepatitis and 16 asymptomatic HCV carrier positive for HCV subjects. Also, pooled normal liver tissues and HepG2 cells were used as controls. RESULTS: Hepatocellular carcinoma and liver disease (LD) showed reduced expression of GSK-3beta, TNFalpha, TNF-R I, TNF-RII, IL-10 and overexpression of IL-6R and CRP with no significant difference between the two groups. AFP was expressed in HCC only (33%). AKT, BCL2 and IL-6 showed normal, reduced and overexpression in studied patients with a significant difference between AFP, AKT overexpression (67% and 30%), BCL2 overexpression (49% and 10%) and reduced IL-6 in between HCC and LD. The morphologically normal tissues adjacent to tumors showed aberrant expression of AKT, IL-6, CRP, TNFalpha and TNFRI. A significant relation was observed between cirrhosis and GSK-3beta, AKT and IL-6 (P = 0.0018, P = 0.018, P = 0.0001; respectively). CONCLUSIONS: Aberrant expressions of AKT, GSK3-B, and BCL2 are common events in HCV-associated LD and HCC. AKT, GSK3-B and IL-6 are significantly associated with cirrhosis and could be used as biomarkers for both early detection and molecular target therapy for the prevention of HCC development. TNFRII, GSK3-B and s-AFP could be used as prognostic factors that can predict the clinical outcome of HCC patients.