[Risk features of HBV in human hepatocarcinogenesis: a nested case-controlled study].

Objective: To identify the association strength of the prevalence of HBeAg, covalently closed circular DNA (cccDNA) and 1762/1764 nucleotide mutations of hepatitis B virus (HBV) with the occurrence of hepatocellular carcinoma (HCC) in Qidong high risk male cohort.

Methods: A cohort of 377 middle aged HBV infected men in Qidong was followed from January 1989 to December 2002. Incident HCC cases were carefully registered.

Tight association of hepatocellular carcinoma with HBV infection in North China.

Background: Hepatocellular carcinoma (HCC) is the second most common cancer in China. Hepatitis B and C viruses (HBV and HCV) and aflatoxins are known risk factors for HCC, but the etiological status of these factors in HCC development is not clear. This study was undertaken to define the absolute importance of HBV in hepatocarcinogenesis of North China.

[Suppression of c-myc expression by interference RNA in HepG2 hepatocellular carcinoma cells].

Objective: To study the inhibitory effect of RNA interference (RNAi) on c-myc expression in hepatocellular carcinoma cell line, HepG2.

Methods: Expression vector of c-myc gene-targeting small interference RNA (siRNA) was constructed (psilencer-c-myc) and transfected into HepG2 cells by lipofectamine, and the unloaded vector was used as control (mock). The expression of c-myc mRNA and protein was identified by quantitive PCR and Western blot.

Nivalenol, a main Fusarium toxin in dietary foods from high-risk areas of cancer of esophagus and gastric cardia in China, induced benign and malignant tumors in mice.

This is the first report that a Fusarium toxin nivalenol (NIV) naturally existing at high levels in dietary food in high-risk areas of cancer of esophagus and gastric cardia in China induced benign and malignant tumors in mice. The levels of two Fusarium toxins, nivalenol and deoxynivalenol (DON) were quantitated using high performance liquid chromatography (HPLC) in a total of 97 samples of dietary wheat flour, barley and corn collected from families in two areas with high mortality rate of cancer of esophagus and gastric cardia (132/100,000), Linxian, Henan province and Cixiang, Hepei province, China. The mean level of NIV and DON in three dietary foods was 830+/-927 microg/kg (range 584-1,780 microg/kg) and 4,281+/-6,114 microg/kg (range 732-10,980 microg/kg) respectively.