Mutation of p53 gene in human fetal gastric mucosal cells by sterigmatocystin in vitro

Cell culture, flow cytometry and silver-staining PCR-SSCP methods were used to explore the effects of sterigmatocystin(ST) (1 mg/L and 3 mg/L) on carcinogenesis and mutation of tumor suppressor gene p53 in human fetal gastric mucosal cells in vitro. Four weeks after treated with ST, the cells showed vigorous growth and malignant transformation foci. Twenty-four weeks after ST treatment, the cells could form cellular colonies in soft agar(the mean colony number was 15 and 17 perdish for ST 1 mg/L and 3 mg/L groups respectively). Flow cytometric analysis showed that both proliferation indexes (PI) and the cellular DNA contents of ST treated cells were much higher than those of normal control. The DNA contents of ST treated cells were in DNA aneuploid range. Mutant p53 protein expression was also significantly higher in ST treated cells. Silver-staining PCR-SSCP analysis showed that abnormal electrophoretic migration bands could be seen at exon 8 of p53 gene in ST-treated groups 22 weeks after ST treatment, while no abnormal bands were found in control group. Thus, the results further confirmed the carcinogenic effects of ST on human fetal gastricmucosal cells.