OBJECTIVETo explore the inhibitory effect of garlic oil on cyclin E expression in gastric adenocarcinoma cells.

METHODSHuman gastric adenocarcinoma SGC7901 cells were cultured routinely and the expressions of transforming growth factor alpha (TGFalpha) and epidermal growth factor receptor (EGFR) are detected by immunofluorescent staining and flow cytometry. The SGC7901 cells were also cultured with RPMI 1640 without calf serum for 48 h, followed by further culture with RPMI 1640 in the presence of 2.5% calf serum before treatment with TGFalpha, garlic oil, or their combination, and cyclin E expression of the cells was then detected by immunofluorescent staining and flow cytometry.

RESULTSThe positivity rates of TGFalpha and EGFR expressions were 46.80% and 57.78 % respectively in SGC7901 cells cultured routinely for 48 h. The positivity rate of cyclin E expression was increased by 7.06% (P<0.001) in SGC7901 cells treated with 30 microg/L TGFalpha for 5 h, decreased by 11.75% (P<0.001) following a 5-hour treatment with 10% garlic oil, and decreased further by 17.11% (Plt;0.001) after treatment with both 30 microg/L TGFalpha and 10% garlic oil for 5 h.

CONCLUSIONSThe gastric adenocarcinoma SGC7901 cells express TGFalpha and EGFR and possess TGFalpha autocrine and paracrine loops to promote cell proliferation. Garlic oil inhibits cyclin E expression in routinely cultured SGC7901 cells and also in TGFalpha-treated ones, suggesting that garlic oil can inhibit the TGFalpha autocrine and paracrine loops, which can be one of the pathways of garlic oil to inhibit cancer cell proliferation.