Baicalein blocked gastric cancer cell proliferation and invasion through modulated platelet type 12-lipoxygenase.

Objectives: Baicalein (BAI) is one of the main ingredients of Scutellaria baicalensis georgi. Its pharmacological effects have been widely reported in various cancers. However, the specific molecular mechanism of BAI in gastric cancer (GC) has not been defined. This study investigates BAI's inhibitory effect on gastric cancer and its potential mechanisms.

Materials and methods: Gastric normal (GES-1 cells) and cancer cells (MKN-74 and MGC-803 cells) were treated with different concentrations of BAI. Cell proliferation and migration were assessed by MTT, colony formation, wound healing, and transwell assays. Flow cytometry and Hoechst 33342 staining were used to detect the cell apoptosis. IF and WB tests were employed to detect EMT-related protein. Finally, the anti-tumor effects of BAI were verified in in vivo xenograft models.

Results: Our results show that the cell viability of MKN-74 and MGC-803 cells was significantly decreased in a time- and dose-dependent manner after BAI treatment by MTT assay. The expression levels of p12-LOX genes, which were determined by quantitative RT-PCR and WB, in MKN-74 cells were higher than those in GES-1 cells. As shown by the wound healing assay and Transwell assay, the treatment with BAI also significantly suppressed GC cell migration and invasion. Besides, BAI inhibited the phosphorylation of ERK1/2 and MEK1/2 in GC cells, as revealed by WB. Furthermore, BAI significantly inhibited tumor growth capacities in a xenograft model.

Conclusion: BAI shows a significant anti-tumor effect and inhibition on tumor cell migration and invasion, which is probably through regulation of p12-LOX modulated epithelial-mesenchymal transformation.