Curcuma wenyujin Y. H. Chen et C. Ling n-Butyl Alcohol Extract Inhibits AGS Cell Helicobacter pylori Promoted Invasiveness by Down-Regulating Caudal Type Homeobox Transcription Factor and Claudin-2 Expression.

OBJECTIVE

To investigate the effects and possible mechanisms of action of Curcuma wenyujin Y. H. Chen et C. Ling n-Butyl alcohol extract (CWNAE) on repression of human gastric cancer (GC) AGS cell invasion induced by co-culturing with Helicobacter pylori (HP).

METHODS

AGS cells were cultured with HP of positive or negative cytotoxin-associated gene A (CagA) and vacuolating cytotoxin gene A (VacA) expression (CagA+/- or VacA+/-) and divided into 5 group. Group A was cultured without HP as a control, Group B with HP, Group C with HP, Group D with HP and CWNAE, and Group E with HP and CWNAE. Methylthiazolyldiphenyl-tetrazolium bromide (MTT) and tumor invasion assays, examinations of morphology and ultramicroscopic structures, quantitative real-time polymerase chain reaction and Western blots were performed to measure the effects and uncover the mechanisms behind these effects of HP and CWNAE on the epithelial-mesenchymal transition (EMT) of AGS cells.

RESULTS

The 10% inhibitory concentration of CWNAE against AGS cells after a 48 h incubation was 19.73±1.30 μg/mL. More AGS cells were elongated after co-culturing with HP than after culturing with HP. In tumor invasion assays, HP significantly enhanced the invasiveness of AGS cells compared to the other experimental groups (all P value <0.05), and this effect was inhibited by CWNAE. Treatment with CWNAE normalized tight junctions and reduced the number of pseudopodia of AGS cells co-cultured with HP. HP up-regulated zincfinger ebox binding homeobox 1 (ZEB1) in AGS cells after co-culturing for 24 h. Expression of caudal type homeobox transcription factor (CDX-2) and claudin-2 was significantly increased by HP (P<0.05), but not by HP.

CONCLUSION

HP promoted the invasiveness of AGS cells through up-regulation of ZEB1 transcription and claudin-2 and CDX-2 expression. CWNAE inhibited these effects of HP on AGS cells by down-regulating ZEB1 transcription, and CDX-2 and claudin-2 expression.