Hypoxia promotes migration and invasion of gastric cancer cells by activating HIF-1α and inhibiting NDRG2 associated signaling pathway.

OBJECTIVE: Gastric cancer has been become the fourth most prevalent cancer in whole world and the third most common cancer in Asian countries. This study aimed to discuss the invasive and migration mechanisms of gastric cells. MATERIALS AND METHODS: Human gastric cancer line, BGC-823 cell, was treated with hypoxia and divided into Hypoxia-12 h, Hypoxia-24 h, Hypoxia-36 h, Hypoxia-48 h and Hypoxia-72 group. Meanwhile, blank BGC-823 cells were assigned as Normal group. mRNA and protein expression of N-myc downstream-regulated gene 2 (NDRG2), Twist, E-cadherin and hypoxia-inducible factor 1α (HIF-1α) were evaluated by using quantitative Real-time PCR (qRT-PCR) and Western blot assay, respectively. Invasion and migration of BGC-823 cells were also examined in this study. RESULTS: Hypoxia treatment significantly enhanced invasion and migration ability of BGC-823 cells compared to that of Normal group (p<0.05). Hypoxia treatment significantly reduced E-cadherin and NDRG2 expression compared to that of Normal group (p<0.05). Hypoxia treatment significantly increased Twist and HIF-1α expression compared to that of Normal group (p<0.05). HIF-1α inhibitor, YC-1, significantly suppressed the effects of hypoxia treatment on E-cadherin and Twist expression (p<0.05). Meanwhile, YC-1 treatment also significantly suppressed the effects of hypoxia treatment on NDRG2 and HIF-1α expression. CONCLUSIONS: Hypoxia promoted the migration and invasion of gastric cancer cell BGC-823 by activating HIF-1α and inhibiting NDRG2 associated signaling pathway.

Study of the regulatory effect of acupuncture on rotation-induced gastric dysrhythmia in rabbits.

AIM: A model of experimental gastric dysrhythmia in rabbits was set up to evaluate the effect of different acupoints on regulating gastric dysrhythmia in rabbits so as to promote acupuncture treatment for this kind of disease. METHODS: A model of gastric dysrhythmia in rabbits was established by the rotation method using the basic electrical rhythm (BER) as an objective index. After puncturing at the points of Zusanli (ST36), Neiguan (PC6), Tiaokou (ST38) and Tianquan (PC2) in the four groups of experimental gastric dysrhythmia rabbits, the difference in regulatory effects on the disturbance and frequency of the gastric electric slow wave was observed. RESULTS: Before needling at the specific acupoints Zusanli and Neiguan, the percentage of disturbance electric slow wave for the Zusanli and Neiguan groups was 57.0785 ± 10.644 and 55.5173 ± 6.0500, respectively; after such needling, the percentage was 43.7823 ± 10.1518 and 43.5147 ± 6.8983 for the Zusanli and Neiguan groups, respectively, while the frequency of electric slow wave for the Zusanli and Neiguan groups was 2.2870 ± 0.3800 and 2.4020 ± 0.3536, respectively, before needling and after needling, the frequency was 2.7090 ± 0.5865 and 2.9220 ± 0.4923 for the Zusanli and Neiguan groups, respectively. Comparing the percentage and frequency for the Zusanli and Neiguan groups before and after needling, the result shows that both groups have a significant difference statistically (P < 0.05) but between the Zusanli and Neiguan groups, there was no significant difference. Before and after needling the nonspecific acupoints of Tiaokou and Tianquan, there was no difference between the Tiaokou and Tianquan groups. Between the Zusanli and Tiaokou groups and the Neiguan and Tianquan groups, there are significant differences in regulating gastric dysrhythmia. CONCLUSION: This model is suitable for the observation of gastric dysrhythmia. The specific acupoints of Zusanli and Neiguan have good effects on the treatment of gastric dysrhythmia.