Effects of Wei Chang An on Expression of Multiple Genes in Human Gastric Cancer Grafted Onto Nude Mice

Aim: To investigate the expression of multiple genes in Chinese jianpi herbal recipe Wei Chang An (WCA) in human gastric cancer cell line SGC-7901.

Methods: A human gastric adenocarcinoma cell line SGC-7901 grafted onto nude mice was used as the animal model. The mice were randomly divided into 3 groups, one control and the two representing experimental conditions. Animals in the two experimental groups received either WCA over a 34-d period or 5-fluorouracil (5-FU) over 6-d period starting at 8th d after grafting. Control animals received saline on an identical schedule. Animals were killed 41 d after being grafted. The expression profiles in paired WCA treated gastric cancer samples and the N.S. control samples were studied by using a cDNA array representing 14181 cDNA clusters. The alterations in gene expression levels were confirmed by Real-time Quantitative polymerase chain reaction (qPCR).

Results: When compared with controls, the average tumor inhibitory rate in WCA group was 44.32% +/- 5.67% and 5-FU 47.04% +/- 11.33% (P < 0.01, respectively). The average labeling index (LI) for PCNA in WCA group and 5-FU group was significantly decreased compared with the control group. Apoptotic index (AI) was significantly increased to 9.72% +/- 4.51% using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate fluorescence nick end labeling (TUNEL) method in WCA group compared with the controls 2.45% +/- 1.37%. 5-FU group was also found to have a significantly increased AI compared with the controls. The expression of cleaved Caspase-3 in WCA group and 5-FU group was significantly increased compared with the control group respectively. There were 45 different expressed sequence tags (ESTs) among the control sample pool and WCA sample pool. There were 24 ESTs up-regulated in WCA samples and 21 ESTs down-regulated. By using qPCR, the expression level of Stat3, rap2 interacting protein x (RIPX), regulator of differentiation 1 (ROD1) and Bcl-2 was lower in WCA group than that in control group respectively. By using SP immunohistochemical method the expression of Phospho-Stat3 (Tyr705) and Bcl-2 in WCA group and 5-FU group was significantly decreased compared with the control group respectively.

Conclusion: WCA could inhibit gastric cancer cell SGC-7901 growth in vivo. WCA could induce gastric cancer cell apoptosis and suppress proliferation. Its mechanisms might be involved in the down-regulation of Stat3, RIPX, ROD1 and Bcl-2 gene.