Search

We and others have shown that Astragalus extract (AE) regulates various cellular processes including inflammation and apoptosis. It remains elusive whether and how AE modulates apoptosis in gastric cancer cells in vitro and in vivo. The objective of this study is to determine the effects and mechanisms of AE on the proliferation and apoptosis of human gastric cancer SGC-7901 cells and on tumor growth in orthotopic transplantation gastric tumor model in nude mice. Human gastric adenocarcinoma SGC-7901 cells and nude mice implanted with gastric cancer cells were treated with different concentration of AE and 5-fluorouracil as control. Cellular proliferation, apoptosis and tumor growth as well as interleukin (IL)-6/signal transducer and activator of transcription (Stat) 3 signals pathway were determined. We found that AE inhibited proliferation but caused apoptosis in human gastric cancer cells. Furthermore, the tumor growth and volume were reduced by AE administration in nude mice implanted with gastric cancer cells. In addition, treatments with AE decreased the expression of Bcl-2 proteins, whereas the expression of Bax was increased after AE treatment in tumor tissues of nude mice transplanted with human gastric cancer cells. This was associated with AE-mediated reduction of IL-6, phosphorylated Stat3, survivin and vascular endothelial growth factor. Overall, AE enhances apoptosis in gastric cancer cells in vitro and in vivo, which is associated with decreased activation of IL-6/Stat3 signals. [ABSTRACT FROM AUTHOR]

Gastrointestinal stromal tumors (GISTs) are the most common among gastrointestinal mesenchymal tumors, but its prognosis has not been accurately predicted by the current risk stratification guidelines, National Institutes of Health classification. In this study, we evaluated the predictive factors for GIST prognosis in a retrospective analysis of 332 patients. The data collected included tumor sites, including the esophagus, stomach, duodenum, small intestine, and extragastrointestinal sites; tumor size; microscopic indicators for malignant tumor behavior, such as the number of dividing cells, cell necrosis, atypical morphology, and invasion into the muscular or mucous layer; and previously established immunohistochemical indicators, CD117, CD34, and discovered on GIST-1 (DOG-1). No single occurrence of any microscopic indicators correlated with the prognosis of GIST; however, the total number of microscopic indicators was a significant prognostic factor of GIST (P < 0.001). Regarding the tumor sites, the order of prognostic risk (from the lowest to the highest) was as follows: the esophagus, stomach, duodenum, small intestine, extragastrointestinal sites, and colorectum. The association between tumor sites and prognosis was significant (P < 0.001). On the other hand, the expression of CD117 or CD34 was not associated with the risk of GIST. Importantly, 91% of the patients (302/332) showed the expression of DOG-1, and the lack of DOG-1 expression was associated with poor prognosis (P < 0.05). In conclusion, both tumor sites and total number of microscopic indicators are independent risk factors associated with the prognosis of GIST. The lack of DOG-1 expression may be predictive of malignant outcome. [ABSTRACT FROM AUTHOR]