Significance of decreased apoptosis, role of Bid expression and Bcl-Xl/Bid ratio in human jejunal stromal tumors

Given that the studies on human small intestinal stromal tumors are very limited, our study was designed to determine the significance of apoptosis, the role of some apoptosis-related proteins, including Bax, Bad, Bid, Bcl-2, Bcl-Xl, and Bcl-W, in jejunal stromal tumors (JST). For this purpose, 52 samples were examined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and immunohistochemistry, including 40 cases from normal jejunum and 12 cases from the JST. The results showed that a significantly decreased apoptosis was observed in JST compared with normal jejunum (median of apoptotic index, 0.13% vs 15.17%, p < 0.001). In univariate analysis, statistically significant differences were shown in percentage of positive-expression of Bid (0.0% vs 77.5%, p < 0.001), Bcl-2 (91.7% vs 42.5%, p = 0.003), and Bcl-Xl (75.0% vs 35.0%, p = 0.014), but not in Bax, Bad, and Bcl-W. Moreover, Bcl-Xl was an independent parameter associated with JST by multivariate Logistic analysis. For the role of ratios of anti-apoptotic proteins to pro-apoptotic proteins, Bcl-Xl / Bid ratio was the most preferable index. In conclusion, decreased apoptosis and expression of Bid, increased level of Bcl-Xl may play some important roles in human JST, and Bcl-Xl / Bid ratio may be as a new potentially associated index, although they should be validated in more studies.