Correlation between Bcl-X expression and B-cell hybridoma apoptosis induced by activin A

In this study, we examined the role of bcl-XL and bcl-Xs in apoptotic cell death of HS-72 cells induced by activin A. Immunoblot analysis revealed that a band of Bcl-XL was detected in HS-72 cells cultured with or without activin A. Although untreated HS-72 cells did not express Bcl-Xs, the expression of Bcl-Xs was significantly increased when cultured with activin A. We also investigated the expression of Bcl-Xs and Bcl-XL in HS-72 cells cultured with activin A in the presence of protein kinase C inhibitor 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H7), which suppressed apoptosis in HS-72 cells induced by activin A. Ex posure to H7 apparently increased the level of Bcl-XL in HS-72 cells cultured with or without activin A. In contrast, no detectable band of Bcl-Xs was found in HS-72 cells cultured with activin A and H7. These findings indicate that Bcl-XL upregulation and Bcl-Xs downregulation induced by H7 might correlate with the suppression of activin A-induced apoptosis in B-lineage cells. CELL SIGNAL 10;7:511-521, 1998. (C) 1998 Elsevier Science Inc.