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 re vealed 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 cult ured 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 prot ein kinase C inhibitor 1-(5-isoquinolinesulfonyl)-2-methylpiperazine d ihydrochloride (H7), which suppressed apoptosis in HS-72 cells induced by activin A. Ex posure to H7 apparently increased the level of Bcl-X L in HS-72 cells cultured with or without activin A. In contrast, no d etectable band of Bcl-Xs was found in HS-72 cells cultured with activi n A and H7. These findings indicate that Bcl-XL upregulation and Bcl-X s 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.