LDL-DEPENDENT REGULATION OF BCL-2 AND CYCLIN-D GENE-EXPRESSION IN LYMPHOCYTES FROM NORMAL AND CML PATIENTS

Effect of low-density lipoprotein (LDL) on the expression of Bcl-2 as well as cyclin 'D' genes was studied in Receptor 'C-k' (+ve) and Recep tor 'C-k'(-ve) human lymphocytes. LDL had no effect upon the elevated levels of Bcl-2 and cyclin 'D' gene products in Receptor 'C-k' (-ve) l ymphocytes (from untreated CML patients), whereas in Receptor 'C-k' (ve) lymphocytes (from normal subjects), the exposure to LDL regulated the level of cyclin 'D' gene product without initiating the expression of bcl-2 gene product. However, blockage of Receptor 'C-k' in normal lymphocytes, through its specific antibody (Ab-RCk) in presence or abs ence of LDL, resulted in the induction of both cyclin 'D' (at 4 h inte rval) and bcl-2 (at 12 h interval) gene products. Based upon these res ults, we propose that Receptor 'C-k' deficiency in cells may inherit d efective apoptosis and capacity proliferation leading to leukemic tran sformation. (C) 1997 Elsevier Science ireland Ltd.