FREQUENT EXPRESSION OF THE CELL DEATH-INDUCING GENE BAX IN REED-STERNBERG CELLS OF HODGKINS-DISEASE

The expression of a cell death-inducing gene, Bax, was investigated in 52 cases of Hodgkin's disease in parallel with Epstein-Barr virus sta tus and was compared with the immunodetection of other apoptosis-regul ating proteins, Mcl-1, Bcl-2, and Bcl-x. Bar immunostaining was found in 92% of the cases, among them 28% with a strong signal in more than 75% of the Reed-Sternberg cells. Mcl-1 was positive in 80% of the case s, whereas Bcl-2 and Bcl-x were found in 53% and 88% of the cases, res pectively. Of 48 (89%) Bax-positive tumors, 43 were found to express a poptosis-inhibiting proteins such as Mcl-1 or Bcl-2. With the exceptio n of 1 case, all Bar-positive tumors also expressed either Bcl-2, Bcl- x, Mcl-1, or combinations of these anti-apoptotic proteins. No correla tion was found between Bar expression and the presence of apoptotic ce lls as detected by morphology and the in situ 3' OH-DNA end-labeling t echnique. Our findings show that the apoptosis-inducing gene Bar expre ssion is frequently expressed in Hodgkin's disease, providing a potent ial explanation for the good chemoresponses generally obtained for pat ients with this neoplastic disorder. (C) 1996 by The American Society of Hematology.