Possible involvement of peripheral-type benzodiazepine receptors in erythroid differentiation of human leukemia cell line, K562.

Possible involvement of the peripheral-type benzodiazepine receptor (PBR) in hemin/protoporphyrin-induced erythroid differentiation of human leukemia K562 cells was investigated by the use of the ligands, diazepam and PK11195. Diazepam itself exhibited differentiation-inducing activity on K562 cells. The PBR-specific antagonist, PK11195, dose-dependently inhibited both diazepam-induced and hemin/protoporphyrin-induced K562 cell differentiation. The results imply that PBR is involved in the erythroid differentiation of K562 cells.