Similarities between the sensitivity to 2-chlorodeoxyadenosine of lymphocytes from CLL patients and bryostatin 1-treated WSU-CLL cells: an infrared spectroscopic study.

Abstract

Infrared (IR) spectroscopy was used to compare the drug resistance mechanism of cells from chronic lymphocytic leukemia (CLL) patients with that of WSU-CLL cells. Bryostatin 1 (Bryo 1), a macrocyclic lactone and protein kinase C activator, was used to render WSU-CLL cells more susceptible to 2-chlorodeoxyadenosine (2-CdA). The IR spectroscopic analysis revealed some changes in protein and DNA content in Bryo 1-treated WSU-CLL cells, however, the most significant alterations were observed in the membrane lipids, which resemble those found between 2-CdA-sensitive and 2-CdA-resistant cells from CLL patients. In addition, Bryo 1 treatment induced WSU-CLL cells to become CD11c, CD25 and tartrate-resistant acid phosphatase- positive, specific markers for hairy cell leukemia, a disease exquisitely sensitive to 2-CdA. Our results suggest that 2- CdA-sensitive CLL cells have cellular characteristics resembling the hairy cell stage. The similarity between the membrane lipids in 2-CdA-sensitive CLL cells and the Bryo 1-treated WSU-CLL cell line supports the suggestion that membrane lipid alteration might be an important step in the drug resistance mechanism of CLL cells. Crown copyright form not completed for this publication. No