Characterization of three hairy cell leukemia- derived cell lines (ESKOL, JOK-1, and Hair-M) by multiplex-FISH, comparative genomic hybridization, FISH, PRINS, and dideoxyPRINS

Hairy cell leukemia (HCL) is a chronic B-lymphocyte leukemia. Due to the proliferative inertia of the malignant cells, HCL-derived cell lines are an important tool for studies on this disease. We have elaborated the karyotypes of three HCL-derived cell lines, ESKOL, JOK-1, and Hair-M, by combining a range of molecular cytogenetic techniques, including multiplex (multicolor) fluorescence in situ hybridization (M-FISH), comparative genomic hybridization (CGH), conventional FISH, primed in situ labeling (PRINS), and dideoxyPRINS. We found ESKOL to be monoclonal with a single chromosome aberration, der(7)t(3;7)(q26.3;q31). JOK-1 also ap- peared to be monoclonal, having the karyotype 48,XY,der(4) t(1;4)(1pter→p32::4qter→pter), der(6)(6qter→p22::q12→ qter),+der(7)t(7;11)(7pter→q21::11p15→pter),der(8)t(5;8;12) (5pter→p14::12p11.2→p12::8q12→q21::8?cen→→24.?2), der(14)t(8;14)(8qter→q24.?2::14q32.3→pter),+20. These karyotypes differ from the original descriptions of ESKOL and JOK-1. The Hair-M cells analyzed by us were found to be peritetraploid with numerous chromosomal rearrangements. The cell line was also found to be multiclonal. On this basis, we do not regard the Hair-M cell line to be suitable for HCL studies.