Fc receptor-like 1-5 molecules are similarly expressed in progressive and indolent clinical subtypes of B-cell chronic lymphocytic leukemia.

Kazemi, Tohid; Asgarian-Omran, Hossein; Hojjat-Farsangi, Mohammad; Shabani, Mahdi; Memarian, Ali; Sharifian, Ramazan Ali; Razavi, Seyed Mohsen; Jeddi-Tehrani, Mahmood; Rabbani, Hodjatallah; Shokri, Fazel

Fc receptor-like (FCRL) 1-5 molecules are exclusively expressed in B-cells and have recently been considered as potential targets for immunotherapy of B-cell malignancies. In this study, the expression pattern of FCRL1-5 molecules was investigated in Iranian patients with B-cell chronic lymphocytic leukemia (B-CLL). Our RT-PCR results have demonstrated that all FCRL molecules, except FCRL4, were expressed in the vast majority of the patients with B-CLL. However, comparison of the relative mRNA expression levels of FCRL between B-CLL ( n = 86) and elderly normal subjects ( n = 10) revealed significantly lower expression levels of FCRL1 ( p < 0.0001), FCRL3 ( p = 0.01) and FCRL4 ( p = 0.002), but not FCRL2 or FCRL5, in cases with B-CLL. No significant differences were observed between the indolent and progressive subtypes of patients with B-CLL. Comparison between the mutated and unmutated subtypes revealed a significantly higher expression level of FCRL3 ( p = 0.017) in patients with mutated CLL. Surface and intracytoplasmic expression of FCRL1, 2, 4 and 5 in leukemic cells of 12 patients by flow cytometry revealed similar results to those obtained by RT-PCR with a few exceptions. Thus, while FCRL4 was expressed in only 2 samples at intracytoplasmic level, FCRL1 and 2 were expressed in the majority of samples, both at surface and intracytoplasm. FCRL5 protein was also detected in 10 samples, but surface expression was confirmed in only 2. Analysis of B-cells from 5 normal subjects by flow cytometry revealed higher expression levels of FCRL molecules compared to CLL. Our results indicate differential expression of FCRL molecules in B-CLL and suggest the potential implication of FCRL1 and 2 for immunotherapeutic interventions. © 2008 Wiley-Liss, Inc.

International Journal of Cancer, 2008, Vol 123, Issue 9, p2113

0020-7136

Academic Journal

10.1002/ijc.23751