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

• Published in: International journal of cancer 2008-11, Vol.123 (9), p.2113-2119
• Main Authors: 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
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; CLL; Cytoplasm - metabolism; FCRL; Flow Cytometry; Hematologic and hematopoietic diseases; Humans; Leukemia, Lymphocytic, Chronic, B-Cell - classification; Leukemia, Lymphocytic, Chronic, B-Cell - metabolism; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Medical sciences; Medicin och hälsovetenskap; Receptors, Cell Surface - genetics; Receptors, Fc - genetics; Receptors, Immunologic - genetics; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - analysis; RT‐PCR; Tumors
• ISSN: 0020-7136; 1097-0215; 1097-0215
• DOI: 10.1002/ijc.23751

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.