title: Expression of multidrug resistance 1 gene in B-cell lymphomas: association with follicular dendritic cells.
abstract: OBJECTIVE
  Multidrug resistance (MDR) in B-cell lymphomas still constitutes a major obstacle to the effectiveness of chemotherapy even in the anti-CD20 antibody therapy era. The aim of this study was to investigate the expression of MDR-associated molecules in reactive lymphadenopathy (RL), follicular lymphoma (FL), and diffuse large B-cell lymphoma (DLBCL).
  
  
  RESULTS
  The expression of mRNA for ABC-transporter family genes was determined by real-time RT-PCR in lymph nodes from RL, FL, and DLBCL cases. MDR1 exhibited significantly stronger expression in RL, FL, and DLBCL than Raji B-cell lymphoma cells. RL and FL showed significantly higher expression than DLBCL. Immunohistochemically, MDR1 positive cells were localized in the germinal centers of RL and center of the nodular lesions of FL showing associations with CD21 positive follicular dendritic cells (FDCs). Raji cells were co-cultured with FDC sarcoma-derived cells and the expression of MDR1 and drug resistance were analyzed. The co-culture of Raji cells with FDCs induced strong expression of MDR1 and introduced resistance to doxorubicin-induced apoptosis.
  
  
  CONCLUSIONS
  These results suggest that FDCs induce MDR1 expression in reactive as well as neoplastic B-cells. Inhibition of the interaction of FDCs with B-cells may provide a novel strategy for treating the chemotherapy resistant fraction.
authors: Department of Comprehensive Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors: Keiko
authors: K
authors: Yagi
authors: Kouhei
authors: K
authors: Yamamoto
authors: Shigeaki
authors: S
authors: Umeda
authors: Shinya
authors: S
authors: Abe
authors: Shiho
authors: S
authors: Suzuki
authors: Iichiroh
authors: I
authors: Onishi
authors: Susumu
authors: S
authors: Kirimura
authors: Masashi
authors: M
authors: Fukayama
authors: Ayako
authors: A
authors: Arai
authors: Masanobu
authors: M
authors: Kitagawa
authors: Morito
authors: M
authors: Kurata
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis*; D017209:Apoptosis / Q000502:physiology; D001402:B-Lymphocytes / Q000378:metabolism; D045744:Cell Line, Tumor; D018920:Coculture Techniques; D020566:Dendritic Cells, Follicular / Q000378:metabolism*; D018432:Drug Resistance, Multiple / Q000502:physiology; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D016393:Lymphoma, B-Cell / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D012333:RNA, Messenger