Visit our Expo - Redox and Inflammation signaling 2012

Session II : Receptor signaling and G proteins Poster II, 8
Expression of chemokine receptor CXCR4 (CD184) in B chronic lymphocytic leukaemia
cells.
Nicolaas H. C. Brons1, Valérie Palissot1, Chantal Schwartz1, Manon Bosseler1,
Bernadette Leners1, Guy J Berchem1,2.
1Laboratoire d'Hémato-Cancérologie Expérimentale, CRP-Santé, 84 Val Fleury, L1526
Luxembourg. E-mail : berchem.guy@chl.lu
2Hémato-Cancérologie, Centre Hospitalier de Luxembourg, 4 rue barblé, L1210
Luxembourg.
Chronic lymphatic leukaemia (CLL) accounts for about 30% of adult leukemias in Western
countries. This lymphoma is very indolent but relentless, with median survivals of almost a
decade. The disease is characterized by the accumulation of a monoclonal population of CD5
positive neoplastic B cells in secondary lymphoid organs, marrow, and blood. Although the
slowly proliferating cells are sensitive to chemotherapeutic agents, chemotherapy is almost
never curative and relapse inevitably follows. In 1975 Kanti Rai has described a clinical
staging system which until now serves as basis for treatment decisions.
The study was aimed to explore the CD184 also known as the CXCR4 chemokine receptor on
B-lineage chronic lymphocyte leukaemia (B-CLL) cells of various disease stages and its
relationship with others receptor expressions. CD 184 is expressed on CLL cells and normal
B cells, it is one of the main receptors that mediate B cell entry in a secondary lymphoid
tissues and their homing to T cell and B cell zones. Marrow stromal cells or nurselike cells
constituvely secrete CXCR12, the ligand for CXCR4, thereby attracting and rescuing CLL B
cells from apoptosis in a contact dependent fashion. Therefore, CD184 has been mentioned as
a possible prognostic marker in CLL. Flow cytometry was used to detect the CXCR4
expression in patients of different Rai stages The samples were measured on a FACSCanto
(BD) and up to 6 markers per tube were analysed by the DivaSoftware (BD). Calibration
curves for the MFE were obtained with Fluorospheres (DakoCytomation, K0110). More than
thirty CD markers have been used to characterized B leukemic cells and correlation was
researched with CD184. Of the 44 persons , 11 were healthy donors, 5 had Rai stage 0
disease, 12 had Rai stage I disease, 3 had Rai stage II disease, 4 had Rai stage III disease, 9
had Rai stage IV disease. CXCR4 was consistently expressed on circulating B-CLL with a
mean fluorescence intensity higher than in cells from healthy volunteers. There was a
correlation between CXCR4 expression and late stage of the disease. Interestingly,
chemotherapeutic treatments seem to decrease level of this marker down to level of earliest
stages. However, there was no correlation of CD184 level and quantitative expressions of
known CD markers tested. Different correlations with previous treatments and known
prognostic factors will be described and clinical implications will be discussed.
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