Inhibition of Phosphatidylcholine-Specific Phospholipase C Induces Down-Regulation of CXCR4 Overexpression & Reduction of 1H-MRS-Detected PCho in Human Lymphoblastoid Cells

Alessandro Ricci¹, Serena Cecchetti¹, Maria Elena Pisanu¹, Luisa Paris¹, Luigi Portella², Stefania Scala², Egidio Iorio¹, Franca Podo¹

CXCR4-CXCL12 axis controls the metastatic homing of tumor cells and may act as target for antitumor therapy. We investigated the 1H-MRS choline profile in relation to changes of CXCR4 expression induced by a selective inhibitor of phosphatidylcholine-specific phospholipase C (PC-plc), tricyclodecan-9-yl-potassium xanthate (D609) in human T-lymphoblastoid cells (CEM). We showed that PC-plc physically associates with CXCR4; inhibition of PC-PLC activity induces down-modulation of CXCR4 from the plasma membrane; 1H MRS analyses of cell extracts showed that an about 2-fold decrease in the phosphocholine signal area may act as marker of simultaneous PC-PLC inhibition and CXCR4 down-modulation in D609-treated CEM cells.