Background & objective: It was reported that chemokine receptor CXCR4 and its ligand stromal cell-derived factor 1(SDF-1) were involved in the proliferation, differentiation, and metastasis of tumor. This study was designed to observe the expression of CXCR4 in NPC cells with different differentiation grade and proliferative ability to primitively clarify the relationship between CXCR4 and the malignity of NPC cells.
Methods: After treated with all-trans-retinoic acid(RA) and telomerase antisense oligodeoxynucleotide (ASODN) respectively, the expression of CXCR4 mRNA and CXCR4 protein in NPC CNE1 and CNE2Z cells were determined by in situ hybridization and immunohistochemistry, respectively; the distribution of cell cycle was examined with flow cytometry and the proliferation of cells was identified by MTT method.
Results: CXCR4 mRNA and CXCR4 protein were strongly expressed in both CNE1 and CNE2Z cells, and their expression in CNE2Z cells was stronger than that in CNE1 cells. After treated with 1x10(-5) mol/L and 1x10(-4) mol/L RA, CNE1 cells were arrested in G1 phase and CNE2Z cells in S phase, while the CXCR4 mRNA expression was significantly decreased in both CNE1 and CNE2Z cells compared with control group cells (P< 0.01). The effect of 1x10(-4) mol/L RA was more powerful than that of 1x10(-5) mol/L RA. After treated with ASODN, the proliferation of CNE1 and CNE2Z cells was inhibited, and the expression of CXCR4 protein was decreased compared with the control (P< 0.01).
Conclusion: CXCR4 is highly expressed in NPC cells,and its expression was associated with differentiation grade and proliferation ability of NPC cells.