Cytotoxic effects of chemokine receptor 4 inhibition by AMD3100 in biliary tract cancer cells: Potential drug synergism with gemcitabine

Abstract

Biliary tract cancer (BTC) remains one of the most life-threatening types of cancer due to the lack of efficient therapies. Advanced tumour stages at the point of diagnosis and high chemoresistance are two of the predominant reasons for a 5-year survival rate of only ~5%. The present study investigated the effect of the chemokine receptor 4 (CXCR4) inhibitor AMD3100 (Plerixafor), alone and in combination with standard gemcitabine chemotherapy, on the proliferation of BTC cells. The expression of CXCR4 was analysed by reverse transcription-quantitative polymerase chain reaction in eight heterogeneously differentiated BTC cell lines. The effects of treatment with the CXCR4 antagonist, AMD3100, on cell viability and anchorage-independent growth, and the possible synergistic cytotoxic effects of AMD3100 with standard chemotherapeutics were assessed. The expression of CXCR4 was observed to a variable extent in all eight BTC cell lines, with SkChA-1 cells exhibiting the highest expression levels. Treatment with AMD3100 led to a marginal decrease in cell viability in the cell lines, with the exception of the CCSW-1 cells, and a significant reduction in the GBC, MzChA-1, SkChA.-1 and TFK-1 cell lines. The combined treatment of the SkChA-1 cells with varying concentrations of AMD3100 and standard gemcitabine chemotherapy revealed a more marked overall cytotoxicity, indicating a potential synergistic effect. In addition, AMD3100 significantly reduced anchorage-independent growth in the SkChA-1 cells. Overall, the results of the present study suggest that the inhibition of CXCR4 by AMD3100, in combination with gemcitabine, may be a suitable strategy for the future therapy of BTC.