干扰hENT1表达增加5-FU在胰腺癌sw1990细胞内浓度

im：To investigate whether 5-FU intracellular concentration increased after hENT1 expression was interfered in pancreatic cancer cell. Methods: pSilence-hENT1 4.1-CMV neo plasmid down-regulated hENT1 specifically was transfected into pancreatic cancer cell (sw1990) and cells were cloned with G418. Cells were harvested after 15, 30 min, 1，2，and 4 h incubation with medium containing 5-FU(100 μg&#8226;ml -1).Then，two 100 μl cell suspensions in each cells were spliced，one for 5-FU detection and another for protein contents. The 5-FU contents in cells were detected by means of capillary zone electrophoresis. The cell number in 100 μl cell suspensions was defined with standard curve of protein content vs. cell number. Cell average volume was defined with hematology analyzer. Finally, the 5-FU content and concentration in a single cell were counted. Results: The hENT1 mRNA expression in pSilence-hENT1Si-SW1990 cells were down-regulated to 50% compared with controls. After 5-FU incubation (100 μg&#8226;ml -1), the concentration of 5-FU in sw1990 cells was 64.95±1.65 pg&#8226;nl -1 at 15min, 84.51± 2.30 pg&#8226;nl -1 at 120 min. Then, a concentration plateau was achieved. In pSilence-hENT1Si- SW1990 cells, in contrast, the concentration of 5-FU in cells was 46.25±2.50 pg&#8226;nl -1 at 15min. A similar concentration of 5-Fu in cells was acquired at 60 min. After that, the concentration of 5-FU in cells was still rising. The concentration of 5-FU in pSilence-hENT1Si- SW1990 cells at 120min that located at a curve plateau was 113.29±6.41 pg&#8226;nl -1, much higher than that in sw1990 cells (p <0.05). No difference of concentration at any point was found between sw1990 cells and pSilence-hENT1control-SW1990 cells (p<0.05). Conclusion：Down-regulating hENT1 expression can raise 5-FU concentration in pancreatic cancer SW1990 cells. Therefore, hENT1 on membrane might be the channel for 5-FU back-flow out of cell in sw1990.