Effects Of The Proliferation And Apoptosis On Human Pancreatic Cancer SW-1990 Cells By BCH Combined With 5-Flourouracil

Background Pancreatic cancer has the characteristics of early infiltration and metastasis,with an overall 5-year survival rate of lower than 3 percent.Most of the cases can not get radical excision after the final diagnosis for the locally advanced stage .Although chemotherapy has already been the principal means In the locally advanced desease, the curative effects are still getting from bad to worse at present, because of tumor cells' drug resistance. Therefore,to seek new effective therapeutic means,basic researchers and clinicians should work together. 5-Flourouracil(5-Fu)is a most commonly used chemotherapeutic in enteron tumors,and it has to meet with the same difficulty. In recent years,many studies have suggested thymidylate synthase(TS) is the key reason to drug resistance of 5-Fu. 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic accid(BCH) has been discovered as an specific inhibitor of system L amino acid transporters(LAT),LAT1 is a neutral amino acid transport system and is a major route for the transport of large neutral amino acids through the plasma membrane. LAT1 has been associated with tumor growth and been proved that highly expressing in the hyperplastic tissue,established cancer cell lines and primary human neoplasms. LAT1 has scarcely been detected in the normal tissues of the grown-up,except cerebrum,orchis,optomeninx and placenta. Many aspects of life science have been involved in the research of LAT1,including diagnosis, therapeutics, metachoresis and prognosis of neoplasma. We have examined the effects and the mechanisms of the proliferation and apoptosis on human pancreatic cancer SW-1990 Cells affected by BCH combined with 5-Fu in order to kown whether the two drugs have the synergism.Purpose To detect the effects of the proliferation and apoptosis on human pancreatic cancer SW-1990 Cells affected by BCH combined with 5-Fu. Investigate the probable mechanisms of suppresses and apoptosis.Methods Pancreatic cancer cell lines SW-1990 was cultured in vitro .Through MTT assay ,screening the most appropriate drug concentration of 5-Fu and BCH to suppress the cellur proliferation; Western blot was used to check out the change of TS and LAT1 in tumor cells after incubated with 5-Fu. Detected the influence of [3H]L-phenylalanine transport by BCH in different concentration. Flow cytometry shew the apoptosis rate change of cells incubated with 5-Fu or BCH respectively and together; again Western blot was used to check out the change of TS and LAT1 in tumor cells after incubated with BCH alone and with 5-Fu.Results MTT assay shows: the proliferation inhibition of SW-1990 Cells increased gradually by 5-Fu under the range of 40mg/L ,given that the proliferation inhibition changed very little as drug concentration more increased;while BCH inhibited the proliferation of cancer cells in a dose-dependent manner and time-dependent manner. The expression of TS soared as the time went on if tumer cells incubated with 5-Fu by Western blot. As to LAT1, it didn,t change much.The function of cells transport [3H]L- phenylalanine was confined when BCH concentration beyound 0.3mmol/L ,and when drug concentration beyound 30 mmol/L,the transporting totally suppressed. Flow cytomery indicated the apoptotic rate of control group was(1.94±0.50)%,compared with 5-Fu group of (20.48±1.88)%,BCH group of (13.36±1.79)%,combinative group of (50.48±1.82)%, all the cells were treated with certain drugs except the control group after 48h.Again by Western blot, the celles,expression of TS decreased when the cells incubated with either BCH or BCH conbined 5-Fu.Conclusion The results suggest that decreased the expression of LAT1 and TS by BCH are the two ways lead to the proliferation inhibition of human pancreatic cancer SW1990 cells and leads to apoptotic cancer cell death .Combined 5-Fu with BCH encreased the cytotoxicity to human pancreatic cancer SW1990 cells of 5-Fu .