Studies On Inducing Apoptosis Effects And Mechanism Of CIK Cells For MGC-803 Gastric Cancer Cell Lines

Objective: To study the anti-proliferation and inducing apoptosis effects ofcytokine-induced killer cells-ClK cells for MGC-803 gastric cancer cell lines and to probe its underlying mechanism.Methods: To detect the anti-proliferation and the cytotoxicity of CIK cells onMGC-803 gastric cancer line by MTT assay . The morphological changes of the apoptosis cel1 were observed by invert microscope, HE stain, scanning and transmission electron microscope. Inducing apoptos is of CIK cells on MGC-803 gastric cancer cell line was evaluated by TUNEL methods;The positive expression of p53, p16, C-myc ,Bcl~2 and bax were determined by immunocytochemistry (ICC). The expression changes of relating-apoptosis gene proteins were deeply studied;The antitumor activity of the CIK were evaluated by mice experiment In vivo.Results:(l)MTT assay showed that the inhibitive rate inhanced obviously with theaddition of Effect/Target rate and extension of time .There are different significantly between different E/T rates at the same time (P<0.01). There are di fferent signi ficantly at different time and the same E/T rate (P<0. 01); (2) Invert microscope observed that CIK cells removed to the target cells and revolred round cancer cells and appeared typical change of rose circulatity. Granule substance appeared in tumor cells cytoplasm. Some CIK cells removed into the tumor cells cytoplasm or nucleolus. Only granule shape patch were restained in some tumor cells .Gastric cancer cells lived well in control group; (3)HE stain showed that the observation of CIK experiment group was the same with in invert microscope; (4) Scanning electron microscope observed that effect cells and target cells contacted each other and holes can be seen on the surface of target cells aftereffect cells and target cells cultivated five hours. Many target cells died by apoptosis and there are many circular apoptotic boby of various diameter and holes on the surface of target cells after fourteen hours and target cells were badly in juried and cracked after twenty-four hours; (5) Transmission electron microscope observed that chromatin condensed and nucleolus disintegrated in many target cells and vacuoles were found at cytoplasm and apoptotic boby formed after effect cells and target cells cultivated together five and fourteen hours. Many targets cells died by apoptosis and necrosis after effect cells and target cells cultivated together twenty-four hours; (6)TUNEL showed that the cells of control group were not to be stained or be stained average 1 ight blue and the cells of experiment group became small and mucleolus were dyed deeply blue. The apoptosis rate of CIK experiment group increased in 5-14 hours and declined in 14-24 hours. The apoptotis rate of CIK experiment groups have different significantly compared with control (P<0. 01); (7) Immunocytochemistry showed that expression of p53 p16 Omyc, Bcl-2 protein in CIK experiment group inclined and Bax protein increased when time was continued and there were different significantly compared with control (P<0. 01); (8)The results in vivo showed that CTK cells had a stronger suppressive effect on tumor growth in mice bearing S180 sarcoma compared with control (P<0. 01). The inhibitory rate of anti-tumor was 65. 24%. Compared with controJ pathology of experiment group showed that there were large area necrocytosis and a lot of lymphocyte et al inflammation cells and few veins.Conclusions : 1. There are anti-prol i foration and inducing apoptosis effects aboutCIK cells against MGC-803 gastric cancer cells.2. CtK cells induce apoptosis of MGC-803 gastric cancer cell line in early phase and induce necrocytosis in late phase. One of the mechanisms can inhance Bax proteins expression and decline p53, Bcl-2 and C-myc proteins expression of tumor cells.3. CIK cells have significantly anti-tumor effect on mice bearing S180 sarcoma in vivo. The inhibition is probably realized by lymphocyte infiltration and inhibiting veins.4. CIK cells are highly efficient cytolytic effector cells which have a stronger...