[Influence of IL-2 on proliferation of cultured human pituitary adenoma cells and its mechanism].

AIM: To investigate the effects of IL-2 on the proliferation, cell cycle, protein kinase C(PKC) and cAMP/cGMP of cultured human pituitary adenoma cells. METHODS: MTT colorimetry, (3)H-TdR and flow cytometry were used to detect the proliferation and radioimmunoassay was used to observe the effect of IL-2 on PKC activity and cAMP/cGMP levels of cultured human pituitary adenoma cells. RESULTS: (1) IL-2 (1 x 10(4), 1 x 10(5) and 5 x 10(5) U/L) stimulated the proliferation and DNA synthesis of cultured human pituitary adenoma cells in a dose-dependent manner. (2) IL-2 (1 x 10(4), 1 x 10(5) and 5 x 10(5) U/L) decreased the ratio of pituitary adenoma cells in G(1) phase and increased the ratio in S and G(2) phase markedly. (3) Compared with control, PMA, a PKC activator, increased the activity of membrane and total PKC in human pituitary adenoma cells. However, after treatment with IL-2 (1 x 10(5) U/L), a significant increase of the activity of cytoplasmic, membrane and total PKC in human pituitary adenoma cells was observed. (4) IL-2 (5 x 10(4), 1 x 10(5) U/L) decreased the amount of cAMP in the cytoplasm of human pituitary adenoma cells, but had no effect on that of cGMP. CONCLUSION: IL-2 can stimulate the proliferation of pituitary adenoma cells through PKC and cAMP/cGMP signaling pathways.

[Effect of tamoxifen on proliferation of cultured breast cancer and cervical carcinoma cell lines].

AIM: To investigate the effects of tamoxifen on proliferation of human breast cancer Bcap-37 cells and cervical carcinoma HeLa cells and to explore it's possible mechanism. METHODS: The techniques of cell culture, growth curves, flow cytometry and laser scanning confocal microscope were used. RESULTS: Tamoxifen (10(-6) mol/L) shifted the growth curve of Bcap-37 cells downward, and shifted the growth curve of HeLa cells upward. Tamoxifen (10(-8) - 10(-6) mol/L) inhibited the proliferation of Bcap-37 cells in a dose-dependent manner, but stimulated the proliferation of HeLa cells in a dose-dependent manner. Bcap-37 cells appeared apoptosis when treated with tamoxifen (10(-6) mol/L), and the same dose stimulated the proliferation of HeLa cells at GI/S phases. The apoptotic rate of Bcap-37 cells was 97.5%. It blocked G1 phase of HeLa cells from 55.5% to 32.8%, and increased the S phase from 29.0% to 49.4%. Tamoxifen (10(-6) mol/L) also increased the releasing of calcium in Bcap-37 and HeLa cells. CONCLUSION: Tamoxifen can significantly influence the proliferation of breast cancer and cervical carcinoma cells possibly by affecting cell cycle and stimulating the releasing of Ca2+ in the cells.

[Enhancement effect of IL-2 on the proliferation of cultured mammary carcinoma cell line Bcap-37].

AIM: To investigate the effects of IL-2 on the proliferation of human mammary carcinoma cell line Bcap-37 and explore its possible mechanism. METHODS: Enhancement effect of IL-2 on proliferation of cultured Bcap-37 cells, the IL-2 expression on the cells, the expressions of IL-2Ralpha, beta, gamma mRNAs in the cells, the effect of IL-2 on DNA content at various periods of cell cycle and on Ca(2+) concentration in the cells were detected or observed by MTT colorimetry, immunohistochemical staining, RT-PCR, flow cytometry and laser scanning confocal microscope, respectively. RESULTS: IL-2 of 1x10(5) to 1x10(6) U/L significantly stimulated the proliferation of cultured Bcap-37 cells. IL-2 was secreted and IL-2Ralpha, beta and gamma were expressed by cultured Bcap-37 cells. IL-2(1x10(5) U/L) increased ratio of Bcap-37 cells in G(2) and S phases and decreased the Ca(2+) release from Bcap-37 cells. CONCLUSION: IL-2 significantly enhance the proliferation of mammary carcinoma cell line Bcap-37. The enhancement effect of IL-2 on Bcap-37 cell proliferation is possibly related to the expression of IL-2R and decreased Ca(2+) concentration in the cells.