[Effects of insulin on proliferation and apoptosis of endometrial carcinoma cell]

To study the expression of insulin receptor (INSR) in endometrial cell line Ishikawa3-H-12, and the effects of insulin on proliferation, cell cycle distribution and apoptosis of Ishikawa3-H-12 cells.

Immunocytochemistry and RT-PCR methods were used to investigate the expression of INSR in Ishikawa3-H-12 cells. The effects of insulin at different concentrations and different time on proliferation, apoptosis and cell cycle distribution of endometrial carcinoma cells were observed by methyl thiazolyl tetrazolium (MTT) assay and fluorescence-activated cell sorting technique.

(1) We demonstrated the expression of INSR in Ishikawa3-H-12 cell line. (2) Incubation with insulin stimulated a dose- and time-dependent proliferation response in Ishikawa3-H-12 cells with the peak response occurring at 48 hours with 1 x 10(-4) mol/L insulin incubation [proliferative rate: (340.2 +/- 15.9)%, vs control (100%), P < 0.05]. (3) The percentage of Ishikawa3-H-12 cells at G(0)/G(1) phase decreased and percentage at S phase increased significantly with insulin treatment in a dose- and time-dependent manner with the peak response occurring at 72 hours with 1 x 10(-4) mol/L insulin incubation [G(0)/G(1) phase (27.7 +/- 2.5)%, S phase (55.2 +/- 1.4)%, vs control: (67.6 +/- 1.5)% and (15.7 +/- 1.0)%, P < 0.05], whereas that of G(2)/M phase did not show significant alteration. (4) The apoptosis rate of Ishikawa3-H-12 cells was decreased gradually with increasing concentration of insulin, while the alteration was time-independent. The peak response occurred with 1 x 10(-4) mol/L insulin incubation [apoptosis rate: (1.76 +/- 0.16)%, (1.70 +/- 0.15)%, (1.56 +/- 0.20)%, (1.31 +/- 0.24)% when incubated at 24, 48, 72 and 96 hours respectively, vs control, P < 0.05].

Insulin can promote the proliferation and inhibit the apoptosis of endometrial carcinoma cells.