The Study On The Effect And Mechanism Of Different Progestogens On Breast Cancer Cell Proliferation

Objective To study whether different progestogens have effects on breast cancer cell lines proliferation,The possible mechanism of the role of progesterone in breast cancer,and provide experimental basis for hormone replacement therapy reasonable selection of hormone species and regimen.Methods The two breast cancer cell lines MCF-7 cell line(ER+, PR+) and MDA-MB-231 cell line(ER-, PR-)were cultured in vitro.Using different concentrations(10-8M, 10-7M,10-6M,10-5M)of different progestogens(natural progesterone,medroxyprogesterone, levonorgestrel, norethisterone, drospirenone, dydrogesterone, megestrol acetate, nomegestrol, desogestrel, cyproterone acetate)and different concentrations(10-14 M, 10-12 M,10-10 M,10-8M,10-6M)of estrogen(17β-E2) stimulate MCF-7 and MDA-MB-23-1 breast cancer cells alone, continuous joint irritation and sequential.Using estrogen receptor antagonist fulvestrant(FUL) and progesterone receptor antagonist mifepristo ne(RU486)alone or incombinate estrogen and progesterone to stimulate cell,Applicating MTT method to detect the various stimulation experiments of two breast cancer cell proliferation,DMEM culture group is the negative control group. Input each experimental results to Spss19.0 statistical package for statistical analysis,to understand different progesterone and estrogen, different hormone stimulus, and application of antagonist effect on two kinds of cells.Results 1.Different progestogens stimulate MCF-7 cell alone show that drospirenone(DRSP) and desogestrel(DSG) at 10-7M concentration growth rate was 117.71% ± 1.55% and 112.24% ± 4.32%, respectively, at 10-7M concentration growth rate was 120.77% ± 2.71% and 119.35 % ± 2.91%,compared with the negative control group were statistically significant differences(P <0.01).Norethindrone(NET) growth rate was 103.70% ± 3.08% at 10-7M time, no significant difference,10-6M concentration growth rate is 110.00% ± 2.49%, with a statistically significant difference(P <0.01). The DRSP, NET, DSG at 10-5M concentration have no significant difference compared to the negative control group.Medroxyprogesterone acetate(MPA), natural progesterone(P4), Nomegestrol(NOM), cyproterone acetate(CYP), megestrol acetate(MA), dydrogesterone(DYD) and There was no statistically significant differencecompared to levonorgestrel(LNG) for each concentration on cell proliferation rate have no significant difference compared to the negative control group.2.The effect of 17β-E2 on MCF-7 cells alone stimulation experiments show that 10-14 M, 10-12 M concentration of estrogen on cells have no proliferation, 10-10 M concentration growth rate was 111.97% ± 5.41%,10-6M concentration growth rate was 108.20%±4.04%,compared with negative control group were statistically significant(P<0.05),10-8M concentration proliferation rate was 118.57% ± 6.01%, with a statistically significant difference(P <0.01).3.Low concentrations of estrogen and different progestogens sequential program to stimulate different proliferation rate of MCF-7 cells were lower than joint program, but the difference was not statistically significant.4.Receptor blocker experimental results show that estrogen and progestogen stimulation with estrogen receptor antagonist group and the addition of two receptor antagonist group can block estrogen and progesterone on proliferation of MCF-7 cells,Join progesterone receptor antagonist group has no proliferation blocking effect. 5.Whether estrogen and progesterone stimulate alone or in combination and sequential stimulate MDA-MB-231 cells,compared with the negative control group, the proliferation rate was not statistically different.Conclusion 1.Proliferative responsed the concentration of 17β-E2 below 10-10 M has no obvious effects on cell proliferation,cell proliferation was significantly when the concentration was higher than 10-10 M,cell proliferation effect was higest at concentration of 10-8M,so choose the minimum effective concentration of estrogen is relatively safe to mammary gland when using hormone replacement therapy.2.Different progestogens have different effect on breast cancer cell,there was obvious proliferation effect when DRSP,DSGand NET stimulate MCF-7cell,P4,NOM,MPA,CYP,MA,LNG,DYD did not show proliferation effect.When adding progesterone in application of HRT,the type and dose of progestin should be carefully chosen,It is better to use non-proliferative effect of progestin such as P4, NOM, etc, to avoid using NET, DRSP, DSG.3.The blocking effect of estrogen antagonist fulvestrant for estrogen and progesterone cause MCF-7 cell proliferation and MDA-MB-231 cell line no reactivity of hormonestimulation show that progesterone effect on breast cell proliferation may be related to the ER,but the mechanism still needs further study.4.Estrogen and progesterone sequential program is slightly lower than continuous joint programs on MCF-7 breast cancer cells proliferation suggest that sequential Whether sequential program is superior to the joint program is yet to be further research.5.In this experiment,under the ultra-high concentrations of 17β-E2,DRSP,DSG stimulation, the growth of breast cancer cell weakened,whether this phenomenon is related to the corresponding receptor depletion needs further study.