Reactions Of Microglia And Correlation Cytokines To Breast Cancer

Objective: To explore the possible mechanism of microglia in the brain metastasis, anddiscover the potential value of microglia actived by IFN-gamma in ant-tumor by investigatingthe effect of conditioned medium (CM) from actived microglia N9cells cultured in vitro onthe proliferation of breast cancer MCF-7cells,.Methods:1. The N9cells and MCF-7cells were co-cultured for12h, then themorphological changes of the two cells were observed by an inverted optical microscope.2. The N9cells were stimulated by lipopolysaccharide (LPS), co-culture with MCF-7cells and the conditioned medium (MCF-7-CM) to produce N9-CM. The tumor necrosisfactor-α (TNF-α) and interleukin-17(IL-17) in N9-CM were examined by ELISA, and theproduction of nitric oxide was detected by Griess system. MCF-7cells were cultured withdifferent concentrations (10%,25%,50%,75%and100%) of N9-CM. The survival rate ofMCF-7cells was detected by MTT method.3. The N9cells were stimulated by interferon-γ(IFN-γ). MCF-7cells were cultured withdifferent concentrations (10%,25%,50%,75%and100%) of N9-CM. The survival rate ofMCF-7cells was detected by MTT method.Results:1. N9cells were activated by co-culture with MCF-7cells, and turned circularor elliptic. MCF-7cells were surrounded by N9cells.2. The secretions of NO, IL-17and TNF-α were induced by LPS, MCF-7cells andMCF-7-CM.3. N9-CM of N9cells inhibited the proliferation of MCF-7cells in24h, and promoted itduring36to48h. In group MCF-7-CM, the proliferative rates of MCF-7cells treated withN9-CM at concentrations of50%-100%were decreased in a time-and concentration-dependent manner. In group MCF-7cells and LPS, N9cells mainly inhibited the proliferationof MCF-7cells.4. In group IFN-γ, the proliferative rates of MCF-7cells treated with N9-CM wereincreased in a concentration-dependent manner; In group MCF-7+IFN-γ, were decreased;and in group LPS+IFN-γ,were mainly decreased.Conclusion: Microglia can be activated by breast cancer cells and decrease theproliferation of the breast cancer cells. This effect is positively related to the levels of NO,IL-17and TNF-α secreted by microglia and the treatment time of these cytokines. Thisexperiment did not found the special value of microglia actived by IFN-gamma in ant-tumor.