Evaluation of human breast adenocarcinoma [MCF-7] cells proliferation in co-culture with human adipocytes in three dimensional collagen gel matrix: norepinephrine as a lipolytic factor

Norepinephrine plays a trophic role in the control of cell replication and differentiation in target cells that express adrenergic receptors. In this study, we have tested the influence of infraphysiological, physiological and supraphysiological concentrations [0.0001 nM, 1 nM, 10000 nM] of human norepinephrine on the proliferation of breast cancer cells [human breast adenocarcinoma [MCF-7]] in co-culture with human adipocytes in three-dimensional collagen gel matrix culture. Cell proliferation and lipolysis rate were measured by 3-[4, 5-dimethylthiazolyl]-2, 5-diphenyl-tetrazolium bromide [MTT] and Oil red O colorimetric assay in second, 7[th] and 14[th] days of culture experiments. Our results showed a direct correlation between lipolysis rate of adipocytes and proliferation rate of MCF-7 cells. Both physiological and supraphysiological concentrations of human norepinephrine significantly [P<0.05] increased the proliferation of MCF-7 cells synchronously with progress of adipocyte lipolysis. The proliferations of MCF-7 cells were significantly decreased after conversion of adipocytes to fibroblast-like cells by supraphysiological concentration of norepinephrine. There was no statistical difference in lipolysis of adipocytes and proliferation of MCF-7 cells in response to infraphysiological concentration of norepinephrine. These findings indicated that norepinephrine stimulated the proliferation of MCF-7 cells in co-culture with human adipocytes as a lipolytic factor and that norepinephrine effect was suppressed by conversion of adipocytes to fibroblast-like cells, suggesting adipocytes as another target for prevention and therapy of breast cancer

effects of cumulus cells on in vitro maturation of mouse germinal vesicle stage oocytes

In vitro maturation [IVM] of oocytes is a promising technique to reduce the costs and avert the side-effects of gonadotropin stimulation for in vitro fertilization [IVF]. The pregnancy rates from oocytes matured in vitro are much lower than those of in vivo stimulation cycles, indicating that optimization of IVM remains a challenge. In this study, we investigated the effect of cumulus cells on maturation and fertilization rate of immature oocytes [Germinal vesicle]. Germinal vesicle [GV] oocytes were recovered from 6-8 weeks old Balb C female mice 48hr after injection of 10 IU pregnant mare serum gonadotropin [PMSG]. Collected oocytes were divided into two groups. Group A: GV oocytes without cumulus [denuded oocyte]. Group B: GV oocytes with cumulus cells [cumulus-oocyte complex]. The oocytes in both groups were cultured in TCM-199 medium in a humidified atmosphere of 5% CO2 in air at 37?C. The maturation, fertilization and developmental rates were recorded after 24hr. Maturation, fertilization and developmental rates in denuded oocytes [DO] were 65.1%, 68.02%, 78.63% respectively, and in cumulus-oocyte complex [COC] were 78.20%, 85.57% and 85.05%, respectively. The maturation, fertilization and developmental rates of COC were significantly higher than those of DO [p<0.05]. The results show that cumulus cells have beneficial effects on maturation, fertilization and cleavage rates of mice oocytes