Genistein Stimulates MCF-7 Breast Cancer Cell Growth by Inducing Acid Ceramidase (ASAH1) Gene Expression

Abstract

Sphingolipid metabolites, such as ceramide (Cer), sphingosine (SPH), and sphingosine 1-phosphate (S1P), contribute to multiple aspects of carcinogenesis including cell proliferation, migration, angiogenesis, and tumor resistance. The cellular balance between Cer and S1P levels, for example, is an important determinant of cell fate, with the former inducing apoptosis and the later mitogenesis. Acid ceramidase (ASAH1) plays a pivotal role in regulating the intracellular concentration of these two metabolites by hydrolyzing Cer into SPH, which is rapidly phosphorylated to form S1P. Genistein is a phytoestrogen isoflavone that exerts agonist and antagonist effects on the proliferation of estrogen-dependent MCF-7 cells in a dose-dependent manner, primarily as a ligand for estrogen receptors. Genistein can also activate signaling through GPR30, a G-protein-coupled cell surface receptor. Based on the relationship between bioactive sphingolipids and tumorigenesis, we sought to determine the effect of genistein on ASAH1 transcription in MCF-7 breast cancer cells. We show herein that nanomolar concentrations of genistein induce ASAH1 transcription through a GPR30-dependent, pertussis toxin-sensitive pathway that requires the activation of c-Src and extracellular signal regulated kinase 1/2 (ERK1/2). Activation of this pathway promotes histone acetylation and recruitment of phospho-estrogen receptor ␣ and specificity protein-1 to the ASAH1 promoter, ultimately culminating in increased ceramidase activity. Finally, we show that genistein stimulates cyclin B2 expression and cell proliferation in an ASAH1-dependent manner. Collectively, these data identify a mechanism through which genistein promotes sphingolipid metabolism and support a role for ASAH1 in breast cancer cell growth.

Role of sphingolipids in oestrogen signalling in breast cancer cells: an update

“…Genistein induces ASAH1 transcription through a GPR30-dependent, pertussis toxin-sensitive pathway that requires the activation of c-Src and ERK1/2. Activation of this pathway promotes histone acetylation and recruitment of phospho-ERa and specificity protein-1 to the ASAH1 promoter, ultimately culminating in increased ceramidase activity (Lucki & Sewer 2011). The mechanism of prolonged activation of SphK1 by E 2 is less clear.…”

“…Interestingly, in these cells a phytoestrogen genistein, which can also activate signalling through GPR30 (Thomas & Dong 2006), has been shown to regulate sphingolipid metabolism by a different mechanism. Genistein stimulated transcription of acid ceramidase (ASAH1) in MCF-7 cells (Lucki & Sewer 2011). Acid ceramidase degrades ceramide and, thus, provides a supply of sphingosine which, in turn, can be phosphorylated by SphK1 and transformed into S1P (Fig.…”

Combination of low-concentration of novel phytoestrogen (8,9)-furanyl-pterocarpan-3-ol from Pachyrhizus erosus attenuated tamoxifen-associated growth inhibition on breast cancer T47D cells

“…The biphasic effect FPC are consistent with previous study in which the other phytoestrogens, genistein and its synthetic analogs could inhibit the growth of cancer cells in vitro, including hormone-dependent breast cancer or not with IC 50 in the range between 10-50 μmol/L (more than 10 μmol/ L) [25,26] . While at concentrations lower than 10 μmol/L or low to moderate dose (6.25 and 12.50 g/kg body weight), the growth of MCF-7 (estrogen receptor-positive cell line) or human breast cancer cells implanted into athymic mice were stimulated by genistein or soy isoflavone extracts [27][28][29] . The biphasic effect of phytoestrogens genistein or FPC is most likely related to estrogen-like effects at low concentrations, while at high concentrations, these phytoestrogens act not only on estrogen receptors, as for example is the inhibition of one or more cellular signaling molecules that control cell growth and cell apoptosis.…”

“…Results of linear regression calculations indicated the IC 50 value of 27.48 nmol/ L ( Figure 1A). In contrast, FPC have estrogenic effects which promote cell proliferation with low concentrations lower than 1 μmol/L ( Figure 1B).…”

Phytoestrogen Suppresses Efflux of the Diagnostic Marker Protoporphyrin IX in Lung Carcinoma

“…S1C). As estrogen and estrogenic compounds often stimulate the proliferation of cancer cells (26)(27)(28), the effect of genistein on the cell growth of A549 cells was examined. As shown in Fig.…”