Quantitative phosphoproteomics reveals genistein as a modulator of cell cycle and DNA damage response pathways in triple-negative breast cancer cells

Abstract

Around one sixth of breast cancer cases are classified as triple-negative breast cancer (TNBC), named after the absence of the expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2); however, patients with TNBC suffer from poor clinical outcome and shortage of targeted therapy. Genistein, an estrogenic soy isoflavone, shows anticancer effects in TNBC cells such as inducing G2/M cell cycle arrest and apoptosis. However, the underlying mechanism of its anticancer effects is poorly understood and its elucidation can help the development of novel therapeutic strategies for TNBC. In this study, by combining isobaric tag-based TMT labeling with titanium dioxide-based phosphopeptide enrichment, we quantitated 5,445 phosphorylation sites on 2,008 phosphoproteins in the TNBC cell line MDA-MB-231, upon genistein treatment. Our analysis revealed 332 genistein-regulated phosphorylation sites on 226 proteins. Our data show that genistein can regulate several biological processes during the cell cycle, including DNA replication, cohesin complex cleavage, and kinetochore formation. Furthermore, genistein can also activate DNA damage response, including activation of ATR and BRCA1 complex. Overall, our study presents evidence at a phosphoproteomic level that genistein is able to inhibit TNBC cell growth by regulating the cell cycle and DNA damage response in a more complex manner. Our findings help elucidate the mechanisms through which genistein exerts its anticancer effects in TNBC cells.

Flavonoids, bioactive components of propolis, exhibit cytotoxic activity and induce cell cycle arrest and apoptosis in human breast cancer cells MDA-MB-231 and MCF-7 – a comparative study

“…Fang et al (95) suggested that GEN induced activation of ATR signaling in MDA-MB-231 cells. Interestingly, GEN activated the BRCA1-A and -B complexes via the ATR signaling pathway.…”

Cytotoxic Effect and Mechanisms from Some Plant-Derived Compounds in Breast Cancer

“…It has a molecular structure of C 15 H 10 O 5 and a molecular mass of 270.24 g/mol [18]. This agent has an antineoplastic effect in BrC [47]. GEN inhibits the growth of MDA-MB-231 cells by altering the phosphorylation of proteins included in cell cycle regulation and DNA damage response predominantly, and GEN induced apoptosis via the upregulation of Bax and p21WAF1 proteins in MDA-MB-231 cells and downregulating the expression of caspase-3 [5,47].…”

“…This agent has an antineoplastic effect in BrC [47]. GEN inhibits the growth of MDA-MB-231 cells by altering the phosphorylation of proteins included in cell cycle regulation and DNA damage response predominantly, and GEN induced apoptosis via the upregulation of Bax and p21WAF1 proteins in MDA-MB-231 cells and downregulating the expression of caspase-3 [5,47]. In a recent study, GEN increases cell cycle arrest in G2/M phase in MDA-MB-231/ERβ1 cells, even though there is a high dose of GEN-arrested cells in G0/G1, just like in the MCF-7 cells.…”

Phytoestrogens: The current state of research emphasizing breast pathophysiology

“…There is in vitro evidence suggesting the possibility of using phytoestrogens as effective therapeutics against TNBC. These studies range from chemoprotective effects to modulation of key cell survival pathways such as cell cycle, cohesion complex cleavage kinetochore formation, NFκβ, and Ras/MAPK/AP (Fang, Zhang, Wang, et al, ; Hedelin et al, ; Li et al, ; Pan et al, ). In addition, gene expression profiling studies using microarrays have been reported in various breast cancer subtypes including TNBC.…”