RANKL-induced migration of MDA-MB-231 human breast cancer cells via Src and MAPK activation

Abstract

Abstract. Accumulating studies have shown that the receptor activator of nuclear factor-κB ligand (RANKL)/RANK pathway plays an important role in tumor metastasis. However, the involvement of the RANKL/RANK signal transduction pathway in breast cancer metastasis remains unclear. The present study, therefore, investigated the role of downstream molecules of RANKL/RANK signaling in breast cancer cells using Transwell chemotaxis assays. RANKL was shown to direct the migration of MDA-MB-231 breast cancer cells. Osteoprotegerin (OPG; soluble decoy receptor of RANKL) inhibited RANKL-induced migration. RANKL activated Src kinase in MDA-MB-231 cells, as shown by Western blotting, and pretreatment with a Src inhibitor abrogated RANKL-induced cell migration, in a similar manner to OPG. Short-hairpin RNA against RANK, delivered via a lentiviral vector, significantly abolished the expression of phosphorylated Src. Stimulation by RANKL induced the phosphorylation of mitogen-activated protein kinases (MAPKs) (ERK, p38, JNK), and specific inhibitors of MAPKs blocked RANKL-induced cell migration. Furthermore, the expression of phosphorylated MAPKs could be blocked by a Src inhibitor and by small interfering RNA against Src. These findings suggest that Src and MAPK pathways may be involved in RANKL-induced MDA-MB-231 breast cancer cell migration.

Poor prognosis of patients with triple-negative breast cancer can be stratified by RANK and RANKL dual expression

“…Common signaling pathways activated through RANK include nuclear factor jB (NFjB), Src, and MAPKs, which are critical regulators of cell fate, survival, local inflammation, and cellular invasion [11,29]. Thus, there has been much interest in targeting of this pathway as a potential therapeutic approach for invasive breast cancer.…”

“…Further, stromal RANKL can enhance pro-survival and proliferative signals of RANK-positive epithelial cells during alveologenesis [7,9,10]. Preclinical studies have suggested that RANK may enhance tumorigenic potential through the expansion of ''stem-like'' cell populations that aid cancer cell migration, invasion, and resistance to chemotherapy [5,[11][12][13][14]. Moreover, targeted gene ablation of RANK or treatment with RANK-Fc, a fusion protein that can neutralize RANK signaling, did not affect primary tumor growth but did significantly inhibit lung and bone metastasis in preclinical models [5,11,15].…”

“…Preclinical studies have suggested that RANK may enhance tumorigenic potential through the expansion of ''stem-like'' cell populations that aid cancer cell migration, invasion, and resistance to chemotherapy [5,[11][12][13][14]. Moreover, targeted gene ablation of RANK or treatment with RANK-Fc, a fusion protein that can neutralize RANK signaling, did not affect primary tumor growth but did significantly inhibit lung and bone metastasis in preclinical models [5,11,15]. Collectively, these reports suggest that activation of RANK-RANKL signaling is involved in tumor development and that targeted inhibition of this pathway may be a viable therapeutic strategy against metastatic breast cancers.…”

Structural and Biochemical Basis for Intracellular Kinase Inhibition by Src-specific Peptidic Macrocycles

“…MDA-MB-231 cells depend upon Src activity for migration, which is necessary for metastasis (Sanchez-Bailon et al, 2012; Sanchez-Bailon et al, 2015; Tang et al, 2011; Tsai et al, 2013). Treatment of cells with 20 μM MC25 decreased the rate of cell migration and the closure of an artificial wound.…”

“…Src kinase, the prototypical SFK, is overexpressed or constitutively activated in many solid tumors types (Summy and Gallick, 2003; Yeatman, 2004) and inhibition of Src decreases metastasis and tumor growth in both cellular and animal cancer models. Therefore, Src is considered a pharmacological target for cancer therapy (Gargalionis et al, 2014; Krishnan et al, 2012; Nagaraj et al, 2011; Tang et al, 2011; Tsai et al, 2013; van Oosterwijk et al, 2013; Zhang and Yu, 2012). However, selective pharmacologic inhibition of Src kinase is challenging, because the eight members of the Src kinase family are highly conserved, and few small-molecule kinase inhibitors can distinguish between them (Anastassiadis et al, 2011; Blake et al, 2000; Brandvold et al, 2015; Brandvold et al, 2012; Georghiou et al, 2012; Gushwa et al, 2012; Kwarcinski et al, 2012).…”