Chemotactic and proangiogenic role of calcium sensing receptor is linked to secretion of multiple cytokines and growth factors in breast cancer MDA-MB-231 cells

Abstract

Breast cancer metastasis to the bone, potentially facilitated by chemotactic and angiogenic cytokines, contributes to a dramatic osteolytic effect associated with this invasive behavior. Based on the intrinsic ability of calcium sensing receptor (CaSR) to control hormonal secretion and considering its expression in the breast, we hypothesized that CaSR plays a chemotactic and proangiogenic role in highly invasive MDA-MB-231 breast cancer cells by promoting secretion of multiple cytokines. In this study, we show that MDA-MB-231 cells stimulated with R-568 calcimimetic and extracellular calcium secreted multiple cytokines and growth factors that induced endothelial cell migration and in vitro angiogenesis. These effects were dependent on the activity of CaSR as demonstrated by the inhibitory effect of either anti-CaSR blocking monoclonal antibodies or calcilytic NPS-2143. Moreover, CaSR knockdown prevented the proangiogenic effect of CaSR agonists. Importantly, CaSR promoted secretion of pleiotropic molecules like GM-CSF, EGF, MDC/CCL22, FGF-4 and IGFBP2, all known to be chemotactic mediators with putative angiogenic factor properties. In contrast, constitutive secretion of IL-6 and β-NGF was attenuated by CaSR. In the case of normal mammary cells, secretion of IL-6 was stimulated by CaSR, whereas a constitutive secretion of RANTES, Angiogenin and Oncostatin M was attenuated by this receptor. Taken together, our results indicate that an altered secretion of chemotactic and proangiogenic cytokines in breast cancer cells is modulated by CaSR, which can be considered a potential target in the therapy of metastatic breast cancer.

Calcium-Sensing Receptor Tumor Expression and Lethal Prostate Cancer Progression

“…In a smaller study from Li et al (24), on a TMA of 148 primary breast tumors, protein expression of CaSR was reported to be down-regulated in neoplastic tissue compared with normal-appearing tissue, and lower CaSR expression was significantly associated with an increased risk of lethal breast cancer progression. The findings by Li et al contrast with our own findings and with prior experimental evidence that suggest CaSR signaling promotes metastatic growth of breast cancer to bone (1,22,25). However, in the context of colorectal cancer and parathyroid tumors, higher CaSR expression has been observed to be protective (26).…”

“…These effects were not observed in the epithelial-derived LNCaP prostate tumor cells (4). Similarly, in bone metastasizing renal cell carcinoma and breast cancer cell lines, extracellular calcium treatment promoted the up-regulation of angiogenic growth factors (22) and the PI3K/AKT pathway and down-regulated PTEN (22,23). Yano et al (3) reported CaSR activation in PC-3 prostate tumor cells by extracellular calcium induced production of the PTH-related protein, which may in turn promote bone resorption and further calcium release, potentially creating a cycle that is favorable for inducing bony metastases (21).…”

“…Moreover, as mentioned above, experimental research suggests that CaSR signaling promotes PI3K/ AKT/mTOR signaling (22,23), which is negatively regulated by PTEN (34,35). We therefore evaluated the association between CaSR and PTEN loss and tested PTEN tumor status as a potential effect modifier of CaSR on lethal prostate cancer.…”

Chemical and physical properties of carbonated hydroxyapatite affect breast cancer cell behavior

“…Dissolution of HA coatings can enhance calcium concentrations in the culture medium [6], which, for example, may activate calcium sensing receptors regulating cytokine and growth factor production [59]. Coatings with elevated carbonate content released more calcium, consistent with the known increase in solubility of carbonated apatite as compared to HA (Suppl.…”

The Angiogenic Secretome in VEGF overexpressing Breast Cancer Xenografts

“…It has demonstrated pro-angiogenic properties in rats via its action on VEGF and Tie-249. GM-CSF has been detected in MDA-MB-231 conditioned media50 but is apparently absent from triple negative tumor samples in humans51. On the other hand, GM-CSF is considered an important mediator of angiogenesis and invasion in a wide variety of solid tumors52.…”