@article {18508,
	title = { Effect of extracellular calcium on regucalcin expression and cell viability in neoplastic and non-neoplastic human prostate cells},
	journal = {Biochimica et Biophysica Acta (BBA) - Molecular Cell Research},
	volume = {1853},
	year = {2015},
	month = {2015-10-01 00:00:00},
	pages = {2621{\textendash}2628},
	publisher = {Elsevier},
	abstract = {<p>Extracellular calcium (Ca<sup>2\&nbsp;+</sup><sub>o</sub>) and its receptor, the Ca<sup>2\&nbsp;+</sup>-sensing receptor (CaSR), play an important role in prostate physiology, and it has been shown that the deregulation of Ca<sup>2\&nbsp;+</sup> homeostasis and the overexpression of CaSR are involved in prostate cancer (PCa). Regucalcin (RGN), a Ca<sup>2\&nbsp;+</sup>-binding protein that plays a relevant role in intracellular Ca<sup>2\&nbsp;+</sup> homeostasis, was identified as an under-expressed protein in human PCa. Moreover, RGN was associated with suppression of cell proliferation, suggesting that the loss of RGN may favor development and progression of PCa. This work aims to unveil the role of Ca<sup>2\&nbsp;+</sup><sub>o</sub> on RGN expression and viability of non-neoplastic (PNT1A) and neoplastic (LNCaP) prostate cell lines. It was demonstrated that Ca<sup>2\&nbsp;+</sup><sub>o</sub> up-regulates RGN expression in both cell lines, but important differences were found between cells for dose- and time-responses to Ca<sup>2\&nbsp;+</sup><sub>o</sub> treatment. It was also shown that high [Ca<sup>2\&nbsp;+</sup>]<sub>o</sub> triggers different effects on cell proliferation of neoplastic and non-neoplastic PCa cells, which seems to be related with RGN expression levels. This suggests the involvement of RGN in the regulation of cell proliferation in response to Ca<sup>2\&nbsp;+</sup><sub>o</sub> treatment. Also, the effect of Ca<sup>2\&nbsp;+</sup><sub>o</sub> on CaSR expression seems to be dependent of RGN expression, which is strengthened by the fact that RGN-knockdown in PNT1A cells increases the CaSR expression, whereas transgenic rats overexpressing RGN exhibit low levels of CaSR. Overall, our results highlighted the importance of RGN as a regulatory protein in Ca<sup>2\&nbsp;+</sup>-dependent signaling pathways and its deregulation of RGN expression by Ca<sup>2\&nbsp;+</sup><sub>o</sub> may contribute for onset and progression of PCa.</p>},
	keywords = {prostate cancer, regucalcin},
	doi = {10.1016/j.bbamcr.2015.07.006},
	url = {http://www.sciencedirect.com/science/article/pii/S0167488915002426},
	author = {Vaz, C. V. and Rodrigues, D. B. and Socorro, S. and Maia, C. J.}
}
