Title:The Emerging Role of Regucalcin as a Tumor Suppressor: Facts and Views
Volume: 16
Issue: 7
Author(s): C. V. Vaz, S. Correia, H. J. Cardoso, M. I. Figueira, R. Marques, C. J. Maia and S. Socorro
Affiliation:
Keywords:
Regucalcin, cancer, tumor suppressor, SMP30, cell proliferation, apoptosis, metabolism, oxidative
stress.
Abstract: Regucalcin (RGN) is a multifunctional protein that was first
described as a calcium (Ca2+)-binding protein playing a relevant role in the
maintenance of intracellular Ca2+ concentration. However, due to its
downregulated expression with aging, RGN is also known as senescence
marker protein-30. The RGN protein is an X-chromosome gene product,
whose transcription is regulated by a myriad of hormonal and non-hormonal
factors. Besides the well-known role in Ca2+ homeostasis, RGN has also
been linked to the control of several intracellular signaling pathways, and
basic biological processes, such as oxidative stress, cell proliferation,
apoptosis, and metabolism. RGN has been shown to have antioxidant
properties by its activity reducing the production of reactive oxygen species and increasing
the antioxidant defenses. The role of RGN suppressing cell proliferation is associated with
the regulation of expression of oncogenes and tumor suppressor genes. It results clear that
all the existent knowledge implicates RGN in the control of the main biological processes
actually recognized as the hallmarks of cancer. Moreover, it has been shown that tumor
onset and progression are underpinned by the loss of RGN expression, whereas RGN
overexpression showed to have a protective role against the development of chemicallyinduced
tumors. This review describes the mechanisms that control the tissue expression of
RGN and discusses the experimental evidence that indicate RGN as a new tumor
suppressor protein.
