Maryam Moradi Binabaj - Department Of Clinical Biochemistry, Faculty Of Medicine, Mashhad University Of Medical Sciences, Mashhad, Iran
Farzad Rahmani - Department Of Clinical Biochemistry, Faculty Of Medicine, Mashhad University Of Medical Sciences, Mashhad, Iran
Seyed Mahdi Hasanian Mehr - Department Of Clinical Biochemistry, Faculty Of Medicine, Mashhad University Of Medical Sciences, Mashhad, Iran

Inorganic polyPhosphate (polyP) is a polymer of orthophosphate molecules which are linked byphosphoanhydride bonds. Polyp has been found in prokaryotes and eukaryotes with different chainlength. Negatively charged polyP is capable to form complexes with proteins, RNA, Ca2+,Mg2+ andnucleic acids. In mammalian cells, polyP is localized in different organs like brain, liver, heart andregions inside the cell including nuclei, mitochondria and plasma membrane. PolyP metabolism ismediated through polyP kinase and polyphosphatase which catalyze synthesis and degradation ofpolyP respectively. But in eukaryotes, polyP synthetizing enzyme is not identified yet. Recentstudies have been shown that polyP in mammalian cell contributes in proliferation andmineralization of stem cells amplifying nuclear cytokine-mediated proinflammatory signaling andmodulating Wnt/β-catenin signaling in primary human umbilical vein endothelial cells.Interestingly, the data presented in a recent study implicated that polyP prevents apoptosis viainducing ERK pathway. Similarly, the results of a recent study showed that polyP has an antiangiogenicand anti-metastatic effect on pulmonary metastasis by reducing metastatic lungcolonies, blocking of bFGF-induced angiogenesis and inhibition of angiogenesis via suppressing theactivation of ERK and p38 MAPK. Taken together, these results clearly suggest that polyP is a newkey modulator of cell proliferation and apoptosis which could regulate clinical and therapeuticoutcomes under (patho)physiological conditions. As a general summary, it can be concluded thatpolyP could be as an important molecule in diagnosis and treatment of disease includinginflammation and cancer. Recent studies provide little information about the importance of polyPand further investigation is needed to understand the exact mechanisms of interactions betweenpolyP and other pathways and role of this molecule in pathogenesis of disease. Furthercharacterization of these mechanisms may provide important clues about the characteristic,application and functions of polyP.