Periostin: A matricellular protein with a multifaceted role in tumorigenesis (Review).

Extracellular matrix (ECM) proteins are key non‑cellular components of the tumor microenvironment and include structural and non‑structural proteins. POSTN belongs to a family of non‑structural matrix cell proteins first identified in bone and periodontal ligaments. POSTN exerts its multiple effects mainly through specific binding to other ECM proteins, growth factors and cytokines. Physiologically, POSTN is rarely expressed in adult tissues, except in the periosteum and some collagen‑rich connective tissues, such as periodontal ligaments and heart valves, but is highly expressed during inflammation, tissue repair, wound healing and malignant transformation. POSTN carries out an important role in tumor development. The present review summarizes the multiple roles of POSTN in tumorigenesis and development. First, the molecular structure of POSTN and its physiological and pathological expression, especially in known tumors is reviewed. Second, the manner in which POSTN affects tumor cells through relevant cancer hallmarks is discussed. Finally, the molecular mechanisms underlying the promotion of cancer by POSTN from the perspective of the TME is summarized.