Role of osteopontin in cancer: From pathogenesis to therapeutics (Review).

Osteopontin (OPN) is an extracellular matrix protein secreted by various types of cells, and serves multiple physiological roles such as modulating bone cell maturation, immune responses, tissue repair and regeneration. Aberrant OPN expression contributes to tumor genesis and development. This indicates that OPN serves a crucial role in tumor genesis and could serve as a potential target for tumor interventions. The present review firstly introduces the molecular structure, receptors and physiological functions of OPN. Subsequently, the present review elaborately addresses the pivotal role served by OPN, and its mechanism in tumor initiation and progression, metastasis, and drug resistance. Furthermore, the present review summarizes currently reported OPN‑based tumor intervention strategies. Lastly, the present review also provides perspectives on how to deepen the insights into the exact role of OPN in tumorigenesis, with the aim of aiding the development of novel strategies for tumor therapeutics. The present review broadens the knowledge regarding the pathophysiological role of OPN, so that novel OPN‑based cancer treatment strategies may be proposed.