The association between periostin and tumor microenvironment: a promising cancer prognostic biomarker and therapeutic target to combat tumor progression and chemoresistance.

Over the past few decades, cancer research has increasingly focused on tumor microenvironment (TME). The TME contains diverse cellular components and secreted factors, including leukocytes, endothelial cells, cancer-associated fibroblasts, and other non-cancerous cells and extracellular matrix proteins. The interactions between tumor cells and microenvironment elements are complex and unpredictable. Nonetheless, these relationships govern and control several cancer traits, including immune response, metastasis, differentiation status, cell proliferation, and resistance to cell death. In this line, Matricellular proteins, including periostin (POSTN), are increasingly recognized for their regulatory roles in the TME and cancer progression. Periostin is involved in tumor biology through matrix remodeling, invasion, and proliferation. In this review, we focused on the role of periostin as a biomarker for cancer growth and treatment resistance and a potential prognostic and therapeutic factor in cancer patients. In addition, we will discuss the periostin's dual role as both a promoter and inhibitor of tumor growth, depending on its concentration and cellular context. Key findings indicate that low periostin levels may suppress cancer progression by preventing epithelial-to-mesenchymal transition (EMT). In contrast, high levels can enhance migration and metastasis through the activation of integrin signaling pathways. Furthermore, we will discuss the implications of targeting periostin in therapeutic strategies, particularly in light of its complex functions within the TME.