Role of Osteopontin in Tumor Microenvironment: A New Paradigm in Cancer Therapy

Cancer is a complex, multifactorial disease, emerged due to dysregulation of one or more cellular signaling cascades by somatic or germ line mutations. However, tumor progression vastly depends on context-dependent interaction between cancer cells and its surrounding microenvironment. Tumor microenvironment plays multifaceted role in tumor progression by providing not only a structural framework but also proliferative, metastatic, and angiogenic signals. It is well established that array of growth factors, cytokines, and chemokines acts at the interface of tumor and stromal cells. Osteopontin (OPN), a chemokine-like protein, is overexpressed in various tumor tissues and cell lines. It has immense potential to regulate various hallmarks of cancer. Presumably, targeting the communication between the tumor cells and surrounding microenvironment using specific antibodies, small molecule inhibitors, and chemotherapeutic agents by exploiting OPN as a central molecule are novel therapeutic strategies for management of cancer.