Osteopontin Expression in Thyroid Cancer: Deciphering EMT-Related Molecular Mechanisms

Abstract

Thyroid cancer is the most common tumor arising from the endocrine system and generally presents good prognosis. However, its aggressive subtypes are related to therapeutic resistance and early metastasis. Epithelial–mesenchymal transition (EMT) and its reverse process, the mesenchymal–epithelial transition (MET), are key events mediating cancer progression, including in thyroid cancer. The matricellular protein osteopontin (OPN) has been reported as a master regulator of EMT in many tumor types. Although high OPN expression has been described and associated with important aspects of thyroid cancer progression, there is no clear evidence regarding OPN as a regulator of EMT in thyroid cancer. Thus, taking together the known roles of OPN in the modulation of EMT in cancer and the information reporting the expression of OPN in thyroid tumor progression, this review aims at summarizing and discussing data related to EMT in thyroid cancer and its putative relation to the roles of OPN in the development of thyroid cancer. These data provide new insights into the molecular mechanisms by which OPN could potentially modulate EMT in thyroid tumors, generating evidence for future studies that may contribute to new therapeutic, prognostic and/or diagnostic tools.

Gene Expression Patterns of Osteopontin Isoforms and Integrins in Malignant Melanoma

“…Recently, OPN has received increasing attention, with several studies investigating its role as a potential biomarker in different cancers, including melanoma (17)(18)(19). We previously observed, in our high-throughput microarray-based gene expression study, that ulcerated melanomas exhibit 6-fold higher expression of the SPP1/ OPN gene compared to non-ulcerated melanomas (20).…”

“…The expression of OPN splice variants has already been investigated in hematological malignancies, thyroid tumors, and gastric cancers ( 18 , 30 ). Wide variations were observed in the expression patterns and the predominantly expressed variant(s) depending on the tumor type; therefore, it is difficult to establish a possible universal nature or profile.…”

Beyond the Biomarker: Unveiling the Multifaceted Role of Osteopontin in Both Physiological and Pathological Processes

“…The understanding of the interplay between microglia and OPN is important for developing therapeutic interventions for CNS diseases [26]. The second underlined that OPN functions as a master regulator, orchestrating epithelial-mesenchymal plasticity in thyroid cancer through the modulation of the PI3K-AKT and MAPK signaling pathways where it induces the expression of transcription factors related to epithelial-mesenchymal transition [27]. The third review explored the significance of both full-length OPN and its protease-cleaved products across various infectious diseases, emphasizing the crucial role of OPN as a biomarker for infectious conditions.…”