A Feedback Loop of LINC00665 and the Wnt Signaling Pathway Expedites Osteosarcoma Cell Proliferation, Invasion, and Epithelial-Mesenchymal Transition

Role of long noncoding RNAs in the regulation of epithelial‑mesenchymal transition in osteosarcoma (Review)

Osteosarcoma (OS) is one of the most widespread malignant bone tissue tumors. However, its early diagnosis is difficult, leading to poor prognoses. Long noncoding RNA (lncRNA) can serve as a molecular marker for the early diagnosis and treatment of OS. lncRNAs regulate the epithelial‑mesenchymal transition (EMT) process to control the occurrence and progression of OS. The present review summarizes the studies on lncRNA regulation of OS via the EMT process. A search of the PubMed database yielded 93 published articles since January 2015, of which 73 focused on lncRNA regulation of OS via the EMT process. The present review has classified lncRNAs based on their relationship with tumors (promoting or inhibiting), mechanism of action and naming convention. Most lncRNAs promote OS through EMT and act via microRNA sponging. Previous studies have focused on lncRNAs with known functions, antisense lncRNAs and long intergenic noncoding RNAs. The findings indicated that lncRNAs can regulate the EMT process through various mechanisms to control OS progression. Further studies on specific lncRNAs and their underlying mechanisms will provide insights for the development of strategies for the diagnosis, prevention and treatment of OS.

Wnt/β-catenin signaling pathway: an attractive potential therapeutic target in osteosarcoma

Osteosarcoma (OS) is the most common bone malignancy in children and adolescents, and although current neoadjuvant chemotherapy has shown efficacy against OS, the long-term survival rate for patients with OS remains low, highlighting the need to find more effective treatments. In cancer cells, abnormal activation of signaling pathways can widely affect cell activity from growth and proliferation to apoptosis, invasion and metastasis. Wnt/β-catenin is a complex and unique signaling pathway that is considered to be one of the most important carcinogenic pathways in human cancer. Research have confirmed that the Wnt/β-catenin signaling pathway is an important driving factor for the occurrence and development of osteosarcoma, and abnormal activation of this pathway can promote the pathological processes of cell proliferation, invasion, migration, tumor angiogenesis and chemical resistance of osteosarcoma. However, inhibition of Wnt/β-catenin signaling pathway can effectively inhibit or reverse the above pathological processes. Therefore, manipulating the expression or function of the Wnt/β-catenin pathway may be a potential targeted pathway for the treatment of OS. In this review, we describe the characteristics of the Wnt/β-catenin signaling pathway and summarize the role and mechanism of this pathway in OS. This paper discusses the therapeutic significance of inhibiting or targeting Wnt/β-catenin pathway in OS and the shortcomings of current studies on this pathway in OS and the problems to be solved. This review helps us to understand the role of Wnt/β-catenin on OS, and provides a theoretical basis and new ideas for targeting Wnt/β-catenin pathway as a therapeutic target for OS.

Hsa-microRNA-1249-3p/Homeobox A13 axis modulates the expression of β-catenin gene in human epithelial cells

Intercellular adhesion is a key function for epithelial cells. The fundamental mechanisms relying on epithelial cell adhesion have been partially uncovered. Hsa-microRNA-1249-3p (hsa-miR-1249-3p) plays a role in the epithelial mesenchymal transition in carcinoma cells, but its physiological function in epithelial cells is unknown. We aimed to investigate the role and molecular mechanisms of hsa-miR-1249-3p on epithelial cell functions. Hsa-miR-1249-3p was overexpressed in human epithelial cells and uterine cervical tissues, compared to cervical carcinoma cells and precancerous tissues, respectively. Hsa-miR-1249-3p was analyzed to verify its regulatory function on Homeobox A13 (HOXA13) target gene and its downstream cell adhesion gene β-catenin. Functional experiments indicated that hsa-miR-1249-3p inhibition prompted the mRNA and protein overexpression of HOXA13 which, in turn, led to the β-catenin protein expression. Moreover, hsa-miR-1249-3p inhibition induced a strong colony forming ability in epithelial cells, suggesting the miR involvement in cell adhesion machinery. These data indicate that hsa-miR-1249-3p regulates the expression of HOXA13 and its downstream cell adhesion gene β-catenin, possible resulting in cell adhesion modification in epithelial cells. This study will allow the set-up of further investigations aimed at exploring the relationship between the hsa-miR-1249-3p/HOXA13 axis and downstream cell adhesion genes.