Establishment of a dynamic osteosarcoma biobank: Ruijin experience

Exosomes in the hypoxic TME: from release, uptake and biofunctions to clinical applications

Hypoxia is a remarkable trait of the tumor microenvironment (TME). When facing selective pressure, tumor cells show various adaptive characteristics, such as changes in the expression of cancer hallmarks (increased proliferation, suppressed apoptosis, immune evasion, and so on) and more frequent cell communication. Because of the adaptation of cancer cells to hypoxia, exploring the association between cell communication mediators and hypoxia has become increasingly important. Exosomes are important information carriers in cell-to-cell communication. Abundant evidence has proven that hypoxia effects in the TME are mediated by exosomes, with the occasional formation of feedback loops. In this review, we equally focus on the biogenesis and heterogeneity of cancer-derived exosomes and their functions under hypoxia and describe the known and potential mechanism ascribed to exosomes and hypoxia. Notably, we call attention to the size change of hypoxic cancer cell-derived exosomes, a characteristic long neglected, and propose some possible effects of this size change. Finally, jointly considering recent developments in the understanding of exosomes and tumors, we describe noteworthy problems in this field that urgently need to be solved for better research and clinical application.

Osteosarcoma from the unknown to the use of exosomes as a versatile and dynamic therapeutic approach

The most common primary malignant tumor of bone in children is osteosarcoma (OS). Nowadays, the prognosis and the introduction of chemotherapy in OS have improved survival rates of patients. Nevertheless, the results are still unsatisfactory, especially, in patients with recurrent disease or metastatic. OS chemotherapy has two main challenges related to treatment toxicity and multiple drug resistance. In this way, nanotechnology has developed nanosystems capable of releasing the drug directly at the OS cells and decreasing the drug's toxicity. Exosomes (Exo), a cell-derived nano-sized and a phospholipid vehicle, have been recognized as important drug delivery systems in several cancers. They are involved in a variety of biological processes and are an important mediator of long-distance intercellular communication. Exo can reduce inflammation and show low toxicity in healthy cells. Furthermore, the incorporation of specific proteins or peptides on the Exo surface improves their targeting capability in several clinical applications. Due to their unique structure and relevant characteristics, Exo is a promising nanocarrier for OS treatment. This review intends to describe the properties that turn Exo into an efficient, as well as safe nanovesicle for drug delivery and treatment of OS.

Emerging role of exosomes as biomarkers in cancer treatment and diagnosis

Cancer is a leading cause of death worldwide and cancer incidence and mortality are rapidly growing. These massive amounts of cancer patients require rapid diagnosis and efficient treatment strategies. However, the currently utilized methods are invasive and cost-effective. Recently, the effective roles of exosomes as promising diagnostic, prognostic, and predictive biomarkers have been revealed. Exosomes are membrane-bound extracellular vesicles containing RNAs, DNAs, and proteins, and are present in a wide array of body fluids. Exosomal cargos have shown the potential to detect various types of cancers at early stages with high sensitivity and specificity. They can also delivery therapeutic agents efficiently. In this article, an overview of recent advances in the research of exosomal biomarkers and their applications in cancer diagnosis and treatment has been provided. Furthermore, the advantages and challenges of exosomes as liquid biopsy targets are discussed and the clinical implications of using exosomal miRNAs have been revealed.