Prostate cancer (PCa) is considered the most prevalent malignancy and the second major cause of cancer‐related death in males from Western countries. PCa exhibits variable clinical pictures, ranging from dormant to highly metastatic cancer. PCa suffers from poor prognosis and diagnosis markers, and novel biomarkers are required to define disease stages and to design appropriate therapeutic approach by considering the possible genomic and epigenomic differences. MicroRNAs (miRNAs) comprise a class of small noncoding RNAs, which have remarkable functions in cell formation, differentiation, and cancer development and contribute in these processes through controlling the expressions of protein‐coding genes by repressing translation or breaking down the messenger RNA in a sequence‐specific method. miRNAs in cancer are able to reflect informative data about the current status of disease and this might benefit PCa prognosis and diagnosis since that is concerned to PCa patients and we intend to highlight it in this paper.

Highlights Lethal forms of the disease are associated with cytokine storm. The severity of COVID-19 was associated with abdominal adipose tissue distribution. Exhaustion markers upregulated in T cells and NK cells from COVID-19 patients. There might be a connection between SARS-CoV-2 related mortality and gut microbiota.

Abstract:: Osteosarcoma (OS) is a primary bone malignancy, which has high incidence in children and adolescents. The affected cells and tissues show the properties of drug-resistance and the prognosis remains poor in OS, therefore there is an essential need for novel therapeutic approaches. MicroRNAs (miRNAs) expression pattern has been established to be involved in the pathogenesis of OS. miRNAs are small non-coding RNA molecules, which negatively regulate gene expression at post-transcriptional level. There are copious miRNAs that have a critical role in the onset of the disease, modulation of disease progression, and response to treatment. At the moment, the recently launched version 3.0 of Human MicroRNA Disease Database (HMDD v3.0) reports that 194 miRNAs are dysregulated in OS that might be involved in proliferation, migration, invasion, and epithelial-mesenchymal transition of tumor cells. The balance between oncogene and tumor suppressor miRNAs has vital importance in the final fate of the cell behaviors in OS. Additionally, networks of miRNAs may act in concert to induce oncogenic or tumor-suppressing properties during the initiation or progression of OS. Up or downregulation of these miRNAs affect the status of the disease, during or after therapy. To date, over 40 miRNAs have been identified in OS disease that possess oncogenic or tumor-suppressing properties, and treatment approaches are trying to establish a proper level of such miRNAs in favor of OS therapy. The role of miRNAs involved in the pathogenesis of OS and their therapeutic potential are the reference points in this review article.