Role of microRNA-494 in tumor progression

Various progresses in tumor therapy during the recent decades have significantly reduced the cancer related deaths globally. However, there is still a high rate of mortality in these patients. The early stage tumors have no aggressive and clear clinical symptoms in the majority of cancer types, which causes a high rate of therapeutic failure in advanced tumor stages. Therefore, identification of the molecular tumor biology can be promising to introduce the early diagnostic markers. MicroRNAs (miRNAs) are the key regulators of cellular processes that can also be involved in tumor progression as tumor-suppressor or oncogene. Due to the high stability of miRNAs in body fluids, they can be used as the non-invasive diagnostic tumor markers. In the present review, we discussed the role of miR-494 in tumor progression. It has been shown that miR-494 has mainly a tumor suppressor function by regulation of transcriptional and structural factors and signaling pathways such as transforming growth factor-β (TGF-β), WNT, and Janus kinase (JAK)-signal transducer and activator of transcription (STAT). The phosphatase and tensin homolog/phosphoinositide 3-kinase (PTEN/PI3K) axis has been also reported as the main target of miR-494 as an oncogene. These findings suggest that miR-494 is a non-invasive diagnostic marker for the early diagnosis and therapeutic management of cancer patients.