MicroRNA-221 and MicroRNA-222 in Common Human Cancers

Expression, Function, and Triggering of Tumor Progression as a Key Modulator

Sima Amini, MSc; Atefe Abak, MSc; Ebrahim Sakhinia, PhD; Alireza Abhari, PhD


Lab Med. 2019;50(4):333-347. 

In This Article


In this article, we have summarized the critical function of the miR-221/-222 in various types of human cancers. Understanding the significant impact of miRNAs in human malignant neoplasms has divulged to scientists a novel starting point for cancer studies. Among the contributions of a large number of miRNAs to cancer mechanisms, miR-221 and miR-222 are considered to be key modulators of cancer progression that are dysregulated in different types of human malignant tumors. These entities are involved in many aspects of cancer, such as invasion, metastasis, angiogenesis, apoptosis, and drug resistance. Our results highlighted the growing comprehension among the scientific community of the role of miR-221/-222 in various cancer types and the great potential of these miRNAs in cancer therapy.

However, we have still not developed standard procedures to understand the profound function of these miRNAs in the formation of tumor cells. Expanding the ways to enhance the efficiency of miRNAs in cancer remedies can be a useful approach to controlling cancer. Also, further studies should be performed to determine the miRNA pathway, involving the expression, function, target genes, and involvement of miRNAs in epigenetic change and drug resistance for cancer progression, other than in gene adjustment, which will enhance their utilization in clinical applications.

In clinical applications, miRNAs have been applied as one of the most hopeful biomarkers for cancer monitoring. Also, biopsies of bodily fluids, including plasma and urine, can be an easily accessed and noninvasive method for tracing the increase or decrease in expression levels of miR-221/-222 in multiple diseases, including cancer. Performing such biopsies may prove to be an authentic technique for the prognosis and diagnosis of various cancers.