MicroRNA-7641 is a Regulator of Ribosomal Proteins and a Promising Targeting Factor to Improve the Efficacy of Cancer Therapy

Many diseases, including myocardial infarction, autoimmune disease, viral diseases, neurodegenerative diseases, and cancers, are frequently diagnosed with aberrant expression of microRNAs (miRNAs) and their allied pathways. This indicates the crucial role of miRNAs in maintaining biological and physiological processes. miR-7641 is a miRNA whose role in disease has not been fully investigated. In the present study, we investigated the expression pattern of miR-7641 and its target genes in different cancer cells, as well as in clinical cancer patients. Our data confirmed RPS16 and TNFSF10 as two direct targets of miR-7641, while gene expression study showed that a group of genes are also deregulated by miR-7641, including many ribosomal proteins that are frequently co-expressed with RPS16 in breast cancer. Direct inhibition of miR-7641 using a locked nucleic acid upregulated the expression of its target genes, sensitized cancer cells, and enhanced the efficiency of therapeutic agents such as doxorubicin. In addition, inhibition of miR-7641 boosted doxorubicin-mediated apoptosis of cancer cells via upregulation of apoptotic molecules Caspase 9 (CAS9) and poly ADP ribose polymerase (PARP) and downregulation of anti-apoptotic molecule BCL2. Thus, miR-7641 might be a clinically important cancer biomarker. Inhibition of miR-7641 expression could be an efficient treatment strategy for clinical patients.