Good cop-bad cop: different roles of hsa-miR-93-5p in colorectal cancer

Colorectal cancer (CRC) is a heterogeneous disease that ranks third and second globally in terms of incidence and mortality rates, respectively. Five-year survival of patients with CRC is approximately 90% if diagnosed in the early stages, and only 13% if the advance disease is present. About 25% of patients already have CRC metastases (mCRC) with the primary CRC diagnosis, while half of the patients will develop metastases with further disease progression. The most common organ in which CRC metastasizes is the liver (colorectal cancer liver metastasis, CRLM). Almost half of CRC patients will die due to complications caused by the presence of metastases, so it is extremely important to discover new therapeutic approaches, as well as prognostic and predictive biomarkers, in order to reduce such a high mortality rate. In the era of personalized medicine, various treatment modalities are available to CRC and mCRC patients, including resective surgery, systemic chemotherapy, and novel targeted biologics, which significantly improved the outcome of CRC patients. The main goal of neoadjuvant systemic chemotherapy is to render currently unresectable disease amenable to resection. The standard cytotoxic drugs used in systemic chemotherapy for the treatment of CRC are: 5-fluorouracil (5-FU), oxaliplatin, and irinotecan applied as single agents or combined. It has been shown that the combination of systemic chemotherapy with targeted biological agents (e.g., bevacizumab which targets vascular endothelial growth factor) leads to a better therapy response compared to the use of systemic chemotherapy alone. MicroRNA (miRNA) molecules belong to a large class of small regulatory non-coding single-stranded RNA molecules that exert negative post-transcriptional regulation of gene expression. MiRNAs are involved in the regulation of fundamental cellular processes such as cell proliferation, differentiation and death, thus these molecules have been proposed as one of the regulators of