MicroRNAs differential expression profile in metastatic colorectal cancer: A pilot study with literature review

Background and objectives: Colorectal cancer is still one of the leading causes of cancer-related deaths worldwide and specific tools to improve disease assessment and treatment response are advocated. The aim of this study was to analyze miRNAs expression in metastatic and non-metastatic colorectal cancer, in order to identify reliable biomarkers suitable for prognosis, treatment and patient's monitoring. Material and methods: Among 25 patients (mean age 71 ± 12 years; Female/Male: 12/13) submitted to laparoscopic colorectal resection between August 2017 and February 2019, miRNAs were extracted from fresh frozen tissues of solid tumors. Gene expression's analysis arising from microarray technology was performed. Results: Pathological evaluation identified 15 metastatic patients (8 presenting with stage III and 7 with stage IV cancers) and 10 non-metastatic patients (4 presenting with stage I and 6 stage II cancers). Bioinformatic analysis of solid biopsies revealed 16 miRNAs (11 upregulated and 5 downregulated) differently expressed between metastatic and non-metastatic groups, with three miRNAs (miR-7515, miR-7109-5p and miR-6831-5p) never linked to colorectal cancer before. Conclusions: Our study showed an association between miRNAs and metastatic colorectal cancer, suggesting their potential role as biomarkers for tumor management, if confirmed by further studies.