MiR-122 is the most abundant microRNA (miRNA) in the liver; it regulates several genes mainly involved in cell metabolism and inflammation. Host factors, diet, metabolic disorders and viral infection promote the development of liver diseases, including hepatocellular carcinoma (HCC). The downregulation of miR-122 in tissue is a common feature of the progression of liver injury. In addition, the release of miR-122 in the bloodstream seems to be very promising for the early diagnosis of both viral and non-viral liver disease. Although controversial data are available on the role of circulating miR-122 as a single biomarker, high diagnostic accuracy has been observed using miR-122 in combination with other circulating miRNAs and/or proteins. This review is focused on comprehensively summarizing the most recent literature on the potential role of circulating miR-122, and related molecules, as biomarker(s) of metabolic liver diseases, hepatitis and HCC.

Background/Objectives: Pancreatic cancer (PC) is among the most aggressive malignancies, often diagnosed at late stages. MicroRNAs (miRNAs) and proteins released from the tumor microenvironment into body fluids represent promising non-invasive biomarkers for early cancer detection. In this study, we took advantage of an innovative ultrasound (US)-based instrument (SonoWell^®, Inno-Sol srl, Rome, Italy) to treat PC cells in order to promote and amplify the release of molecules, with the aim of identifying novel putative diagnostic PC biomarkers. Methods: Three human pancreatic adenocarcinoma cell lines (T3M-4, Panc02.03, and PaCa-44) and a non-cancerous pancreatic epithelial line (HPanEPic) were subjected to US using the SonoWell instrument. MiRNAs released in the supernatants were profiled by TaqMan-based qRT-PCR microfluidic cards, while proteins were analyzed by antibody arrays. Publicly available datasets of circulating miRNAs in PC patients were also reviewed. Results: Expression levels of 22 miRNAs in T3M-4 cells, 11 in Panc02.03, and 22 in PaCa-44, none of which were identified in the non-cancerous cell line profiling, were increased in the supernatant of US-treated as opposed to control cells. Among the statistically significant miRNAs or miRNAs common to at least two tumor cell lines, the expression levels of miR-155-5p, miR-320a, miR-32-5p, and miR-93-5p were also found to be significantly upregulated in sera from PC patients compared to the results for healthy controls. With regard to proteins released after sonication, several molecules were identified as candidate biomarkers in cancer US supernatants (Beta-2 microglobulin, CA125, CA19-9, CEA, CRP, Galectin-3, TIMP-1, uPA, and VEGF-A). Conclusions: We demonstrated that US-mediated sonoporation can promote and amplify the release of small molecules, miRNAs, and proteins into cell culture supernatants for consideration as putative biomarkers, thus encouraging further studies aimed at directly validating their expression levels in sera/plasma from PC patients and at deepening their role in the treatment of PC.