miR-122, the expression of which is regulated by several transcription factors, such as HNF1A, was recently reported to be associated with type 2 diabetes (T2DM) and hepatocellular carcinoma.
Scientific research over the period of three decades has reported it as an important player in various liver malignancies such as hepatocellular cancers (HCCs), hepatocellular adenoma (HA), and a more specific HNF-1α-inactivated human hepatocellular adenoma (H-HCAs).
The expression in HA was variable and differed between molecular subtypes of this neoplasm: inflammatory and HNF1A mutation-associated type are characterized by overexpression of c-MET to an extent comparable with poorly-differentiated HCC, whereas Wnt/β-catenin dysfunction-associated type lacks overexpression, and the amount of c-MET protein accumulated in its cells is similar to the levels in non-neoplastic tissue and well- to moderately-differentiated HCC.
Biallelic inactivating mutations of HNF1A have been frequently identified in hepatocellular adenomas (HCA), rare benign liver tumors usually developed in women under oral contraceptives, and in rare cases of hepatocellular carcinomas developed in non-cirrhotic liver.