Recently, increasing evidences indicate that microRNAs can be potential tools for cancer diagnosis Y-27632 order and prognosis [4]. MicroRNAs are small noncoding RNA gene products about 22 nt long that are found in divers organisms and play key roles in post-transcriptional regulation of targeted gene expression through sequence-specific interaction with the 3′-untranslated region (3′-UTR) of targeted genes [5]. MicroRNAs are important players

in basic cellular functions such as, embryonic development, cell growth, apoptosis, and differentiation. However, dysregulation of microRNA is also common in various cancers. The dysregulated miRNAs play roles in carcinogenesis or tumor progression by altering the normal gene expression patterns. MicroRNA-20a (miR-20a) was found to be down-regulated in several

solid tumors, such as breast cancer [6] and pancreatic carcinoma [7], while miR-20a were found to be significantly up-regulated in colon adenocarcinoma [8] and gliomas [9]. This indicates that miR-20a may be a tissue specific microRNA. On the other hand, miR-20a has been shown to inhibit proliferation and metastasis of pancreatic carcinoma cell by directly down-regulating Stat3, that is activated in primary pancreatic cancer and is involved in various physiologic functions, including apoptosis, cell cycle regulation, angiogenesis, and metastasis [7]. Bioinformatic target gene predictions followed by experimental target gene validations revealed that miR-20a act in a common manner by down-regulating an overlapping Histone Methyltransferase inhibitor set of target genes, including E2F family, cyclin-dependent kinase inhibitor CDKN1a/p21, which were mostly involved in regulation and execution of G1/S transition in the cell cycle [10]. Our previous study has shown that miR-20a was correlated

with HCC recurrence [11]. However, the biological functions of miR-20a in HCC were not clear and the association between miR-20a and HCC prognosis following LT has not been evaluated yet. In our current study, we evaluated Baricitinib miR-20a expression levels in 100 formalin-fixed paraffin-embedded (FFPE) tumor tissues of patients with HCC and found that miR-20a was significantly down-regulated in HCC. Based on gain-of-function approach, we proved that miR-20a could inhibit HCC cell proliferation and induce apoptosis in vitro. Furthermore, the Mcl-1 (myeloid cell leukemia sequence 1) protein, an antiapoptotic member of Bcl-2 family, which is usually overexpressed in a variety of human cancers including HCC [12] and plays a pivotal role in protecting cells from apoptosis and tumor carcinogenesis [13], was identified as a direct target of miR-20a. This result provided a possible regulation pathway for Mcl-1 and a candidate target for HCC treatment.