We demonstrated a decrease of TSLC1 protein in ≈80% of HCCs, suggesting its involvement in the tumorigenic process of human HCCs. One miRNA usually affects several target genes, thus other genes besides TSLC1 could also be affected by miR-216a and contributing to the increase of cell proliferation and migration activities. For example, the AMOT, MTSS1,

INTS7, and IL2RG genes (as revealed by the microarray analysis of Table 2S) could also be the putative targets for miR-216a and worthy to be investigated. The mechanisms for the decrease of TSLC1 have been extensively investigated in many Poziotinib in vitro tumors that were caused either by allelic loss or by promoter methylation.23-25 Because our current study demonstrated that the elevation of miR-216a, through its putative target sites at the 3′ UTR of the TSLC1 gene, could decrease its protein expression, it thus provided a novel mechanism for the decrease of this important tumor suppressor gene in early hepatocarcinogenesis. No significant change in the mRNA levels of TSLC1 in most HCCs has been supported further by the microarray analysis released by the oncoHCC database.26 Thus, it argued against the promoter methylation. Intriguingly, we noted that a similar situation for the decrease of TSLC1 protein levels, independent of promoter methylation, was also reported in neuroblastoma

and bladder cancers.27, 28 The contribution of a miR-216a-mediated PI3K Inhibitor Library clinical trial decrease of TSLC1 in these tumors warrants further investigation. Although it is well documented that the androgen Anacetrapib pathway is involved in hepatocarcinogenesis,13, 20, 21 the target genes affected by

this pathway remain largely unidentified. Recently, Feng et al.29 identified the cell-cycle-related kinase as one putative target gene activated by the androgen pathway and contributing to male HCC. In addition to the protein coding gene, our current study suggested that AR is able to regulate the transcription of specific miRNAs, indirectly affecting the genes with the potential for tumorigenesis. As we noted, the androgen pathway was reported to regulate the expression of several miRNAs in the prostate cancer cells, including miR-141,30 miR-125b,31 and miR-21,32 which all showed a functional effect on the carcinogenic process. Whether the precancerous liver tissues of male HBV patients also affect these miRNAs awaits further clarification. The results from the current study warranted initiating nonbias genome-wide approaches for identifying the whole spectrum of miRNAs regulated by the androgen pathway in hepatocarcinogenesis. We thank the Taiwan Liver Cancer Network (TLCN) for providing the hepatocellular carcinoma tissue samples and related clinical data (all are anonymous) for our research work. This network currently includes five major medical centers (National Taiwan University Hospital, Chang-Gung Memorial Hospital-Linko, Veteran General Hospital-Taichung, Chang-Gung Memorial Hospital, Kaohsiung, and Veteran General Hospital, Kaohsiung).