Published online Mar 27, 2021. doi: 10.4254/wjh.v13.i3.328
Peer-review started: November 23, 2020
First decision: December 12, 2020
Revised: December 14, 2020
Accepted: March 2, 2021
Article in press: March 2, 2021
Published online: March 27, 2021
2-Acetylaminofluorene (2-AAF) dose dependently promoted hepatic precancerous lesion. Over diethylnitrosamine (DEN), 2-AAF decreased autophagy. Over DEN, 2-AAF decreased apoptosis and tumor suppression gene. Over DEN, 2-AAF increased hepatic cell proliferation. 2-AAF epigenetically regulated long-noncoding RNA (lncRNA) RP11-513I15.6/miRNA-1262/miR-1298 (microRNA = miRNA = miR).
Urgent need for hepatocellular carcinoma (HCC) rat model for preclinical trials.
The present study aimed to develop a model of chemically-induced pre precancerous nodules in rat liver using DEN + 2-AAF and explore the putative molecular mechanism at the genetic and epigenetic levels.
Bioinformatics-based selection of molecular parameters to investigate the oncogenic mechanism of the chemicals used in the HCC model followed by induction of animal model by. intraperitoneal injection of DEN for three weeks consecutively, followed by one intraperitoneal injection of 2-AAF at three different doses (100, 200 and 300 mg/kg. Rats were sacrificed after 10 wk and 16 wk. Liver functions, level of alpha-fetoprotein, glutathione S-transferase-P and proliferating cell nuclear antigen staining of liver tissues were performed. The mRNA level of RAB11A, BAX, p53, and Cyclin E and epigenetic regulation by lncRNA RP11-513I15.6, miR-1262, and miR-1298 were assessed in the sera and liver tissues of the rats.
2-AAF administration significantly increased the percent area of the precancerous foci and cell proliferation along with a significant decrease in RAB11A, BAX, and p53 mRNA, and the increase in Cyclin E mRNA was associated with a marked decrease in lncRNA RP11-513I15.6 expression with a significant increase in both miR-1262 and miR-1298.
Administration of DEN to rats produced changes in hepatocytes with increased glutathione S-transferase-P and proliferating cell nuclear antigen expression and development of precancerous hepatic foci. The transformed cells proliferated when challenged with another carcinogen (2-AAF) as a promoter. These changes increased with the elevated dose of 2-AFF and duration of the experiment. DEN and 2-AAF affected the mRNA-biomarkers, including RAB11A, BAX, p53, and Cyclin E. Thus, the oncogenic properties of DEN and 2-AAF were observed in induced HCC model, which might be attributed to the suppression of p53, autophagy, and apoptosis along with the activation of the cell cycle. Moreover, it significantly increased the level of miR-1262 and miR-1298 with a concomitant decrease in the expression of lncRNA-RP11-513I15.6. This phenomenon led to the hypothesis that lncRNA-RP11-513I15.6 is a part of competing endogenous RNA, decreasing the level of miR-1262 and miR-1298, which, in turn, regulates the selected target mRNAs.
More in vitro functional studies are urgently need to explore the competing endogenur role of lncRNA in HCC pathogenesis.