Basic Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Sep 28, 2015; 21(36): 10367-10374
Published online Sep 28, 2015. doi: 10.3748/wjg.v21.i36.10367
Ursodeoxycholic acid induces apoptosis in hepatocellular carcinoma xenografts in mice
Hui Liu, Hong-Wei Xu, Yu-Zhen Zhang, Ya Huang, Guo-Qing Han, Tie-Jun Liang, Li-Li Wei, Cheng-Yong Qin, Cheng-Kun Qin
Hui Liu, Hong-Wei Xu, Ya Huang, Guo-Qing Han, Tie-Jun Liang, Li-Li Wei, Cheng-Yong Qin, Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, Shandong Province, China
Yu-Zhen Zhang, Department of Surgery, Heze Peony District People’s Hospital, Heze 274000, Shandong Province, China
Cheng-Kun Qin, Department of General Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, Shandong Province, China
Author contributions: Liu H, Xu HW, Zhang YZ and Huang Y designed the experiments; Liu H, Xu HW, Zhang YZ, Huang Y, Han GQ and Liang TJ performed the research; Wei LL and Qin CY contributed new reagents/analytic tools; Liu H, Xu HW, Huang Y and Liang TJ analyzed the data; Liu H and Xu HW wrote the paper; and Qin CK revised the manuscript.
Supported by Grants from the Shandong Provincial Science and Technology Committee of China, No. 2013GSF11852; and the Shandong Provincial Natural Science Foundation of China, No. ZR2014HM106.
Institutional animal care and use committee statement: All animal experiments were carried out with approval by an ethics committee in accordance with the National Institutes of Health Guide for the Care and Use of Laboratory Animals and further approved by the Institutional Care Committee (Shandong University, Jinan, China).
Conflict-of-interest statement: None of the authors have any possible conflicts of interest.
Data sharing statement: There are no additional data available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Cheng-Kun Qin, Department of General Surgery, Shandong Provincial Hospital Affiliated to Shandong University, No. 324 Jingwu Weiqi Road, Jinan 250021, Shandong Province, China. qin_chengkun@163.com
Telephone: +86-531-68778365 Fax: +86-531-87068344
Received: January 14, 2015
Peer-review started: January 16, 2015
First decision: April 24, 2015
Revised: May 23, 2015
Accepted: August 28, 2015
Article in press: August 31, 2015
Published online: September 28, 2015
Abstract

AIM: To evaluate the efficacy of ursodeoxycholic acid (UDCA) as a chemotherapeutic agent for the treatment of hepatocellular carcinoma (HCC).

METHODS: BALB/c nude mice were randomized into four groups 24 h before subcutaneous injection of hepatocarcinoma BEL7402 cells suspended in phosphate buffered saline (PBS) into the right flank. The control group (n = 10) was fed a standard diet while treatment groups (n = 10 each) were fed a standard daily diet supplemented with different concentrations of UDCA (30, 50 and 70 mg/kg per day) for 21 d. Tumor growth was measured once each week, and tumor volume (V) was calculated with the following equation: V = (L × W2) × 0.52, where L is the length and W is the width of the xenograft. After 21 d, mice were killed under ether anesthesia, and tumors were excised and weighed. Apoptosis was evaluated through detection of DNA fragmentation with gel electrophoresis and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay. Western blot analysis was performed to determine the expression of apoptosis-related proteins BAX, BCL2, APAF1, cleaved caspase-9, and cleaved caspase-3.

RESULTS: UDCA suppressed tumor growth relative to controls. The mean tumor volumes were the following: control, 1090 ± 89 mm3; 30 mg/kg per day, 612 ± 46 mm3; 50 mg/kg per day, 563 ± 38 mm3; and 70 mg/kg per day, 221 ± 26 mm3. Decreased tumor volumes reached statistical significance relative to control xenografts (30 mg/kg per day, P < 0.05; 50 mg/kg per day, P < 0.05; 70 mg/kg per day, P < 0.01). Increasing concentrations of UDCA led to increased DNA fragmentation observed on gel electrophoresis and in the TUNEL assay (control, 1.6% ± 0.3%; 30 mg/kg per day, 2.9% ± 0.5%; 50 mg/kg per day, 3.15% ± 0.7%, and 70 mg/kg per day, 4.86% ± 0.9%). Western blot analysis revealed increased expression of BAX, APAF1, cleaved-caspase-9 and cleaved-caspase-3 proteins, which induce apoptosis, but decreased expression of BCL2 protein, which is an inhibitor of apoptosis, following administration of UDCA.

CONCLUSION: UDCA suppresses growth of BEL7402 hepatocellular carcinoma cells in vivo, in part through apoptosis induction, and is thus a candidate for therapeutic treatment of HCC.

Keywords: Hepatocellular carcinoma, Inhibitory effects, Mechanisms, Ursodeoxycholic acid, Xenografts

Core tip: Hepatocellular carcinoma (HCC) ranks as the sixth most common cancer worldwide. Prognosis of HCC patients remains poor, however, due to the lack of effective therapies. In this study, ursodeoxycholic acid (UDCA) was investigated as a potential chemotherapeutic agent in a mouse model of HCC. Tumor growth was inhibited by increasing concentrations of UDCA over a 21-d period, and the effect was elicited through apoptosis. UDCA is thus a candidate chemopreventive and chemotherapeutic agent for HCC.