Basic Research
Copyright ©2008 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Mar 28, 2008; 14(12): 1858-1865
Published online Mar 28, 2008. doi: 10.3748/wjg.14.1858
Over-expressed and truncated midkines promote proliferation of BGC823 cells in vitro and tumor growth in vivo
Qing-Ling Wang, Hui Wang, Shu-Li Zhao, Ya-Hong Huang, Ya-Yi Hou
Qing-Ling Wang, Hui Wang, Shu-Li Zhao, Ya-Hong Huang, Ya-Yi Hou, Immunology and Reproductive Biology Lab, Medical School and State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing 210093, Jiangsu Province, China
Author contributions: Wang QL, Hou YY and Huang YH designed the research; Wang QL performed the research; Wang QL, Wang H and Zhao SL analyzed the data; Wang QL and Wang H wrote the paper; Hou YY and Huang YH revised the paper.
Correspondence to: Ya-Yi Hou, Immunology and Reproductive Biology Lab, Medical School and State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210093, Jiangsu Province, China. yayihou@nju.edu.cn
Telephone: +86-25-83686341
Fax: +86-25-83686341
Received: November 7, 2007
Revised: December 10, 2007
Published online: March 28, 2008
Abstract

AIM: To determine whether midkine (MK) and its truncated form (tMK) contribute to gastric tumorigenesis using in vitro and in vivo models.

METHODS: Human MK and tMK plasmids were constructed and expressed in BGC823 (a gastric adenocarcinoma cell line) to investigate the effect of over-expressed MK or tMK on cell growth and turmorigenesis in nude mice.

RESULTS: The growth of MK-transfected or tMK-transfected cells was significantly increased compared with that of the control cells, and tMK-transfected cells grew more rapidly than MK-transfected cells. The number of colony formation of the cells transfected with MK or tMK gene was larger than the control cells. In nude mice injected with MK-transfected or tMK-transfected cells, visible tumor was observed earlier and the tumor tissues were larger in size and weight than in control animals that were injected with cells without the transfection of either genes.

CONCLUSION: Over-expressed MK or tMK can promote human gastric cancer cell growth in vitro and in vivo, and tMK has greater effect than MK. tMK may be a more promising gene therapeutic target compared with MK for treatment of malignant tumors.

Keywords: Midkine; Truncated midkine; Gastric cancer; BGC823; Tumorigenisis