Brief Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. May 14, 2012; 18(18): 2253-2261
Published online May 14, 2012. doi: 10.3748/wjg.v18.i18.2253
CD74 and macrophage migration inhibitory factor as therapeutic targets in gastric cancer
Ying-Xia Zheng, Ming Yang, Ting-Ting Rong, Xiang-Liang Yuan, Yan-Hui Ma, Zhi-Hao Wang, Li-Song Shen, Long Cui
Ying-Xia Zheng, Ting-Ting Rong, Xiang-Liang Yuan, Yan-Hui Ma, Zhi-Hao Wang, Li-Song Shen, Department of Laboratory Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
Ming Yang, Long Cui, Department of Anorectal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
Author contributions: Zheng YX and Yang M contributed equally to this work; Cui L and Shen LS designed the research; Rong TT and Wang ZH performed the research; Zheng YX, Yang M, Yuan XL and Ma YH analyzed the data; Zheng YX, Shen LS and Cui L wrote the paper.
Supported by Shanghai Municipal Natural Science Foundation, No. 09DZ1907203 and No. 10411950400 and National Natural Science Foundation of China, No. 81072009
Correspondence to: Long Cui, MD, PhD, Department of Anorectal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China. fzuyoup@163.com
Telephone: +86-21-25077106 Fax: +86-21-27075173
Received: September 27, 2011
Revised: February 6, 2012
Accepted: February 16, 2012
Published online: May 14, 2012
Abstract

AIM: To investigate the relationship and molecular features of CD74/macrophage migration inhibitory factor (MIF)/Toll-like receptor 4 (TLR4) in gastric cancer.

METHODS: CD74, MIF and TLR4 expression in the paraffin-embedded sections of gastric cancer from 120 patients were detected by immunohistochemical staining. Knock down of CD74 expression in gastric cancer cell line MKN-45 was performed by lentivirus transduction and detected by Western blotting. MKN-45 cell proliferation assay under the stimulants was measured by the cell counting kit 8 (CCK8) assay and MIF concentration in the culture medium was detected by enzyme-linked immunosorbent assay. Surface staining of CD74 in the MKN-45 cell line under the stimulation of lipopolysaccharide (LPS) was measured by flow cytometry. MIF, CD74 and TLR4 co-localization in the MKN-45 cell line was performed by the immunoprecipitation.

RESULTS: CD74, MIF and TLR4 were found to be expressed in gastric cancer and increased significantly in the advanced stage, and were also associated with lymph node metastasis. Correlation analysis revealed that CD74 was positively correlated with MIF (r = 0.2367, P < 0.01) and both proteins were also associated with TLR4 (r = 0.4414, r = 0.5001, respectively, P < 0.01). LPS can significantly promote MKN-45 cell proliferation (3.027 ± 0.388 vs 4.201 ± 0.092, P < 0.05), induce MIF production (54.333 ± 2.906 pg/mL vs 29.667 ± 3.180 pg/mL, P < 0.01) and cell surface expression of CD74 (75.6% ± 4.046% vs 9.4% ± 0.964%, P < 0.01) at LPS concentration of 1 μg/mL compared to medium control. Knockdown of CD74 or using anti-CD74 and MIF antagonist ISO-1 significantly reduced LPS-induced MKN-45 cell proliferation (4.201 ± 0.092 vs 3.337 ± 0.087, 4.534 ± 0.222 vs 3.368 ± 0.290, 4.058 ± 0.292 vs 2.934 ± 0.197, respectively, P < 0.01). MIF, CD74 and TLR4 could co-localize in the MKN-45 cell line.

CONCLUSION: Upregulation of MIF, CD74 and TLR4 are associated with increasing clinical stage and provide an opportunity as novel gastric cancer chemoprevention and/or treatment strategy.

Keywords: Gastric cancer; CD74; Migration inhibitory factor; Toll-like receptors; Gastric epithelial cells