Original Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Jan 14, 2012; 18(2): 136-143
Published online Jan 14, 2012. doi: 10.3748/wjg.v18.i2.136
Characterization of gastric cancer models from different cell lines orthotopically constructed using improved implantation techniques
Yan Li, Bo Li, Chun-Ping Xiang, Yu Zhang, Yuan-Yuan Li, Xiao-Ling Wu
Yan Li, Xiao-Ling Wu, Department of Gastroenterology, the Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
Bo Li, Department of Surgery, the First People’s Hospital, Chongqing 400020, China
Chun-Ping Xiang, Department of Pathology, Children’s Hospital, Chongqing Medical University, Chongqing 400014, China
Yu Zhang, Department of Pathology, the First People’s Hospital, Chongqing 400020, China
Yuan-Yuan Li, Department of Pathology, Chongqing Medical University, Chongqing 400016, China
Author contributions: Li Y conceived of the study, established the animal models and drafted the manuscript; Li B participated by establishing the animal model; Xiang CP and Zhang Y performed paraffin sections and hematoxylin and eosin staining; Li YY performed immunohistochemistry staining; and Wu XL guided and supervised all the experiments.
Supported by A grant from the Natural Science Foundation of China, No. 30830040
Correspondence to: Xiao-Ling Wu, Professor, Department of Gastroenterology, the Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China. xiaolianbei@sina.com
Telephone: +86-23-63693325 Fax: +86-23-63711527
Received: March 21, 2011
Revised: June 21, 2011
Accepted: June 28, 2011
Published online: January 14, 2012

AIM: To develop orthotopic gastric cancer mouse models from different cell lines and characterize the tumor features to assist further in preclinical trials and clinical treatment strategies.

METHODS: Human gastric cancer SGC-7901 and BGC-823 cell suspensions were injected subcutaneously into nude mice to develop solid tumors, and tumor tissue pieces were then implanted under the serous coat of the stomach. An autopsy was performed on all animals of the SGC-7901 and BGC-823 models to observe the primary tumor growth and metastases using pathological and immunohistochemical methods.

RESULTS: Both models showed large tumors in situ resulting in pressure and infiltration of the adjacent organs. The gastric cavity became smaller, along with stenosis of the cardia or pylorus. There were biological and statistical differences between the two models. The metastasis rate in involved organs (lymph nodes, kidney, spleen, testis) was significantly higher in the BGC-823 model compared to the SGC-7901 model (P < 0.05 or P < 0.01). The median survival of the BGC-823 model was shorter than that of SGC-7901 (23 d vs 84 d, P < 0.05). Histopathologically, the primary tumor and metastatic lesions of the two models showed obvious atypia and mucus in the cytoplasm. Compared with the SGC-7901 model, BGC-823 appeared more poorly differentiated (absence of adenoid structure), had a smaller volume, and richer capillary structure. Immunohistochemical staining revealed cytokeratin 20 and epithelial membrane antigen expression was positive in the SGC-7901 tumors, while negative in BGC-823 ones.

CONCLUSION: Models using the SGC-7901 and BGC-823 cell lines were established which could function in gastric cancer research on carcinogenesis mechanism and drug discovery. The two models showed different tumor behavior and the latter was more malignant than the former.

Keywords: Gastric cancer, Orthotopic implantation, Mouse model, Metastasis, Cell line