Orthotopic Implantation of Intact Tumor Tissue Leads to Metastasis of OCUM-2MD3 Human Gastric Cancer in Nude Mice Visualized in Real Time by Intravital Fluorescence Imaging.

Abstract

BACKGROUND/AIM:

Orthotopic (literally "correct place") implantation of cancer in nude mice has long been known to be superior to subcutaneous transplantation because the orthotopic tumor can metastasize. We reported previously on surgical orthotopic implantation (SOI) of gastric cancer tissue in nude mice resulting in the formation of metastases in 100% of the mice with extensive primary growth to the regional lymph nodes, liver, and lung. In contrast, when cell suspensions were used to inject gastric cancer cells orthotopically, metastases occurred in only 6.7% of the mice with local tumor formation, emphasizing the importance of orthotopically implanting intact tissue to allow full expression of metastatic potential. However, the different behavior of tumors implanted orthotopically by the two methods has not been visualized in real time.

MATERIALS AND METHODS:

OCUM-2MD3 human gastric cancer cells labeled with the fluorescent protein Azami-Green were implanted orthotopically as cells or tissue in nude mice.

RESULTS:

Orthotopic implantation of cells resulted in local spread on the stomach. In contrast, SOI of tumor tissue of OCUM-2MD3 resulted in vessel spread of the Azami-Green-expressing cancer cells. Metastasis was also observed in the left lobe of the liver after SOI.

CONCLUSION:

These results demonstrate the physiological importance of intact cancer tissue for orthotopic implantation in order for tumors to properly grow and express their metastatic potential.

• Authors: Takashi Murakami, Yong Zhang, Xiaoen Wang, Yukihiko Hiroshima, Hiroaki Kasashima, Masakazu Yashiro, Kosei Hirakawa, Atsushi Miwa, Tasuku Kiyuna, Ryusei Matsuyama, Kuniya Tanaka, Michael Bouvet, Itaru Endo, Robert M Hoffman
• Journal: Anticancer research (Anticancer Res) Vol. 36 Issue 5 Pg. 2125-30 (May 2016) ISSN: 1791-7530 [Electronic] Greece
• PMID: 27127113 (Publication Type: Journal Article)
• Copyright: Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Topics

• Animals
• Cell Line, Tumor
• Heterografts
• Humans
• Mice
• Mice, Nude
• Optical Imaging
• Stomach Neoplasms (pathology)