Direct external imaging of nascent cancer, tumor progression, angiogenesis, and metastasis on internal organs in the fluorescent orthotopic model

Mouse tumor models have undergone profound improvements in the fidelity of emulating human disease. Replacing ectopic s.c. implantation with organ-specific orthotopic implantation reproduces human tumor growth and metastasis. Strong fluorescent labeling with green fluorescent protein along with inexpensive video detectors, positioned externally to the mouse, allows the monitoring of details of tumor growth, angiogenesis, and metastatic spread. However, the sensitivity of external imaging is limited by light scattering in intervening tissue, most especially in skin. Opening a reversible skin-flap in the light path markedly reduces signal attenuation, increasing detection sensitivity many-fold. The observable depth of tissue is thereby greatly increased and many tumors that were previously hidden are now clearly observable. This report presents tumor images and related quantitative growth data previously impossible to obtain. Single tumor cells, expressing green fluorescent protein, were seeded on the brain image through a scalp skin-flap. Lung tumor microfoci representing a few cells are viewed through a skin-flap over the chest wall, while contralateral micrometastases were imaged through the corresponding skin-flap. Pancreatic tumors and their angiogenic microvessels were imaged by means of a peritoneal wall skin-flap. A skin-flap over the liver allowed imaging of physiologically relevant micrometastases originating in an orthotopically implanted tumor. Single tumor cells on the liver arising from intraportal injection also were detectable. Possible future technical developments are suggested by the image, through a lower-abdominal skin-flap, of an invasive prostate tumor expressing both red and green fluorescent proteins in separate colonies.

[1]  P. Malone,et al.  Prostate , 1995 .

[2]  Y. Miyagi,et al.  Governing step of metastasis visualized in vitro. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[3]  Meng Yang,et al.  Use of histoculture and green fluorescent protein to visualize tumor cell host interaction , 1997, In Vitro Cellular & Developmental Biology - Animal.

[4]  Y. Miyagi,et al.  Cancer invasion and micrometastasis visualized in live tissue by green fluorescent protein expression. , 1997, Cancer research.

[5]  Y. Miyagi,et al.  Visualization of the metastatic process by green fluorescent protein expression. , 1997, Anticancer research.

[6]  H. Shimada,et al.  Widespread skeletal metastatic potential of human lung cancer revealed by green fluorescent protein expression. , 1998, Cancer research.

[7]  Xiaoen Wang,et al.  Surgical orthotopic implantation allows high lung and lymph node metastatic expression of human prostate carcinoma cell line PC‐3 in nude mice , 1998, The Prostate.

[8]  H. Shimada,et al.  Genetically fluorescent melanoma bone and organ metastasis models. , 1999, Clinical cancer research : an official journal of the American Association for Cancer Research.

[9]  H. Shimada,et al.  A fluorescent orthotopic bone metastasis model of human prostate cancer. , 1999, Cancer research.

[10]  C. Contag,et al.  Visualizing the kinetics of tumor-cell clearance in living animals. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[11]  G. Naumov,et al.  Cellular expression of green fluorescent protein, coupled with high-resolution in vivo videomicroscopy, to monitor steps in tumor metastasis. , 1999, Journal of cell science.

[12]  M. Coburn,et al.  Cutaneous window for in vivo observations of organs and angiogenesis. , 2000, The Journal of surgical research.

[13]  H. Shimada,et al.  Whole-body optical imaging of green fluorescent protein-expressing tumors and metastases. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[14]  R. Hoffman,et al.  Visualizing gene expression by whole-body fluorescence imaging. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[15]  P. Jiang,et al.  Whole-body and intravital optical imaging of angiogenesis in orthotopically implanted tumors , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[16]  W. Falk,et al.  A primary tumor promotes dormancy of solitary tumor cells before inhibiting angiogenesis. , 2001, Cancer research.

[17]  Xiaoen Wang,et al.  Spatial–temporal imaging of bacterial infection and antibiotic response in intact animals , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[18]  R. B. Campbell,et al.  In vivo measurement of gene expression, angiogenesis and physiological function in tumors using multiphoton laser scanning microscopy , 2001, Nature Medicine.

[19]  J. Folkman,et al.  Generation of multiple angiogenesis inhibitors by human pancreatic cancer. , 2001, Cancer research.

[20]  B. Glick,et al.  Rapidly maturing variants of the Discosoma red fluorescent protein (DsRed) , 2002, Nature Biotechnology.

[21]  Meng Yang,et al.  Chronologically-specific metastatic targeting of human pancreatic tumors in orthotopic models , 2004, Clinical and Experimental Metastasis.

[22]  Meng Yang,et al.  A highly metastatic Lewis lung carcinoma orthotopic green fluorescent protein model , 2004, Clinical & Experimental Metastasis.

[23]  Yohei Miyagi,et al.  Metastatic patterns of lung cancer visualized live and in process by green fluorescence protein expression , 1997, Clinical & Experimental Metastasis.

[24]  Robert M. Hoffman,et al.  Orthotopic Metastatic Mouse Models for Anticancer Drug Discovery and Evaluation: a Bridge to the Clinic , 2004, Investigational New Drugs.