Anatomical and Functional Imaging of Tumors in Animal Models

Abstract

This review focuses on anatomical (computed tomography, magnetic resonance imaging) and functional (positron emission tomography) imaging methods for tumor localization and identification of experimentally induced tumors in animal models, especially pheochromocytoma. Although anatomical imaging can precisely locate primary and metastatic tumors, functional imaging has high specificity for some tumors, especially those of endocrine origin. This is due to the fact that endocrine tumor cells take up hormone precursors, express hormone receptors and transporters, and synthesize, store, and release hormones. These characteristic properties of endocrine tumors enable investigators to create highly specific radiopharmaceuticals, particularly for positron emission tomography. For example, localization of pheochromocytoma involves [18F]-6F-dopamine. It is a highly specific radiopharmaceutical since it uses the norepinephrine transporter system expressed in most pheochromocytoma cells. Here we review both anatomical and functional imaging methods that are used conjointly in order to localize and identify specific characteristics of tumors.

Noninvasive monitoring of a murine model of metastatic pheochromocytoma: A comparison of contrast‐enhanced microCT and nonenhanced MRI

“…Un-anesthetized six to eight weeks female athymic nude mice (NCr-nu, Taconic, Germantown, NY) were injected by tail vein with mouse pheochromocytoma cells (MPC 4/30PRR) (5). The MPC cells were maintained as described previously (3,4,7,8). The number of injected MPC cells varied from 1 × 10 6 to 5 × 10 6 per injection in 100 μl of PBS (Sigma Chemicals Co., St. Louis).…”

“…There is interest in developing animal models and imaging techniques of metastatic pheochromocytoma to use in experimental treatment studies. In the present study, we used a previously described mouse model of metastatic pheochromocytoma (3,4) established by using mouse pheochromocytoma (MPC) cells harvested from tumors from Nf1 knockout mice (5). This syngeneic model of metastatic pheochromocytoma produces a metastatic pattern similar to that seen in human metastatic pheochromocytoma including involvement of the liver, lung, ovaries, adrenal glands, and bone metastases.…”

Expression of somatostatin receptors, dopamine D2 receptors, noradrenaline transporters, and vesicular monoamine transporters in 52 pheochromocytomas and paragangliomas

“…NAT belongs to the SLC6 family of plasma membrane transporters and acts by rapidly sequestering released biogenic amines (Amara et al 1998). In neuroendocrine tumors, NAT allows the entry of radiolabeled elements such as 131 I-MIBG (Glowniak et al 1993) and 18 F-dopamine ( 18 F-DA) (Martiniova et al 2006). MIBG accumulation is well correlated to NAT expression in neuroblastomas (Mairs et al 1994), but data are lacking for PCC.…”

“…One is based on meta-iodobenzylguanidine (MIBG), a biogenic amine analog taken up by membrane noradrenaline transporter (NAT) and concentrated in tumors via vesicular monoamine transporters (VMAT). This molecule is labeled by 123 I for diagnosis and 131 I for diagnosis and treatment (Kolby et al 2003, Cleary & Phillips 2006, Martiniova et al 2006. The second approach is based on somatostatin (SRIF) receptor radioligands (Reubi et al 2000a).…”

Familial pheochromocytomas and paragangliomas

“…Additionally, knowledge of the genetics of pheochromocytoma/paraganglioma has led to developments that have improved our understanding of the disease process as a whole. For example, the development of the mouse pheochromocytoma cell line (MPC) from NF1 (Powers, Evinger, Tsokas et al, 2000), and the more aggressive mouse tumor tissue (Martiniova, Lai, Elkahloun et al, 2009), have greatly improved and eased our ability to study pheochromocytoma signaling pathways as well as test new imaging modalities (Martiniova, Perera, Brouwers et al, 2011, Martiniova, Ohta, Guion et al, 2006, Martiniova, Cleary, Lai et al, 2012). …”