Differentiation of angiogenic burden in human cancer xenografts using a perfusion-type optical contrast agent (SIDAG).
BACKGROUND
Use of fluorescence imaging in oncology is evolving rapidly, and nontargeted fluorochromes are currently being investigated for clinical application. Here, we investigated whether the degree of tumour angiogenesis can be assessed in vivo by planar and tomographic methods using the perfusion-type cyanine dye SIDAG (1,1'-bis- [4-sulfobutyl]indotricarbocyanine-5,5'-dicarboxylic acid diglucamide monosodium).


METHODS
Mice were xenografted with moderately (MCF7, DU4475) or highly vascularized (HT1080, MDA-MB435) tumours and scanned up to 24 hours after intravenous SIDAG injection using fluorescence reflectance imaging. Contrast-to-noise ratio was calculated for all tumours, and fluorochrome accumulation was quantified using fluorescence-mediated tomography. The vascular volume fraction of the xenografts, serving as a surrogate marker for angiogenesis, was measured using magnetic resonance imaging, and blood vessel profile (BVP) density and vascular endothelial growth factor expression were determined.


RESULTS
SIDAG accumulation correlated well with angiogenic burden, with maximum contrast to noise ratio for MDA-MB435 (P < 0.0001), followed by HT1080, MCF7 and DU4475 tumours. Fluorescence-mediated tomography revealed 4.6-fold higher fluorochrome concentrations in MDA-MB435 than in DU4475 tumours (229 +/- 90 nmol/l versus 49 +/- 22 nmol/l; P < 0.05). The vascular volume fraction was 4.5-fold (3.58 +/- 0.9% versus 0.8 +/- 0.53%; P < 0.01), blood vessel profile density 5-fold (399 +/- 36 BVPs/mm2 versus 78 +/- 16 BVPs/mm2) and vascular endothelial growth factor expression 4-fold higher for MDA-MB435 than for DU4475 tumours.


CONCLUSIONS
Our data suggest that perfusion-type cyanine dyes allow assessment of angiogenesis in vivo using planar or tomographic imaging technology. They may thus facilitate characterization of solid tumours.
Wall
Alexander
A
Department of Clinical Radiology, University Hospital of Münster, 48129 Münster, Germany. walla@uni-muenster.de
Persigehl
Thorsten
T
Hauff
Peter
P
Licha
Kai
K
Schirner
Michael
M
Müller
Silke
S
von Wallbrunn
Angelika
A
Matuszewski
Lars
L
Heindel
Walter
W
Bremer
Christoph
C
D000230:Adenocarcinoma / Q000098:blood supply; D000818:Animals; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000098:blood supply; D002232:Carbocyanines; D045744:Cell Line, Tumor; D003287:Contrast Media; D005354:Fibrosarcoma / Q000098:blood supply; D005453:Fluorescence; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging / Q000379:methods; D008545:Melanoma / Q000098:blood supply; D051379:Mice; D009369:Neoplasms / Q000098:blood supply* / Q000737:chemistry; D009389:Neovascularization, Pathologic / Q000175:diagnosis*; D055095:Optics and Photonics; D014054:Tomography / Q000379:methods*; D014183:Transplantation, Heterologous; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis
C430879:1,1'-bis-(4-sulfobutyl)indotricarbocyanine-5,5'-dicarboxylic acid diglucamide; D002232:Carbocyanines; D003287:Contrast Media; D042461:Vascular Endothelial Growth Factor A