Assessment of the hepatic tumor extracellular matrix using elastin-specific molecular magnetic resonance imaging in an experimental rabbit cancer model

Sci Rep. 2020 Nov 27;10(1):20785. doi: 10.1038/s41598-020-77624-8.

Abstract

To investigate the imaging performance of an elastin-specific molecular magnetic resonance imaging (MRI) probe with respect to the extracellular matrix (ECM) in an experimental hepatic cancer model. Twelve rabbits with hepatic VX2 tumors were examined using 3 T MRI 14, 21, and 28 days after tumor implantation for two subsequent days (gadobutrol, day 1; elastin-specific probe, day 2). The relative enhancement (RE) of segmented tumor regions (central and margin) and the peritumoral matrix was calculated using pre-contrast and delayed-phase T1w sequences. MRI measurements were correlated to histopathology and element-specific and spatially resolved mass spectrometry (MS). Mixed-model analysis was performed to assess the performance of the elastin-specific probe. In comparison to gadobutrol, the elastin probe showed significantly stronger RE, which was pronounced in the tumor margin (day 14-28: P ≤ 0.007). In addition, the elastin probe was superior in discriminating between tumor regions (χ2(4) = 65.87; P < 0.001). MRI-based measurements of the elastin probe significantly correlated with the ex vivo elastinstain (R = .84; P <0 .001) and absolute gadolinium concentrations (ICP-MS: R = .73, P <0 .01). LA-ICP-MS imaging confirmed the colocalization of the elastin-specific probe with elastic fibers. Elastin-specific molecular MRI is superior to non-specific gadolinium-based contrast agents in imaging the ECM of hepatic tumors and the peritumoral tissue.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Contrast Media
  • Elastin / metabolism*
  • Extracellular Matrix / metabolism*
  • Extracellular Matrix / pathology
  • Female
  • Gadolinium
  • Liver Neoplasms, Experimental / diagnostic imaging*
  • Liver Neoplasms, Experimental / metabolism*
  • Liver Neoplasms, Experimental / pathology
  • Magnetic Resonance Imaging
  • Molecular Probes
  • Organometallic Compounds
  • Rabbits

Substances

  • Contrast Media
  • Molecular Probes
  • Organometallic Compounds
  • gadobutrol
  • Elastin
  • Gadolinium