ABSTRACT
This chapter provides an overview of the various cells and proteins within the tumor microenvironment, applicable as targets for molecular imaging, including cell types, extracellular matrix components, and alternative approaches. Tumor vasculature associated features such as perfusion, permeability, and density can be visualized using Magnetic Resonance Imaging (MRI), positron emission tomography, computed tomography, fluorescence molecular tomography, optical coherence tomography, and photoacoustic imaging. Hyaluronidase is a protein involved in hyaluronan hydrolysis, and is used as addition to chemotherapy to improve drug delivery by remodeling of the extracellular matrix. The activity of hyaluronidase was evaluated using MRI contrast agents conjugated to hyaluronan, which show increased relaxivity after degradation. Transglutaminases are enzymes that catalyze modification of proteins. Higher levels of phosphatidylcholine, the most abundant phospholipid in men, are more observed in cancer tissue compared to normal tissue and this overexpression is associated with malignant transformation, invasion, and metastatic potential.
