Abstract
An early and reliable assessment of therapeutic efficacy during the treatment of cancer is essential to achieve an optimal treatment regimen and patient outcome. The use of labeled peptides to monitor tumor response is associated with several advantages. For example, peptides are very stable, non-immunogenic, are easy to label for imaging, they undergo rapid clearance from the circulation, can penetrate tumor tissue, and are inexpensive to synthesize. In this review, studies using recombinant and non-recombinant peptides to monitor the response of glioblastoma multiforme, lung, breast, pancreas, colon, prostate, and skin carcinomas to radiation and/or chemotherapeutics such as camptothecin, doxorubicin, etoposide, 5-fluorouracil, paclitaxel, AG3340, sunitinib, and dasatinib, are presented. A consideration of the imaging techniques available to monitor peptide localization, including near-infrared (NIR) fluorescence, magnetic resonance imaging (MRI), positron emission tomography (PET), and ultrasonography, is also included. Peptides that have been successfully used to monitor various tumor types and therapies have been shown to target proteins that undergo changes in expression in response to treatment, endothelial cells that respond to radiation, or mediators of apoptosis. Peptides that are able to selectively bind responsive versus unresponsive tumors have also been identified. Therefore, the advantages associated with the use of peptides, combined with the capacity for selected peptides to assess tumor response as demonstrated in various studies, support the use of labeled peptides to evaluate the effectiveness of a given cancer therapy.
Keywords: Early prediction, monitor response, noninvasive imaging, recombinant peptide, response assessment, tumor response, Cancer Therapy, glioblastoma multiforme, skin carcinomas, chemotherapeutics, camptothecin, doxorubicin, 5-fluorouracil, paclitaxel, AG3340, sunitinib, dasatinib, imaging, near-infrared (NIR) fluorescence, magnetic resonance im-aging (MRI), positron emission tomography (PET), ultrasonography, apoptosis, radiation therapy, anti-angiogenic drugs, antibod-ies, genomic heterogeneity, computerized tomography, tyrosine kinase inhibitors, tumor-associated macrophage, fluorodeoxyglucose, positron emis-sion tomography (PET), tumor biomark-ers, necrosis, diffusion weighted imaging (DWI), dynamic contrast enhancement (DCE), magnetic reso-nance spectroscopy (MRS), positron emis-sion tomography, non-Hodgkin lymphoma, single-photon emis-sion computed tomography (SPECT), arginine-glycine-aspartic (RGD), biomarker, cell adhesion molecules, intercellular, molecule-1 (ICAM-1), murine, near infrared fluores-cence (NIR), AlexaFluor (AF) dye, immunohistochemistry, Lewis lung, cyanine-7, streptavidin, Immunofluorescence assays, human colon carcinoma, estrogen recep-tor/progesterone-negative, green fluores-cent protein, human pancreatic carcinoma, Src family kinases, focal adhesion, fibronectin matrix, hema-toxylin-eosin, tumor vascularization, albu-min, galactose, lipids, sensitive particle acoustic quantification (SPAQ), angiogenesis, glucosamino, phosphatidylserine (PS), ELISA, annexin V, topoisomerase II inhibi-tor, fluorescence microscopy assays, fluorescein isothiocyanate, hematoxylin-eosin, deoxynucleotidyl transferase, underglycosylated mucin-1, heterodimeric, human epi-dermoid carcinoma cells, rhodamine, propidium iodide, enzymatic proteolysis, T-lymphocyte cells, gastric carcinomas, adenocarcinomas, gemcitabine, iron oxide nanoparticles, oncogenic process