Optical imaging of MMP expression and cancer progression in an inflammation‐induced colon cancer model

Abstract

The purpose of this study was to use a near-infrared (NIR) fluorescent cyclic His-Try-Gly-Phe peptide to characterize and image the expressions of matrix metalloproteinases (MMPs), which are correlated with cancer promotion, in an inflammation-induced colorectal cancer (ICRC) model. We explored the relationship between the development of colon cancer and the expression of MMPs at the same colonic sites in ICRC models. To develop ICRC models, mice were administered a single intraperitoneal dose (10 mg/kg) of azoxymethane (AOM) and exposed orally to 2% dextran sodium sulfate (DSS) for one week. MMP-2 expression and b-catenin activation in colonic lesions were characterized by immunohistochemical (IHC) staining. After being treated with inducers for some time, cancerous lesions were found to express high b-catenin and MMP-2. The profiles of MMP expression were correlated with b-catenin activation in the colonic lesions. c(KAHWGFTLD)NH 2 (C6) peptide was prepared by standard Fmoc peptide synthesis to target MMPs. Molecular weight of Cy5.5-C6 was 1,954.78 g/mol (calculated MW 5 1955.23 g/mol). The in vitro characterization of Cy5.5-C6 showed MMP binding specificity in a cell experiment. In vivo NIRF imaging showed high accumulation of Cy5.5-C6 in tumors with associated expression of MMP-2 in colonic lesions after intravenous injection. The MMP-2 specificity of Cy5.5-C6 was confirmed by successful inhibition of probe uptake in the tumor due to the presence of excess C6 peptide. The use of Cy5.5-C6 to target MMP-2 has the potential to be developed into an effective molecular imaging agent to monitor ICRC progress.Human colorectal cancer (CRC) is one of the most common fatal malignancies and the leading cause of death. Most deaths related to CRC result from systemic metastatic disease rather than the primary tumor in the local lesion.1-3 Key processes for the metastasis of CRC include cleavage of the basement membrane and destruction of the extracellular matrix (ECM), leading to systemic circulation of tumor cells and invasion into blood vessels and lymphatic channels. 4-6The matrix metalloproteinases (MMPs) are a family of enzymes that participate in the degradation of ECM and basement membrane, and in several other pathological events, such as atherosclerosis, tumor invasion and inflammatory bowel disease. [7][8][9] The expressions and activities of MMPs are often abnormally elevated in cancers compared to normal tissues, and these elevated levels are correlated with cancer invasion and metastasis as well as prognosis. In particular, it has been established that the levels of MMPs can be used to predict the metastatic activities and prognoses of cancer patients. 10,11 Of the MMPs, MMP-2 and -9 (gelatinase A and B) are the most highly correlated with metastatic capacity in CRC. Thus, considering the roles of MMP-2 and -9 in tumor progression, invasion and metastasis, we hypothesized that they would be good targets for noninvasive molecular imaging of tumors and for use in predicting the metastatic potential of cancer.M...

Matrix metalloproteinase-9 involvement in the structural plasticity of dendritic spines

“…In recent years, a number of new MMP-9 activity biosensors have been developed (Faust et al, 2008; Fudala et al, 2011; Akers et al, 2012; Gustafson et al, 2013) in response to the perceived shortcomings of classical zymographic approaches. The potential of MMP-9 as a prognostic marker of cancer led to considerable interest in developing diagnostic and analytical probes to detect the proteolytic activity of MMP-9 in cancer (for a survey of several MMP-9 activity probes used in cancer detection, see Roy et al, 2011; for a review of MMP-9 detection methods in cancer, see Scherer et al, 2008; for MMP-9 near-infrared fluorescence probes in in vivo imaging, see Wallis de Vries et al, 2009; Kaijzel et al, 2010; Akers et al, 2012; Lee et al, 2012). We recently developed a genetically encoded fluorescence resonance energy transfer (FRET)-based MMP-9 activity biosensor (Stawarski et al, 2014) that is compatible with live cell imaging approaches and can be used to study the effects of MMP-9 on structural plasticity with very high spatiotemporal resolution.…”

Preparation and Evaluation of 99mTc‐labeled anti‐CD11b Antibody Targeting Inflammatory Microenvironment for Colon Cancer Imaging

“…Hence, signal intensities strongly correlated with tumor stages from adenoma to adenocarcinoma . In accordance, MMP‐activatable probes were manifested effectively in an inflammation‐induced colon cancer model as well . However, these probes utilizing the NIRF were with a questionable clinical values.…”

Development of a Novel PET Tracer [18F]AlF-NOTA-C6 Targeting MMP2 for Tumor Imaging

“…Although C6 conjugated with Cy5.5 has been successfully used for the visualization of tumors in vivo , such as prostate PC3, glioma U87, and inflammation-induced colon tumors [ 17 , 18 ], to our knowledge, this study is the first time that C6 was labeled with [ 18 F]-fluoride. Tumor imaging and biodistribution experiments have shown the potential of [ 18 F]AlF-NOTA-C6 as an imaging agent for MMP2-positive tumors.…”

“…The resulting peptide was more stable and exhibited a 4-fold increase in gelatinase inhibition. C6, with conjugation of a Cy5.5 near-infrared fluorescent dye molecule (Cy5.5-C6), has been visualized in vivo in many tumor models, such as prostate PC3, glioma U87, and inflammation-induced colon tumors [ 17 , 18 ]. However, this optical approach has low tissue penetrance and does not enable deep tissue localization; thus, its use in the clinic is restricted [ 1 ].…”