Background & objective: Matrix metalloproteinases (MMPs)play the important role in many steps of tumor growth and metastasis. Type IV collagenase, which is a key member of MMPs family, has been viewed as a promising target in tumor study. The aim of this study was to evaluate the tumor-specific distribution of the anti-type IV collagenase monoclonal antibody (mAb) 3G11 by radioimaging in tumor-bearing nude mice.
Methods: MAb 3G11 purified by affinity chromatography was labeled with either 131- or 125- iodide by the Iodogen method. Immunoreactivity of mAb 3G11 was determined by ELISA. (131)I-labeled 3G11 was incubated in three different media at 37 Celsius degree and its in vitro stability was tested. Normal BALB/c mice were injected intravenously with 388.5 kBq per mouse of (125)I-labeled 3G11 to explore the pharmacokinetic patterns. The scintigraphic images of human lung carcinoma PG xenografts grown subcutaneously in BALB/c nude mice were made after intravenously administrating of 6.44 MBq per mouse of (131)I-labeled 3G11.
Results: MAb 3G11 was more than 98% in purity via affinity purification. The immunoreactivity of mAb 3G11 decreased by approximately 10%-20% after cold iodination. Patterns of blood clearance of mAb 3G11 was defined as two-compartment model, with T(1/2alpha) and T(1/2beta) calculated to be 7.2 h and 345.2 h, respectively. (131)I-labeled 3G11 was almost stable in vitro for 72 h. A clear image of the xenografted tumor was obtained at 72 h, and it further improved at 120 h.
Conclusion: MAb 3G11 showed high specificity and affinity with tumor tissue through scintiscanning.