Amplification, Cloning, Sequences Analysis Of Heavy Chain Variable-region McAb Genes And Preparation Of Recombinant Immunotoxin For Urinary Bladder Cancer

Bladder cancer is the most common malignant turmor of urinary tract, up to now, there are not optimal therapeutic modality for it. Targeting therapy of McAb have opened up a new perspective for cure bladder cancer, unfortunately, the most of used McAb are mouse original, the foreign immunoglobulin can elicit an anti- globulin response that may cause allergic reaction and interfere with the therapy. Recently, McAb mediated targeting therapy has been inno-vated by genetic engineering to create less immunogenic and more effective antibodies. Some antibodies are easily cleared from the circulation and have a better tumor accessibility, especially, armed with toxin, the anti-tumor effectiveness could be enhanced powerfully.This study consisted of amplification, cloning and sequences analysis of heavy chain variable- region genes from a hybridoma produced an antibody that reacts with human urinary bladder cancer cells, we used Polymerase chain reaction (PCR) for amplification of the functional antibody genes. After sequenceing, the DNA fragment was cloned into an Escherichia coli expressive vector that containing a portion of Pseudomonas Exotoxingene. The results of experiment revealed that the expressed protein could block the binding of parent McAb with bladder cancer cells by immunoflurescence assay. Although the initial trials results showed blocking activity being not so prominent, the study should be possible to select a better and more suitable targeting products for next trial. On the other hand, cloning functional heavy chain variable-region antibody gene also provided the groundwork for preparation of single chain antibody, single chain immunotoxin and human/mouse chimeric antibodies. We anticipate that the recombinant immunotoxin would play a important role in the adjunct treatment of metastatic bladder cancer.