Development of 36 clones producing human monoclonal antibodies specific to cancer cells and their ability to inhibit cancer cell growth.

The development of a specific antibody for cancer therapy could enable a potent strategy for overcoming cancer. As ideal immunotherapy, a human monoclonal antibody (HuMoAb) might have a useful antitumor effect without any lethal toxicities. Thirty-six unique clones producing HuMoAbs were successfully developed using tumor infiltrating lymphocytes collected from 28 patients with several malignant solid tumors. The 36 tumor-specific immunoglobins were found among 9,450 clones after 43 fusions by the conventional hybridoma method. Among these 36 HuMoAbs, 9 had a remarkable tumor-specific reaction and no reaction with normal tissues, as determined with quantum dots-streptavidin and a fluorescence microscope. The inhibition of cell proliferation by the HuMoAbs was evaluated with the MTT assay. Over 40% cell growth inhibition was confirmed with 4 of the 36 HuMoAbs. Two of the antibodies had highly-specific reactivity to carcinomatous lesions with strong growth inhibition and up to 94.3% inhibition of the control growth. In conclusion, 36 clones with HuMoAbs that have specific reactions with cancer cells were successfully established. These HuMoAbs might be utilized as either anticancer or drug delivery agents.