Background: Human cancer cell lines express human choriogonadotropin (hCG), its subunits and derivatives, regardless of their origin and type. It appears that hCG is a common phenotype in human cancer cell lines. In this research, the effects of hCG targeting monoclonal antibodies (7D9, T18H7 and T8B12) on human cancer cell lines were evaluated.
Methods:  Monoclonal antibody secreting hybridomas were proliferated and injected intraperitoneally to Balb/C mice after treatment with pristine. Two weeks later, ascites fluid was collected. Purification of aforementioned antibodies from ascites fluid was performed using G-protein affinity followed by ion exchange chromatography. SDS-PAGE and ELISA confirmed the structure and functional integrity of the purified antibodies, respectively. Two human cancer cell lines "Hela" and "MDA" were treated by the purified antibodies. Three days later, different wells were imaged and the cells counted.
Results:  SDS-PAGE gel (None-reducing) indicated consistency of band migration patterns with control antibodies. ELISA test using hCG antigens indicated that the produced antibodies could detect hCG antigens. Cell lines were cultured and treated with different concentrations of each antibody. Counting and imaging different wells of treated plates, indicated that 7D9 antibody had a more significant (P<0.01) cytotoxic effect on cancer cell lines than the control cells.
Conclusion: HCG targeting monoclonal antibodies can be used for targeted cancer therapy, as human cancer cells express hCG gene. 7D9 antibody that exhibits protease activity is a proper candidate for this purpose, as it possesses both antagonistic and enzymatic properties.