[Growth inhibitory action of RGNTF-McAb on human retinoblastoma cell line Y-79].

The monoclonal antibody against the retinal ganglion neuronotrophic factor (RGNTF-McAb) was used in immunostaining of the Western blotting membrane separated from extract of human retinoblastoma cell line Y-79 to find that the latter contained a 30KD protein which was immunologically similar to the RGNTF secreted from the tectum of rat. The effect of different concentrations of RGNTF-McAb on the growth of Rb cells in cultures of different seeding concentrations was studied, revealing that the growth inhibitory action of RGNTF-McAb increased with increasing concentrations, up to 67% inhibition. Morphologically the growth and division of Rb cells were significantly inhibited as compared to the controls. The RGNTF-anti-idiotypic antibody was used for the localization of the RGNTF receptor, which the immunoreactive positive staining indicated to be on the surface of Rb cell membrane. The RGNTF-McAb could thus neutralize the RGNTF and inhibit growth of the Rb cells. These findings support the application of RGNTF-McAb to the treatment of retinoblastoma.