USE OF A DNA MICROFLUOROMETRIC ASSAY TO MEASURE PROLIFERATE RESPONSE OF MINK LUNG CELLS TO PURIFIED TGF beta AND TO TGFp ACTIVITY FOUND IN PROSTATE CELL CONDITIONED MEDIUM

摘要

The proliferative response of MvlLu cells to purified TGF beta_1, or TGFp-like activity released by various cells into medium conditioned over a 24-h period was quantitated by adapting a rapid DNA fluorometric assay. Acid activation of the conditionedmedium allowed the amount of biologically latent versus active TGFP to be quantitated. A neutralizing antibody specific for TGF beta_(1, 1.2, and 2,0) completely blocked the growth inhibition observed treating MvlLu cells with either purified TGF beta_1or medium containing secreted TGFp-like activity conditioned by DU145 prostate cells. In contrast to other assays commonly used to measure TGFP activity, the proliferative response is related directly to DNA content rather than as a reflection of enzymatic activity or incorporation of ~3H-thymidine. The necessity for radioactive isotope usage has been eliminated, and the biological response can be quantitated over a period of days.