Effect of cold insoluble globulin on carcinoma cell growth in vitro

The effects of cold insoluble globulin (CIG) on short-term cultures of Walker 256 carcinoma cells have been determined. Carcinoma cell proliferation in the presence of normal or heat-treated (opsonically inactive) rat serum, affinity-purified CIG, albumin, or medium alone was measured by determination of [3H]TdR incorporation into cellular DNA and by actual cell counts. The addition of serum or affinity-purified CIG significantly reduced proliferation compared with that which occurred in the presence of albumin or medium alone. The reduced proliferation caused by CIG is due to an inhibition of cell growth (cytostasis) rather than to cell death (cytotoxicity) as demonstrated by a lack of [125I]UdR release from prelabeled carcinoma cells incubated with CIG.