Inhibition of tumor cell growth by a human B-cell line

An Adenocarcinoma cell line (Breast-M) and an Epstein-Barr virus (EBV)-infected B-cell line (Hairy-BM) were established from breast tumor tissue. The Hairy-BM was CD20+, CD25 (Tac)+ and surface immunoglobulin (sIg)+. Hairy-BM suppressed the in vitro proliferation of Breast-M in a time and a dose-dependent manner. The suppression was also found in 5 different human tumor targets showing tumor-Hairy-BM binding, but not; in 2 murine tumor targets showing no significant tumor-Hairy-BM binding. Lytic activity of Hairy-BM was found only against Breast-M.