Studies on a Cell Line Derived from the L1210 Murine Leukemia with Altered Surface Properties and Decreased Capacity for Tumor Production¹ Free

A cell line (L1210/A) was derived from the murine leukemia L1210 and differed from L1210 in the following respects: (a) L1210/A adhered strongly to glass or plastic surfaces, and L1210 grows in suspension culture. (b) L1210/A produced a slow-growing tumor in BALB/c × DBA/2 F₁ mice. Inoculation of 10⁶ cells killed these mice in about 21 days, in contrast to the 7-day survival with L1210; (c) L1210/A demonstrated a lower electrophoretic mobility than L1210; (d) incorporation of precursors into nucleic acid, protein, and glycoprotein was much slower in L1210/A; (e) L1210/A cells contain considerably less surface glycoprotein in papain-sensitive linkages; (f) level of a transferase involved in addition of sialic acid to a suitable receptor was lower in L1210/A, as were levels of several glycosidases.

We find alterations in the surface, as demonstrated by altered electrophoretic mobility, associated with a cell type (L1210/A) less capable of surviving in the environment of the host, hence less rapidly lethal to the host. Lowered levels of enzymes involved in glycoprotein metabolism apparently contribute to cell surface alterations.

When grown in spinner culture, L1210/A cells respond by elevation of levels of enzymes involved in glycoprotein metabolism; electrophoretic mobility and enzyme levels return to values associated with L1210 cells. However, the tumor-producing ability of the spinner line is still below that of L1210, and the spinner culture cells will adhere to the vessel if stirring is stopped. Growth of L1210/A cells in spinner culture does not, therefore, produce a cell line equivalent to L1210.