Different calcium requirements for proliferation of conditionally and unconditionally tumorigenic mouse cells.

Abstract

Conditionally tumorigenic BALB/3T3 mouse [fibroblast] cells (which produce tumors in BALB/c mice only under special conditions) cannot sustain DNA synthesis and consequently stop proliferating in media containing low concentrations (0-0.02 mM) of physiologically available Ca. Cells neoplastically transformed (tumorigenic in mice without special assistance) in vitro by different oncogens [SV40 and Kirsten murine sarcoma virus] can sustain DNA synthesis and proliferate in such Ca-deficient media. The possible importance for tumor growth of an ability to withstand Ca deprivation is examined. This property may be a reliable indicator of neoplastic transformation.