Am. Eijan et al., DIFFERENTIAL NITRIC-OXIDE RELEASE AND SENSITIVITY TO INJURY IN DIFFERENT MURINE MAMMARY-TUMOR CELL-LINES, INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE, 2(5), 1998, pp. 625-630
The purpose of this study was to determine whether nitric oxide (NO) p
roduction by different mammary tumor cell lines correlated with their
sensitivity to NO mediated injury. Three mammary tumor cell lines LM2,
LM3 and LMM3 syngeneic to BALB/c mice were cultured in vitro with IFN
gamma + LPS. Different levels of NO production among the three lines
were detected in culture supernatants. The only tumor cell line which
did not produce NO (LM2) showed the highest sensitivity to SNP-derived
NO cytotoxicity (87%), while LM3 and LMM3 which both produced higher
levels of Nb than LM2, showed lower cytotoxicity by SNP (39% and 22% r
espectively). Spleen cells (SC) from M2 tumor bearing mice (TBM) were
able to lyse LM2 cells by NO-dependent mechanisms. SC from M3-TBM exer
ted cytotoxicity against LM3 cells mainly by NO-independent mechanisms
. Thus, we postulate an inverse correlation between NO production and
NO mediated cytotoxicity in the three mammary tumor cell lines. It is
possible that tumor cells producing NO develop mechanisms to resist NO
injury.