TBJ MURINE NEUROBLASTOMA RESISTS DIBUTYRYL CYCLIC AMP-INDUCED DIFFERENTIATION AND EFFECTS ON METALLOPROTEINASE SECRETION

Background: Nonmetastatic C1300 murine neuroblastoma and TBJ, a metast atic variant, exhibit different mechanisms of metastasis and invasion. Methods: In this study, they were examined for response to 1 mmol/L d ibutyryl cyclic AMP in vitro. Results: (1) dCAMP induced morphological differentiation in 20% to 40% of C1300 cells, whereas TBJ resisted di fferentiation. (2) Untreated TBJ expressed 92-kDa metalloproteinase, w hereas C1300 expressed none, These results were nor affected by dCAMP. (3) Growth curves of untreated C1300 and TBJ were exponential. Dibuty ryl CAMP induced a plateau in C1300 growth that was confirmed by incre ased S-phase cells by cell cycle analysis. Conclusions: TBJ growth was unaffected by dCAMP. Apoptosis, as assayed by Hoechst-merocyanine sta ining test, was not involved in the growth plateau. Copyright (C) 1998 by W.B. Saunders Company.