Transformation of C3H/10T1 2 cells and induction of EBV-early antigen in Raji cells by altertoxins I and III.
Moulds of the genus Alternaria are common contaminants of some food crops. Some isolates have been shown to produce mutagenic compounds called altertoxins. Altertoxin I (ATX-I) and altertoxin III (ATX-III) were examined for activity in the Raji cell Epstein-Barr virus early antigen (EBV-EA) induction system and in the C3H/10T1 2 murine fibroblast cell transformation system. Exposure of Raji cells to ATX-I or ATX-III activated EBV-EA expression by 8- and 9.5-fold, respectively. A single exposure of C3H/10T1 2 cultures to ATX-I or ATX-III resulted in significant increases in cell transformation, and the response to ATX-I was stronger. Both altertoxins enhanced the transformation of C3H/10T1 2 cells, and chronic exposure of non-initiated C3H/10T1 2 cells to ATX-I and ATX-III, starting 6 days after cells were plated, resulted in cell transformation in 8 59 and 12 37 dishes, respectively, compared with transformation in only 2 63 control dishes. Since activation of EBV-EA in Raji cells has been positively correlated with tumour promoters, these data together indicate that ATX-I and ATX-III are not just mutagens but have a potential role in cell transformation.
Osborne
L C
LC
Division of Microbiology, Food and Drug Administration, Cincinnati, OH 45226, USA.
Jones
V I
VI
Peeler
J T
JT
Larkin
E P
EP