GGN-MRP is an extract from the Maillard reaction products of nitrite with glucose and glycine in
the Maillard browning system. No genotoxicity of GGN-MRP in culture hepatocyte was found. A
two-stage transformation protocol was used to transform chemically mouse embryo fibroblast
C3H10T1/2 cells. To initiate transformation, the cells were treated with benzo[a]pyrene [B(a)P; 0.1
µg/mL], and GGN-MRP (0.01, 0.1, and 1.0 mg/mL) was employed to subsequently complete the
transformation process. Malignant transformed foci were formed in B(a)P-initiated and GGN-MRPpromoted
C3H10T1/2 cells after 8 weeks. Cells treated with GGN-MRP alone failed to induce
transformation. However, cells initiated with B(a)P and promoted by GGN-MRP demonstrated
oncogenic properties. Transformed colonies derived from GGN-MRP-treated cells exhibited enhanced
growth rate, anchorage independence, and tumorgenicity in animals relative to parent cells. These
results indicated that GGN-MRP contains a tumor promoter and may induce tumor promotion by
two-stage oncogenesis.
