Related Experiment Videos
Effect of adenosine 3',5' monophosphate on the mutation frequency induced by N-methyl-N'-nitro-N-nitrosoguanidine
1Institut de Recherche Interdisciplinaire, Faculty of Medicine, Free University of Brussels, Campus Erasme, Belgium.
Abstract:
The effect of increased cellular concentrations of adenosine 3',5' monophosphate (cAMP) upon mutation frequency induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was studied in V79 Chinese hamster lung cells. Incubation with either forskolin, which increased the accumulation of cAMP, or 8BrcAMP, an analogue of cAMP, resulted in an increase in the mutation frequency which was concentration-dependent, regardless of whether these agents were added before or after mutagen treatment. Increased cAMP concentrations were shown in these cells to inhibit growth; however, this does not seem to be the mechanism responsible for the increase in mutation frequency as low serum concentrations which also retard growth reduced the mutation frequency observed with MNNG.
Insights
Elevated cyclic adenosine monophosphate (cAMP) levels increase mutation frequency in V79 cells treated with N-methyl-N′-nitro-N-nitrosoguanidine (MNNG). This effect is concentration-dependent and not due to growth inhibition.
Area of Science:
- Cellular biology
- Molecular toxicology
- Genetics
Background:
- Cyclic adenosine monophosphate (cAMP) is a crucial second messenger involved in various cellular processes.
- N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) is a known mutagen that induces DNA damage.
- Understanding factors influencing mutagenicity is vital for assessing environmental and chemical risks.
Purpose of the Study:
- To investigate the impact of increased intracellular cAMP concentrations on MNNG-induced mutation frequency in V79 Chinese hamster lung cells.
- To determine if cAMP-mediated growth inhibition contributes to changes in mutation frequency.
Main Methods:
- V79 cells were treated with forskolin or 8-bromoadenosine 3',5'-monophosphate (8BrcAMP) to elevate cAMP levels.
- Cells were subsequently exposed to N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) to induce mutations.
- Mutation frequency was assessed, and cell growth was monitored under varying serum concentrations.
Main Results:
- Both forskolin and 8BrcAMP significantly increased mutation frequency in a dose-dependent manner.
- The elevation in mutation frequency occurred irrespective of whether cAMP-modulating agents were administered before or after MNNG treatment.
- While increased cAMP inhibited cell growth, this was not the primary mechanism for enhanced mutagenicity, as reduced serum, which also inhibited growth, decreased MNNG-induced mutations.
Conclusions:
- Elevated cellular cAMP levels potentiate the mutagenic effects of MNNG in V79 cells.
- The observed increase in mutation frequency is directly linked to cAMP modulation, not secondary to growth inhibition.
- These findings highlight a novel role for cAMP in modulating chemical mutagenesis.