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Is N-methyl-N'-nitro-N-nitrosoguanidine a hormonal carcinogen? (Review)
Abstract:
The hormonal aspect of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) is discussed in relation to its carcinogenic potency for the gastric epithelium. The action of MNNG, as assessed in terms of a) the affinities for both the glucocorticoid receptor and androgen receptor of mouse, b) the effects on the turnover of hydrocortisone and dihydrotestosterone in the glandular stomach of mouse, c) the induction of ornithine decarboxylase in the same tissue, and d) the interfering effect on the hydrocortisone - linked acceleration of water turnover at the whole body level of a mouse, points to the steroid-mimetic nature of the carcinogen. It is suggested that MNNG may behave like an androgen antagonist on the one hand, and like a chimera between glucocorticoid agonist and glycocorticoid antagonist on the other hand. The proposition that a chemical carcinogen may have an interplay with the steroid and thyroid hormone receptor superfamily in the induction of malignant transformation is reviewed in the light of recent progress of steroid receptor biology.
Insights
N-methyl-N-nitro-N-nitrosoguanidine (MNNG), a carcinogen, may mimic steroid hormones. This interaction with hormone receptors could play a role in its carcinogenic effects on the gastric epithelium.
Area of Science:
- Endocrinology
- Carcinogenesis
- Molecular Biology
Background:
- N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) is a known carcinogen.
- The role of hormonal signaling in carcinogenesis is an area of active research.
Purpose of the Study:
- To investigate the hormonal mechanisms underlying the carcinogenic potency of MNNG on gastric epithelium.
- To explore the potential steroid-mimetic properties of MNNG.
Main Methods:
- Assessing MNNG's affinity for mouse glucocorticoid and androgen receptors.
- Evaluating MNNG's effects on hydrocortisone and dihydrotestosterone turnover in mouse gastric tissue.
- Measuring MNNG's induction of ornithine decarboxylase.
- Examining MNNG's interference with hydrocortisone-mediated water turnover.
Main Results:
- MNNG exhibits affinities for glucocorticoid and androgen receptors.
- MNNG influences the turnover of hydrocortisone and dihydrotestosterone.
- MNNG induces ornithine decarboxylase in gastric tissue.
- MNNG interferes with hydrocortisone-linked water turnover, suggesting steroid-mimetic activity.
Conclusions:
- MNNG displays steroid-mimetic properties, potentially acting as an androgen antagonist and a mixed glucocorticoid agonist/antagonist.
- Chemical carcinogens may interact with the steroid hormone receptor superfamily in cancer induction.
- Further research into steroid receptor biology is crucial for understanding MNNG's carcinogenesis.