Dietary folate deficiency suppresses N-methyl-N-nitrosourea-induced mammary tumorigenesis in rats
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Epidemiologic studies have suggested that dietary folate intake is inversely related to breast cancer risk. However, epidemiologic evidence has not been consistent nor has it provided unequivocal support for this purported inverse relationship. This study investigated the effect of dietary folate on N-methyl-N-nitrosourea (MNU)-induced mammary tumorigenesis in rats. Weanling, female Sprague-Dawley rats were fed diets containing either 0 (deficient; n = 22), 2 (basal dietary requirement, control; n = 20) or 8 mg (supplemented; n = 20) folate/kg diet for 30 weeks. At 50 days of age, rats received an i.p. injection of MNU (50 mg/kg body wt). At necropsy, all macroscopic mammary tumors were identified and examined microscopically. The effect of dietary folate on genomic DNA methylation in mammary tumorigenesis was determined by the in vitro methyl acceptance assay. The incidence of mammary adenoma and adenocarcinoma in the folate-deficient group was lower than that of the control and folate-supplemented groups (55 versus 90 and 75%, respectively, P = 0.043). Kaplan-Meier analyses also demonstrated a similar trend in the rates of appearance of either adenoma or adenocarcinoma (P = 0.06). In contrast, folate supplementation did not significantly modulate mammary tumorigenesis compared with the control group. Although mammary tumors were significantly hypomethylated compared with non-neoplastic mammary tissues in each dietary group (P < 0.03), folate status did not significantly affect the extent of DNA methylation. The data suggest that dietary folate deficiency of a moderate degree suppresses, whereas folate supplementation at four times the basal dietary requirement does not significantly modulate, mammary tumorigenesis in this model. The role of folate in mammary tumorigenesis needs to be clarified for safe and effective prevention of breast cancer.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it