Abstract 2098: The effect of in utero folic acid supplementation on colorectal cancer risk in the offspring in a chemical carcinogen rodent model
Notice bibliographique
Résumé
Abstract Background: Epidemiologic studies suggest that dietary intake and blood levels of folate are inversely related to colorectal cancer (CRC) risk. However, animal studies and recent human intervention trials have suggested that although folate supplementation may decrease the risk of developing de novo CRC, folate supplementation may promote the progression of existing, undiagnosed preneoplastic lesions in the colorectum to CRC. Total intake and blood levels of folate in North America have dramatically increased over the past decade owing to mandatory folic acid (FA; the synthetic form of folate) fortification and 30-40% of the population taking multivitamins containing FA. It is unknown whether high folate in the intrauterine environment may affect CRC risk in the offspring. We therefore investigated the effect of FA supplementation provided in utero and postnatally on CRC risk in the offspring in the azoxymethane (AOM) rat model of CRC. Methods: Female Sprague-Dawley rats were placed on either a control diet (2mg FA/kg diet) or a supplemented diet (5mg FA) for 3 weeks prior to breeding, and remained on the diet throughout pregnancy and lactation. Male pups from each maternal diet group were randomized to either the control or supplemented diet (n=55 per group) at weaning (21 days of age). At 5 and 6 weeks of age, 2 weekly s.c. injections of AOM were given. At 34 weeks of age, all rats were sacrificed and tumor incidence, multiplicity and burden as well as plasma folate and homocysteine (Hcy; an accurate inverse indicator of folate status) and liver folate concentrations were determined. Results: Plasma and liver folate concentrations accurately reflected dietary FA levels (p<0.001), and a significant interaction was found between maternal and pup diets (p< 0.02). Plasma Hcy was lower in pups fed the 5mg diet (p=0.036). Maternal FA supplementation significantly decreased the risk of developing CRC in the offspring (p=0.003) whereas postnatal FA supplementation had no significant effect. Pups from dams on the control diet had a nearly 3-fold increased risk of developing CRC compared with those from dams on FA supplementation (odds ratio=2.78; 95% CI, 1.41-5.50). There was no significant effect of interaction between maternal and pup diets on CRC incidence. Total number of tumors and sum of tumor diameter were significantly different among the diet groups (p=0.014 and p=0.006, respectively) with FA supplemented pups from dams on the control diet bearing a higher number of tumors and a larger tumor diameter than other groups (p<0.03). Conclusions: Notwithstanding the limitations associated with this model, our data suggest that FA supplementation provided in utero, but not postnatally, may protect the offspring from developing CRC. Although FA supplementation may promote the progression of established precursors of CRC, FA supplementation may decrease the risk of developing de novo CRC.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».