Project description:Previous studies in our laboratory have shown that low folate diet (control diet with 2mg folate/kg, low folate diet with 0.3mg folate/kg) can induce intestinal tumors in BALB/c mice. We used microarrays to compare MTHFR+/+ BALB/c mice fed control diet and MTHFR+/- BALB/c mice fed low folate diet. After weaning, 4 BALB/c Mthfr +/+ mice were fed with a control diet (CD, 2mg folate/kg) and 4 BALB/c Mthfr +/- mice were fed a low folate diet (FD, 0.3mg folate/kg) for 1 year. Both diets contain succinylsulfanthiozole (1%) to prevent folate synthesis by intestine microbial biota.
Project description:Previous studies in our laboratory have shown that low folate diet (control diet with 2mg folate/kg, low folate diet with 0.3mg folate/kg) can induce intestinal tumors in BALB/c mice. We used microarrays to compare MTHFR+/+ BALB/c mice fed control diet and MTHFR+/- BALB/c mice fed low folate diet.
Project description:Previous studies in our laboratory have shown that low folate diet (control diet with 2mg folate/kg, low folate diet with 0.3mg folate/kg) can induce intestinal tumors in BALB/c mice. In addition, we reported that C57Bl/6J mice did not form tumors under the same conditions. We used microarrays to identify the genetic differences between BALB/c and C57Bl/6J mice that promote tumorigenesis in BALB/c mice. Two groups of mice will be used in the micro-array experiment. One group will consist of four BALB/c mice and the second group will consist of four C57Bl/6 mice. Both groups have mild MTHFR deficiency (Mthfr+/-) and will receive low folate diet (0.3 mg folate/kg) for one year. RNA samples will be extracted from duodenum, the first section of the small intestine where tumors were observed in BALB/c mice. Eight Affymetrix GeneChip Mouse Gene 1.0 ST Array Chips will be used in this experiment.
Project description:5,10-Methylenetetrahydrofolate reductase (MTHFR) is an enzyme that plays a key role in providing methyl groups for DNA methylation, including during spermatogenesis. A common genetic variant in humans (MTHFR 677C>T), results in reduced enzyme activity and has been linked to various disorders, including male infertility. A new animal model has been created by reproducing the human equivalent of the polymorphism in mice using CRISPR/Cas9. Biochemical parameters in the Mthfr 677TT mice recapitulate alterations found in MTHFR 677TT men. Our aims were to: 1) characterize the sperm DNA methylome of the Mthfr 677CC and TT mice on a control diet (2mg folic acid/kg diet) and 2) assess the effects of folic acid deficiency (0.3mg/kg diet) and supplementation (10 mg/kg diet) on the sperm DNA methylome. Body and reproductive organ weights, testicular sperm counts, and histology were examined. DNA methylation in sperm was assessed using bisulfite pyrosequencing, Illumina Mouse Methylation Array and whole genome bisulfite sequencing. Reproductive parameters and imprinted gene methylation were unaffected by genotype or diets. The largest effect was due to genotype, with sperm from 677TT mice showing more hypo- than hypermethylation. Folate-deficient diets resulted in sperm hyper- and hypomethylation in CC and TT mice. Folic acid supplementation caused mostly hypermethylation in sperm of males of both genotypes and was found to partially correct the DNA methylation alterations in sperm associated with the TT genotype. The new mouse model will be useful in understanding the role of MTHFR deficiency in male fertility and in designing folate supplementation regimens for the clinic.
Project description:Previous studies in our laboratory have shown that low folate diet (control diet with 2mg folate/kg, low folate diet with 0.3mg folate/kg) can induce intestinal tumors in BALB/c mice. In addition, we reported that C57Bl/6J mice did not form tumors under the same conditions. We used microarrays to identify the genetic differences between BALB/c and C57Bl/6J mice that promote tumorigenesis in BALB/c mice.
Project description:Defects in homocysteine and folate metabolism are associated with increased risks for neural tube and congenital heart defects, cardiovascular disease and stroke, cancers, and neurodegeneration. In many but not all cases, dietary supplementation with folate significantly reduces the severity and incidence of these conditions. Common polymorphisms modulate these metabolic pathways and disease risks, but do not fully account for the particular birth defects and adult diseases that occur in at-risk individuals. To test whether other pathways contribute to disease pathogenesis, we analyzed global and pathway-specific changes in gene expression and levels of selected metabolites after depletion and repletion of dietary folate in two genetically distinct inbred strains of mice. Compared to the C57BL/6J strain, A/J showed greater homeostatic response to folate perturbation by retaining a higher serum folate level and minimizing global gene expression changes. Remarkably, folate perturbation led to systematic strain-specific differences only in the expression profile of the cholesterol biosynthesis pathway and translated to changes in levels of serum and liver total cholesterol. By genetically increasing serum and liver total cholesterol levels in APOE deficient mice, we modestly but significantly improved folate retention during folate depletion, suggesting an interplay between homocysteine and folate metabolism and cholesterol metabolism. Absence of measurable changes in global methylation patterns or amelioration of effects with supplementation with an alternative methyl donor suggest that dietary folate perturbations do not act through large-scale or general changes in methylation. These results suggest that homeostatic responses in cholesterol metabolism contribute to the beneficial effects of dietary folate supplementation. Keywords: time course, stress response, diet, genetic, homeostasis Six-week old female A/J and C57BL/6J mice were purchased from the Jackson Laboratory. All mice were raised on a control diet containing four ppm folic acid (Basal Diet 5755, TestDiet) for one week before the start of studies. Selected mice were then placed on folic acid deficient diet (58C3, TestDiet) containing 1% succinylsulfathiazole, a non-absorbable antibiotic commonly used to suppress folate production by bacteria in the intestine. We had nine different treatment plans per strain with eight replicate mice per treatment. There were four folic acid depletion treatment in which mice were placed on folic acid deficient diet for 1, 2, 7, or 14 days. There were two folic acid repletion treatment in which mice were placed on folic acid deficient diet for 14 days followed by 1 day on control diet and another set of mice on 14 days of folic acid deficient diet followed by 7 days of control diet. There were three control time points in which mice were placed on the control diet for 0, 9, or 22 days. Eight biological replicate liver tissue from each treatment was pooled and total RNA from each pool and total RNA from Universal Mouse Reference RNA (Stratagene) were aminoallyl labeled with Cy3 and Cy5 in duplicate, with reversing of dyes.
Project description:Deciphering the impact of metabolic intervention on response to anticancer therapy represents a path toward improved clinical responses. Here, we identify amino acid-related pathways connected to the folate cycle whose activation predicts sensitivity to MYC-targeting therapies in acute myeloid leukemia (AML). We establish that folate restriction and deficiency of the rate-limiting folate-cycle enzyme, MTHFR ― which exhibits reduced-function polymorphisms in about 10% of Caucasians ― enhance resistance to MYC targeting by BET and CDK7 inhibitors in cell lines, primary patient samples and syngeneic mouse models of AML. Further, this effect is abrogated by supplementation with the MTHFR enzymatic product, CH3-THF. Mechanistically, folate cycle disturbance reduces H3K27/K9 histone methylation, and activates a SPI1 transcriptional program counteracting the effect of BET inhibition. Our data provide a rationale for screening MTHFR polymorphisms and the folate cycle status to exclude patients least likely and nominate those most likely to benefit from MYC-targeting therapies.
Project description:Deciphering the impact of metabolic intervention on response to anticancer therapy represents a path toward improved clinical responses. Here, we identify amino acid-related pathways connected to the folate cycle whose activation predicts sensitivity to MYC-targeting therapies in acute myeloid leukemia (AML). We establish that folate restriction and deficiency of the rate-limiting folate-cycle enzyme, MTHFR ― which exhibits reduced-function polymorphisms in about 10% of Caucasians ― enhance resistance to MYC targeting by BET and CDK7 inhibitors in cell lines, primary patient samples and syngeneic mouse models of AML. Further, this effect is abrogated by supplementation with the MTHFR enzymatic product, CH3-THF. Mechanistically, folate cycle disturbance reduces H3K27/K9 histone methylation, and activates a SPI1 transcriptional program counteracting the effect of BET inhibition. Our data provide a rationale for screening MTHFR polymorphisms and the folate cycle status to exclude patients least likely and nominate those most likely to benefit from MYC-targeting therapies.