Tumorigenesis In Offspring Research Articles

Oxidative damage-induced hyperactive ribosome biogenesis participates in tumorigenesis of offspring by cross-interacting with the Wnt and TGF-\u03b21 pathways in IVF embryos

In vitro fertilization (IVF) increases the risk of tumorigenesis in offspring. The increased oxidative damage during IVF may be involved in tumor formation. However, the molecular mechanisms underlying this phenomenon remain largely unclear. Using a well-established model of oxidatively damaged IVF mouse embryos, we applied the iTRAQ method to identify proteins differentially expressed between control and oxidatively damaged zygotes and explored the possible tumorigenic mechanisms, especially with regard to the effects of oxidative damage on ribosome biogenesis closely related to tumorigenesis. The iTRAQ results revealed that ribosomal proteins were upregulated by oxidative stress through the Nucleolin/β-Catenin/n-Myc pathway, which stimulated ribosomes to synthesize an abundance of repair proteins to correct the damaged DNA/chromosomes in IVF-derived embryos. However, the increased percentages of γH2AX-positive cells and apoptotic cells in the blastocyst suggested that DNA repair was insufficient, resulting in aberrant ribosome biogenesis. Overexpression of ribosomal proteins, particularly Rpl15, which gradually increased from the 1-cell to 8-cell stages, indicated persistent hyperactivation of ribosome biogenesis, which promoted tumorigenesis in offspring derived from oxidatively damaged IVF embryos by selectively enhancing the translation of β-Catenin and TGF-β1. The antioxidant epigallocatechin-3-gallate (EGCG) was added to the in vitro culture medium to protect embryos from oxidative damage, and the expression of ribosome-/tumor-related proteins returned to normal after EGCG treatment. This study suggests that regulation of ribosome biogenesis by EGCG may be a means of preventing tumor formation in human IVF-derived offspring, providing a scientific basis for optimizing in vitro culture conditions and improving human-assisted reproductive technology.

Combined maternal and post-weaning high fat diet inhibits male offspring's prostate cancer tumorigenesis in transgenic adenocarcinoma of mouse prostate model.

High fat diet (HFD) and its responsive change of gut microbiota are associated with numerous diseases in human and animal studies. But how maternal and post-weaning HFD may influence the tumorigenesis of prostate cancer (PCa) in male offspring has not yet been reported. We studied both solitary and combined effects of maternal or/and post-weaning HFD on the tumorigenesis of prostate in offspring using a transgenic adenocarcinoma of mouse prostate (TRAMP) model. TRAMP male mice (n = 24) were born to and fostered onto control diet or HFD-fed mothers, the weaned pups were further fed control or fat diet. All mice were sacrificed at the 28th week. The prostate histopathology was performed. The gut microbiota was analyzed by fecal 16S rRNA pyrosequencing, and the serum metabolites were determined by LC-MS/MS. Our results indicated that post-weaning HFD could significantly promote the PCa tumorigenesis in offspring (P = 0.031), and similar results were found in maternal HFD group but with no significant differences (P = 0.056). However, combined maternal and post-weaning HFD could significantly reduce the PCa tumorigenesis in offspring (P = 0.019). Significant differences in specific microbial populations and serum metabolites were observed across groups. For example, mice with combined maternal and post-weaning HFD had higher abundance of gut Lachonospiraceae, Roseburia, and Amycolatopsis, increased serum L-methionine (P = 0.0052), and decreased serum α-linolenic acid (P < 0.001). This study highlights the inhibitory effects of combined maternal and post-weaning HFD on PCa tumorigenesis, and provides new insights into the interactions between diet, gut microbiota, serum metabolites, and PCa.

Increased Transgenerational Intestinal Tumorigenesis in Offspring of Ionizing Radiation Exposed Parent APC1638N/+ Mice

The purpose of the study was to assess transgenerational intestinal tumorigenic effects of low dose ionizing radiation employing a well-characterized mouse model of human colorectal cancer. Mice (6 to 8 weeks old APC1638N/+ mice; n=20 per study group) were exposed to whole-body 25 cGy x-rays and mated 2 days post-irradiation. Intestinal tumorigenesis in male and female F1 mice from No Parents Irradiated (NPI), Both Parents Irradiated (BPI), and Male Parent Irradiated (MPI) groups were compared 210 days after birth. Male and female Direct Parent Irradiated (DPI) groups were additional controls for male and female F1 groups respectively. Data showed higher intestinal tumor frequency (± standard error of the mean) in male and female F1 from BPI (male: 7.81 ± 0.91; female: 5.45 ± 0.36) as well as from MPI (male: 6.30 ± 0.33; female: 4.45 ± 0.33) mice relative to F1 from NPI mice (male: 4.2 ± 0.48; female: 3.35 ± 0.37). Compared to male and female DPI (male: 5.55 ± 0.40; female: 3.60 ± 0.22), tumor frequency in F1 mice of BPI and MPI, though higher, was not statistically significant except for DPI vs. BPI in male mice. Additionally, both BPI and MPI showed increased frequency of larger tumors relative to NPI. In summary, our observations demonstrated that the APC1638N/+ mice due to its low spontaneous tumor frequency could serve as an effective model to study risk of transgenerational carcinogenesis in gastrointestinal tissues after exposure to clinically relevant low doses of ionizing radiation.

Fetal alcohol exposure and mammary tumorigenesis in offspring: role of the estrogen and insulin-like growth factor systems.

Fetal alcohol spectrum disorders affect a significant number of live births each year, indicating that alcohol consumption during pregnancy is an important public health issue. Environmental exposures and lifestyle choices during pregnancy may affect the offspring's risk of disease in adulthood, leading to the idea that a woman's risk of breast cancer may be pre-programmed prior to birth. Exposure of pregnant rats to alcohol increases tumorigenesis in the adult offspring in response to mammary carcinogens. The estrogen and insulin-like growth factor (IGF-I) axes occupy central roles in normal mammary gland development and breast cancer. 17-β estradiol (E2) and IGF-I synergize to regulate formation of terminal end buds and ductal elongation during pubertal development. The intracellular signaling pathways mediated by the estrogen and IGF-I receptors cross-talk at multiple levels through both genomic and non-genomic mechanisms. Several components of the E2 and IGF-I systems are altered in early development in rat offspring exposed to alcohol in utero, therefore, these changes may play a role in the enhanced susceptibility to mammary carcinogens observed in adulthood. Alcohol exposure in utero induces a number of epigenetic alterations in non-mammary tissues in the offspring and other adverse in utero exposures induce epigenetic modifications in the mammary gland. Future studies will determine if fetal alcohol exposure can induce epigenetic modifications in genes that regulate E2/IGF action at key phases of mammary development, ultimately leading to changes in susceptibility to carcinogens.

Maternal exercise during pregnancy reduces risk of mammary tumorigenesis in rat offspring

Breast cancer is the most common cancer among women. Emerging research indicates that modifying lifestyle factors during pregnancy may convey long-term health benefits to offspring. This study was designed to determine whether maternal exercise during pregnancy leads to reduced mammary tumorigenesis in female offspring. Pregnant rats were randomly assigned to exercised and sedentary groups, with the exercised group having free access to a running wheel and the sedentary group housed with a locked wheel during pregnancy. Female pups from exercised or sedentary dams were weaned at 21 days of age and fed a high fat diet without access to a running wheel. At 6 weeks, all pups were injected with the carcinogen N-methyl-N-nitrosourea. Mammary tumor development in all pups was monitored for 15 weeks. Pups from exercised dams had a substantially lower tumor incidence (42.9%) compared with pups from sedentary dams (100%). Neither tumor latency nor histological grade differed between the two groups. These data are the first to demonstrate that exercise during pregnancy potentiates reduced tumorigenesis in offspring. This study provides an important foundation towards developing more effective modes of behavior modification for cancer prevention.

Maternal exercise during pregnancy reduces risk of mammary tumorigenesis in rat offspring (886.1)

Breast cancer is the most common cancer among women. Emerging research indicates that modifying lifestyle factors during pregnancy may convey long‐term health benefits to offspring. This study was designed to determine whether maternal exercise during pregnancy leads to reduced mammary tumorigenesis in female offspring. Pregnant rats were randomly assigned to exercised and sedentary groups, with the exercised group having free access to a running wheel and the sedentary group housed with a locked wheel during pregnancy. Female pups from exercised or sedentary dams were weaned at 21 days of age and fed a high fat diet without access to a running wheel. At 6 weeks, all pups were injected with the carcinogen N‐methyl‐N‐nitrosourea (MNU). Mammary tumor development in all pups was monitored for 15 weeks. Pups from exercised dams had a substantially lower tumor incidence (42.9%) compared to pups from sedentary dams (100%). Of the pups with tumors, the pups from exercised dams had a higher tumor frequency (1.7±0.4 tumors/rat) than pups from sedentary dams (1.2±0.2 tumors/rat). Neither tumor latency nor histological grade differed between the two groups. These data are the first to demonstrate that exercise during pregnancy potentiates reduced tumorigenesis in offspring. This study provides an important foundation towards developing more effective modes of behavior modification for cancer prevention.Grant Funding Source: Supported by NIH R25CA128770 and ICTSI NIH/NCRR TR000006

Modulation of paternal B vitamin intake does not affect tumorigenesis but does alter growth trajectory in Apc1638N mouse offspring (137.7)

Modulation of paternal B vitamin intake does not affect tumorigenesis but does alter growth trajectory in Apc1638N mouse offspring Sabet JA1,2, Mason JB1,2, Bronson RT3, Crott JW1,21Friedman School of Nutrition Science and Policy at Tufts University, Boston, MA2Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA3Rodent Histopathology Core, Harvard Medical School, Boston, MA It is well established that maternal nutrition can impact on offspring health and physiology; however the contribution of paternal nutrition to offspring health is less understood. We have shown that maternal B‐vitamin supplementation suppresses, while deficiency promotes, intestinal tumorigenesis in a mouse model of colorectal cancer. We sought to determine whether modulating paternal intake of vitamins B2, B6, B12, and folate similarly alters intestinal tumorigenesis in offspring. Male APC1638N mice were fed diets containing control, deficient, or supplemental quantities of vitamins B2, B6, B12, and folate for 8 wk before mating with control‐fed wild‐type females. APC1638N offspring were maintained on control diets until 28 wk of age. No differences in tumor incidence, size or grade were found between offspring of different paternal diet groups. Overall, male offspring exhibited a greater tumor incidence and burden than female offspring. Among female offspring, growth was significantly retarded in the progeny of deficient and supplemented fathers compared to control fathers. Modulation of paternal B‐vitamin intake prior to mating did not alter offspring intestinal tumorigenesis but did impact offspring growth in a sex‐specific fashion in APC1638N mice. Analyses to profile DNA methylation changes in sperm and gene expression changes in offspring liver are underway.Grant Funding Source: Supported by NCI grant 1 R03CA162505‐1

Suppression of Wnt1-induced mammary tumor growth and lower serum insulin in offspring exposed to maternal blueberry diet suggest early dietary influence on developmental programming

Despite the well-accepted notion that early maternal influences persist beyond fetal life and may underlie many adult diseases, the risks imposed by the maternal environment on breast cancer development and underlying biological mechanisms remain poorly understood. In this study, we investigated whether early exposure to blueberry (BB) via maternal diet alters oncogene Wnt1-induced mammary tumorigenesis in offspring. Wnt1-transgenic female mice were exposed to maternal Casein (CAS, control) or blueberry-supplemented (CAS + 3%BB) diets throughout pregnancy and lactation. Offspring were weaned to CAS and mammary tumor development was followed until age 8 months. Tumor incidence and latency were similar for both groups; however, tumor weight at killing and tumor volume within 2 weeks of initial detection were lower (by 50 and 60%, respectively) in offspring of BB- versus control-fed dams. Dietary BB exposure beginning at weaning did not alter mammary tumor parameters. Tumors from maternal BB-exposed offspring showed higher tumor suppressor (Pten and Cdh1) and lower proproliferative (Ccnd1), anti-apoptotic (Bcl2) and proangiogenic (Figf, Flt1 and Ephb4) transcript levels, and displayed attenuated microvessel density. Expression of Pten and Cdh1 genes was also higher in mammary tissues of maternal BB-exposed offspring. Mammary tissues and tumors of maternal BB-exposed offspring showed increased chromatin-modifying enzyme Dnmt1 and Ezh2 transcript levels. Body weight, serum insulin and serum leptin/adiponectin ratio were lower for maternal BB-exposed than control tumor-bearing offspring. Tumor weights and serum insulin were positively correlated. Results suggest that dietary influences on the maternal environment contribute to key developmental programs in the mammary gland to modify breast cancer outcome in adult progeny.

Maternal blueberry diet suppresses Wnt1‐induced mammary tumor progression in offspring

Despite the well‐accepted notion of peri‐natal origins of adult diseases, the factors and regulatory mechanisms underlying breast cancer development remain unclear. Diet is a highly modifiable determinant of breast cancer risk, and the effects of the in utero nutritional environment persist beyond fetal life. We investigated whether in utero/lactational exposure to blueberry (BB) via maternal diet alters the trajectory of Wnt1‐induced mammary tumorigenesis in offspring. Wnt1 transgenic mice were exposed to maternal diets of casein (CAS; n=33) or blueberry‐supplemented CAS (3% BB; n=28) from gestation day 4 until post‐natal day 21. Offspring were then weaned to CAS and mammary tumor development was followed until age 8 months. While tumor incidence and latency were similar for both groups, tumor weight (by 2‐fold, p=0.034) and growth rate (by 60%; p=0.008) were reduced in offspring of BB‐ versus CAS‐fed dams. Tumors from the BB group had higher expression of tumor suppressors PTEN and E‐cadherin and lower cyclin D1 and pro‐apoptotic Bcl2 levels. Transcript levels for DNA methylation enzymes DNMT1 and EZH2 were higher in BB tumors. Serum levels of insulin and serum leptin/adiponectin ratio were lower for tumor‐bearing BB than CAS offspring at sac. Our findings support a role for nutritional epigenetics in adult breast cancer outcome.Grant Funding Source : USDA‐CRIS (RCMS), DOD‐BCRP (OR) and NIH‐NCI (FAS).

Maternal B vitamin supplementation from preconception through weaning suppresses intestinal tumorigenesis in Apc1638N mouse offspring

ObjectiveVariations in the intake of folate are capable of modulating colorectal tumorigenesis; however, the outcome appears to be dependent on timing. This study sought to determine the effect of altering...

Maternal B‐vitamin intake impacts on Wnt‐related genes, apoptosis and tumorigenesis in the intestine of mouse offspring

Observations that high maternal folate intake is associated with reduced risk of several pediatric cancers led us to propose that maternal supplementation with folate and related B vitamins may also protect against colorectal cancer in offspring. Using Apc1638N mice, we showed that supplementing mothers with vitamins B2, B6, B12 and folate suppressed intestinal tumorigenesis in offspring. Maternal depletion did not increase tumor incidence but was associated with a higher prevalence of invasive tumors. We previously showed the Wnt pathway to be sensitive to B vitamin status and therefore focused on perturbations to this pathway as a possible mechanism to explain differences in tumor incidence. Expression of Apc, SFRP1, Wif-1 and Wnt5a in the intestine of offspring decreased with decreasing maternal B vitamin intake. The SFRP1 promoter was hypermethylated amongst pups of deficient dams while genomic methylation was slightly but significantly lower in offspring of deficient compared to control dams. Apoptosis was also highest amongst the deficient group while proliferation of the small intestinal mucosa was not different between groups. These data indicate that maternal B vitamin intake can impact on the methylation and expression of cancer relevant genes as well as tumorigenesis in the intestine of offspring.

Maternal B‐vitamin supplementation from preconception through weaning suppresses intestinal tumorigenesis among offspring in the Apc+/1638N mouse

Folate and other B‐vitamins play important roles in DNA methylation, and adequate intakes of these nutrients have been implicated in the prevention of colon cancer. Concentrations of B‐vitamins in the maternal diet may impact disease susceptibility in offspring. Therefore, we investigated the effect of maternal B‐vitamin intake on intestinal tumorigenesis in offspring. Three groups of 6‐week old female C57BL/6 mice were fed diets either deficient, replete, or supplemented with folate, vitamin B2, B6, and B12 for 4 weeks, then mated with male Apc+/1638N mice. Females remained on their respective diets throughout mating, pregnancy and the suckling period (11 weeks total). After weaning, all Apc+/1638N pups were fed a replete diet (AIN‐93), regardless of maternal diet. At 32 weeks of age, 58% and 63% of pups born to deficient and replete mothers, respectively, exhibited tumors in the small intestine compared to 21% of pups born to supplemented mothers (p&lt;0.025). Furthermore, a higher percentage of tumors collected from pups of deficient mothers displayed invasive behavior compared to tumors from pups of replete mothers (p=0.03). These data indicate that maternal B‐vitamin supplementation suppresses tumorigenesis in Apc+/1638N offspring relative to deficient and replete maternal diets and furthermore that maternal B‐vitamin depletion accelerates the acquisition of invasive characteristics in tumors.Grant Funding Source: USDA CRIS # 1950‐5100‐074‐01S

Gender-specific modulation of tumorigenesis by folic acid supply in theApc+/Minmouse during early neonatal life

Epidemiological studies suggest an inverse association between folic acid intake and colorectal cancer risk. Conversely, conventional treatment of existing tumours includes the use of folate antagonists. This suggests that the level of exposure to folate and its timing in relation to stage of tumorigenesis may be critical in determining outcomes. We hypothesised that folic acid depletion in utero and during early neonatal life may affect tumorigenesis in offspring. To investigate this hypothesis, female C57Bl6/J mice were randomised to a folic acid adequate (2 mg folic acid/kg diet) or folic acid depleted diet (0.4 mg folic acid/kg) from mating with Apc+/Min sires and throughout pregnancy and lactation. At weaning the Apc+/Min offspring were randomised to a folic acid adequate (2 mg folic acid/kg diet) or depleted (0.26 mg folic acid/kg diet) diet, creating four in utero/post-weaning dietary regimens. At 10 weeks post-weaning, mice were killed and the intestinal tumour number and size were recorded. Folic acid depletion during pregnancy and post-weaning reduced erythrocyte folate concentrations in offspring significantly. Folic acid depletion during pregnancy and lactation did not affect tumour multiplicity or size. However, female mice fed normal folic acid diets post-weaning had more, and larger, tumours when compared with depleted females and both depleted and adequate folic acid fed males. These data suggest that folate depletion post-weaning was protective against neoplasia in female Apc+/Min mice and highlights the need for further investigation of the optimal timing and dose of folic acid supplementation with regard to colorectal cancer risk.

Transplacental effects of a 15% olive-oil diet on chemically-induced tumorigenesis in offspring.

We evaluated whether feeding pregnant female rats a diet high in olive-oil, that showed a tumor-preventive effect in adults, has a similar preventive effect on chemically-induced cancer in offspring (i.e. mammary glands and colon cancer in rats). The control group was fed the same 7% corn-oil diet as their mothers. Experimental group I was fed a 7% corn-oil diet while their mothers received a 15% olive-oil diet. Experimental group II was fed the same 15% olive-oil diet as their mothers. Female offspring were twice administered 7,12-dimethylbenz(a)antracene (DMBA) in doses of 10 mg/rat. Male offspring were injected 6 times with 1, 2-dimethylhydrazine (DMH) in doses of 20 mg/kg body weight. Effect of DMBA was manifested in a high rate of tumorigenesis: the number of tumor-bearing rats in control offspring reached 52.0%. This effect increased to 60.6% among offspring of experimental group II and to 67.7% in offspring of experimental group I. The mean tumor size increased significantly in control offspring. Following administration of DMH number of tumor-bearing rats was similar in all groups of offspring: 36.7%, 40.7% and 42.8%. Tumor types differed: the majority of tumors in the control group were benign polyps and adenomas (72.1%) and the number of adenocarcinomas was low (27.9%). The number of malignant tumors increased to 37.5% in offspring of experimental group II and to 45.5% in offspring of experimental group I. In control group offspring, a distinct tendency to increased body weight and a significant increase in spleen weight were seen. The findings indicate that feeding mothers a diet high in fat concentrations, even those with known tumor preventive significance in adults, lose this cancer-inhibiting role in offspring.

Maternal exposure to genistein during pregnancy increases carcinogen-induced mammary tumorigenesis in female rat offspring.

A high estrogenic environment in utero may increase subsequent breast cancer risk. It was therefore determined whether a maternal exposure during pregnancy to the phytoestrogen genistein or zearalenone, both of which exhibit estrogenic activities in vitro and in vivo, alters breast cancer risk among female offspring. Pregnant rat dams were treated daily with subcutaneous injections of 20, 100 or 300 microgram genistein, 20 microgram zearalenone, or vehicle between days 15 and 20 of gestation. The offspring were given 7, 12-dimethylbenz(a)anthracene (DMBA) at the age of 2 months to induce mammary tumors. The results indicate that in utero exposure to genistein, but not to zearalenone, dose-dependently increased the incidence of DMBA-induced mammary tumors, when compared with the controls. Tumor growth characteristics were not altered. Prior to the carcinogen administration, the number of estrogen receptor (ER) binding sites, determined using a ligand binding assay, were significantly elevated in the mammary glands of genistein offspring. In contrast, the mammary protein kinase C (PKC) activity was significantly reduced in the genistein offspring. Our results suggest that a maternal exposure to subcutaneous administration of genistein can increase mammary tumorigenesis in the offspring, mimicking the effects of in utero estrogenic exposures. Further, increased ER protein levels and reduced PKC activity in the mammary gland may be involved in increasing susceptibility to carcinogen-induced mammary tumorigenesis in rats exposed to genistein in utero.

Transplacental tumor-preventive effects of polyclonal antibodies generated against the soluble 53 kDa antigen on mammary tumorigenesis in offspring.

This study was designed to determine whether immunizing females with polyclonal antibodies generated against the soluble 53 kDa tumor-associated antigen (s53 TAA) has a tumor-preventive effect on their progeny and whether this effect is manifested in some biochemical characteristics. Rat females were immunized before mating with anti-s53 IgG (50 microg/rat in Freund's complete and incomplete adjuvant, three times during a month) and their 5-week-old offspring was exposed to the carcinogen (dimethylbenz(a)antracene, 10 mg/rat). Results of these experiments were studied 4 months later. Vaccination of mothers decreased the tumorigenic effects of DMBA on their offspring. Blood levels of soluble TAA were analyzed in offspring of different groups. Two TAA were isolated from the blood, with molecular masses of 64 and 53 kDa. Their concentrations differed in offspring obtained from different maternal groups. Vaccination itself resulted in a marked increase in the blood levels of TAA, not only in the mothers but also in their offspring, however, this increase was not significant in tumor-bearing animals. In offspring from non-vaccinated mothers, tumorigenesis resulted in high overexpression of s53. In offspring from vaccinated mothers, a high blood level of s53 was shown even in tumor-free animals, probably due to maternal vaccination. We conclude that maternal vaccination before pregnancy increases immunoreactivity in offspring and can reduce risk of tumors in those progeny.

Lung tumorigenesis and hyperplasia in offspring associated with the Ahd allele following in utero exposure to 3-methylcholanthrene

This study was conducted to determine if the Ah genotype could influence the incidence of tumorigenesis in offspring exposed to 3-methylcholanthrene (3-MC) during the fetal period. Male F 1 hybrids ( Ah b Ah d ) were backcrossed to Ah d Ah d females, resulting in pregnant mice containing litters with a 1:1 ratio of Ah b Ah d (AHH-inducible) and Ah d Ah d (AHH-noninducible) fetuses. Dams were exposed by gavage to corn oil or to 3-MC at 7, 21, or 63 mg/kg on Days 15, 16, and 17 of gestation, or to the positive control urethane at 1 mg/g ip on Day 17. The phenotype of surviving offspring was determined by hepatic aryl hydrocarbon hydroxylase (AHH) activity. The lung was the major site of neoplastic involvement in adult offspring 6 months after in utero exposure to 3-MC. Dose-related responses in all 3-MC treatment groups were obtained for percent nodule-bearing animals, percentage adenoma-bearing animals, mean number of nodules per animal, mean nodular size per animal, and diffuse bronchiolar hyperplasia. Correlation of Ah phenotype with adult tumorigenesis indicated that genetically nonresponsive ( Ah d Ah d ) offspring had a higher incidence of nodules, adenomas, and diffuse bronchiolar hyperplasia than responsive offspring within the same treatment group. Thus, when fetuses are exposed in the same maternal environment to 3-MC, genetic differences in Ah genotype may influence susceptibility to transplancental carcinogenesis.