Strategies to Prevent or Remediate Cancer and Treatment-Related Aging

Up to 85% of adult cancer survivors and 99% of adult survivors of childhood cancer live with an accumulation of chronic conditions, frailty, and/or cognitive impairments resulting from cancer and its treatment. Thus, survivors often show an accelerated development of multiple geriatric syndromes and need therapeutic interventions. To advance progress in this area, the National Cancer Institute convened the second of 2 think tanks under the auspices of the Cancer and Accelerated Aging: Advancing Research for Healthy Survivors initiative. Experts assembled to share evidence of promising strategies to prevent, slow, or reverse the aging consequences of cancer and its treatment. The meeting identified research and resource needs, including geroscience-guided clinical trials; comprehensive assessments of functional, cognitive, and psychosocial vulnerabilities to assess and predict age-related outcomes; preclinical and clinical research to determine the optimal dosing for behavioral (eg, diet, exercise) and pharmacologic (eg, senolytic) therapies; health-care delivery research to evaluate the efficacy of integrated cancer care delivery models; optimization of intervention implementation, delivery, and uptake; and patient and provider education on cancer and treatment-related late and long-term adverse effects. Addressing these needs will expand knowledge of aging-related consequences of cancer and cancer treatment and inform strategies to promote healthy aging of cancer survivors.

Vitamin E and macrophage cyclooxygenase regulation in the aged

Aging is associated with increased evidence of cardiovascular disease (CVD). Atherosclerosis, a major cause of CVD, is an inflammatory process whose development is influenced by several proinflammatory mediators. Products of arachidonic acid metabolism, in particular, prostaglandin (PG) E(2) and thromboxane (TX) A(2), play an important role in the development of atherosclerosis. We showed previously that the aged have higher PGE(2) production compared with their young counterparts. This age-associated increase in PGE(2) production is mainly a consequence of increased cyclooxygenase (COX) activity. We demonstrated further that increased COX activity in old mice is due to the increased expression of mRNA and protein for the inducible form of COX, COX-2. Vitamin E has been shown to reduce PGE(2) production and risk of CVD. In aged mice, we showed that a vitamin E-induced decrease in PGE(2) production is due to decreased COX activity. However, vitamin E had no effect on COX mRNA and protein levels, indicating a post-translational regulation of COX by vitamin E. Further experiments indicated that vitamin E decreases COX activity through reducing formation of peroxynitrite, a hydroperoxide shown to be involved in the activation of COX-2. Other homologues of tocopherols were also effective in inhibiting COX activity, but their degree of inhibition varied. The varied potency to inhibit COX activity was not explained totally by differences in their antioxidant capacity. Vitamin E-induced inhibition of COX activity might contribute to its effect of reducing CVD risk.

Vitamin E improves bone quality in the aged but not in young adult male mice

It is generally viewed that with advancing age, humans and other animals including mice experience a gradual decline in the rate of bone formation. This, in part, may be due to the rise in oxygen-derived free radical formation. Vitamin E, a strong antioxidant, functions as a free radical scavenger that potentially can suppress bone resorption while stimulating bone formation. Although the effects of vitamin E on immune functions are well documented, there is a paucity of information on its effect on skeletal health in vivo. The purpose of this study was to explore the influence of vitamin E supplementation on bone in young adult and old mice. Six and twenty-four month-old male C57BL/6NIA mice each were divided into two groups and fed a diet containing either adequate (30 mg/kg diet) or high (500 mg/kg diet) levels of vitamin E. Thirty days later, mice were killed and bones were removed for analyses including biomechanical testing using three-point bending and mRNA expressions of insulin-like growth factor-I (IGF-I), osteocalcin, and type 1alpha-collagen using Northern blot. In old but not the young adult mice, high-dose vitamin E enhanced bone quality as evident by improved material and structural bone properties in comparison with adequate. This improved quality was accompanied by increases in bone dry weight, protein, and mRNA transcripts for osteocalcin, type Ialpha-collagen, and IGF-I. These data demonstrate that high-dose vitamin E has pronounced effects on bone quality as well as matrix protein in old mice by augmenting bone matrix protein without reducing bone mineralization as evidenced by unaltered bone density.

Healthy ageing: the natural consequences of good nutrition-a conference report

Many countries are witnessing a marked increase in longevity and with this increased lifespan and the desire for healthy ageing, many, however, suffer from the opposite including mental and physical deterioration, lost productivity and quality of life, and increased medical costs. While adequate nutrition is fundamental for good health, it remains unclear what impact various dietary interventions may have on prolonging good quality of life. Studies which span age, geography and income all suggest that access to quality foods, host immunity and response to inflammation/infections, impaired senses (i.e., sight, taste, smell) or mobility are all factors which can limit intake or increase the body's need for specific micronutrients. New clinical studies of healthy ageing are needed and quantitative biomarkers are an essential component, particularly tools which can measure improvements in physiological integrity throughout life, thought to be a primary contributor to a long and productive life (a healthy "lifespan"). A framework for progress has recently been proposed in a WHO report which takes a broad, person-centered focus on healthy ageing, emphasizing the need to better understand an individual's intrinsic capacity, their functional abilities at various life stages, and the impact by mental, and physical health, and the environments they inhabit.

High-performance liquid chromatography with coulometric electrode array detector for the determination of quercetin levels in cells of the immune system

There is mounting evidence emphasizing the importance of intracellular antioxidant levels for maintenance of the immune function. The flavonoid quercetin, a natural antioxidant, has been shown to modulate enzymes involved in the regulation of the inflammatory response. However, up to now, there have been no studies describing quercetin levels in cells of the immune system. A gradient reversed-phase HPLC technique to identify and quantify intracellular levels of quercetin and its application in mice splenocytes are described. Mobile phases were a 0.01 M sodium phosphate monobasic solution adjusted to pH 2.8 with 85% orthophosphoric acid (buffer, Solvent A) and methanol (Solvent B) with a flow rate of 1 ml/min. An eight-channel coulometric electrode array detector was used. In vitro supplementation with increasing concentration of quercetin (25, 50, and 100 microM) raises intracellular quercetin levels in a dose-dependent manner. The method has the required features of specificity and sensitivity for monitoring quercetin uptake in cells of the immune system.

Prostaglandins and their metabolites in the gastrointestinal tract of Yucatan miniature swine

Concentration of prostaglandins E1, E2, F2alpha, and 15 keto, 13, 14-dihydro F2alpha (MPF2alpha), were measured in gastric, duodenal, jejunal, and ileal mucosa, and in the luminal contents of these gastrointestinal segments in miniature swine at 30, 60, and 120 min after they ingested a liquid nutrient meal. Large quantities of E1 and F2alpha were present in gastric contents at 30 min with lesser amounts of E2 and MPF2alpha. The concentrations of E1, E2, and F2alpha in the gastric contents decreased progressively with time after feeding. The total quantity and the concentrations of E1 and F2alpha decreased with passage of ingesta through the duodenum and jejunum. Mucosal concentrations of E1 and F2alpha were greatest in the duodenum and proximal jejunum and lowest in gastric mucosa. These results indicate that there is considerable production and metabolism of prostaglandins in the gastrointestinal tract, with major amounts secreted into the luminal contents of the stomach and duodenum after food intake.

Prostaglandins in human duodenal secretions

Prostaglandins E1, E2 and F2 alpha were measured in duodenal secretions from two healthy, fasting male subjects. Secretions were collected by duodenal intubation prior to, and following, stimulation by secretin and cholecystokinin. Prostaglandins were measured with a radioimmunoassay technique. The ranges of concentrations found were PGE1: 2.4-110 ng/ml, PGE2: 0.004-1.51 ng/ml, and PGG2 alpha: 0.44-14.6 ng/ml.

Long-Term Supplementation with Fruits and Vegetables Prolongs Lifespan and Reduces Tumor Incidence in Mice Fed a Western-Style High-Fat Diet

Objectives

Epidemiological studies suggest that consumption of fruits and vegetables (FV) was negatively associated with the incidence of certain cancers and positively associated with life expectancy. To date, a causal relationship has not been demonstrated. The objectives of the current study were to investigate the effects of long-term FV supplementation on health- and life-span in normal weight and obese mice.

Methods

Male C57BL/6J mice (5-wk) were randomly assigned to one of four groups (60/group): low fat control (LF-C, 10% kcal fat), high fat control (HF-C, 45% kcal fat), and each with 15% of a unique mixture of FV (patent pending) (w/w) (LF-FV and HF-FV). All mice were euthanized when a group reached 50% mortality. Survival analysis was performed using log-rank (Mantel-Cox) test; a two-sided Fisher's exact test was performed to compare difference in tumor incidence.

Results

After 21 months of feeding, HF-C group was the first to reach 50% mortality. Further, a Kaplan-Meier survival curve demonstrated that, at termination, HF-C group had higher mortality (50.0%) compared to LF-C group (18.3%, p = 0.0008). Notably, HF-FV group had significantly lower mortality (23.3%) compared to HF-C mice (p = 0.008), and there was no significant difference in mortality between HF-FV and LF-C. Mortality was lower in LF-FV (11.7%) compared to LF-C (18.3%), although this difference was not statistically significant. Furthermore, tumor incidence in HF-C group (73.3%) was significantly higher than that in LF-C group (30.0%, p < 0.0001). HF-FV group had 23.3% lower tumor incidence compared to HF-C group (p = 0.014). There was no significant difference in tumor incidence between LF-C (30.0%) and LF-FV groups (31.7%).

Conclusions

Our findings provide the first causal evidence that long-term intake of a diet supplemented with a wide variety of fruits and vegetables could extend lifespan and decrease tumor incidence in mice fed a Western-style high-fat diet. These results provide a foundation for further investigation into the benefits of fruit and vegetable supplementation on aging and age-related disease.

Funding Sources

This material is based upon work supported by the U.S. Department of Agriculture – Agricultural Research Service (ARS), under Agreement No. 58–8050-9–004.

BMI-based Prenatal Vitamins to Ameliorate Oxidative Stress in Obese Pregnant Women: A Randomized Controlled Trial (P11-135-19)

Objectives

Obesity during pregnancy is associated with inflammation and oxidative stress and concomitant depletion of nutritional antioxidant defenses, which may be implicated in adverse perinatal and long-term childhood outcomes. The objective of this study is to determine whether providing a BMI-based prenatal vitamin (BMI-PNV) to pregnant women with obesity would raise concentrations of key antioxidant vitamins (vit) and decrease markers of inflammation and oxidative stress during pregnancy.

Methods

This was a double-blind, randomized controlled trial of a BMI-PNV (higher amounts of vit C (250%), E (200%), B6 (900%) and folic acid (200%)) compared to a standard prenatal vita (Std-PNV) in obese pregnant women. We recruited pregnant women with a BMI ≥ 30kg/m2 at their initial prenatal visit (< 13weeks gestation) and collected blood and urine at baseline, 24–28 weeks and 32–36 weeks to measure vit C, E, B6 and folate and markers of inflammation (C Reactive Protein, interleukin (IL)-6, 8 and 1β) and oxidative stress (8-epi-PGF2α and malonyldialehyde). We collected pregnancy and infant health data from enrollment to delivery. We used linear regression to evaluate associations between treatment arm and outcomes.

Results

We enrolled 126 participants (63 in each arm) and 102 (51 per arm) completed follow-up through delivery. Mean ± SD baseline BMI was 35.7 ± 6.3 kg/m2 in the BMI-PNV and 35.5 ± 4.8kg/m2 in the STD-PNV groups. The baseline demographic characteristics are presented in Table 1. Randomization was mostly successful, but there were baseline differences between groups in biomarker levels and infection status for which we adjusted. Concentrations of vitamins B6 and C were greater in the BMI-PNV group than in the Std-PNV group at 24–28 weeks (B6: β = 0.86nmol/L, P < 0.0001; C: β = 0.15 umol/L, P = 0.02) and vitamin B6 at 32–36 weeks (β = 0.66 nmol/L, P = 0.0002) (Table 2). There were no differences in any biomarker of inflammation or oxidative stress by randomization group. There were no differences in maternal or neonatal clinical outcomes by randomization group.

Conclusions

Providing higher concentrations of key antioxidant vitamins during pregnancy increased systemic concentrations of some of the antioxidant nutrients but did not decrease markers of inflammation and oxidative stress. Larger studies are needed to examine the impact on clinical outcomes.

Funding Sources

NIH National Institute of Child Health and Human Development, NIH Office of Dietary Supplements, Charles H. Hood Foundation.

Supporting Tables, Images and/or Graphs

Supplementation with a Novel Combination of Fruits and Vegetables Prevented High Fat Diet-Induced Cognitive Impairment in Mice

Objectives

Dementia and cognitive decline are typical age-related neurological disorders. However, obesity has been linked to premature senescence manifestations in various systems including the central nervous system. Nutritional interventions play a role in curbing obesity-associated disorders. Epidemiological studies suggest that increased consumption of fruits and vegetables (F&V) is associated with a reduced risk of cognitive impairment and dementia. The objective of this study was to investigate the causal role of F&V consumption in prevention of high fat diet-induced cognitive impairment in mice.

Methods

Freeze-dried powder of a mixture of 24 F&V was added into the animal diets. Male C57BL/6 J mice (6 wk) were randomly assigned to one of the three diet groups (12/group): low fat (LF, 10% kcal fat), high fat (HF, 45% kcal fat), and HF plus 15% F&V (HF + F&V). The novel object recognition test was used to evaluate cognitive function at 17 weeks. After 20 weeks, mice were euthanized. Blood and liver were collected and biochemical variables and gene expression levels were determined. Fecal microbiota was characterized by 16S rRNA sequencing.

Results

Compared to the LF group, mice fed the HF diet for 17 weeks had significant cognitive impairment. F&V supplementation significantly reduced the HF diet-induced cognitive impairment. Further, compared to mice fed the LF diet, those fed the HF diet had significantly higher levels of liver lipid peroxides (measured as MDA), and circulating pro-inflammatory cytokines and sphingolipid ceramides, all of which are known to contribute to neuroinflammation and cognitive deficits. These HF diet-induced adverse effects were significantly reduced in mice fed the HF + F&V diet. In addition, F&V supplementation alleviated HF diet-induced gut dysbiosis and greatly reduced abundance of some of the bacteria associated with inflammation.

Conclusions

This study provides evidence for the causal role of F&V intake in preventing high fat diet-induced cognition impairment in mice. The beneficial effects of F&V supplementation in improving cognitive function might be due to F&V-induced changes in gut dysbiosis, inflammatory cytokines, and ceramides.

Funding Sources

This material is based upon work supported by the U.S. Department of Agriculture — Agricultural Research Service (ARS), under Agreement No. 58-1950-4-003.

Long-Term Supplementation With Fruits and Vegetables Prevents Western-Style High-Fat Diet-Induced Cognitive Impairment in Mice

Objectives

Aging, obesity and a high-fat diet is associated with increased risk of cognitive impairment. Epidemiological studies suggest that increased fruits and vegetables (FV) intake is associated with a reduced risk of cognitive dysfunction. However, causal relationship between FV intake and cognition has not been established. The objective of this study was to investigate the causal effect of long-term FV supplementation in context of a low fat or Western-style high-fat diet in mice.

Methods

Using a 2 × 2 factorial prospective design, male C57BL/6J (5-wk) were randomly assigned to one of four groups (20/group): low fat control (LF-C, 10% kcal fat), high fat control (HF-C, 45% kcal fat), and each with 15% of a unique mixture of FV (patent pending) (w/w) (LF-FV and HF-FV). Novel object recognition test (NOR), a cognitive test for measuring exploration, memory, and object recognition, was performed to evaluate mouse cognitive function at 18 months. As rodents have an innate preference for exploring novelty, a mouse that remembers the familiar object will spend more time exploring the novel object, which indicates intact cognitive function. Next, recognition index (RI) was calculated based on the time the mouse spent exploring the new object over total object exploration time. The performance was analyzed with ANOVA, followed by Tukey's multiple comparisons test when appropriate.

Results

Compared to the LF-C group, mice fed the HF diet for 18 months had significantly lower RI in the NOR test (RI = 0.2100 for LF-C and RI = −0.04559 for HF-C, respectively, p < 0.0001), indicating cognitive impairment in the HF-C group. FV supplementation significantly mitigated the HF diet-induced cognitive impairment (RI = 0.2066 for HF-FV vs. RI = −0.04559 for HF-C, p < 0.0001). No significant difference in RI was observed between the LF-C mice (RI = 0.2100) and the LF-FV mice (RI = 0.2323).

Conclusions

This study provides evidence for a causal role of high intake of FV in preventing Western-style high-fat diet-induced cognition impairment in mice. The mechanisms by which FV improves cognitive function is currently under investigation.

Funding Sources

This material is based upon work supported by the U.S. Department of Agriculture – Agricultural Research Service (ARS), under Agreement No. 58-8050-9-004.

Probiotic Supplementation Regulates Placental and Fetal Development in C57BL6/J Mice (P20-008-19)

Objectives

Maternal high-fat (HF) diet predisposes offspring to metabolic syndrome, in part, by inducing alterations during placental development resulting in abnormal fetal development and offspring birth weight. We previously reported in a rat model that a maternal malnutrition diet increases fetal inflammation, and placental vascularization, and decreases offspring birth weight followed by adult-onset obesity. In the current study, we investigated when during gestational development a maternal HF diet induces changes in placental weight, lipid content, and inflammation. We further investigated whether probiotic supplementation offsets HF-diet induced adverse outcomes.

Methods

Two-month old female C57BL/6 mice were fed diets of 16% fat (normal-fat, NF) or 45% fat (high-fat, HF) for 8 weeks followed by 4 weeks of probiotic (Bifidobacterium animalis subsp. lactis, BB-12) supplementation. Fetuses and placentae were examined mid- (D12) and late- (D19) gestation

Results

Placental length, width, and weight as well as fetal weight were decreased in the HF group at D12. Probiotic supplementation reversed the HF diet-induced reduction in placental weight at D12. These beneficial effects of probiotic supplementation were absent at D19 as fetal weights from all HF diet fed groups weighed less regardless of probiotic supplementation. Probiotic supplementation reduced placental TNF-alpha mRNA at D12 and IL-10 mRNA at D19. Triacylglyceride concentration was increased at D19 by HF diet, in part, by the preceding increases in lipoprotein lipase (LPL) and plasma membrane-associated fatty-acid binding protein (FABPpm) mRNA expression at D12.

Conclusions

These findings suggest that maternal HF diet alters placental size and weight as well as fetal weight and that probiotic supplementation renders a protective effect against these changes in mid-gestation. Future studies are needed to determine whether the protective mechanism of probiotic supplementation in mid-gestation has beneficial effects on offspring developmental programming.

Funding Sources

USDA Agricultural Research Service Project #3062-51000-052-00D.

Development and Validation of a Fecal Extraction Procedure for the Assessment of Multiple Fecal Biomarkers of Intestinal Inflammation (P13-025-19)

Objectives

Fecal biomarkers have emerged as an important tool to assess intestinal inflammation and permeability. Commonly measured biomarkers include calprotectin (CP), myeloperoxidase (MPO), alpha-1-antitrypsin (AAT) and neopterin (NEO). We sought to develop a simple, fast and cost-effective single extraction procedure for use in determining all four biomarkers of interest. The applicability and sensitivity of this procedure for use in healthy adults was examined.

Methods

Sample extraction buffers and methods including sample weight, dilution, homogenization and centrifugation were all considered in the development of a single extraction procedure. An extraction buffer that included phosphate-buffered saline, phenylmethylsulfonyl fluoride, bovine serum albumin and Tween 20 was used to extract fecal samples. To assess the applicability and sensitivity of the single extraction procedure, concentrations of CP, MPO, AAT and NEO were measured using commercially available sandwich ELISA kits, according to manufacturer's instructions.

Results

CP, MPO and AAT concentrations were measured in fecal samples of healthy adults (aged 50–80 years, n = 85) and found to be comparable to findings of previously published studies in healthy populations. Mean concentrations of CP and AAT were 3.6 ± 3.8 µg/g of wet weight (range 0.14–18.0 µg/g) and 2.3 ± 0.73 µg/g (range 0.76–5.2 µg/g), respectively. Mean fecal MPO concentrations were 135 ± 24 ng/g (range 3–1290 ng/g). NEO concentrations were examined in a subset of healthy adults (n = 10), with mean concentrations of 18 ± 1 ng/g (range 17–20 ng/g).

Conclusions

We demonstrated the efficacy of a single extraction procedure used to assess multiple fecal biomarkers of intestinal inflammation. This simple, fast and inexpensive extraction method will facilitate the determination of multiple fecal biomarkers which is critical in validating their use as clinical or predictive biomarkers of intestinal inflammation.

Funding Sources

Supported by the U.S. Department of Agriculture – Agricultural Research Service (ARS), under Agreement No. 58–1950-4–003, the Bill & Melinda Gates Foundation and Canadian Institutes of Health Research Postdoctoral Fellowship.

Dietary Fruit and Vegetable Supplementation Suppresses Diet-induced Atherosclerosis in LDL Receptor Knockout Mice (OR24-07-19)

Objectives

Epidemiological studies have shown that consumption of fruits and vegetables (F&V) is inversely associated with incidence of cardiovascular disease (CVD). However, the evidence for causality and underlying mechanisms is lacking. Our objective was to determine if increased consumption of F&V could prevent atherosclerosis and its underlying mechanisms.

Methods

A unique blend of the most commonly consumed 24 F&V was freeze-dried into a powder and mixed into diets. Thirty six 4-week old male LDL receptor knockout mice were randomly assigned to one of 3 diet groups (12/group): low fat (LF, 10 kcal% fat), high-fat (27 kcal% fat) with 0% F&V (HF), and HF plus 15% F&V diet (HF + FV, equivalent to 8–9 servings for humans). After 20 weeks, mice were euthanized and blood, aorta, and liver tissue were collected. Aortic atherosclerotic lesion, hepatic steatosis, plasma lipid profile and pro-inflammatory cytokine levels were measured.

Results

No significant differences were found in body weight among the 3 groups. Mice fed HF diet had larger aortic atherosclerotic lesion and hepatic steatosis area than mice fed LF diet by 6.5 and 1.9 fold, respectively (p < 0.001). HF + FV group had 80% less aortic lesion and hepatic steatosis than HF group (p < 0.001). Mice fed HF diet had significantly higher plasma TG and LDL and lower HDL levels than mice fed LF diet, and this dyslipidemia was prevented by F&V supplementation. Further, HF + FV group had lower plasma TNFα levels compared to HF0 group (p < 0.05). Spearman correlation analysis showed that aortic atherosclerotic lesion and hepatic steatosis area were negatively correlated with plasma HDL (p < 0.001) and significantly and positively correlated with TNFα, and the ratios of LDL/HDL, TG/HDL, and non HDL/HDL.

Conclusions

Our results demonstrate a causal role of high intake of F&V in preventing HF-induced atherosclerosis and hepatic steatosis, which may be mediated through improved dyslipidemia and reduced inflammation.

Funding Sources

U.S. Department of Agriculture – Agricultural Research Service.

Supporting Tables, Images and/or Graphs