William J. Turbitt

Dietary methionine restriction inhibits prostatic intraepithelial neoplasia in TRAMP mice

Prostate cancer (PCa) is a major aging‐related disease for which little progress has been made in developing preventive strategies. Over the past several years, methionine restriction (MR), the feeding of a diet low in methionine (Met), has been identified as an intervention which significantly extends lifespan and reduces the onset of chronic diseases, including cancer, in laboratory animals. We, therefore, hypothesized that MR may be an effective strategy for inhibiting PCa.

Bioactive growth hormone in older men and women: It's relationship to immune markers and healthspan

OBJECTIVEnThe consequences of age-related decline in the somatotropic axis of humans are complex and remain largely unresolved. We tested the hypothesis that hGH measurements of plasma by bioassay vs immunoassay from samples obtained from free-living, elderly individuals would reveal a dichotomy in GH activities that are correlated with the functional status of the donors, i.e. their healthspan.nnnDESIGNnForty-one men and women of advanced age (men: N=16, age, 80.5±6.5years; height, 173.1±6.9cm; body mass, 81.8±13.0kg) and (women: N=25, age, 80.7±7.2years; height, 157.7±6.0cm; body mass, 68.8±17kg), were recruited for a cross-sectional study. Participants filled out PROMIS (Patient-Reported Outcomes Measurement Information System, U. S. Department of Health and Human Services) scales, undertook physical performance tests and had fasted blood samples obtained at rest for measurement of hormonal and immunology biomarkers.nnnRESULTSnWhen measured by the well-established rat tibial line GH bioassay, one half of the plasma samples (n=20) contained bioassayable GH (bGH), but the other half (n=21) failed to mount increases in tibial plate width above saline injected controls. This difference did not correlate with the age, sex or physical functionality of the plasma donor. It also did not correlate with hGH concentrations measured by immunoassay. In those cases in which bGH was detected, various hierarchical regression models predicted that GHRH, c-peptide, VEGF, NPY, IL-4 and T-regulatory lymphocytes were associated with the difference and predicted bGH.nnnCONCLUSIONnResults from this study suggest that the actions of bGH at the cellular level may be modified by other factors and that this may explain the lack of correlations observed in this study.

Fish Oil Enhances T Cell Function and Tumor Infiltration and Is Correlated With a Cancer Prevention Effect in HER-2/neu But Not PyMT Transgenic Mice

Few studies have explored the effects of omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation on immune modulation in murine models of mammary carcinogenesis. HER-2/neu and PyMT mice were randomized to 2 dietary interventions: AIN-93G-based diet with 1) 11% of diet (per gram weight) as corn oil (CO) or 2) 10% of diet as menhaden fish oil plus 1% of diet as corn oil (FO). FO significantly reduced the incidence and multiplicity of tumors (P < 0.001) in HER-2/neu, but not PyMT mice. FO-fed mice had significantly larger splenocyte counts than CO-fed mice in both the HER-2/neu and PyMT models; and in both models this was comprised of an increase in most cell types, including Gr-1+/CD11b+ cells. T cells from FO-fed HER-2/neu mice produced significantly more interleukin-2 (P = 0.004) and interferon-γ (P = 0.012) in response to in vitro stimulation with anti-CD3 (0.5 µg/ml). Lastly, FO-fed HER-2/neu mice had significantly more tumor immune infiltrates than CO-fed mice, including NK1.1+, F4/80+, and Gr-1+/CD11b+ cells (P ≤ 0.05). Greater Th1 cytokine production and significantly more tumor immune infiltrates in FO-fed Her2/neu mice may account for the cancer prevention effect of fish oil in this model.

Abstract 1260: Diet and exercise-induced weight maintenance may be preventing mammary tumor growth and metastatic burden by enhancing antitumor immunity and/or reducing protumorigenic factors

Two lifestyle factors that increase cancer risk and progression are weight gain and sedentary behavior. Possible mechanisms underlying this relation include changes in metabolic, inflammatory, and immune mediators. Few studies have examined the effect of body weight and exercise on the efficacy of immunotherapeutic strategies. An emerging immunotherapeutic strategy is PD-1 checkpoint blockade, which selectively targets the membrane protein programmed cell death-1 (PD-1) on T cells to promote a sustained, antitumor effector response. Thus, the goal of the current study was to determine if preventing weight gain through diet (10% reduction in calories) and exercise (voluntary running wheel activity) will improve the response to the dual administration of a whole tumor cell vaccine and PD-1 checkpoint blockade. Female BALB/c mice were randomized to sedentary, weight gain (WG) or exercising, weight maintenance (WM) groups (n=32/group). After 8 weeks, all mice were orthotopically injected with 5x104 luciferase-transfected 4T1.2 cells into the fourth mammary fat pad and continued on their intervention for 35 days. After injection, WG and WM mice were randomized into vaccination (VAX) or vehicle (VEH) groups, and 1x106 irradiated 4T1.2 cells or HBSS vehicle control, respectively, was administered at day 7 post-tumor injection. Mice were further randomized (n=8/group) to receive anti-PD-1 (10 mg/kg/mouse) or isotype control at day 9 and 12 post-tumor injection. All WM groups, regardless of immunotherapy intervention, weighed significantly less than WG groups over the course of the study (p Citation Format: William J. Turbitt, Yitong Xu, Andrea M. Mastro, Connie J. Rogers. Diet and exercise-induced weight maintenance may be preventing mammary tumor growth and metastatic burden by enhancing antitumor immunity and/or reducing protumorigenic factors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1260. doi:10.1158/1538-7445.AM2017-1260

Abstract 243: Diet and exercise-induced weight maintenance, alone and in combination with a whole tumor cell vaccine, delays mammary tumor growth and reduces MDSC accumulation

Obesity and physical inactivity increase breast cancer risk, while the prevention of weight gain by diet and exercise can be protective. Numerous biological mechanism(s) have been proposed to explain the beneficial effects of weight maintenance; however few studies have examined the immune response to energy balance. We have previously shown that diet and exercise-induced weight maintenance (WM) achieved via a 10% restriction in calories and access to voluntary running wheels in combination with a whole tumor cell vaccine (VAX) significantly reduced mammary tumor growth and metastases in the 4T1 mammary tumor model. This WM-induced reduction in tumor growth occurred concurrently with an elevation in tumor specific IFN-γ production and a reduction in the number of myeloid-derived suppressor cells (MDSCs). However, because tumor size is positively correlated with immune suppression, the goal of the current study was to investigate if mice in the WM+VAX intervention had enhanced anti-tumor immune responses and/or fewer MDSCs controlling for tumor size. Female BALB/c mice were randomized into weight gain (WG) and WM groups (n=8/group) and had access to voluntary running wheels or standard cages, respectively. WG mice were fed ad libitum while WM mice were energy-restricted by 10% to maintain a stable body weight. After 8 weeks on the intervention, all mice were orthotopically injected with 5x104 4T1.2 cells into the fourth mammary fat pad and continued on their intervention. Once injected, both WG and WM mice were further randomized into vaccination (VAX) and vehicle control (VEH) groups (n=4/gr) and administered 1x106 irradiated 4T1.2 cells (VAX) or HBSS (VEH) at day 7 post-tumor implantation. Primary tumor growth was quantified, and mice were sacrificed when tumor volume reached 0.1-0.2 cm3. WM mice weighed significantly less than WG mice over the course of the study (p Citation Format: Yitong Xu, William J. Turbitt, Andrea M. Mastro, Connie J. Rogers. Diet and exercise-induced weight maintenance, alone and in combination with a whole tumor cell vaccine, delays mammary tumor growth and reduces MDSC accumulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 243. doi:10.1158/1538-7445.AM2017-243

Abstract 2877: Exercise, alone and in combination with a whole tumor cell vaccine reduces mammary tumor cell growth and enhances anti-tumor immunity

Regular, moderate exercise (EX) can reduce both the incidence and recurrence of breast cancer (BC), and improve survival. Numerous biological mechanism(s) have been proposed to explain these beneficial clinical effects of EX. However, little work has been done to examine the effect of EX on immunomodulation, i.e. the balance between anti-tumor immunity and the emergence of immunosuppressive cells, in particular myeloid derived suppressor cells (MDSC). We have previously demonstrated that moderate EX significantly enhances antigen-specific CD4+ and CD8+ T cell responses and reduces regulatory T cell function in tumor free-mice. Thus, the goal of the current study was to determine if EX could enhance effector function and reduce immunosuppression in tumor bearing mice, and determine if there were any synergistic effects of EX and the administration of a whole tumor cell vaccine on the aforementioned outcomes. Female Balb/c mice were randomized into EX or sedentary control (SED) groups (n = 14-16/group) and had access to running wheel or standard cages, respectively, for 12 weeks prior to the injection of 5×10^4 lucerifase-transfected 4T1.2 tumor cells into the 4th mammary fat pad. Mice were further randomized into vaccination (n = 6-8/group) or vehicle control (n = 4/group) and administered 1×10^6 irradiated 4T1.2 cells (VAC) or HBSS (VEH) at day 7, 14, 21, and 28 post tumor injection. All mice were fed the AIN-76A diet; however, the EX mice (n = 14) were fed 90% of caloric intake of SED animals to remain in energy balance (prevent weight gain) over the course of the study. Primary tumor growth was quantified, and at sacrifice (day 35) organs were collected to assess the following endpoints: splenic antigen-specific CD8+ effector function and myeloid derived suppressor cell (MDSC) accumulation, and metastatic burden in femurs. EX mice, with or without vaccine, weighed significantly less than SED mice (p Citation Format: William J. Turbitt, Donna Sosnoski, Andrea Mastro, Connie Rogers. Exercise, alone and in combination with a whole tumor cell vaccine reduces mammary tumor cell growth and enhances anti-tumor immunity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2877. doi:10.1158/1538-7445.AM2015-2877

Abstract 3691: Fish oil increases immune cell infiltration of tumors and reduces the incidence of mammary carcinogenesis in Her2neu mice.

The role of omega-3 fatty acids (n-3 FA) in breast cancer prevention is widely studied, however much controversy exists in the field. In numerous preclinical models including the Her2neu transgenic model, consumption of n-3 FA provides a protective effect in mammary carcinogenesis. However, to date few studies have explored the effect of n-3 FA supplementation on immune modulation and if such changes contribute to the cancer prevention effects of n-3 FA. The goal of the current study was to explore the role of fish oil, as the source of n-3 FA, on immune markers and tumor yield in a Her2/neu transgenic model. Her2neu mice were randomized to two dietary interventions: AIN-93G-based diet with 1) 11% of diet (per gram weight) as corn oil (CO) or 2) 10% of diet as menhaden fish oil plus 1% of diet as corn oil (FO) (n=30/gr). FO significantly reduced the incidence and multiplicity of tumors in Her2neu mice (P Citation Format: William J. Turbitt, Shawntawnee D. Collins, Haifang Xu, Sharlene Washington, Cesar Aliaga, Karam El-Bayoumy, Andrea Manni, Connie J. Rogers. Fish oil increases immune cell infiltration of tumors and reduces the incidence of mammary carcinogenesis in Her2neu mice. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3691. doi:10.1158/1538-7445.AM2013-3691