Project description:Aberrant production and/or function of multiple host systemic factors (e.g., metabolic and immune-inflammatory mediators) act in concert to promote a âtumorigenicâ host milieu that directly promotes an aggressive malignant phenotype as well as drug resistance. Hence, strategies with the capacity to simultaneously act across multiple host systemic pathways may be required to optimize therapeutic outcomes in solid tumors. We hypothesized that chronic aerobic training, a pleiotropic whole-body intervention, modulates multiple systemic host pathways that, in turn, effectively alters cancer cell phenotype in vitro. Plasma samples from patients with solid tumors exposed to chronic aerobic training or sedentary control were comprehensively characterized for changes in immune, inflammatory, and metabolic pathways. Compared with sedentary control, aerobic training caused significant reductions in interleukin (IL)-4, macrophage inflammatory protein-1 beta (MIP1-β), vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-α), and hepatocyte growth factor (HGF). There were no significant changes in leukocyte phenotype or any plasma metabolite signatures. Exposure of estrogen receptor (ER) distinct human breast cancer cell lines (MCF-7 and MDA-MB-231) to post-intervention serum from breast cancer patients exposed to aerobic training caused marked increases in proliferation, migration, and apoptosis, compared to control patient serum. Only the combination of cytokines significantly reduced in plasma following aerobic training recapitulated the phenotype observed with patient serum in MCF-7 cells whereas only the single addition of MIP-1β or HGF significantly increased apoptosis in MDA-MB-231 cells. Co-culturing of MDA-MB-231 cells with patient exercise serum and a HGF neutralizing antibody increased proliferation and completely abrogated exercise serum-induced apoptosis. Finally, whole-genome microarray of MDA-MB-231 cells exposed to exercise or control patient serum revealed differential modulation of 310 genes including PTEN, CDK3, and IGFBP1. Our findings indicate the widespread potential of chronic aerobic training to modulate host immune-inflammatory systemic factors in patients with solid tumors. Modulation of such pathways directly alters breast cancer phenotypes providing novel insight into the molecular pathways by which exercise may inhibit malignant progression. MDA-MB-231 cells were plated at 250,000 cells/well in triplicate with 10% FBS in 6-well plates and left overnight to adhere. Media was suctioned off and replaced with serum free media. Patient serum was then added to the wells at a 10% final concentration and RNA was harvested using Qiagen RNeasy kit after 4 days.
Project description:Aberrant production and/or function of multiple host systemic factors (e.g., metabolic and immune-inflammatory mediators) act in concert to promote a ‘tumorigenic’ host milieu that directly promotes an aggressive malignant phenotype as well as drug resistance. Hence, strategies with the capacity to simultaneously act across multiple host systemic pathways may be required to optimize therapeutic outcomes in solid tumors. We hypothesized that chronic aerobic training, a pleiotropic whole-body intervention, modulates multiple systemic host pathways that, in turn, effectively alters cancer cell phenotype in vitro. Plasma samples from patients with solid tumors exposed to chronic aerobic training or sedentary control were comprehensively characterized for changes in immune, inflammatory, and metabolic pathways. Compared with sedentary control, aerobic training caused significant reductions in interleukin (IL)-4, macrophage inflammatory protein-1 beta (MIP1-β), vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-α), and hepatocyte growth factor (HGF). There were no significant changes in leukocyte phenotype or any plasma metabolite signatures. Exposure of estrogen receptor (ER) distinct human breast cancer cell lines (MCF-7 and MDA-MB-231) to post-intervention serum from breast cancer patients exposed to aerobic training caused marked increases in proliferation, migration, and apoptosis, compared to control patient serum. Only the combination of cytokines significantly reduced in plasma following aerobic training recapitulated the phenotype observed with patient serum in MCF-7 cells whereas only the single addition of MIP-1β or HGF significantly increased apoptosis in MDA-MB-231 cells. Co-culturing of MDA-MB-231 cells with patient exercise serum and a HGF neutralizing antibody increased proliferation and completely abrogated exercise serum-induced apoptosis. Finally, whole-genome microarray of MDA-MB-231 cells exposed to exercise or control patient serum revealed differential modulation of 310 genes including PTEN, CDK3, and IGFBP1. Our findings indicate the widespread potential of chronic aerobic training to modulate host immune-inflammatory systemic factors in patients with solid tumors. Modulation of such pathways directly alters breast cancer phenotypes providing novel insight into the molecular pathways by which exercise may inhibit malignant progression.
Project description:Various studies have shown that aerobic exercise can prevent or alleviate cancer-induced muscle wasting. To reproduce at least partially in vitro some molecular differences of aerobic muscle exercise that are independent from systemic inflammation or the hormonal milieu, we infected fully differentiated myotubes with adenoviruses expressing PGC1α, one of the main transcriptional coactivators involved in muscle adaptation to endurance exercise. We then compared the effect of PGC1α expression at 48h in myotubes infected with GFP, used as control.
Project description:Microarray analysis was performed with RNA isolated from vastus lateralis muscle biopsies of lean/overweight subjects following 18 days of aerobic exercise training. Samples from lean active individuals were also included. Exercise training led to robust changes in trained muscle. The lean active group profile was distinct from the pre-exercise samples. These results help define the molecular changes associated with aerobic training and contrast with an active phenotype.
Project description:Low aerobic exercise capacity is a risk factor for diabetes and strong predictor of mortality; yet some individuals are exercise resistant, and unable to improve exercise capacity through exercise training. To test the hypothesis that resistance to aerobic exercise training underlies metabolic disease-risk, we used selective breeding for 15 generation to develop rat models of low- and high-aerobic response to training. Before exercise training, rats selected as low- and high-responders had similar exercise capacities. However, after 8-wks of treadmill training low-responders failed to improve their exercise capacity, while high-responders improved by 54%. Remarkably, low-responders to aerobic training exhibited pronounced metabolic dysfunction characterized by insulin resistance and increased adiposity, demonstrating that the exercise resistant phenotype segregates with disease risk. Low-responders had impaired exercise-induced angiogenes0is in muscle; however, mitochondrial capacity was intact and increased normally with exercise training, demonstrating that mitochondria are not limiting for aerobic adaptation or responsible for metabolic dysfunction in low-responders. Low-responders had increased stress/inflammatory signaling and altered TGFβ signaling, characterized by hyperphosphorylation of a novel exercise-regulated phosphorylation site on SMAD2. Using this powerful biological model system we have discovered key pathways for low exercise training response that may represent novel targets for the treatment of metabolic disease.
Project description:Aerobic glycolysis (the Warburg effect) has been demonstrated to facilitate tumor progression by producing lactate, which has important roles as a proinflammatory and immunosuppressive mediator. However, how aerobic glycolysis is directly regulated is largely unknown. Here, we show that ectopic Zeb1 directly increases the transcriptional expression of HK2, PFKP and PKM2, which are glycolytic rate-determining enzymes, thus promoting the Warburg effect and breast cancer proliferation, migration, and chemoresistance in vitro and in vivo. In addition, Zeb1 exerts its biological effects to induce glycolytic activity in response to hypoxia via the PI3K/Akt/HIF-1α signaling axis, which contributes to fostering an immunosuppressive tumor microenvironment (TME). Mechanistically, breast cancer cells with ectopic Zeb1 expression produce lactate in the acidic tumor milieu to induce the alternatively activated macrophage M2-like phenotype through stimulation of the PKA/CREB signaling pathway. Clinically, the expression of Zeb1 is positively correlated with dysregulation of aerobic glycolysis, accumulation of M2-like tumor-associated macrophages (TAMs) and a poor prognosis in patients with breast cancer. In conclusion, these findings identify a Zeb1-dependent mechanism as a driver of breast cancer progression that acts by stimulating tumor-macrophage interplay, which could be a viable therapeutic target for the treatment of advanced human cancers.
Project description:Low aerobic exercise capacity is a risk factor for diabetes and strong predictor of mortality; yet some individuals are exercise resistant, and unable to improve exercise capacity through exercise training. To test the hypothesis that resistance to aerobic exercise training underlies metabolic disease-risk, we used selective breeding for 15 generation to develop rat models of low- and high-aerobic response to training. Before exercise training, rats selected as low- and high-responders had similar exercise capacities. However, after 8-wks of treadmill training low-responders failed to improve their exercise capacity, while high-responders improved by 54%. Remarkably, low-responders to aerobic training exhibited pronounced metabolic dysfunction characterized by insulin resistance and increased adiposity, demonstrating that the exercise resistant phenotype segregates with disease risk. Low-responders had impaired exercise-induced angiogenes0is in muscle; however, mitochondrial capacity was intact and increased normally with exercise training, demonstrating that mitochondria are not limiting for aerobic adaptation or responsible for metabolic dysfunction in low-responders. Low-responders had increased stress/inflammatory signaling and altered TGFM-NM-2 signaling, characterized by hyperphosphorylation of a novel exercise-regulated phosphorylation site on SMAD2. Using this powerful biological model system we have discovered key pathways for low exercise training response that may represent novel targets for the treatment of metabolic disease. Cardiac and skeletal muscle from 3 high and 3 low responder rats were examined for differential miRNA expression using Exiqon microarrays
Project description:Skeletal muscle adapts to exercise training of various modes, intensities and durations with a programmed gene expression response. This study dissects the independent and combined effects of exercise mode, intensity and duration to identify which exercise has the most positive effects on skeletal muscle health. Full details on exercise groups can be found in: Kraus et al Med Sci Sports Exerc. 2001 Oct;33(10):1774-84 and Bateman et al Am J Cardiol. 2011 Sep 15;108(6):838-44. This study uses a middle aged group of subjects that have 3+ markers of metabolic syndrome. One group remains an inactive control, while 5 groups undergo 9 mo supervised exercise training. Exercise groups are as follows: Inactive control (group B); Mild aerobic exercise - low amount/mod intensity (group A); Moderate aerobic exercise - low amt/vig intensity (group D); High aerobic exercise - high amt/vig intensity (group C); resistance training only (group F); and mod aerobic + resistance training (group E). Each group has 10 subjects (5 men and 5 women), however 3 subjects failed array QC, leaving 8 subjects in group E and 9 subjects in group F. Data were all analyzed pre to post training in a RM ANCOVA, covaried for age and sex or regression to determine genotype/phenotype interactions.
Project description:Maximal aerobic exercise capacity (V̇O2max) is one of the strongest predictors of morbidity and mortality. Aerobic exercise training can increase V̇O2max, but inter-individual variability is marked and unexplained physiologically. The mechanisms underlying this variability have major clinical implications for extending human healthspan. Here, we report the first comprehensive, RNA-seq study of circulating transcriptome signatures related to ΔV̇O2max. We used RNA-seq to characterize transcriptomic predictors of ΔV̇O2max in healthy women who completed a 16-week, randomized controlled trial comparing higher vs. lower aerobic exercise training volume and intensity (four training groups, fully crossed). We found striking baseline gene expression differences in subjects who responded to aerobic exercise training with robust (R) vs. little/no (NR) ΔV̇O2max.