Johnson Cancer Research Center

Tumor-derived circulating exosomes, enriched with a group of tumor antigens, have been recognized as a promising biomarker source for cancer diagnosis via a less invasive procedure. Quantitatively pinpointing exosome tumor markers is appealing, yet challenging. In this study, we developed a simple microfluidic approach (ExoSearch) which provides enriched preparation of blood plasma exosomes for in situ, multiplexed detection using immunomagnetic beads. The ExoSearch chip offers a robust, continuous-flow design for quantitative isolation and release of blood plasma exosomes in a wide range of preparation volumes (10 μL to 10 mL). We employed the ExoSearch chip for blood-based diagnosis of ovarian cancer by multiplexed measurement of three exosomal tumor markers (CA-125, EpCAM, CD24) using a training set of ovarian cancer patient plasma, which showed significant diagnostic power (a.u.c. = 1.0, p = 0.001) and was comparable with the standard Bradford assay. This work provides an essentially needed platform for utilization of exosomes in clinical cancer diagnosis, as well as fundamental exosome research.

Effective surface area on rough substrates for bacterial adhesion is examined by analyzing the solid area fraction of surfaces, where the bacterial medium is in contact with the solid surface.

Exosomes are cell-derived nano-sized vesicles that have been recently recognized as new mediators for many cellular processes and potential biomarkers for non-invasive disease diagnosis and the monitoring of treatment response. To better elucidate the biology and clinical value of exosomes, there is a pressing need for new analytical technologies capable of the efficient isolation and sensitive analysis of such small and molecularly diverse vesicles. Herein, we developed a microfluidic exosome analysis platform based on a new graphene oxide/polydopamine (GO/PDA) nano-interface. To the best of our best knowledge, we report for the first time, the GO-induced formation of a 3D nanoporous PDA surface coating enabled by the microfluidic layer-by-layer deposition of GO and PDA. It was demonstrated that this nanostructured GO/PDA interface greatly improves the efficiency of exosome immuno-capture, while at the same time effectively suppressing non-specific exosome adsorption. Based on this nano-interface, an ultrasensitive exosome ELISA assay was developed to afford a very low detection limit of 50 μL(-1) with a 4 log dynamic range, which is substantially better than the existing methods. As a proof of concept for clinical applications, we adapted this platform to discriminate ovarian cancer patients from healthy controls by the quantitative detection of exosomes directly from 2 μL plasma without sample processing. Thus, this platform could provide a useful tool to facilitate basic and clinical investigations of exosomes for non-invasive disease diagnosis and to aid precision treatment.

Clinical diagnosis requiring central facilities and site visits can be burdensome for patients in resource-limited or rural areas. Therefore, development of a low-cost test that utilizes smartphone data collection and transmission would beneficially enable disease self-management and point-of-care (POC) diagnosis. In this paper, we introduce a low-cost iPOC3D diagnostic strategy which integrates 3D design and printing of microfluidic POC device with smartphone-based disease diagnosis in one process as a stand-alone system, offering strong adaptability for establishing diagnostic capacity in resource-limited areas and low-income countries. We employ smartphone output (AutoCAD 360 app) and readout (color-scale analytical app written in-house) functionalities for rapid 3D printing of microfluidic auto-mixers and colorimetric detection of blood hemoglobin levels. The auto-mixing of reagents with blood via capillary force has been demonstrated in 1 second without the requirement of external pumps. We employed this iPOC3D system for point-of-care diagnosis of anemia using a training set of patients (nanemia = 16 and nhealthy = 6), which showed consistent measurements of blood hemoglobin levels (a.u.c. = 0.97) and comparable diagnostic sensitivity and specificity, compared with standard clinical hematology analyzer. Capable of 3D fabrication flexibility and smartphone compatibility, this work presents a novel diagnostic strategy for advancing personalized medicine and mobile healthcare.

A characterization method was developed, which visualizes the wetted solid area fraction ( f s ) of the Cassie–Baxter model on a roughened surface.

Synthetic triptycene analogs (TT code number) mimic the antitumor effects of daunorubicin (DAU) in vitro, but have the advantage of blocking nucleoside transport, inhibiting both DNA topoisomerase I and II activities, and retaining their efficacy in multidrug-resistant (MDR) tumor cells. Since TT bisquinones induce poly(ADP-ribose) polymerase-1 (PARP-1) cleavage at 6 h and internucleosomal DNA fragmentation at 24 h, which are, respectively, early and late markers of apoptosis, these antitumor drugs were tested for their ability to trigger the release of mitochondrial cytochrome c (Cyt c) and the caspase activation cascade in the HL-60 cell system. Based on their ability to reduce the viability of wild-type, drug-sensitive HL-60-S cells in the nanomolar range, six lead antitumor TT bisquinones have been identified so far: TT2, TT13, TT16, TT19, TT24 and TT26. In accord with the fact that effector caspase-3 is responsible for PARP-1 cleavage, 4 microM concentrations of DAU and these TT bisquinones all maximally induce caspase-3 activity at 6 h in HL-60-S cells, an effect which persists when the drugs are removed after a 1-h pulse treatment. Since caspase-3 may be activated by initiator caspase-9 and -8, it is significant to show that such caspase activation cascade is induced by 4 microM DAU and TT bisquinones at 6 h in HL-60-S cells. Although the relationship is not perfect, the ability of TT analogs to induce caspase-3, -8 and -9 activities may be linked to their quinone functionality and cytotoxicity. Interestingly, 4 microM concentrations of TT bisquinones retain their ability to induce caspase-3, -8 and -9 activities at 6 h in the MDR HL-60-RV cell line where 4 microM DAU becomes totally ineffective. The release of mitochondrial Cyt c is also detected within 6 h in HL-60-S cells treated with 4 microM DAU or TT bisquinones, a finding consistent with the fact that Cyt c is the apoptotic trigger that activates caspase-9. Caspase-2 and -8 may both act upstream of mitochondria to promote Cyt c release, but caspase-2 is already maximally activated 6 h after 4 microM DAU or TT13 treatments, whereas DAU- or TT-induced caspase-8 and -9 activities peak at 9 h. Pre-treatments with 15 microM of the caspase-2 inhibitor benzyloxycarbonyl (z)-Val-Asp-Val-Ala-Asp (VDVAD)-fluoromethyl ketone (fmk) totally block DAU- and TT13-induced caspase-2, -8 and -9 activities, whereas pre-treatments with 15 microM of the caspase-8 inhibitor z-Ile-Glu-Thr-Asp (IETD)-fmk prevent DAU and TT13 from inducing caspase-8 activities without affecting their caspase-2- and -9-inducing activities, suggesting that the induction of apical caspase-2 activity by these drugs may be a critical upstream event required for the activation of other downstream caspases, including caspase-9 and the mitochondrial amplification loop through caspase-8. However, the mechanisms by which DAU and TT13 induce the release of mitochondrial Cyt c appear to be caspase-independent since they are both insensitive to similar pre-treatments with 100 microM of these specific caspase-2 and -8 inhibitors. Moreover, pre-treatments with 10 microg/ml of the antagonistic anti-Fas DX2 and ZB4 monoclonal antibodies (mAbs), and the neutralizing anti-Fas ligand (FasL) NOK-1 mAb are all unable to prevent DAU and TT13 from inducing Cyt c release and caspase-2, -8 and -9 activities, suggesting that the Fas-FasL signaling pathway is not involved in the mechanism by which these quinone antitumor drugs trigger apoptosis in HL-60 cells.

Since synthetic analogs of 1,4-anthraquinone (AQ code number), such as AQ8, AQ9 and AQ10, can trigger cytochrome c release without caspase activation and retain their ability to induce apoptosis in multidrug-resistant (MDR) tumor cells, fluorescent probes of transmembrane potential have been used to determine whether these anti-tumor compounds might directly target mitochondria in cell and cell-free systems to cause the collapse of mitochondrial membrane potential (/Deltapsim) that is linked to permeability transition pore (PTP) opening. Using JC-1 dye, the abilities of various AQ analogs to induce the /Deltapsim in wild-type and MDR HL-60 cells are rapid (within 2.5-10 min), irreversible after drug removal, concentration dependent in the 0.256-10 micromol/l range and generally related to their anti-tumor activities in vitro. The /Deltapsim caused by AQ9 and AQ10, which are more potent than mitoxantrone, staurosporine and the reference depolarizing agent carbonyl cyanide m-chlorophenylhydrazone (CCCP) in HL-60 cells, are not prevented by caspase-2 or -8 inhibitors, suggesting that activations of these apical caspases upstream of mitochondria are not involved in this process. Antitumor AQ analogs (0.256-10 micromol/l) also mimic the abilities of the known depolarizing agents CCCP, alamethicin, gramicidin A and 100 micromol/l CaCl2 to directly induce within 15 min the /Deltapsim in isolated mitochondria prepared from mouse liver and loaded with rhodamine 123 dye. The fact that 20 micromol/l Ca2+, which is insufficient to trigger depolarization on its own, is required to reveal the depolarizing effect of AQ9 in isolated mitochondria suggests that anti-tumor AQ analogs might interact with the PTP to alter its conformation and increase its Ca2+ sensitivity. Indeed, such Ca2+-dependent /Deltapsim of isolated mitochondria treated with 1.6 micromol/l AQ9 or 100 micromol/l Ca2+ are blocked by ruthenium red. Daunorubicin (DAU) is unable to mimic the rapid /Deltapsim caused by anti-tumor AQ analogs within 2.5-40 min of treatment in HL-60 cells or isolated mitochondria. Moreover, the /Deltapsim caused by 1.6 micromol/l AQ9 or 100 micromol/l Ca2+ in isolated mitochondria are similarly blocked by cyclosporin A (CsA), bongkrekic acid and decylubiquinone, which prevent PTP opening, suggesting that, in contrast to DAU, anti-tumor AQ analogs that directly target mitochondria to trigger the Ca2+-dependent and CsA-sensitive /Deltapsim, might induce PTP opening and the mitochondrial pathway of apoptosis even in the absence of nuclear signals.

Synthetic triptycene analogs (TT code number) mimic the antitumor effects of daunorubicin in the nanomolar range in vitro, but have the advantage of blocking nucleoside transport and retaining their efficacy in multidrug-resistant (MDR) tumor cells. Since TT bisquinones induce poly(ADP-ribose) polymerase-1 cleavage at 6 h and internucleosomal DNA fragmentation at 24 h, which are, respectively, early and late markers of apoptosis, these lead antitumor drugs were tested for their ability to trigger the DNA topoisomerase (Topo) inhibitions responsible for the initial and massive high-molecular-weight cleavage of DNA required for tumor cells to commit apoptosis. Interestingly, antitumor TTs have the unusual ability to inhibit, in a concentration-dependent manner, the relaxation of supercoiled plasmid DNA catalyzed by both purified human Topo I and II enzymes. However, if there is a relationship between the ability of TT analogs to inhibit Topo activities and their quinone functionality and cytotoxicity, it is far from perfect, suggesting that other molecular targets may be involved in the mechanism of action of these antitumor drugs. Moreover, one of the most cytotoxic TT bisquinone, 6-bromo-7-methoxy- or 7-bromo-6-methoxy-2-N-methylamino-1 H,4 H,5 H,8H-9,10-dihydro-9,10-[1',2']benzenoanthracene-1,4,5,8-tetraone (TT24), inhibits Topo II activity more effectively than amsacrine (m-AMSA) and matches the Topo I inhibitory effect of camptothecin (CPT). The dual inhibitory activity of TT24 is substantiated by the findings that TT24 mimics the action of m-AMSA in the Topo II assay, where the Topo I inhibitor CPT is ineffective, and also mimics the action of CPT in the Topo I assay, where the Topo II inhibitor etoposide is ineffective. Because of their ability to target nucleoside transport and topoisomerase activities, synthetic TT bisquinones might represent a novel class of bifunctional drugs valuable to develop new means of polychemotherapy and circumvent MDR.

A parametric study was conducted to improve our understanding pertaining to the fundamental physics of electrokinetic instability (EKI) and to explore the effectiveness of manipulating EKI waves to control/enhance fluid mixing inside a Y-shaped microchannel. The dependence of the critical strength of the applied static electric field to trigger the EKI waves on the conductivity ratio of the two mixing streams inside the Y-shaped microchannel was quantified at first. The effects of the applied electric field strength on the evolution of the EKI waves and the resultant fluid mixing were assessed in terms of scalar concentration distributions, shedding frequency of the EKI waves and fluid mixing efficiency. The effectiveness of manipulating the EKI waves by adding alternative perturbations to the applied static electric fields were also explored for the further enhancement of the fluid mixing inside the Y-shaped microchannel. The measurement results revealed that the relationship between the critical strength of the applied static electric field and the conductivity ratio of the two mixing streams in the Y-shaped microchannel can be represented well by a power function with the power index about -0.246. The fluid mixing efficiency was found to increase monotonically with the increasing strength of the applied electric field. The fluid mixing process was found to be further enhanced by adding alternative perturbations to the applied static electric fields with the mixing process being most enhanced when the frequency of the alternative perturbation is close to the natural shedding frequency of the EKI waves. The fluid mixing efficiency was found to increase rapidly as the amplitude of the alternative perturbation increases.

The work presented here aims at utilizing poly-N-isopropyl-acrylamide/acrylic acid copolymers to create nanostructured layers on mica surfaces by a simple spin-casting procedure. The average composition of the copolymers determined by elemental analysis correlates excellently with the feed composition indicating that the radical polymerization process is statistical. The resulting surfaces were characterized by Atomic Force Microscopy (magnetic AC-mode) at the copolymer/air interface. Postpolymerization modification of the acrylic acid functions with perfluoro-octyl-iodide decreased the tendency towards spontaneous formation of nanopores. Crosslinking of individual polymer chains permitted the generation of ultraflat layers, which hosted the mycobacterial channel protein MspA, without compromising its channel function. The comparison of copolymers of very similar chemical composition that have been prepared by living radical polymerization and classic radical polymerization indicated that differences in polydispersity played only a minor role when poly-N-isopropyl-acrylamide/acrylic acid copolymers were spincast, but a major role when copolymers featuring the strongly hydrophobic perfluoro-octyl-labels were used. The mean pore diameters were 23.8+/-4.4 nm for P[(NIPAM)(95.5)-co-(AA)(4.5)] (PDI (polydispersity index)=1.55) and 21.8+/-4.2 nm for P[(NIPAM)(95.3)-co-(AA)(4.7)] (PDI=1.25). The depth of the nanopores was approx. 4 nm. When depositing P[(NIPAM)(95)-co-(AA)(2.8)-AAC(8)F(17 2.2)] (PDI=1.29) on Mica, the resulting mean pore diameter was 35.8+/-7.1 nm, with a depth of only 2 nm.

Research has indicated that excessive vitamin A can have deleterious impacts on bone. Retinoic acid (RA), the most active metabolite of vitamin A, has been tested in clinical trials for treatment of lung cancer and emphysema. These trials are not measuring Bone Mineral Content (BMC) or Bone Mineral Density (BMD). In this study, we used an animal model to determine potential deleterious effects of all-trans RA on bone mass when used as a means to protect against or treat cigarette smoke-induced lung injuries, and also to evaluate BMC as a potential early indicator of osteoporosis risk. Twenty-four male weanling rats were fed either a control diet or a RA-supplemented diet. Half of each group was exposed to 40 cigarettes per day, 5 days per week, for 4 weeks. BMC and BMD were measured at weeks 2 and 4. RA supplementation in all groups significantly decreased (p < 0.05) only BMC at week 2 and both BMC and BMD (both p < 0.05) at week 4. The same results were observed when BMC was expressed relative to body weight. These data suggest that caution should be used when RA is used to treat smoke-related lung injuries.

This chapter contains sections titled: Introduction Absorption of and Emission from Nanoparticles Quantum Dots: A Brief Overview Electrochemistry of Nanoparticles Conclusion Further Reading References Problems Answers

Background Radiation is an important and effective anti‐cancer therapy, but is associated with many side effects. Radiation exposure may cause damage to the heart and coronary vasculature. Exercise training is currently being investigated in cancer research as a treatment or adjuvant to anti‐cancer therapies, and has been shown to mitigate deleterious changes in coronary vascular function, such as with aging. We hypothesized that impairments in endothelium‐dependent vasodilation of coronary resistance arterioles that occur in response to radiation exposure would be mitigated with exercise training. Methods 12 male Fischer 344 rats (3‐4 months old) were randomly assigned to one of four groups: control (CON; n=3), exercise (EX; n=3), control radiated (RAD; n=3), or exercise radiated (EX RAD; n=3). After increasing intensity over the first 3 weeks, EX and EX RAD animals ran on a motorized treadmill 5 days/week for 60 minutes/day, at an intensity of 15 m/min and 15° incline for the remainder of 12 weeks of training. After the conclusion of exercise training, all groups of animals were subjected 2 Gy whole body radiation by X‐Rad 350 x‐ray irradiator and euthanized within 8 hours. Hearts were harvested and left anterior descending (LAD) arteriole sections were isolated and fixed on glass pipets. Vessels were pressurized at 60 cm H2O. Once a minimum of 20% tone was developed, vessels were exposed to cumulative doses of bradykinin (10‐13‐10‐7 M), an endothelium‐dependent vasodilator, and vessel diameter was recorded at each dose. Results No differences were detected for CON vs. EX or CON vs. EX RAD. Vasodilation for RAD was significantly reduced vs. CON (p = 0.007). EX RAD was significantly increased vs. RAD (p = 0.025). Conclusions There were no differences between CON and EX; however, vasodilation was impaired for radiated animals, suggesting even one dose of 2 Gy radiation can cause significant impairment in endothelium‐dependent vasodilation of coronary arterioles. Exercise training attenuated this impairment and restored endothelium‐dependent vasodilation to levels not different from control animals. These findings are significant, given that exercise training may be used as a simple and safe method to preserve coronary arteriole function in patients receiving radiation therapy.

Background The efficacy of conventional anti‐cancer treatments is dependent, in part, on tumor blood flow and oxygenation. Tumor vasculature is abnormal relative to healthy tissue, leading to reduced blood flow and oxygen delivery, and thus, treatment resistance. An emerging adjuvant to conventional treatment to overcome resistance to radiation is heat therapy. While heat therapy may sensitize tumors to radiation via increases in tumor blood flow and thus, oxygenation, we hypothesized that heat‐induced radiosensitization occurs independent, in part, of tumor blood flow or oxygenation. Methods Clonogenic cell survival, cell viability, and cell cycle distribution were assessed using human prostate cancer (PC‐3) cells in vitro . Individual tissue culture flasks of PC‐3 cells were randomized into 6 groups: normothermic non‐radiated (NT‐NR, n=8), normothermic radiated (NT‐R, n=8), acute hyperthermic non‐radiated (HTA‐NR, n=8), acute hyperthermic radiated (HTA‐R, n=8), chronic (repeated) hyperthermic non‐radiated (HTC‐NR, n=8), and chronic (repeated) hyperthermic radiated (HTC‐R, n=8). NT‐NR and NT‐R flasks were maintained in an incubator at 37° C for the duration of experiments. HTA‐NR and HTA‐R flasks were maintained in an incubator at 37° C and heated in a separate incubator to 41° C for 60 minutes prior to radiation. HTC‐NR and HTC‐R flasks were maintained at 37°C and heated to 41°C for 60 minutes every 48 hours for 3 heat treatments. Non‐radiated flasks were subjected to 0 Gy radiation, while radiated flasks were subjected to 2 Gy radiation. For clonogenic cell survival, cells were then plated in 60 mm tissue culture dishes at a density of 500 cells/plate and 1000 cells/plate in 5 replicates each per flask and allowed to grow for 8 days in an incubator at 37° C. Cell survival was assessed via counting the number of fixed and stained colonies >50 cells at the completion of 8 days of incubation. For cell viability, cells were plated into 96‐well plates and incubated for 24, 48, and 72 hours before addition of MTT reagent for quantification of absorbance. For determination of cell cycle distribution, cells were stained with propidium iodide and analyzed via flow cytometry. Data are presented as mean ± SEM. Results Clonogenic cell survival was significantly reduced between NT‐NR vs. NT‐R, HTA‐NR, HTA‐R, and HTC‐R (100 % ± 9.7% vs. 59.1 % ± 5.9 %, 72.4% ± 8.5%, 40.3% ± 3.1%, and 43.3% ± 3.4%, respectively; p < 0.05). There were no differences between NT‐R and HTA‐NR or HTC‐NR. Percentage of cells in G0/G1 was significantly increased and percentage of cells in G2/M was significantly decreased in NT‐R and HTC‐NR vs. NT‐NR and HTA‐NR. Conclusions This investigation indicates that mild‐temperature hyperthermia before radiation treatment does not enhance the efficacy of radiation treatment, but that heat therapy alone may be as effective as low‐dose radiation in vitro . Further, given that 2 Gy radiation alone (representative of one radiation fraction given clinically) was not more effective at reducing cancer cell survival, heat therapy may be an effective strategy to limit cancer progression before radiation therapy begins. Support or Funding Information NIH HL137156‐01A1, RSG‐14‐150‐01‐CCE

Background The use of immunocompromised animals has been indispensable in cancer and immunology research. The use of exercise with these models in these areas of research has increased dramatically over the past decade, with little to no evidence of how immune modification of strains of animals is impacting exercise capacity and/or responses to training. This data is critical for extrapolation to exercise recommendations in humans as the majority of cancer patients do not present with primary immunodeficiency diseases. Recently, observations of lower skeletal muscle oxidative capacity between RNU (NIH Nude, immunocompromised) and Copenhagen rats (immunocompetent) have been speculated to result from possible differences between immune function in animals. The purpose of this study was to determine if there are differences in maximal aerobic capacity, through assessment of V̇o 2max , between immune‐competent and ‐compromised animals of the same strain. We tested the hypothesis that immunocompromised animals would have a lower aerobic capacity than their immunocompetent counterparts. Methods RNU 316 (NU−/−, T‐cell deficient; n=10) and RNU 118 (NU+/−, no deficiency; n=10) male rats (~4 months old) were obtained from Charles River. Both groups were acclimated to motorized treadmill running at varying speeds (20–40 m/min) for 3–5 sessions before beginning V̇o 2max assessment. V̇o 2max graded treadmill testing consisted of a 2‐minute warm‐up at 25 m/min at a 5% incline followed by 2 minutes at 35 m/min, and subsequent increases in speed of 5 m/min every minute after until a plateau was seen in oxygen consumption with increased speed, or test termination was required for safety of the animal. Tests were repeated a minimum of two times (3 maximally) per animal to verify maximum values were achieved. Results There were no significant differences in body mass (NU−, 347±12 g, NU+, 321±8 g; p=0.17). V̇o 2max was lower in NU− vs NU+ animals (80.0±1.5 vs. 88.4±1.9 ml·min −1 ·kg −1 ; p<0.01). There was a significant difference in respiratory exchange ratio (RER) at V̇o 2max (NU−, 1.05±0.01 vs. NU+, 0.98±0.01; p<0.05), but no difference in CO 2 production (NU−, 83.7±1.3 vs. NU+, 86.7±1.5 ml·min −1 ·kg −1 ; p>0.05). Conclusion This study suggests that immunocompromised animals have a decreased aerobic capacity compared to immunocompetent counterparts. This should be considered when both designing exercise interventions in immunedeficient/compromised animals as well as interpretations derived from such studies. Support or Funding Information NIH HL137156‐01A1 ACS RSG‐14‐150‐01‐CCE

Background Prostate cancer is the most commonly diagnosed non‐skin cancer in men accounting for 20% of all diagnoses. Exercise intolerance is common in cancer patients, in particular, in those undergoing adjuvant therapies (i.e., androgen deprivation therapy) that leads to reductions in quality of life. Recent evidence suggests prostate cancer, independent of treatment, hastens fatigue (i.e., reduces time to exhaustion) which is associated with atrophic effects on whole heart and left ventricular (LV) mass. However, moderate‐intensity endurance training mitigates cardiac mass loss in prostate tumor‐bearing rats. Using a pre‐clinical orthotopic model of prostate cancer, we tested the hypothesis that prostate cancer would reduce aerobic capacity, assessed as maximal oxygen consumption (V̇o 2max ). We also investigated whether moderate‐intensity endurance training would mitigate any loss of aerobic capacity associated with prostate cancer. Methods Dunning R‐3327 MatLyLu prostate adenocarcinoma cells (2×10 5 ) in 0.1ml of physiological saline solution were injected in the ventral lobe of 4–5‐month‐old male RNU (NIH nude) rat (n=10). These animals were randomized into 2 groups, Tumor Bearing Exercise (TBEX, n=6) or Tumor Bearing Sedentary (TBS, n=4). After ~5 days of recovery, TBEX animals began progressive exercise training on a motorized treadmill at 25 m/min with a 5% incline for 10 minutes a day progressing to 60 min/day for a ~5 week period. Pre‐injection (Pre) and post‐exercise training (Post) animals performed V̇o 2max testing at least twice to verify attainment of maximal value (i.e validation test), with a minimum of 24 h of recovery between bouts to ensure reproducibility. Results There were no significant differences (all p>0.05) in tumor mass between groups (TBEX 6.4±1.1; TBS 7.6±1.2 g), body mass (TBEX 322±15; TBS 361±16 g), or Pre‐injection V̇o 2max (TBEX 82.2±2.1; TBS 78.5±2.5 ml·min −1 ·kg −1 ). Heart to body mass ratio was lower in TBS group compared to TBEX (2.9±0.1 vs. 3.3±0.1 mg/g, p<0.05). Following training, TBEX had increases in V̇o 2max (6.4±1.3 ml·min −1 ·kg −1 , p<0.05) whereas TBS had a decrease in aerobic capacity ( − 5.6±2. ml ·min −1 ·kg −1 , p<0.05). Conclusion This study suggests that prostate cancer, independent of treatment significantly diminishes maximal aerobic capacity. Further, moderate‐ intensity exercise training not only mitigates this cancer‐associated loss, but effectively improves aerobic capacity vs. values obtained prior to cancer development. Given prostate cancer patients often present fatigue and loss of quality of life, moderate‐ intensity exercise training may be useful to improve both facets via maintaining or improving aerobic capacity. Support or Funding Information NIH HL137156‐01A1ACS RSG‐14‐150‐01‐CCE