Male Copenhagen Rats Research Articles

Metformin protects against small intestine damage induced by diabetes and dunning's prostate cancer: A biochemical and histological study.

The oral biguanide metformin is used to treat type 2 diabetic mellitus (T2DM). Anti-cancer effects have been proven by metformin in different hormone-sensitive tumors, including breast, pancreatic, colon, and prostate cancer. Therefore, we investigated whether metformin could defend against small intestine damage in Dunning's prostate cancer. The study divided the six groups of male Copenhagen rats into the following categories: control, diabetic (D), cancer (C), diabetic + cancer (DC), cancer + metformin (CM), and diabetic + cancer + metformin (DCM). After sacrifice, the small intestines were removed to assess biochemical markers and histopathological evaluation. Biochemical evaluations showed that glutathione (reduced) levels and other enzyme activities related antioxidant systems, paraoxonase, sodium potassium ATPase, acetylcholinesterase activities were decreased. In contrast, lipid peroxidation, total oxidant status, reactive oxygen species, interleukin-1β, interleukin-6, tumor necrosis factor-α, sucrase, maltase, trypsin, myeloperoxidase, xanthine oxidase activities, protein carbonyl contents and sialic acid levels were raised in the damaged groups. Treatment with metformin restored all of this. The histological assessment revealed moderate to severe damage in the small intestine following processes D and C. According to the study's findings, metformin treatment led to a notable decline in histopathological damage in the C and DC. A slight lowering in inflammatory cells and an improvement in the damaged gland integrity in the small intestine were noted with metformin treatment.​ Metformin use protected the small intestinal tissue damage and decreased oxidative stress.

Tumor microenvironment (Part I): Tissue integrity in a rat model of peripheral neural cancer

ICAM–1 (intercellular adhesion molecule 1) and MPZ (myelin protein zero) are thought to be a factor in the integrity of nerve tissues. In this report, we attempted to trace the expression of ICAM–1, responsible for cell-to-cell adhesion, and of MPZ, the main constituent of myelin sheath, in malignant tissues of the sciatic nerve (SN) in inbred male Copenhagen rats. AT–1 Cells (anaplastic tumor 1) were injected in the perineurial sheath, and tissues of the SNs were collected after 7, 14 and 21 days and compared to a sham-operated group of rats (n = 6 each). Tissues were sectioned and histologically examined, under light microscope, and stained for measuring the immunoreactivity of ICAM–1 and MPZ under laser scanning microscope. The cancer model was established, and the tumor growth was confirmed. ICAM–1 showed severe decreases, proportional to the growing anaplastic cells, as compared to the sham group. MPZ revealed, however, a distinct defensive pattern before substantially decreasing in a comparison with sham. These results support the notion that malignancies damage peripheral nerves and cause severe axonal injury and loss of neuronal integrity, and clearly define the role of ICAM–1 and MPZ in safeguarding the nerve tissues.

Oxidative brain and cerebellum injury in diabetes and prostate cancer model: Protective effect of metformin.

The body can host the spread of prostate cancer cells. Metastases from prostate cancer are more frequently seen in the brain, liver, lungs, and lymph nodes. A well-known antidiabetic drug, metformin, is also known to have antitumor effects. Our study focuses on the evaluation of potential metformin protective effects on brain and cerebellum damage in streptozotocin (STZ)-induced diabetic and Dunning prostate cancer models. In this investigation, six groups of male Copenhagen rats were created: control, diabetic (D), cancer (C), diabetic + cancer (DC), cancer + metformin, and diabetic + cancer + metformin. The brain and cerebellum tissues of the rats were taken after sacrifice. Oxidative stress markers including reduced glutathione level, lipid peroxidation, glutathione reductase, glutathione peroxidase, glutathione-S-transferase, catalase, superoxide dismutase activities, reactive oxygen species, total oxidant and total antioxidant status, lactate dehydrogenase, xanthine oxidase, acetylcholinesterase activities, protein carbonyl contents, nitric oxide and OH-proline levels, sodium potassium ATPase, carbonic anhydrase, and glucose-6-phosphate dehydrogenase activities; glycoprotein levels including hexose, hexosamine, fucose, and sialic acid levels; and histone deacetylase activity as a cancer marker were determined. Oxidative stress markers were impaired and glycoprotein levels and histone deacetylase activity were increased in the D, C, and DC groups. Metformin therapy reversed these effects. Metformin was found to protect the brain and cerebellum of STZ-induced diabetic rats with Dunning prostate cancer from harm caused by MAT-Lylu metastatic cells.

13 C NMR quantification of polyamine syntheses in rat prostate.

Currently, many prostate cancer patients, detected through the prostate specific antigen test, harbor organ-confined indolent disease that cannot be differentiated from aggressive cancer according to clinically and pathologically known measures. Spermine has been considered as an endogenous inhibitor for prostate-confined cancer growth and its expression has shown correlation with prostate cancer growth rates. If established clinically, measurements of spermine bio-synthesis rates in prostates may predict prostate cancer growth and patient outcomes. Using rat models, we tested the feasibility of quantifying spermine bio-synthesis rates with 13 C NMR. Male Copenhagen rats (10weeks, n = 6) were injected with uniformly 13 C-labeled L-ornithine HCl, and were sacrificed in pairs at 10, 30, and 60 min after injection. Another two rats were injected with saline and sacrificed at 30 min as controls. Prostates were harvested and extracted with perchloric acid and the neutralized solutions were examined by 13 C NMR at 600 MHz. 13 C NMR revealed measurable ornithine, as well as putrescine-spermidine-spermine syntheses in rat prostates, allowing polyamine bio-synthetic and ornithine bio-catabolic rates to be calculated. Our study demonstrated the feasibility of 13 C NMR for measuring bio-synthesis rates of ornithine to spermine enzymatic reactions in rat prostates. The current study established a foundation upon which future investigations of protocols that differentiate prostate cancer growth rates according to the measure of ornithine to spermine bio-synthetic rates may be developed.

451 Interactions between tumor, age, and chemotherapy in cognitive impairments and neuroinflammation

OBJECTIVES/GOALS: We will use a novel syngeneic model of prostate cancer to examine impairments and uncover potential changes in inflammatory signaling in the brains of animals with and without tumors. We will then investigate the interaction between peripheral tumor, age, and chemotherapy on cognitive impairments and any accompanying neuroinflammation METHODS/STUDY POPULATION: Male Copenhagen rats (aged 3 or 10 months) were subjected to tumor fragment implantation (Dunning R2237G cells) or sham surgery. Once tumors were palpable, animals received either docetaxel (4.5mg/kg, intraperitoneal) or it’s vehicle once every other day for 5 days (3 injections total) followed by a two-week recovery period. During this time, TNFa and IL-6 was quantified in plasma samples obtained once per week for two weeks. Hippocampal-mediated visuospatial and working memories were assessed using the novel object task and percent alternation in a y-maze, respectively. Afterwards, trunk blood and hippocampal tissue were isolated. TNFa and IL-6 protein was quantified in plasma. Hippocampal tissue was probed for markers of neuroinflammation, including increases in TNFa, IL-6, and reactive microglia RESULTS/ANTICIPATED RESULTS: The presence of a tumor alone produces deficits in hippocampal-mediated visuospatial memory and working memory regardless of treatment and persistent elevations in TNFa and IL-6 in plasma. Docetaxel administration also produces impairments in hippocampal-mediated visuospatial memory, but not in working memory. We anticipate these cognitive impairments will be accompanied by hippocampal neuroinflammation. We expect age and docetaxel chemotherapy to exacerbate working memory deficits and markers in hippocampal neuroinflammation, including increases in TNFa, IL-6 and reactive microglia DISCUSSION/SIGNIFICANCE: This study will provide insight into the interaction between tumor, age, and chemotherapy in impairments in visuospatial memories. This model provides a substrate upon which interventions can be tested to ensure the efficacy of the cancer treatment is maintained when treating these cognitive impairments.

Drug repurposing: Metformin's effect against liver tissue damage in diabetes and prostate cancer model.

There are evidences linking diabetes to the pathogenesis and progression of various cancers. Metformin is a well-known antidiabetic drug that reduces the levels of circulating glucose and insulin in patients with both insulin resistance and hyperinsulinemia. Aim of the present study was to evaluate the effect of metformin on the liver of rats bearing prostate cancer, diabetes and prostate cancer + diabetes via histopathological and biochemical methods. Male Copenhagen rats were divided into six groups. Control group, diabetic group, cancer group, diabetic + cancer group, diabetic + cancer + metformin group, cancer + metformin group. Diabetes was induced by injecting single dose of streptozotocin (65mg/kg) to Copenhagen rats, cancer induced 2 × 104 Mat-LyLu cells. Metformin treatment was administered daily by gavage following inocculation of the Mat- Lylu cells to fifth and sixth group. The experiment was terminated on the 14th day following Mat-LyLu cell injection. At the end of the experimental period, the rats were sacrificed, and liver tissue was taken. Liver damage was scored. Biochemically, serum prostate-specific antigen level was determined by employing Enzyme Linked Immuno Sorbent Assay method. In addition, the activities of different enzyme and biochemical parameters were determined spectrophotometrically inform the hepatic tissue specimens. The findings of this study reveal that histopathological and biochemical damage in cancer and diabetic + cancer groups decreased significantly in the metformin treated groups. These highlights that the antidiabetic drug metformin can be repositioned for attenuating liver tissue damage associated with prostate cancer and diabetes.

Head-up tilt does not enhance prostate tumor perfusion or oxygenation in young rats.

Solid tumors contain hypoxic regions that contribute to anticancer therapy resistance. Thus, mitigating tumor hypoxia may enhance the efficacy of radiation therapy which is commonly utilized for patients with prostate cancer. Increasing perfusion pressure in the prostate with head-up tilt (HUT) may augment prostate tumor perfusion and decrease hypoxia. The purpose of this study was to determine if an increase in the vascular hydrostatic gradient via 70° HUT increases tumor perfusion and decreases tumor hypoxia in a preclinical orthotopic model of prostate cancer. Male Copenhagen rats (n=17) were orthotopically injected with Dunning R-3327 (AT-1) prostate adenocarcinoma cells to induce prostate tumors. After tumors were established, prostate tumor perfusion and hypoxia were measured in rats during level (0°) and 70° HUT positions. To compare the magnitude of the hydrostatic column to that present in humans, ultrasound was used to measure the heart to prostate distance in male human subjects to estimate the prostate vascular hydrostatic pressure with the upright posture. In young rats, no differences were detected in prostate tumor perfusion or prostate tumor hypoxia with 70° HUT versus the level position. However, from the retrospective study, young rats increased prostate vascular resistance to HUT, whereas aged rats lacked this response. Tumor vessels co-opted from existing functional vasculature in young rats may be sufficient to negate increases in perfusion pressure with HUT seen in aged rats. Additionally, in humans, the estimated hydrostatic column at the level of the prostate is five times greater than that of the rat. Therefore, 70° HUT may elicit increases in prostate/prostate tumor blood flow in humans that is not seen in rats.

Effect of Moderate and High Intensity Exercise on Hypoxia and Radiosensitivity in Tumor‐Bearing Rats

Background Prostate tumors typically have hypoxic regions that are resistant to traditional radiation therapy. Prior evidence from our laboratory has demonstrated improved perfusion and reduced hypoxia of prostate tumors with moderate intensity exercise training; such changes have potential to enhance radiation therapy. However, there is a dearth of evidence for the magnitude of alterations of intra-tumor hypoxia markers with exercise, as well as the ideal intensity of exercise for combating hypoxia in solid tumors. Using a pre-clinical orthotopic model of prostate cancer, we tested the hypothesis that exercise training at both moderate and high intensities would result in a decrease in hypoxia assessed via immunohistochemical analysis of hypoxic markers. Further, that enhanced radiotherapy responses would occur in exercise trained tumor bearing animals compared to sedentary counterparts. Methods Immunocompetent male Copenhagen rats aged 6 months (n=48) were injected orthotopically (ventral lobe of prostate) with 1x105 Dunning R-3327 AT-1 prostate adenocarcinoma cells. All animals were first acclimated to treadmill exercise and randomized into three groups: tumor bearing sedentary (TBS, n=20), moderate intensity training, (TBMIT, n=12), or high intensity training (TBHIT, n=16). After 7 days of recovery from surgery, both exercise groups began progressive exercise training on a motorized treadmill at either 20/min with a 5% incline, or 30m/min 15% incline for 10 minutes a day progressing to 60 min/day for TBMIT and TBHIT, respectively, for approximately 5 weeks. Immunohistochemical analysis and whole-body ionizing radiation (2 Gy) were performed at the end of the 5-week period of training followed by clonogenic cell survival assay to assess survival fraction. Results There were no significant differences (p>0.05) in tumor mass between groups (TBS 7.8±1.1; TBMIT 7.2±1.3; TBHIT 6.4±0.9 g). Overall expression levels of hypoxia inducible factor 1-alpha (HIF-1a, n=40) were significantly greater in the TBS group vs both the TBMIT and TBHIT (TBS 37.9±7.4; TBMIT 25.5±6.1; TBHIT 14.4±5.7%, p<0.05), with a trend for increased expression in TBMIT vs TBHIT (p=0.059). The survival fraction (n=8) was also significantly higher in TBS when compared to both TBMIT and TBHIT (TBS 39.9±5.3; TBMIT 23.2±3.2; TBHIT 20.7±4.9%, p<0.05). Conclusion This study suggests that compared to sedentary counterparts, both chronic moderate and high intensity exercise training modify the tumor microenvironment (decreased levels of HIF-1a) favorably. Given exercise therapy is becoming increasingly recommended to mitigate fatigue and increase quality of life in patients, a potential therapeutic component could add to the efficacy of exercise prescription in a clinical setting.

High Intensity Training Impacts on Prostate Cancer Induced Cardiac Atrophy in a Pre‐Clinical Model

BackgroundRecent evidence suggests prostate cancer independent of treatment has atrophic effects on whole heart and left ventricular (LV) mass which are associated with reduced endurance exercise capacity. In conjunction, preliminary evidence has shown that moderate exercise training mitigated cardiac mass loss in prostate tumor‐bearing rats. Using a pre‐clinical orthotopic model of prostate cancer, we tested the hypothesis that high intensity training could prevent the associated cardiac atrophy seen in prostate cancer. We also investigated whether high intensity training would attenuate any detriments seen in LV function with prostate cancer.MethodsDunning R‐3327 AT‐1 prostate cancer cells (1×105) were cultured and harvested for injection in 0.1ml of physiological saline solution in the ventral lobe of 5–6‐month‐old male Copenhagen rats (n=24). These animals were randomized into 2 groups, Tumor Bearing Exercise (TBEX, n=15) or Tumor Bearing Sedentary (TBS, n=8). After 5 days of recovery, TBEX animals began exercise on a treadmill at 25m/min with a 15° incline for 45–60 min/day based on tolerance for 18±2 days. Pre‐surgery (Pre), and post exercise training (Post) animals underwent echocardiographic evaluation using the parasternal short axis view to examine ventricle dimensions via a commercially available system (Vivid S6, GE Health Care).ResultsThere were no significant differences in tumor mass between groups (TBEX 3.4±0.7g, TBS 2.9±0.6g p=0.31), or body weights (TBEX 317±5g, TBS 333±7g p=0.20). Heart to body mass ratio was lower in SEDTB group compared to EXTB (2.3±0.1mg/g, 2.5±0.1mg/g, p=0.04). LV to body mass ratio was also lower in the SEDTB group (1.64±0.1mg/g, 1.81±0.1mg/g, p=0.04). There were no significant differences for Pre‐measures of LV function between groups. From Pre‐Post EXTB had significant increases in SV (0.64±0.04ml, 0.76±0.05ml, p=0.03) while SEDTB had no significant difference (0.68±0.03ml, 0.69±0.03ml, p=0.96).ConclusionThis study suggests that high‐intensity exercise can improve LV function and increase LV mass, versus sedentary counterparts, with prostate cancer. Given cardiac dysfunction often manifests with conventional anti‐cancer treatments, a short‐term high‐intensity training program, prior to treatment, may improve patient outcome.Support or Funding InformationAmerican Cancer Society (RSG‐14‐150‐01‐CCE)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Expression profiles of TRPV1, TRPV4, TLR4 and ERK1/2 in the dorsal root ganglionic neurons of a cancer-induced neuropathy rat model.

BackgroundThe spread of tumors through neural routes is common in several types of cancer in which patients suffer from a moderate-to-severe neuropathy, neural damage and a distorted quality of life. Here we aim to examine the expression profiles of transient receptor potential vanilloid 1 (TRPV1) and of transient receptor potential vanilloid 4 (TRPV4), toll-like receptor 4 (TLR4) and extracellular signal-regulated kinase (ERK1/2), and to assess the possible therapeutic strategies through blockade of transient receptor potential (TRP) channels.MethodsCancer was induced within the sciatic nerves of male Copenhagen rats, and tissues from dorsal root ganglia (DRG) were collected and used for measurements of immunofluorescence and Western blotting. The TRPV1 antagonist capsazepine, the selective TRPV4 antagonist HC-067047 and the calcium ions inhibitor ruthenium red were used to treat thermal and/or mechanical hyperalgesia.ResultsTransient receptor potential vanilloid 1 showed a lower expression in DRGs on days 7 and 14. The expression of TRPV4, TLR4 and ERK1/2 showed an increase on day 3 then a decrease on days 7 and 14. TRPV1 and TLR4 as well as TRPV4 and ERK1/2 co-existed on the same neuronal cells. The neuropathic pain was reversed in dose-dependent manners by using the TRP antagonists and the calcium ions inhibitor.ConclusionThe decreased expression of TRPV1 and TRPV4 is associated with high activation. The increased expression of TLR4 and ERK1/2 reveals earlier immune response and tumor progression, respectively, and their ultimate decrease is an indicator of nerve damage. We studied the possible role of TRPV1 and TRPV4 in transducing cancer-induced hyperalgesia. The possible treatment strategies of cancer-induced thermal and/or mechanical hyperalgesia using capsazepine, HC-067047 and ruthenium red are examined.

Prostate Cancer Cell Viability and Migration in Serum and Prostate Conditioned Media from Moderate‐Intensity Exercise Trained Rats

Physical activity is associated with diminished risk of several cancers and preclinical studies suggest exercise training may alter tumor cell growth in certain tissues (e.g., adipose). We hypothesized that serum and prostate conditioned media (PCM) from moderate‐intensity exercise trained rats will decrease prostate cancer cell growth, while prostate 5α‐reductase 2 expression will decrease. We evaluated the effects of serum and PCM from moderate‐intensity exercise trained rats on prostate cancer cell viability and migration. In addition, we determined whether moderate‐intensity exercise training would modulate 5α‐reductase 2 protein expression, an essential component of androgen metabolism in prostate cancer. Male Copenhagen rats (~2–3 mo old) were randomly assigned to an exercise‐trained group (n = 10) and a sedentary control group (n = 10). The exercise‐trained rats ran on a motorized treadmill for 5 days/week at 15 m/min, 15° incline for 60 min/day for a 10‐ to 11‐week training period. Serum was collected from both rat groups, and used to supplement media at 5% concentration with and without 5% fetal bovine serum (FBS). Rat prostates were harvested, cut into two approximately equal sections with one section incubated with media for 24 hours to prepare PCM, and immunohistochemistry performed on the other section to quantify 5α‐reductase 2 expression. Dunning R‐3327 AT‐1 prostate cancer cells were grown in PCM, or media supplemented with either 5% serum from the exercise‐trained or sedentary groups with and without 5% FBS for 24–96 hours. Tumor cell viability and migration were determined using MTT and transwell migration assays, respectively. Serum or PCM from exercise‐trained rats did not significantly decrease cell viability compared to serum (e.g. 0.41 ± 0.04 vs. 0.50 ± 0.05 viable cell number, p = 0.14) or PCM (e.g. 0.40 ± 0.07 vs. 0.50 ± 0.08 viable cell number, p = 0.50; all at 48 hour incubation) from sedentary rats, respectively. However, the addition of FBS to serum from exercise‐trained rats significantly decreased cell viability compared to FBS and serum from sedentary rats (e.g. 0.49 ± 0.05 vs. 0.69 ± 0.06 viable cell number, p = 0.02; 48 hour incubation). Serum alone, serum and FBS, or PCM from exercise‐trained rats did not significantly impact cell migration compared to sedentary control (54.7 ± 3.3 vs. 64.2 ± 9.2 cells/field, p = 0.27; 29.3 ± 2.6 vs. 29.3 ± 2.5 cells/field, p &gt; 0.99; 55.9 ± 10.5 vs. 52.8 ± 8.1 cells/field, p = 0.82), respectively. 5α‐reductase 2 in the prostate was not significantly changed with exercise compared to sedentary group (0.87 ± 0.21 vs. 0.78 ± 0.18 positive cells/tissue area (μm2), p = 0.76). In conclusion, prior exercise status did not modify several key characteristics of prostate tumor cell growth and viability from conditioned media from host‐tissue (prostate) or serum in vitro. Whether exercise training alters similar prostate tumor cell growth characteristics in vivo is unknown.Support or Funding InformationAmerican Cancer Society RSG 14‐150‐1‐CCE (BJB)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effects of a Pre‐Clinical Model of Prostate Cancer on Left Ventricular Function in Sedentary and Exercise Trained Rats

BackgroundProstate cancer is the most common type of non‐skin cancer found in men making it a primary area of concern. Preliminary evidence suggests prostate cancer independent of treatment has atrophic effects on whole heart and left ventricular (LV) mass which are associated with reduced endurance exercise capacity in rats, highlighting a major area of concern. Using a pre‐clinical orthotropic model of prostate cancer, echocardiography was used to test the hypothesis that prostate cancer would impact LV function. We also investigated whether moderate exercise training would attenuate any detriments seen in LV function with prostate cancer.MethodsDunning R‐3327 AT‐1 prostate cancer cells (1×104) were cultured and harvested for injection in 0.1 ml of physiological saline solution in the ventral lobe of 3–4 month‐old male Copenhagen rats (n=19). These animals were randomized into 2 groups, Tumor Bearing Exercise (TBEX) n=10 or Tumor Bearing Sedentary (TBS) n=9. After ~1‐week recovery, TBEX animals began exercise on a treadmill at 15 m/min with a 15° incline for 60 min/day for ~30 days. Twenty additional cancer free controls were randomized into exercise control (EXC) (n=10) or Sedentary control (SEDC). Pre‐surgery (V1), and ~30 days post exercise commencement (V3) animals underwent echocardiographic evaluation using the parasternal short axis view to examine ventricle dimensions via a commercially available system (Vivid S6, GE Health Care).ResultsThere were no significant differences in tumor mass between groups (TBEX 8.62±1.7g, TBS 6.6±1.3g p=0.29), or body weights (TBEX 299±9g, TBS 284±6g p=0.22) and (EXC 351±5g, SEDC 341±7g). There were no significant differences for V1 for any measures of LV function for all 4 groups. From V1–V3 EXC had significant increases in SV (103±5 ul, 126±7 ul, p=0.003) while SEDC had no significant difference (114±3 ul, 111±10 ul, p=0.78). SV for TBEX and TBS did not significantly change from V1–V3, but at V3 TBEX had significantly larger SV (TBEX=116±6 ul, TBS= 99±5 ul, p=0.022). Strain and strain rate were not significantly different from V1–V3 for all groups, however the strain (p=0.001) and strain rate (p=0.005) were both significantly different between control groups.ConclusionInformation gleaned from the current investigation suggests prostate cancer itself does not significantly reduce left ventricular function in sedentary animals. However, increases in left ventricular function found in normal healthy exercise trained animals was reduced in tumor bearing animals performing the same exercise regime.Support or Funding InformationAmerican Cancer Society RSG 14‐150‐1‐CCE (BJB)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

NO EFFECT OF HEAD UP TILT ON TUMOR PERFUSION IN A RAT PRE‐CLINICAL MODEL OF PROSTATE CANCER

Previous research has demonstrated an enhanced prostate tumor blood flow and oxygenation associated with the augmented mean arterial pressure during exercise. Further, prostate tumor arterioles lack functional smooth muscle and have a diminished myogenic response. Thus, we tested the hypothesis that with elevations in the heart‐to‐prostate tumor hydrostatic gradient 70° head‐up tilt (HUT) would result in an enhanced perfusion of the prostate tumor. An enhanced tumor perfusion may improve tumor oxygenation and radiation therapy outcomes.MethodsDunning AT‐1 tumor cells (1×104) were injected into the ventral prostate of male Copenhagen rats (n=7) and studies were performed ~ 6 weeks after cell injection. After 5 minutes in each body position, fluorescent microspheres (red and blue/green, ~250,000 spheres per label) were injected via the carotid artery in the level and HUT body positions. Blood flow was determined in the tumor, kidneys and soleus muscle. Vascular conductance was calculated as blood flow divided by mean arterial pressure (MAP). Blood flow and conductance rates were calculated and a two‐tailed paired t‐test was conducted to compare values in the level vs. HUT positions.ResultsAverage tumor weight was 7.1 ± 0.5 g. MAP was not different between level and HUT (p = 0.15). Adequate blood flow distribution, as determined by a &lt;15% difference in flow between the left/right kidney and/or soleus muscle, was achieved in all animals. Tumor blood flow was not different between level and HUT (12.0 ± 1.1 vs. 10.4 ± 0.8 ml/100 g/min, respectively). No difference was observed between body positions in tumor vascular conductance (p&gt;0.05).DiscussionContrary to our hypothesis, we did not see any significant differences in either blood flow or vascular conductance in the tumor with HUT. With HUT, the prostate shows an increase in vascular resistance; thus, the combination of immature and co‐opted host tissue arterioles present in tumors may have resulted in an unchanged perfusion of the tumor with tilt. Specifically, there would be an enhanced vascular resistance of the host‐tissue (prostate) that may counter hydrostatic differences in perfusion pressure. These findings suggest that elevations in the hydrostatic gradient via HUT may not be sufficient to enhance prostate tumor perfusion.Support or Funding InformationAmerican Cancer Society RSG 14‐150‐1‐CCE (BJB)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Photoacoustic imaging to assess pixel-based sO2 distributions in experimental prostate tumors.

A protocol for photoacoustic imaging (PAI) has been developed to assess pixel-based oxygen saturation (sO2) distributions of experimental tumor models. The protocol was applied to evaluate the dependence of PAI results on measurement settings, reproducibility of PAI, and for the characterization of the oxygenation status of experimental prostate tumor sublines (Dunning R3327-H, -HI, -AT1) implanted subcutaneously in male Copenhagen rats. The three-dimensional (3-D) PA data employing two wavelengths were used to estimate sO2 distributions. If the PA signal was sufficiently strong, the distributions were independent from signal gain, threshold, and positioning of animals. Reproducibility of sO2 distributions with respect to shape and median values was demonstrated over several days. The three tumor sublines were characterized by the shapes of their sO2 distributions and their temporal response after external changes of the oxygen supply (100% O2 or air breathing and clamping of tumor-supplying artery). The established protocol showed to be suitable for detecting temporal changes in tumor oxygenation as well as differences in oxygenation between tumor sublines. PA results were in accordance with histology for hypoxia, perfusion, and vasculature. The presented protocol for the assessment of pixel-based sO2 distributions provides more detailed information as compared to conventional region-of-interest-based analysis of PAI, especially with respect to the detection of temporal changes and tumor heterogeneity.

A Novel Model of Cancer-Induced Peripheral Neuropathy and the Role of TRPA1 in Pain Transduction.

Background Models of cancer-induced neuropathy are designed by injecting cancer cells near the peripheral nerves. The interference of tissue-resident immune cells does not allow a direct contact with nerve fibres which affects the tumor microenvironment and the invasion process. Methods Anaplastic tumor-1 (AT-1) cells were inoculated within the sciatic nerves (SNs) of male Copenhagen rats. Lumbar dorsal root ganglia (DRGs) and the SNs were collected on days 3, 7, 14, and 21. SN tissues were examined for morphological changes and DRG tissues for immunofluorescence, electrophoretic tendency, and mRNA quantification. Hypersensitivities to cold, mechanical, and thermal stimuli were determined. HC-030031, a selective TRPA1 antagonist, was used to treat cold allodynia. Results Nociception thresholds were identified on day 6. Immunofluorescent micrographs showed overexpression of TRPA1 on days 7 and 14 and of CGRP on day 14 until day 21. Both TRPA1 and CGRP were coexpressed on the same cells. Immunoblots exhibited an increase in TRPA1 expression on day 14. TRPA1 mRNA underwent an increase on day 7 (normalized to 18S). Injection of HC-030031 transiently reversed the cold allodynia. Conclusion A novel and a promising model of cancer-induced neuropathy was established, and the role of TRPA1 and CGRP in pain transduction was examined.

Assessment of tumor response to oxygen challenge using quantitative diffusion MRI in an animal model

PurposeTo assess tumor response to oxygen challenge using quantitative diffusion magnetic resonance imaging (MRI).Materials and MethodsA well‐characterized Dunning R3327‐AT1 rat prostate cancer line was implanted subcutaneously in the right thigh of male Copenhagen rats (n = 8). Diffusion‐weighted images (DWI) with multiple b values (0, 25, 50, 100, 150, 200, 300, 500, 1000, 1500 s/mm2) in three orthogonal directions were obtained using a multishot FSE‐based Stejskal‐Tanner DWI sequence (FSE‐DWI) at 4.7T, while rats breathed medical air (21% oxygen) and with 100% oxygen challenge. Stretched‐exponential and intravoxel incoherent motion (IVIM) models were used to calculate and compare quantitative diffusion parameters: diffusion heterogeneity index (α), intravoxel distribution of diffusion coefficients (DDC), tissue diffusivity (Dt), pseudo‐diffusivity (Dp), and perfusion fraction (f) on a voxel‐by‐voxel basis.ResultsA significant increase of α (73.9 ± 4.7% in air vs. 78.1 ± 4.5% in oxygen, P = 0.0198) and a significant decrease of f (13.4 ± 3.7% in air vs. 10.4 ± 2.7% in oxygen, P = 0.0201) were observed to accompany oxygen challenge. Correlations between f and α during both air and oxygen breathing were found; the correlation coefficients (r) were −0.90 and −0.96, respectively. Positive correlations between Dt and DDC with oxygen breathing (r = 0.95, P = 0.0003), f and DDC with air breathing were also observed (r = 0.95, P = 0.0004).ConclusionQuantitative diffusion MRI demonstrated changes in tumor perfusion in response to oxygen challenge. J. Magn. Reson. Imaging 2015;42:1450–1457.

Assessment of tumor response to oxygen challenge using quantitative diffusion MRI in an animal model.

To assess tumor response to oxygen challenge using quantitative diffusion magnetic resonance imaging (MRI). A well-characterized Dunning R3327-AT1 rat prostate cancer line was implanted subcutaneously in the right thigh of male Copenhagen rats (n = 8). Diffusion-weighted images (DWI) with multiple b values (0, 25, 50, 100, 150, 200, 300, 500, 1000, 1500 s/mm(2) ) in three orthogonal directions were obtained using a multishot FSE-based Stejskal-Tanner DWI sequence (FSE-DWI) at 4.7T, while rats breathed medical air (21% oxygen) and with 100% oxygen challenge. Stretched-exponential and intravoxel incoherent motion (IVIM) models were used to calculate and compare quantitative diffusion parameters: diffusion heterogeneity index (α), intravoxel distribution of diffusion coefficients (DDC), tissue diffusivity (Dt), pseudo-diffusivity (Dp), and perfusion fraction (f) on a voxel-by-voxel basis. A significant increase of α (73.9 ± 4.7% in air vs. 78.1 ± 4.5% in oxygen, P = 0.0198) and a significant decrease of f (13.4 ± 3.7% in air vs. 10.4 ± 2.7% in oxygen, P = 0.0201) were observed to accompany oxygen challenge. Correlations between f and α during both air and oxygen breathing were found; the correlation coefficients (r) were -0.90 and -0.96, respectively. Positive correlations between Dt and DDC with oxygen breathing (r = 0.95, P = 0.0003), f and DDC with air breathing were also observed (r = 0.95, P = 0.0004). Quantitative diffusion MRI demonstrated changes in tumor perfusion in response to oxygen challenge.

Exercise training combined with antioxidant supplementation prevents the antiproliferative activity of their single treatment in prostate cancer through inhibition of redox adaptation

In preclinical models, exercise training (ET) or pomegranate juice (PJ) prevents prostate cancer progression. Here, we hypothesized that physical exercise combined with antioxidants could induce synergistic effects through oxidative stress modulation. Forty male Copenhagen rats with prostate tumors were divided into four groups: control, PJ, ET, and PJ+ET. Rats from the PJ group consumed 750µl of PJ daily, rats from the ET group ran on a treadmill 5 days per week, and PJ+ET rats received the combined treatment. Each week, tumor growth was evaluated. After 4 weeks of treatment, the rats were euthanized and blood, muscles, and tumors were collected. Tumor Ki67, extracellular signal-regulated kinase (ERK) activation, Bcl-2 expression, and enzymatic and nonenzymatic antioxidant defenses, as well as oxidative stress markers (oxidized base, lipid peroxidation, protein carbonylation), were measured. PJ or ET significantly decreased prostate tumor proliferation (Ki67 staining, p<0.05) through the modulation of ERK phosphorylation, whereas the combination of treatments did not limit cancer progression. PJ significantly reduced Bcl-2 expression in tumors (p<0.05) and the combination of PJ and ET prevented this effect. PJ or ET increased enzymatic antioxidant defenses in muscle, PJ increased nonenzymatic antioxidant defenses in plasma and whole blood. In addition, PJ reduced TBARS and 8-oxodGuo levels in tumors as well as ET (p<0.05), whereas protein carbonyl levels were not affected by these two strategies. Paradoxically, association of PJ+ET did not increase antioxidant defenses and no reduction in oxidative stress markers was induced. Loading cancer cells with antioxidants blunts the positive effects of ET and interferes with important reactive oxygen species-mediated physiological processes such as antioxidant adaptations.

Modulation of Blood Flow, Hypoxia, and Vascular Function in Orthotopic Prostate Tumors During Exercise

Previous studies have hypothesized that tumor blood flow may be elevated or reduced during exercise, which could impact the tumor microenvironment. However, to date technical limitations have precluded the measurement of tumor blood flow during exercise. Using an orthotopic preclinical model of prostate cancer, we tested the hypotheses that during exercise tumors would experience 1) diminished vascular resistance, 2) augmented blood flow, 3) increased numbers of perfused vessels, and 4) decreased tissue hypoxia and, furthermore, that the increased perfusion would be associated with diminished vasoconstriction in prostate tumor arterioles. Dunning R-3327 MatLyLu tumor cells were injected into the ventral prostate of male Copenhagen rats aged 4 to 6 months randomly assigned to tumor-bearing (n = 42) or vehicle control (n = 14) groups. Prostate tumor blood flow, vascular resistance, patent vessel number, and hypoxia were measured in vivo in conscious rats at rest and during treadmill exercise, and vasoconstrictor responsiveness of resistance arterioles was investigated in vitro. During exercise there was a statistically significant increase in tumor blood flow (approximately 200%) and number of patent vessels (rest mean ± standard deviation [SD] = 12.7±1.3; exercise mean ± SD = 14.3±0.6 vessels/field; Student t test two-sided P = .02) and decreased hypoxia compared with measurements made at rest. In tumor arterioles, the maximal constriction elicited by norepinephrine was blunted by approximately 95% vs control prostate vessels. During exercise there is enhanced tumor perfusion and diminished tumor hypoxia due, in part, to a diminished vasoconstriction. The clinical relevance of these findings are that exercise may enhance the delivery of tumor-targeting drugs as well as attenuate the hypoxic microenvironment within a tumor and lead to a less aggressive phenotype.

Acidic priming enhances metastatic potential of prostate cancer cells in vivo and in vitro

Acidic priming enhances metastatic potential of prostate cancer cells in vivo and in vitro