Effect of exercise training on lymphocyte subpopulations in chemically and hormonally induced prostate cancer: flow cytometry analysis

Introduction: Long-term and regular exercise training is suggested to have an immunomodulatory effect, protecting against several diseases. This work aimed to analyse the effect of exercise training on peripheral lymphocyte subpopulations in a model of prostate cancer (PCa) chemically and hormonally induced. Methods: Fifty-five male Wistar Unilever rats of 4 weeks of age were randomly divided into four experimental groups as follow: control sedentary group (SED+CONT; n=10), control exercised group (EX+CONT; n=10), induced sedentary group (SED+PCa; n=15) and induced exercised group (EX+PCa; n=20). Prostate lesions were induced through the sequential administration of flutamide (50 mg/kg, TCI Chemicals, USA), testosterone propionate (100 mg/kg, TCI Chemicals, Portland, USA) and N-methyl-N-nitrosourea (30 mg/kg, Sigma Chemical, Spain), and subcutaneous implantation of tubes filled with crystalline testosterone (Sigma Chemical, Spain). At eight weeks of age, exercised animals started the training in a treadmill (Treadmill Control LE 8710, USA), 5 days/weeks, for 53 weeks. Animals were sacrificed at 61 weeks of age through an intraperitoneal injection of ketamine (75 mg/kg, Imalgene® 1000, Merial S.A.S., France) and xylazine (10 mg/kg, Rompun® 2%, Bayer Healthcare S.A., Germany), followed by exsanguination by cardiac puncture. Peripheral blood of all animals was collected by intracardiac puncture and transferred into tubes containing EDTA salt as an anticoagulant for flow cytometry analysis. The following conjugated monoclonal antibodies were used: cyCD3-BV421, CD3-FITC, CD25-APC, CD45-BV510, CD127-PE, CD161-FITC, CD4-PE/Cy7, CD45RA-APC/Cy7, OX-82-PE and CD8a-PerCP. The flow cytometry immunophenotyping was performed in a BD FACSCantoTM II cytometer (BD Biosciences, USA) and data were analysed with InfinicytTM, flow cytometry software 1.7 version. The prostate was collected and stained with H&E for histopathological analysis. Statistical analysis was performed using SPSS 25. The differences were considered statistically significant at p<0.05. Results: A higher level of CD161+NK cells were observed in EX+PCa group when compared with SED+PCa group (p0.05). Conclusion: These results reinforce the beneficial role of exercise in anti-tumour immune response. Additional studies are warranted to better understand these results

Effects of physical exercise in biochemical parameters and dorsolateral prostate lesions: data from a rat model of prostate cancer

Prostate cancer (PCa) is among the most prevalent cancers worldwide. Physical exercise is widely recognized due to its beneficial effects. This study aimed to evaluate the effects of physical exercise on biochemical parameters and in dorsolateral prostate lesions in a rat model of PCa. Ninety-five male Wistar Unilever rats were randomly divided into eight groups sacrificed at 35 (groups I) or 61 weeks of age (groups II): control sedentary groups (Cont+Sed I (n=10); Cont+Sed II (n=10)); induced sedentary group (PCa+Sed I (n=10); PCa+Sed II (n=15)); control exercised groups (Cont+EX I (n=10); Cont+EX II (n=10)) and induced exercised groups (PCa+EX I (n=10); PCa+EX II (n=20)). All procedures were approved (DGAV, no. 021326). Animals from exercised groups started the exercise program in a treadmill at 8 weeks of age, for 28 weeks or 53 weeks. The animals were trained 5 days/week, 60 min per day. Prostate lesions were induced at 12 weeks of age, with sequential administration of flutamide, testosterone propionate and N-methyl-N-nitrosourea, and subcutaneous implants of crystalline testosterone. Animals were sacrificed at 35 or 61 weeks of age. Peripheral blood of all animals was collected by intracardiac puncture. A complete necropsy was performed. The dorsolateral prostate tissues sections were processed for histological analysis. Data were analysed using SPSS 25. p<0.05 were considered statistically significant. Serum levels of albumin and cholesterol were higher in group PCa+Sed I when compared with group PCa+Sed II (p0.05). Dorsolateral prostate lesions were classified as dysplasia, prostatic intraepithelial neoplasia (PIN) and microinvasive carcinoma. The number of prostate lesions was higher in animals from groups II than in those from groups I, mainly in PCa+Sed II animals when compared with PCa+Sed I (p0.05). Overall, the animals sacrificed at 61 weeks of age developed more dorsolateral prostate lesions than animals sacrificed at 35 weeks of age, which may be related to a longer testosterone exposure

Peripheral lymphocyte subpopulations in prostate cancer - data from an animal model

Introduction: Prostate cancer (PCa) is one of the most common cancers among men worldwide. The presence of immune cells in human cancer raises a fundamental question in oncology. The interaction between immune system and PCa is an important field for translational research. This work aimed to characterize the peripheral lymphocyte subpopulations in a PCa animal model. Methods: Twenty-five male Wistar Unilever rats (Rattus norvegicus) with twelve weeks of age were randomly divided into two groups: Control (n=10) and Induced (n=15). All procedures were approved by the Portuguese Competent Authority (DGAV no. 021326). Prostate lesions were induced through the administration of flutamide (50 mg/kg, TCI Chemicals, USA), testosterone propionate (100 mg/kg, TCI Chemicals, USA) and N-methyl-N-nitrosourea (30 mg/kg, Sigma Chemical Co., Spain), and crystalline testosterone implants. Animals were humanely sacrificed at 61 weeks of age. Peripheral blood of all animals was collected by intracardiac puncture and transferred into tubes containing EDTA salt as an anticoagulant for flow cytometry analysis. The following conjugated monoclonal antibodies were used: cyCD3-BV421, CD3-FITC, CD25-APC, CD45-BV510, CD127-PE, CD161-FITC, CD4-PE/Cy7, CD45RA-APC/Cy7, OX-82-PE and CD8a-PerCP. The flow cytometry immunophenotyping was performed in a BD FACSCantoTM II cytometer (BD Biosciences, USA) and data were analysed with InfinicytTM, flow cytometry software 1.7 version. Statistical analysis was performed using SPSS 25. The differences were considered statistically significant at p<0.05. Results: Although differences did not reach the level of statistical significance, the populations of CD3+ and CD4+ lymphocytes were higher in control group when compared with induced group (p>0.05). Similarly, CD8+ lymphocyte population was higher in control group than in induced group (9.56±0.74 vs 6.38±0.32) (p<0.05). Inversely, the population of regulatory T cells (TRegs) (2.99±0.46 vs 4.630±0.35), the TRegs/CD8 ratio (0.35±0.09 vs 0.45±0.08) and the TRegs/Natural Killer ratio (0.52±0.05 vs 1.03±0.13) were higher in induced group when compared with control one (p<0.05). Conclusion: The population of Tregs increased in induced animals, while the population of NK decreased in these animals, which is in accordance with data previously published by other authors reporting the increase of Tregs and decrease of NK cells in animals with cancer. The characterization of these immune system subpopulation can be important for other studies such as preclinical cancer models

Validation of the rat model of prostate cancer: correlating seminal vesicle lesions with dorsolateral prostate lesions

Background/aim: Lesions in the seminal vesicle are described in the most used protocols for prostate cancer (PCa) induction. This study aimed to characterize the lesions of seminal vesicles associated with a protocol of PCa induction in rats to contribute to better characterization of this model. Materials and methods: Forty-five male Wistar Unilever rats were randomly divided into two control groups: CONT1 (n=10) and CONT2 (n=10); and two PCa-induced groups: IND1 (n=10) and IND2 (n=15), sacrificed at 35 and 61 weeks, respectively. Animals from the induced groups were exposed to a multistep protocol for PCa induction. Animals, seminal vesicles and dorsolateral prostate were weighed. Seminal vesicles and dorsolateral prostate were submitted to histopathological and immunohistochemical analysis. Results: Animals in which PCa was induced had a lower mean body weight when compared with the control animals (p<0.05). The relative mean seminal vesicle weight was higher in groups with PCa when compared with control groups (p<0.05). Although the differences were not statistically significant, animals from the IND2 group developed more lesions than animals from the IND1 and CONT2 groups. It is worth noting that the animals from group IND2 developed papillary adenomas and carcinomas in situ, which were not observed in any other group. Similar to observations in seminal vesicles, animals from group IND2 developed more dorsolateral prostate lesions than animals from the IND1 group (p<0.05). Conclusion: We observed that the longer the exposure to testosterone was, the greater was the incidence of preneoplastic and neoplastic lesions in both the seminal vesicle and the prostate, suggesting that testosterone exposure affects the spectrum of developed lesions

Effects of physical exercise in biochemical parameters and dorsolateral prostate lesions: data from a rat model of prostate cancer

Background: Prostate cancer (PCa) is among the most prevalent cancers worldwide. Physical exercise is widely recognized due to its beneficial effects. This study aimed to evaluate the effects of physical exercise on biochemical pa- rameters and in dorsolateral prostate lesions in a rat model of PCa. Materials and Methods: Ninety-five male Wistar Unilever rats were randomly divided into eight groups sacrificed at 35 (groups I) or 61 weeks of age (groups II): control sedentary groups (Cont+Sed I (n = 10); Cont+Sed II (n = 10)); induced sedentary group (PCa+Sed I (n = 10); PCa+Sed II (n = 15)); control exercised groups (Cont+EX I (n = 10); Cont+EX II(n = 10)) and induced exercised groups (PCa+EX I (n = 10); PCa+EX II (n = 20)). All procedures were approved (DGAV, no. 021326). Animals from exercised groups started the exer- cise program in a treadmill at 8 weeks of age, for 28 weeks or 53 weeks. The animals were trained 5 days/week, 60 min per day. Prostate lesions were induced at 12 weeks of age, with sequential administration of flutamide, testosterone propion- ate and N-methyl-N-nitrosourea, and subcutaneous implants of crystalline testosterone. Animals were sacrificed at 35 or 61 weeks of age. Peripheral blood of all animals was col- lected by intracardiac puncture. A complete necropsy was performed. The dorsolateral prostate tissues sections were processed for histological analysis. Data were analysed using SPSS 25. p 0.05). Dorsolateral prostate lesions were classified as dysplasia, prostatic intraep- ithelial neoplasia (PIN) and microinvasive carcinoma. The number of prostate lesions was higher in animals from groups II than in those from groups I, mainly in PCa+Sed II animals when compared with PCa+Sed I (p 0.05). Conclusions: Overall, the animals sacrificed at 61 weeks of age developed more dorsolateral prostate lesions than ani- mals sacrificed at 35 weeks of age, which may be related to a longer testosterone exposure

Physical exercise in a chemically and hormonally induced rat model of prostate cancer: friend or foe?

Introduction: Physical exercise is widely recognized for its beneficial health effects, namely in prostate cancer (PCa). This study aimed to evaluate the effect of physical exercise in a rat model of chemically and hormonally induced PCa.Results: Body weight was lower in exercised groups than in sedentary, either in control or in PCa groups (p0.05) and animals from PCa-exercised group showed 70.0% of dysplasia, 58.8% of PIN and 58.8% of microinvasive carcinoma (p>0.05). Conclusions: No group showed systemic signs of inflammation or clinical abnormalities. Although the prostate lesions frequencies were slightly lower in exercised PCa-induced animals than in sedentary ones, data didn ́t achieve statistical significance. However, our results suggest that physical exercise may have some preventive effect on the PCa-lesion’s development. These data deserve more investigation to clarify the effect of exercise training on prostate cancer prevention

Exercise training as a potential therapeutic agent for prostate neoplasia in a rat model of prostate cancer: new insights into an enigma

Introduction: Exercise training is widely recognized for its beneficial health outcomes, namely in prostate cancer (PCa). This study aimed to evaluate the effect of exercise training on dorsolateral prostate lobe lesions in a rat model of chemically and hormonally induced prostate cancer. Material & methods: Fifty-five male Wistar Unilever rats (Rattus norvegicus) of 12 weeks of age were randomly divided into four groups: control sedentary (n=10), PCa-sedentary (n=15), control exercised (n=10) and PCa-exercised (n=20). Animals from exercised groups started the exercise training in a treadmill (Treadmill Control LE 8710, Harvard Apparatus, USA), at the age of 8 weeks, for 35 weeks (5 days/week). The PCa induction protocol consisted of flutamide (50 mg/kg, TCI Chemicals) administration for 21 consecutive days, followed by a single administration of N-methyl-N-nitrosourea (30 mg/kg, Isopac®, Sigma Chemical Co.) and testosterone propionate implants. Animals were sacrificed at 61 weeks of age. The dorsolateral prostate tissues sections were processed for light microscopy and classified histologically according to Bosland [1]. Data were analysed using SPSS 25 and values were statistically significant at p<0.05. Results: Identified lesions were classified as dysplasia, prostatic intraepithelial neoplasia (PIN) and microinvasive carcinoma. Although control animals also developed prostate lesions, the frequency was lower than in induced groups. The PCa-induced animals showed a slightly decrease in the frequency of lesions: animals from PCa-sedentary group showed 85.7% of dysplasia, 64.3% of PIN and 64.3% of microinvasive carcinoma (p>0.05) and animals from PCa-exercised group showed 70.0% of dysplasia, 58.8% of PIN and 58.8% of microinvasive carcinoma (p>0.05). All animals from all groups on study showed inflammation on the dorsolateral prostate acini. Inflammation was higher in PCa-exercised dorsolateral prostate than in PCa-sedentary (100% and 57.1%, respectively, p<0.05). Conclusions: Dysplasia, PIN and microinvasive carcinoma on dorsolateral prostate were observed in all groups on study; though the frequencies were slightly lower in exercised PCa-induced animals than in sedentary ones, data didn ́t achieve statistical significance. However, our results suggest that exercise training may have some preventive effect on the PCa-lesion’s development. These data deserve more investigation to clarify the effect of exercise training on prostate cancer prevention

Exercise training as a potential therapeutic agent for prostate neoplasia in a rat model of prostate cancer: new insights into an enigma

Introduction: Exercise training is widely recognized for its beneficial health outcomes, namely in prostate cancer (PCa). This study aimed to evaluate the effect of exercise training on dorsolateral prostate lobe lesions in a rat model of chemically and hormonally induced prostate cancer. Material & methods: Fifty-five male Wistar Unilever rats (Rattus norvegicus) of 12 weeks of age were randomly divided into four groups: control sedentary (n=10), PCa-sedentary (n=15), control exercised (n=10) and PCa-exercised (n=20). Animals from exercised groups started the exercise training in a treadmill (Treadmill Control LE 8710, Harvard Apparatus, USA), at the age of 8 weeks, for 35 weeks (5 days/week). The PCa induction protocol consisted of flutamide (50 mg/kg, TCI Chemicals) administration for 21 consecutive days, followed by a single administration of N-methyl-N-nitrosourea (30 mg/kg, Isopac®, Sigma Chemical Co.) and testosterone propionate implants. Animals were sacrificed at 61 weeks of age. The dorsolateral prostate tissues sections were processed for light microscopy and classified histologically according to Bosland [1]. Data were analysed using SPSS 25 and values were statistically significant at p<0.05. Results: Identified lesions were classified as dysplasia, prostatic intraepithelial neoplasia (PIN) and microinvasive carcinoma. Although control animals also developed prostate lesions, the frequency was lower than in induced groups. The PCa-induced animals showed a slightly decrease in the frequency of lesions: animals from PCa-sedentary group showed 85.7% of dysplasia, 64.3% of PIN and 64.3% of microinvasive carcinoma (p>0.05) and animals from PCa-exercised group showed 70.0% of dysplasia, 58.8% of PIN and 58.8% of microinvasive carcinoma (p>0.05). All animals from all groups on study showed inflammation on the dorsolateral prostate acini. Inflammation was higher in PCa-exercised dorsolateral prostate than in PCa-sedentary (100% and 57.1%, respectively, p<0.05). Conclusions: Dysplasia, PIN and microinvasive carcinoma on dorsolateral prostate were observed in all groups on study; though the frequencies were slightly lower in exercised PCa-induced animals than in sedentary ones, data didn ́t achieve statistical significance. However, our results suggest that exercise training may have some preventive effect on the PCa-lesion’s development. These data deserve more investigation to clarify the effect of exercise training on prostate cancer prevention

Animal models of colorectal cancer: from spontaneous to genetically engineered models and their applications

Colorectal cancer is one of the most common gastrointestinal malignancies in humans, affecting approximately 1.8 million people worldwide. This disease has a major social impact and high treatment costs. Animal models allow us to understand and follow the colon cancer progression; thus, in vivo studies are essential to improve and discover new ways of prevention and treatment. Dietary natural products have been under investigation for better and natural prevention, envisioning to show their potential. This manuscript intends to provide the readers a review of rodent colorectal cancer models available in the literature, highlighting their advantages and disadvantages, as well as their potential in the evaluation of several drugs and natural compounds’ effects on colorectal cancer