RESUMEN
BACKGROUND: The aim of this study was to evaluate modifications in proteoglycan morphology and composition in the prostatic stroma of 18-month-old gerbils after surgical castration, in association or not with an androgenic blockade. METHODS: The animals (n = 5) were sorted into groups subjected or not to antiandrogen treatment (flutamide 10 mg/kg/day) administered for the total postsurgery period and euthanized at 7- or 30-day postcastration; the control group consisted of intact animals. Tissue analysis included immunohistochemical assessment (perlecan and chondroitin sulfate) and proteoglycan morphology was analyzed by transmission electron microscopy. RESULTS: Chondroitin sulfate frequency was increased 7 days postcastration with an androgenic blockade. The presence of these carbohydrates was rare after 30 days of androgenic blockade treatment. There was a significant increase in the amount of perlecan in the prostate stroma from groups subjected to castration plus flutamide for 7 or 30 days. Ultrastructural analysis showed that the incidence of areas occupied by proteoglycans and basement membrane was altered by treatment. In addition, androgenic blockade results in changes in the amount, thickness, and morphology of these structures. At 30 days postcastration, with or without flutamide treatment, larger proteoglycans were common. CONCLUSIONS: In this study, in particular, the decrease in chondroitin sulfate after the longer period might be understood as a prostatic response to androgenic deprivation, while the high frequency and permanence of perlecan led to the assumption that its modulation could be androgen-independent. Length and form alterations in proteoglycans as well as associations among them and with the basement membrane were dynamic events in the prostate microenvironment.
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Flutamida , Próstata , Masculino , Animales , Flutamida/farmacología , Gerbillinae , Andrógenos/farmacología , Sulfatos de Condroitina/farmacología , OrquiectomíaRESUMEN
OBJECTIVES: This study evaluated raloxifene (ral) effects on LNCaP prostate tumour cells modulating the activity of GPER1/GPR30 receptors. METHODS: LNCaP cells were submitted for 40/120 min and 12 h to the following treatments: C: RPMI + DMSO; R: RPMI + Ral; G: RPMI + Ral + G15 (GPER1 antagonist). Trypan blue staining measured cell viability. Migratory potential (12 h) was measured by transwell migration test in translucent inserts, which were then stained with DAPI and analysed under a fluorescence microscope for quantification. Cells from 40- and 120-min treatments were subjected to protein extraction to the study of AKT, pAKT, ERK, pERK, ERß and SIRT1. KEY FINDINGS: There is a reduction in cellular viability in R compared to C at all evaluated times, and an increased cell viability in G when compared to R; cell viability was similar in C and G in all times studied. The migration assay demonstrated a significant decrease in migration potential of tumour cells in R compared to C and G. Ral treatment reduced pERK expression and increased pAKT in the treated groups after 40 min, pointing out to an antiproliferative and apoptotic effect in the GPER1-controlled rapid-effect pathways. CONCLUSIONS: Raloxifene was able to modulate GPER1 in LNCaP prostate tumour cells, decreasing cell viability and their migratory potential.
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Movimiento Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Neoplasias de la Próstata/tratamiento farmacológico , Clorhidrato de Raloxifeno/farmacología , Receptores de Estrógenos/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Línea Celular Tumoral , Humanos , Masculino , Persona de Mediana Edad , Próstata/efectos de los fármacos , Próstata/metabolismo , Neoplasias de la Próstata/patología , Proteínas Proto-Oncogénicas c-akt , Transducción de SeñalRESUMEN
BACKGROUND: Studies have shown that exposure to environmental chemicals known as endocrine disruptors can cause permanent changes in genital organs, such as the prostate. Among these environmental chemicals stands out bisphenol A (BPA). Another factor associated with prostate changes is the consumption of a high-fat diet. Although the relationship between the consumption of a high-fat diet and an increased risk of prostate cancer is well established, the mechanisms that lead to the establishment of this disease are not completely understood, nor the simultaneous action of BPA and high-fat diet. METHODS: Adult gerbils (100 days old) were divided in four groups (n = 6 per group): Control (C): animals that received a control diet and filtered water; Diet (D): animals that received a high-fat diet and filtered water; BPA: animals that received a control diet and BPA - 50 µg kg-1 day-1 in drinking water; BPA + Diet (BPA + D): animals that received a high-fat diet + BPA - 50 µg kg-1 day-1 in drinking water. After the experimental period (6 months), the dorsolateral and ventral prostate lobes were removed, and analyzed by several methods. RESULTS: Histological analysis indicated premalignant and malignant lesions in both prostatic lobes. However, animals of the D, BPA, and BPA + D groups showed a higher incidence and larger number of prostatic lesions; inflammatory foci were also common. Markers to assess prostate lesions, such as increased activation of the DNA repair system (PCNA-positive cells), androgen receptor (AR), and number of basal cells, confirmed the histology. However, serum levels of testosterone did not change under the experimental conditions. CONCLUSIONS: The results indicated that the methodology used was effective in generating metabolic changes, which directly compromised prostatic homeostasis. Diet and BPA appear to modulate the activation of the AR pathway and thereby optimize tumor establishment in the gerbil prostate.
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Compuestos de Bencidrilo/efectos adversos , Dieta Alta en Grasa/efectos adversos , Fenoles/efectos adversos , Próstata , Neoplasias de la Próstata , Administración Oral , Animales , Compuestos de Bencidrilo/administración & dosificación , Carcinogénesis/inducido químicamente , Carcinogénesis/metabolismo , Modelos Animales de Enfermedad , Disruptores Endocrinos , Estrógenos no Esteroides/administración & dosificación , Estrógenos no Esteroides/efectos adversos , Gerbillinae , Masculino , Fenoles/administración & dosificación , Próstata/efectos de los fármacos , Próstata/metabolismo , Próstata/patología , Neoplasias de la Próstata/inducido químicamente , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Receptores Androgénicos/metabolismo , TiempoRESUMEN
One of the recognized issues in prostate cancer research is the lack of animal models allowing the research of pathological, biochemical, and genetic factors in immunocompetent animals. Our research group has successfully employed the gerbil in several studies for prostate diseases. In the present work, we aimed to analyze the effect of chronic bacterial inflammation on N-methyl-N-nitrosourea (MNU)-induced prostate carcinogenesis in gerbils. Histopathological assessment of the prostatic complex revealed that treatment combinations with MNU plus testosterone or bacterial infection resulted in a promotion of prostate cancer, with bacterial inflammation being more effective in increasing premalignant and malignant tissular alterations than testosterone in the prostate. Furthermore, chronic bacterial inflammation itself induced premalignant lesions in the ventral lobe and increased their frequency in the dorsolateral lobe as well as malignant lesions in the ventral prostate. These animals showed a rich inflammatory microenvironment, characterized as intraluminal and periductal foci. These data indicate that chronic inflammation induced by Escherichia coli acts as a potent tumor promoter, in the early stages of carcinogenesis in the gerbil, in line with the hypothesis of inflammation supporting several steps of tumor development in the prostate gland.
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Modelos Animales de Enfermedad , Gerbillinae , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Animales , Carcinogénesis , Inflamación/inducido químicamente , Inflamación/metabolismo , Inflamación/patología , Masculino , Metilnitrosourea , Neoplasias de la Próstata/inducido químicamenteRESUMEN
BACKGROUND: Estrogens are critical players in prostate growth and disease. Estrogen therapy has been the standard treatment for advanced prostate cancer for several decades; however, it has currently been replaced by alternative anti-androgenic therapies. Additionally, studies of its action on prostate biology, resulting from an association between carcinogens and estrogen, at different stages of life are scarce or inconclusive about its protective and beneficial role on induced-carcinogenesis. Thus, the aim of this study was to determine whether estradiol exerts a protective and/or stimulatory role on N-methyl-N-nitrosurea-induced prostate neoplasms. METHODS: We adopted a rodent model that has been used to study induced-prostate carcinogenesis: the Mongolian gerbil. We investigated the occurrence of neoplasms, karyometric patterns, androgen and estrogen receptors, basal cells, and global methylation status in ventral and dorsolateral prostate tissues. RESULTS: Histopathological analysis showed that estrogen was able to slow tumor growth in both lobes after prolonged treatment. However, a true neoplastic regression was observed only in the dorsolateral prostate. In addition to the protective effects against neoplastic progression, estrogen treatment resulted in an epithelium that exhibited features distinctive from a normal prostate, including increased androgen-insensitive basal cells, high androgens and estrogen receptor positivity, and changes in DNA methylation patterns. CONCLUSIONS: Estrogen was able to slow tumor growth, but the epithelium exhibited features distinct from a normal prostatic epithelium, and this unstable microenvironment could trigger lesion recurrence over time.
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Andrógenos , Estradiol , Próstata , Neoplasias de la Próstata , Andrógenos/metabolismo , Andrógenos/farmacología , Animales , Carcinogénesis/efectos de los fármacos , Carcinogénesis/patología , Carcinógenos/farmacología , Daño del ADN/efectos de los fármacos , Progresión de la Enfermedad , Células Epiteliales/patología , Estradiol/metabolismo , Estradiol/farmacología , Masculino , Metilnitrosourea/farmacología , Próstata/efectos de los fármacos , Próstata/patología , Neoplasias de la Próstata/inducido químicamente , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/fisiopatología , Neoplasias de la Próstata/prevención & control , Factores Protectores , RatasRESUMEN
Developmental toxicity caused by environmental exposure to heavy metals during the perinatal period has raised questions about offspring health. Cadmium (Cd) is an endocrine-disrupting chemical with the potential to interfere with morphogenesis and susceptibility to diseases in reproductive organs. Taking into account that in the rat prostate morphogenesis occurs during the perinatal period, and that pregnant females absorb and retain more dietary Cd than their non-pregnant counterparts, it is important to understand the effects of perinatal Cd exposure on the adult rat prostate. Therefore this study investigated the effects of gestational and lactational Cd exposure on adult offspring rat prostate histopathology. Pregnant rats (n = 20) were divided into two groups: Control (treated with aqueous solution of sodium acetate 10 mg/l) and treated (treated with aqueous solution of cadmium acetate 10 mg/l) administered in the drinking water. After weaning, male offspring from different litters (n = 10) received food and water 'ad libitum'. The animals were euthanized at postnatal day 90 (PND90), the ventral prostates (VPs) were removed, weighed and examined histopathologically. Blood was collected for the measurement of testosterone (T) levels. Immunohistochemistry for androgen receptor (AR) and Ki67, and a TUNEL assay were performed. There were no differences in T levels, cell proliferation and apoptosis indexes, or AR immunostaining between the experimental groups. Stromal inflammatory foci and multifocal inflammation increased significantly in the treated group. These changes were associated with inflammatory reactive epithelial atypia and stromal fibrillar rearrangement. In conclusion, VP was permanently affected by perinatal Cd exposition, with increased incidence of inflammatory disorders with ageing.
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Acetatos/toxicidad , Cadmio/toxicidad , Disruptores Endocrinos/toxicidad , Efectos Tardíos de la Exposición Prenatal , Próstata/efectos de los fármacos , Animales , Femenino , Lactancia , Masculino , Intercambio Materno-Fetal , Embarazo , Efectos Tardíos de la Exposición Prenatal/metabolismo , Efectos Tardíos de la Exposición Prenatal/patología , Próstata/embriología , Próstata/metabolismo , Próstata/patología , Ratas Wistar , Receptores Androgénicos/metabolismo , Testosterona/sangreRESUMEN
In the present study, it was evaluated the susceptibility of prostatic lesions in male adult rats exposed to Di-N-butyl-phthalate during fetal and lactational periods and submitted to MNU plus testosterone carcinogenesis protocol. Pregnant females were distributed into four experimental groups: CN (negative control); CMNU (MNU control); TDBP100 (100 mg/kg of DBP); TDBP500 (500 mg/kg of DBP). Females from the TDBP groups received DBP, by gavage, from gestation day 15 (GD15) to postnatal day 21 (DPN21), while C animals received the vehicle (corn oil). CMNU, TDBP100, and TDBP500 groups received a single intraperitoneal injection of MNU (50 mg/kg) on the sixth postnatal week. After that, testosterone cypionate was administered subcutaneously two times a week (2 mg/kg) for 24 weeks. The animals were euthanized on PND220. Distal segment fragments of the ventral (VP) and dorsolateral prostate (DLP) were fixed and processed for histopathological analysis. Protein extracts from ventral prostate were obtained, and western blotting was performed to AR, ERα, MAPK (ERK1/2), and pan-AKT. Stereological analysis showed an increase in the epithelial compartment in TDBP100 and TDBP500 compared to CN. In general, there was increase in the incidence of inflammation and metaplasia/dysplasia in the DBP-treated groups, mainly in DLP, compared to CN and CMNU. Proliferation index was significant higher in TDBP500 and PIN (prostatic intraepithelial neoplasia) was more frequent in this group compared to CMNU. Western blot assays showed an increase in the expressions of AR and MAPK (ERK1/2) in the TDBP100 compared to CN, and ERα and AKT expressions were higher in the TDBP500 group compared do CN. These results showed that different doses of DBP during prostate organogenesis in Wistar rats could increase the incidence of premalignant lesions in initiated rats inducing distinct biological responses in the adulthood. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1185-1195, 2016.
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Dibutil Ftalato/toxicidad , Metilnitrosourea/toxicidad , Próstata/efectos de los fármacos , Testosterona/análogos & derivados , Animales , Western Blotting , Receptor alfa de Estrógeno/metabolismo , Femenino , Inflamación/etiología , Inflamación/metabolismo , Lactancia , Masculino , Exposición Materna , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Embarazo , Próstata/metabolismo , Próstata/patología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Wistar , Receptores Androgénicos/metabolismo , Testosterona/sangre , Testosterona/toxicidad , Regulación hacia Arriba/efectos de los fármacosRESUMEN
BACKGROUND: Characterization of novel rodent models for prostate cancer studies requires evaluation of either spontaneous and carcinogen-induced tumors as well as tumor incidence in different prostatic lobes. We propose a new short-term rodent model of chemically induced prostate carcinogenesis in which prostate cancer progression occurs differentially in the dorsolateral and ventral lobes. METHODS: Adult gerbils were treated with MNU alone or associated with testosterone for 3 or 6 months of treatment. Tumor incidence, latency, localization, and immunohistochemistry (AR, PCNA, smooth muscle α-actin, p63, MGMT, and E-cadherin) were studied in both lobes. RESULTS: Comparisons between both lobes revealed that lesions developed first in the DL while the VL presented longer tumor latency. However, after 6 months, there was a dramatic increase in tumor multiplicity in the VL, mainly in MNU-treated groups. Lesions clearly progressed from a premalignant to a malignant phenotype over time and tumor latency was decreased by MNU + testosterone administration. Three-dimensional reconstruction of the prostatic complex showed that the DL developed tumors exclusively in the periurethral area and showed intense AR, PCNA, and MGMT immunostaining. Moreover, VL lesions emerged throughout the entire lobe. MNU-induced lesions presented markers indicative of an aggressive phenotype: lack of basal cells, rupture of the smooth muscle cell layer, loss of E-cadherin, and high MGMT staining. CONCLUSIONS: There are distinct pathways involved in tumor progression in gerbil prostate lobes. This animal provides a good model for prostate cancer since it allows the investigation of advanced steps of carcinogenesis with shorter latency periods in both lobes.
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Alquilantes/toxicidad , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Metilnitrosourea/toxicidad , Neoplasias de la Próstata/inducido químicamente , Neoplasias de la Próstata/patología , Testosterona/toxicidad , Animales , Gerbillinae , Masculino , Próstata/efectos de los fármacos , Próstata/patología , Factores de TiempoRESUMEN
The present study examined the response of the prostate epithelium of senescent gerbils submitted to orchiectomy and with or without steroidal blockade. Animals were divided into five groups, all surgically castrated except the control group composed of intact animals. In the experimental groups, doses of flutamide and/or tamoxifen were applied for 1, 3, 7 and 30 days postcastration. The structural methods applied reveal that castration, whether associated or not with anti-steroidal drugs, promoted short- and long-term decrease in wet and relative weights of the prostate. The quantitative decline of epithelial compartment proportion observed at the end of treatment was due to the sum of slight changes in the epithelium and lumen. The apoptotic index had risen significantly at 1 day and declined at 7 days postcastration. Androgen receptor (AR) expression decreased after 3 days of hormonal ablation, coinciding with the highest levels of apoptosis and cell proliferation observed in all treated groups. The majority of cells remained differentiated in all groups due to CK 8/18 expression. Some animals remained with injuries such as carcinomas and adenocarcinomas after hormonal ablation. In the latter a mixture of AR-positive and AR-negative cells was identified. Microinvasive carcinomas found in the group treated for 30 days consisted of PCNA-positive, inflammatory and non-proliferating cells. Low apoptosis incidence and bcl-2 positive cells were observed in these lesions. The treatments promoted a reduction of lesions in older gerbils, but treatment-resistant tumours will improve understanding of the events that lead to hormone resistance.
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Envejecimiento/metabolismo , Envejecimiento/patología , Síndrome de Resistencia Androgénica/metabolismo , Síndrome de Resistencia Androgénica/patología , Próstata/metabolismo , Próstata/patología , Antagonistas de Andrógenos/farmacología , Andrógenos/sangre , Andrógenos/deficiencia , Animales , Apoptosis/fisiología , Peso Corporal/fisiología , Estradiol/sangre , Estradiol/deficiencia , Antagonistas de Estrógenos/farmacología , Flutamida/farmacología , Gerbillinae , Masculino , Orquiectomía , Tamaño de los Órganos/fisiología , Próstata/efectos de los fármacos , Tamoxifeno/farmacología , Testosterona/sangre , Testosterona/deficienciaRESUMEN
In the present study prostate lesions were induced in gerbils (Meriones unguiculatus) treated with a single N-methyl-N-nitrosourea (MNU) dose; thus, the incidence, latency and histology of these lesions were evaluated. Fibrillar elements of the extracellular matrix associated with microinvasive sites were also investigated. Animals were divided into 5 groups, including 2 control groups: (1) remained untreated; (2) received the corn oil vehicle (vehicle, 0.1 ml/application) and three different tumor induction regimens: (1) received MNU (30 mg/kg) and weekly testosterone (2 mg/kg) (MNU+testosterone); (2) received only MNU (30 mg/kg); (3) received weekly testosterone doses (2 mg/kg). After 3 and 6 months the animals were dissected and the prostates were evaluated morphologically, immunohistochemically and quantitatively. MNU plus androgen contributed to the development of prostatic intraepithelial neoplasia, microinvasive carcinoma and adenocarcinoma in gerbil prostate. However, these lesions occurred earlier in time in groups that received MNU and androgen compared to control animals as they over time also developed to a high extent microinvasive lesions. Cytochemistry and immunohistochemistry showed that these injuries were commonly associated with inflammatory cells whereas the epithelial cells presented proliferative activity. The alpha-methylacyl-CoA racemase (AMACR) expression in prostate cancer cells facilitated diagnosis of gerbil lesions. Testosterone, MNU and MNU+testosterone showed an increased epithelial volume, although the secretory activity was significantly suppressed mainly at neoplastic foci. In the prostatic stroma, reticular fibers increased significantly in MNU, MNU+testosterone and among the lesions found in these groups, while collagen fibers decreased at neoplastic sites. The disruption of the basement membrane was proven at malignant sites by ultrastructural analysis and type IV collagen and laminin degradation. The prostate carcinogenesis mediated by MNU and androgen stimulated the emergence of proliferative lesions in gerbils after short periods and showed the importance of a dynamic remodeling of stromal components for cellular invasiveness.