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1.
Life Sci ; 242: 117149, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31830481

RESUMO

AIMS: The purpose of this study was to describe a suitable experimental model for studying aging-related prostate disorders including cancer. MATERIALS AND METHODS: 12-month old Wistar rats were kept in control conditions (n = 12) or treated (n = 16) for 6 months with Silastic implants filled with testosterone (T) and estradiol (E2). After the experiment period (at 18 months of age), animals were euthanized and the prostate and other organs were harvested, dissected, weighed, and processed for morphological, ultrastructural and molecular analyses. KEY FINDINGS: We demonstrated that male rats of Wistar strain nicely recapitulate the carcinogenesis process taking place in the aging prostate through the arising of benign, precancerous and malignant lesions, and above all yields a modest incidence of spontaneous PCa (~36%). Moreover, our results highlight that 100% incidence of PCa and precancerous lesions such as prostatic intraepithelial neoplasia and proliferative inflammatory atrophy were achieved in this rat strain after T + E2 treatment, without changing the broad spectrum of changes that naturally emerge in the prostate at advanced ages. Such enhancement of precancerous lesions and tumors was linked to a decreased expression of E-cadherin and ß-catenin in parallel with an increase in Vimentin and N-cadherin, hallmark modifications of epithelial-mesenchymal transition. SIGNIFICANCE: Our findings provide solid evidence that aged Wistar rats may be an excellent model for studies regarding human prostate biology and related disorders including cancer.

3.
Oncol Rep ; 42(5): 2139-2148, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31436299

RESUMO

Curcumin is a natural antioxidant polyphenol, which decreases epithelial­mesenchymal transition (EMT) and cell migration in cervical cancer cells. However, the mechanism by which such a decrease occurs is unclear. It is well established that cervical cancer can be caused by high­risk human papillomavirus (HPV), which overexpresses E6 and E7 oncoproteins. Recent findings have suggested that viral oncoproteins regulate the expression of Pirin, which is an oxidative stress sensor involved in EMT and cell migration. Molecular markers associated with EMT, pirin and HPV were evaluated using reverse transcription­reverse quantitative PCR and western blotting. In addition, the migratory ability of cells was evaluated using a Transwell assay. In order to evaluate the role of Pirin in curcumin­mediated inhibition of EMT, SiHa cervical carcinoma cells, which contain two integrated copies of HPV16, were exposed to curcumin. Cell migration, and the expression levels of EMT biomarkers and the pirin protein, which is a product of the PIR gene, were subsequently evaluated. The results demonstrated a significant decrease in EMT following exposure to 20 µM curcumin for 72 h. This finding was supported by a decrease in the protein expression levels of N­cadherin, Vimentin and Slug. Furthermore, it was observed that PIR expression and Pirin protein levels were significantly decreased when SiHa cells were exposed to curcumin. Subsequently, to analyze the effects of Pirin on EMT, SiHa cells were transfected with a small interfering RNA (siRNA) to knockdown PIR. A significant increase in E­cadherin mRNA expression and a decrease in N­cadherin protein expression were observed. In addition, a similar decrease was observed when SiHa cells were exposed to both PIR siRNA and curcumin. Finally, a significant decrease in SiHa cell migration was observed in the presence of 20 µM curcumin compared with in the control group. These findings suggested that curcumin may decrease EMT, at least in part by a Pirin­dependent mechanism. Therefore, Pirin protein may be an important pharmacological target for cervical cancer treatment.

4.
Front Immunol ; 10: 1394, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31281317

RESUMO

In colorectal cancer (CRC), cancer-associated fibroblasts (CAFs) are the most abundant component from the tumor microenvironment (TM). CAFs facilitate tumor progression by inducing angiogenesis, immune suppression and invasion, thus altering the organization/composition of the extracellular matrix (i.e., desmoplasia) and/or activating epithelial-mesenchymal transition (EMT). Soluble factors from the TM can also contribute to cell invasion through secretion of cytokines and recently, IL-33/ST2 pathway has gained huge interest as a protumor alarmin, promoting progression to metastasis by inducing changes in TM. Hence, we analyzed IL-33 and ST2 content in tumor and healthy tissue lysates and plasma from CRC patients. Tissue localization and distribution of these molecules was evaluated by immunohistochemistry (using localization reference markers α-smooth muscle actin or α-SMA and E-cadherin), and clinical/histopathological information was obtained from CRC patients. In vitro experiments were conducted in primary cultures of CAFs and normal fibroblasts (NFs) isolated from tumor and healthy tissue taken from CRC patients. Additionally, migration and proliferation analysis were performed in HT29 and HCT116 cell lines. It was found that IL-33 content increases in left-sided CRC patients with lymphatic metastasis, with localization in tumor epithelia associated with abundant desmoplasia. Although ST2 content showed similarities between tumor and healthy tissue, a decreased immunoreactivity was observed in left-sided tumor stroma, associated to metastasis related factors (advanced stages, abundant desmoplasia, and presence of tumor budding). A principal component analysis (including stromal and epithelial IL-33/ST2 and α-SMA immunoreactivity with extent of desmoplasia) allowed us to distinguish clusters of low, intermediate and abundant desmoplasia, with potential to develop a diagnostic signature with benefits for further therapeutic targets. IL-33 transcript levels from CAFs directly correlated with CRC cell line migration induced by CAFs conditioned media, with rhIL-33 inducing a mesenchymal phenotype in HT29 cells. These results indicate a role of IL-33/ST2 in tumor microenvironment, specifically in the interaction between CAFs and epithelial tumor cells, thus contributing to invasion and metastasis in left-sided CRC, most likely by activating desmoplasia.

5.
Asian J Androl ; 21(6): 557-564, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31031331

RESUMO

Secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein highly expressed in bone tissue that acts as a chemoattractant factor promoting the arrival of prostate cancer (PCa) cells to the bone marrow. However, the contribution of SPARC during the early stages of tumor progression remains unclear. In this study, we show that SPARC is highly expressed in PCa tissues with a higher Gleason score. Through stable knockdown and overexpression of SPARC in PC3 and LNCaP cells, respectively, here we demonstrate that endogenous SPARC induces the epithelial-mesenchymal transition (EMT), decreasing E-cadherin and cytokeratin 18 and increasing N-cadherin and vimentin. Moreover, SPARC induces the expression of EMT regulatory transcription factors Snail family transcriptional repressor 1 (Snail), Snail family transcriptional repressor 2 (Slug), and zinc finger E-box binding homeobox 1 (Zeb1). In addition, SPARC knockdown in PC3 cells decreases migration and invasion in vitro, without modifying cell proliferation. Our results indicate that SPARC might facilitate tumor progression by modifying the cellular phenotype in cancer cells.

6.
Asian J Androl ; 21(5): 460-467, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30880686

RESUMO

One of the factors promoting tumoral progress is the abnormal activation of the epithelial-mesenchymal transition (EMT) program which has been associated with chemoresistance in tumoral cells. The transcription factor zinc finger E-box-binding homeobox 1 (ZEB1), a key EMT activator, has recently been related to docetaxel resistance, the main chemotherapeutic used in advanced prostate cancer treatment. The mechanisms involved in this protective effect are still unclear. In a previous work, we demonstrated that ZEB1 expression induced an EMT-like phenotype in prostate cancer cell lines. In this work, we used prostate cancer cell lines 22Rv1 and DU145 to study the effect of ZEB1 modulation on docetaxel resistance and its possible mechanisms. The results showed that ZEB1 overexpression conferred to 22Rv1 cell resistance to docetaxel while its silencing made DU145 cells more sensitive to it. Analysis of resistance markers showed no presence of ATP-binding cassette subfamily B member 1 (MDR1) and no changes in breast cancer resistance protein (BCRP) or ATP-binding cassette subfamily C member 10 (MRP7). However, a correlation between ZEB1, multidrug resistance-associated protein 1 (MRP1), and ATP-binding cassette subfamily C member 4 (MRP4) expression was observed. MRP4 inhibition, using MK571, resensitized cells with ZEB1 overexpression to docetaxel treatment. In addition, modulation of ZEB1 and subsequent change in MRP4 expression correlated with a lower apoptotic response to docetaxel, characterized by lower B-cell lymphoma 2 (Bcl2), high BCL2-associated X protein (Bax), and high active caspase 3 expression. The response to docetaxel in our model seems to be mediated mainly by activation of the apoptotic death program. Our results showed that modulation of MRP4 could be a mediator of ZEB1-related resistance to docetaxel in prostate cancer, making it a possible marker for chemotherapy response in patients who do not express MDR1.

7.
Artigo em Inglês | MEDLINE | ID: mdl-30724672

RESUMO

Okadaic acid group (OA-group) is a set of lipophilic toxins which are characterised by being produced by species associated with the genera Dinophysis and Prorocentrum. OA-group has been regularly detected in endemic shellfish species from the southern zone of Chile only through the mouse bioassay. The purpose of this work was to determine the variability of OA-group toxins in endemic aquatic organisms (bivalves, crabs, gastropods and fish) and to establish the relationship with the concentration of fatty acids (FAs) detected in the evaluated species. The toxicity of OA-group and the FA profiles were determined using LC-MS/MS and gas chromatography with flame-ionisation detection, respectively. In the study area, the dinoflagellate Dinophysis acuta was detected in densities ≈2000 cells ml-1 with a toxicity ≈18.3 pg OA equiv cel-1. The analysis identified OA and dinophysistoxin-1 in shellfish in a range of ≈90 to ≈225 µg OA eq kg-1, where no toxins in fish were detected. A positive relationship between the FA level and the concentration of OA-group toxins in the digestive glands of bivalves and gastropods was established, noted for high levels of saturated FAs (C14:0 and C16:0). The toxic variability of OA-group toxins determined in the different species allowed us to establish that the consumption of these vectors, regulated by non-analytical methods, can be harmful when consumed by humans, thus suggesting that the sanitary regulations for the control of OA-group in Chile should be updated.


Assuntos
Organismos Aquáticos/química , Ácidos Graxos/análise , Toxinas Marinhas/química , Toxinas Marinhas/toxicidade , Ácido Okadáico/química , Ácido Okadáico/toxicidade , Animais , Bivalves/química , Braquiúros/química , Cromatografia Líquida , Peixes , Gastrópodes/química , Especificidade da Espécie , Espectrometria de Massas em Tandem
8.
Sci Rep ; 8(1): 11467, 2018 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-30065348

RESUMO

Syndecan 1 (SDC-1) is a cell surface proteoglycan with a significant role in cell adhesion, maintaining epithelial integrity. SDC1 expression is inversely related to aggressiveness in prostate cancer (PCa). During epithelial to mesenchymal transition (EMT), loss of epithelial markers is mediated by transcriptional repressors such as SNAIL, SLUG, or ZEB1/2 that bind to E-box promoter sequences of specific genes. The effect of these repressors on SDC-1 expression remains unknown. Here, we demonstrated that SNAIL, SLUG and ZEB1 expressions are increased in advanced PCa, contrarily to SDC-1. SNAIL, SLUG and ZEB1 also showed an inversion to SDC-1 in prostate cell lines. ZEB1, but not SNAIL or SLUG, represses SDC-1 as demonstrated by experiments of ectopic expression in epithelial prostate cell lines. Inversely, expression of ZEB1 shRNA in PCa cell line increased SDC-1 expression. The effect of ZEB1 is transcriptional since ectopic expression of this gene represses SDC-1 promoter activity and ZEB1 binds to the SDC-1 promoter as detected by ChIP assays. An epigenetic mark associated to transcription repression H3K27me3 was bound to the same sites that ZEB1. In conclusion, this study identifies ZEB1 as a key repressor of SDC-1 during PCa progression and point to ZEB1 as a potentially diagnostic marker for PCa.


Assuntos
Neoplasias da Próstata/genética , Sindecana-1/genética , Fatores de Transcrição/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Adesão Celular/genética , Linhagem Celular Tumoral , Epigênese Genética/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Masculino , Células PC-3 , Regiões Promotoras Genéticas/genética , Fatores de Transcrição da Família Snail/genética , Transcrição Genética/genética
9.
Asian J Androl ; 20(3): 294-299, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29271397

RESUMO

It has been reported that one of the factors that promotes tumoral progression is the abnormal activation of the epithelial-mesenchymal transition program. This process is associated with tumoral cells acquiring invasive and malignant properties and has the transcription factor zinc finger E-box-binding homeobox 1 (ZEB1) as one of its main activators. However, the role of ZEB1 in promoting malignancy in prostate cancer (PCa) is still unclear. Here, we report that ZEB1 expression correlates with Gleason score in PCa samples and that expression of ZEB1 regulates epithelial-mesenchymal transition and malignant characteristics in PCa cell lines. The results showed that ZEB1 expression is higher in samples of higher malignancy and that overexpression of ZEB1 was able to induce epithelial-mesenchymal transition by upregulating the mesenchymal marker Vimentin and downregulating the epithelial marker E-Cadherin. On the contrary, ZEB1 silencing repressed Vimentin expression and upregulated E-Cadherin. ZEB1 expression conferred enhanced motility and invasiveness and a higher colony formation capacity to 22Rv1 cells whereas DU145 cells with ZEB1 silencing showed a decrease in those same properties. The results showed that ZEB1 could be a key promoter of tumoral progression toward advanced stages of PCa.


Assuntos
Transição Epitelial-Mesenquimal/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo , Caderinas/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos , Masculino , Gradação de Tumores , Invasividade Neoplásica/genética , Neoplasias da Próstata/patologia , Vimentina/metabolismo
10.
Toxins (Basel) ; 9(6)2017 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-28604648

RESUMO

The saxitoxin-group (STX-group) corresponds to toxic metabolites produced by cyanobacteria and dinoflagellates of the genera Alexandrium, Gymnodinium, and Pyrodinium. Over the last decade, it has been possible to extrapolate the areas contaminated with the STX-group worldwide, including Chile, a phenomenon that has affected ≈35% of the Southern Pacific coast territory, generating a high economic impact. The objective of this research was to study the toxicity of the STX-group in all aquatic organisms (bivalves, algae, echinoderms, crustaceans, tunicates, cephalopods, gastropods, and fish) present in areas with a variable presence of harmful algal blooms (HABs). Then, the toxic profiles of each species and dose of STX equivalents ingested by a 60 kg person from 400 g of shellfish were determined to establish the health risk assessment. The toxins with the highest prevalence detected were gonyautoxin-4/1 (GTX4/GTX1), gonyautoxin-3/2 (GTX3/GTX2), neosaxitoxin (neoSTX), decarbamoylsaxitoxin (dcSTX), and saxitoxin (STX), with average concentrations of 400, 2800, 280, 200, and 2000 µg kg-1 respectively, a species-specific variability, dependent on the evaluated tissue, which demonstrates the biotransformation of the analogues in the trophic transfer with a predominance of α-epimers in all toxic profiles. The identification in multiple vectors, as well as in unregulated species, suggests that a risk assessment and risk management update are required; also, chemical and specific analyses for the detection of all analogues associated with the STX-group need to be established.


Assuntos
Contaminação de Alimentos/análise , Saxitoxina/análise , Alimentos Marinhos/análise , Animais , Cianobactérias , Dinoflagelados , Cadeia Alimentar , Invertebrados/química , Invertebrados/metabolismo , Macrocystis/química , Macrocystis/metabolismo , Salmão/metabolismo , Saxitoxina/metabolismo
11.
Artigo em Inglês | MEDLINE | ID: mdl-27646025

RESUMO

Contamination of shellfish with lipophilic marine biotoxins (LMB), pectenotoxins (PTXs), yessotoxins (YTXs) and okadaic acid (OA) toxin groups in southern Chile is a constant challenge for the development of miticulture considering the high incidence of toxic episodes that tend to occur. This research is focused on using methodologies for assessing the decrease in toxins of natural resources in Chile with high value, without altering the organoleptic properties of the shellfish. The species were processed through steaming (1 min at 121°C) and subsequent canning (5 min at 121°C). Changes in the profiles of toxins and total toxicity levels of LMB in endemic bivalves and gastropods were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The total reduction of toxicity (≈ 15%) was not related to the destruction of the toxin, but rather to the loss of LMB on removing the shells and packing media of canned products (***p < 0.001). Industrial processing of shellfish reduces LMB contents by up to 15% of the total initial contents, concomitant only with the interconversion of PTX-group toxins into PTX-2sa. In soft bottom-dwelling species with toxicities beyond the standard for safe human consumption (≥ 160 µg OA-eq kg-1), toxicity can be reduced to safe levels through industrial preparation procedures.


Assuntos
Bivalves/química , Contaminação de Alimentos/análise , Manipulação de Alimentos , Gastrópodes/química , Toxinas Marinhas/análise , Toxinas Marinhas/toxicidade , Animais , Chile
12.
Oncol Rep ; 35(3): 1309-17, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26708143

RESUMO

Gastric cancer (GC) is the third most common cause of cancer death worldwide. Natural killer cells play an important role in the immune defense against transformed cells. They express the activating receptor NKG2D, whose ligands belong to the MIC and ULBP/RAET family. Although it is well established that these ligands are generally expressed in tumors, the association between their expression in the tumor and gastric mucosa and clinical parameters and prognosis of GC remains to be addressed. In the present study, MICA and MICB expression was analyzed, by flow cytometry, in 23 and 20 pairs of gastric tumor and adjacent non-neoplasic gastric mucosa, respectively. Additionally, ligands expression in 13 tumors and 7 gastric mucosa samples from GC patients were evaluated by immunohistochemistry. The mRNA levels of MICA in 9 pairs of tumor and mucosa were determined by quantitative PCR. Data were associated with the clinicopathological characteristics and the patient outcome. MICA expression was observed in 57% of tumors (13/23) and 44% of mucosal samples (10/23), while MICB was detected in 50% of tumors (10/20) and 45% of mucosal tissues (9/20). At the protein level, ligand expression was significantly higher in the tumor than in the gastric mucosa. MICA mRNA levels were also increased in the tumor as compared to the mucosa. However, clinicopathological analysis indicated that, in patients with tumors >5 cm, the expression of MICA and MICB in the tumor did not differ from that of the mucosa, and tumors >5 cm showed significantly higher MICA and MICB expression than tumors ≤5 cm. Patients presenting tumors >5 cm that expressed MICA and MICB had substantially shorter survival than those with large tumors that did not express these ligands. Our results suggest that locally sustained expression of MICA and MICB in the tumor may contribute to the malignant progression of GC and that expression of these ligands predicts an unfavorable prognosis in GC patients presenting large tumors.


Assuntos
Antígenos de Histocompatibilidade Classe I/biossíntese , Neoplasias Gástricas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Masculino , Pessoa de Meia-Idade , Subfamília K de Receptores Semelhantes a Lectina de Células NK/biossíntese , Subfamília K de Receptores Semelhantes a Lectina de Células NK/imunologia , RNA Mensageiro/biossíntese , Neoplasias Gástricas/imunologia , Neoplasias Gástricas/patologia
13.
Mol Med Rep ; 13(1): 778-86, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26648419

RESUMO

The incidence and mortality rates of prostate cancer (PCa) are increasing, and PCa is almost the second­leading cause of cancer­associated mortality in men. During tumor progression, epithelial cells decrease the number of adhesion molecules, change their polarity and position, rearrange their cytoskeleton and increase their migratory and invasive capacities. These changes are known under the concept of epithelial­mesenchymal transition (EMT). EMT is characterized by an upregulation of certain transcription factors, including SNAIL1, which represses genes that are characteristic of an epithelial phenotype, including E­cadherin, and indirectly increase the expression levels of genes, which are associated with the mesenchymal phenotype. It has been suggested that the transcription factor, SNAIL1, decreases the proliferation and increases the migratory and invasive capacities of PCa cell lines. The present study was performed using LNCaP and PC3 cell lines, in which the expression levels of SNAIL1 were increased or silenced through the use of lentiviral vectors. The expression levels of EMT markers were quantified using reverse transcription­quantitative polymerase chain reaction and western blot analysis. In addition, cell survival was analyzed using an MTS assay; cell proliferation was examined using an antibody targeting Ki­67; migration on plates with 8 µm pores to allow the passage of cells; and invasiveness was analyzed using a membrane chamber covered in dried basement membrane matrix solution. The levels of apoptosis were determined using a Caspase 3/7 assay containing a substrate modified by caspases 3 and 7. The results demonstrated that the overexpression and silencing of SNAIL1 decreased cell proliferation and survival. However, the overexpression of SNAIL1 decreased apoptosis, compared with cells with the SNAIL1­silenced cells, in which cell apoptosis increased. The migration and invasive capacities increased in the cells overexpressing SNAIL1, and decreased when SNAIL1 was silenced. In conclusion, PCa cells overexpressing SNAIL1 exhibited characteristics of an EMT phenotype, whereas the silencing of the SNAIL1 transcriptional repressor promoted an epithelial­like phenotype, with decreased migration and invasion, characteristic of mesenchymal cells.


Assuntos
Movimento Celular , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Fatores de Transcrição/metabolismo , Apoptose , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Transição Epitelial-Mesenquimal , Vetores Genéticos/metabolismo , Humanos , Lentivirus/metabolismo , Masculino , Invasividade Neoplásica , Fatores de Transcrição da Família Snail
14.
Oncol Lett ; 10(4): 2142-2148, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26622809

RESUMO

Prostate cancer is one of the most prevalent oncological diseases in males worldwide, and the mortalities resulting from this type of cancer are mainly due to metastasis. The most common models for the study of metastasis are transgenic and immunocompromised mice, which enable the study of the metastatic process in a controlled way by the injection of prostate cancer cells into the mice. In the present study, NOD-SCIDγ mice were injected orthotopically with PC3 cells in the anterior prostate in order to establish a metastatic model. The results demonstrated the development and growth of a primary tumor that preceded the formation of micrometastases in the lung, liver and pancreas, followed by macrometastases in the liver. This model adequately represents the dynamics of the metastatic process, and may be useful for novel therapeutic assays and post-surgical relapse studies.

15.
Oncol Rep ; 34(6): 2837-44, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26503286

RESUMO

Metastatic prostate cancer (mPCa) is one of the most prevalent cancers in men worldwide. The main cause of death in these patients is androgen-resistant metastatic disease. Surgery of the primary tumor has been avoided in these patients as there is no strong evidence that supports a beneficial effect. From the biological point of view, it appears rational to hypothesize that the primary tumor may contribute to the establishment and growth of metastases. Considering this, we propose that cytoreductive surgery (CS) in advanced metastatic stage slows the progression of metastatic disease. To test this, we used a mouse model of resectable orthotopic prostate cancer (PCa) and performed CS. After surgery, metastases were smaller and less numerous in the treated mice; an effect that was observable until the end of the experiment. These results suggest that CS alone delays the progression of metastatic disease and that although this effect may be temporary, it may translate to prolonged survival, especially when used with adjuvant therapy.


Assuntos
Procedimentos Cirúrgicos de Citorredução , Progressão da Doença , Prostatectomia , Neoplasias da Próstata/cirurgia , Animais , Quimioterapia Adjuvante , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Metástase Neoplásica , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia
16.
Artigo em Inglês | MEDLINE | ID: mdl-25769036

RESUMO

Harmful algae blooms (HABs) are the main source of marine toxins in the aquatic environment surrounding the austral fjords in Chile. Huichas Island (Aysén) has an history of HABs spanning more than 30 years, but there is limited investigation of the bioaccumulation of marine toxins in the bivalves and gastropods from the Region of Aysén. In this study, bivalves (Mytilus chilenses, Choromytilus chorus, Aulacomya ater, Gari solida, Tagelus dombeii and Venus antiqua) and carnivorous gastropods (Argobuccinum ranelliformes and Concholepas concholepas) were collected from 28 sites. Researchers analysed the accumulation of STX-group toxins using a LC with a derivatisation post column (LC-PCOX), while lipophilic toxins (OA-group, azapiracids, pectenotoxins and yessotoxins) were analysed using LC-MS/MS with electrospray ionisation (+/-) in visceral (hepatopancreas) and non-visceral tissues (mantle, adductor muscle, gills and foot). Levels of STX-group and OA-group toxins varied among individuals from the same site. Among all tissue samples, the highest concentrations of STX-group toxins were noted in the hepatopancreas in V. antiqua (95 ± 0.1 µg STX-eq 100 g(-1)), T. dombeii (148 ± 1.4 µg STX-eq 100 g(-1)) and G. solida (3232 ± 5.2 µg STX-eq 100 g(-1); p < 0.05); in the adductor muscle in M. chilensis (2495 ± 6.4 µg STX-eq 100 g(-1); p < 0.05) and in the foot in C. concholepas (81 ± 0.7 µg STX-eq 100 g(-1)) and T. dombeii (114 ± 1.2 µg STX-eq 100 g(-1)). The highest variability of toxins was detected in G. solida, where high levels of carbamate derivatives were identified (GTXs, neoSTX and STX). In addition to the detected hydrophilic toxins, OA-group toxins were detected (OA and DTX-1) with an average ratio of ≈1:1. The highest levels of OA-group toxins were in the foot of C. concholepas, with levels of 400.3 ± 3.6 µg OA eq kg(-1) (p < 0.05) and with a toxic profile composed of 90% OA. A wide range of OA-group toxins was detected in M. chilensis with a toxicity < 80 µg OA eq kg(-1), but with 74% of those toxins detected in the adductor muscle. In all evaluated species, there was no detection of lipophilic toxins associated with biotransformation in molluscs and carnivorous gastropods. In addition, the STX-group and OA-group toxin concentrations in shellfish was not associated with the presence of HAB. The ranking of toxin concentration in the tissues of most species was: digestive glands > mantle > adductor muscle for the STX-group toxins and foot > digestive gland for the OA-group toxins. These results gave a better understanding of the variability and compartmentalisation of STX-group and OA-group toxins in different bivalve and gastropod species from the south of Chile, and the analyses determined that tissues could play an important role in the biotransformation of STX-group toxins and the retention of OA-group toxins.


Assuntos
Bivalves/metabolismo , Gastrópodes/metabolismo , Carne/análise , Ácido Okadáico/análise , Saxitoxina/análise , Animais , Biotransformação , Bivalves/classificação , Chile , Cromatografia Líquida , Gastrópodes/classificação , Proliferação Nociva de Algas , Intoxicação por Frutos do Mar , Espectrometria de Massas em Tandem
17.
Int J Oncol ; 45(3): 985-94, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24990514

RESUMO

Cancer stem cells (CSCs) have the ability to self-renew and differentiate to give rise to heterogeneous phenotype of the tumor cells. It is believed that these cells are involved in metastasis, recurrence and therapy resistance in various cancers. CSCs have been identified in prostate cancer (PCa), one of the most diagnosed malignancies in men over the world, for which chemotherapy resistance is a major problem in the treatment of castration-resistant advanced stages. Molecular signatures, gene expression and functional features have been reported for PCa CSCs. Most data come from cell lines which may not represent the actual tumor. In the present work, a CSCs enriched population obtained from PCa explants was functionally characterized and analyzed for drug resistance. Tumorsphere cultures positive for ABCG2 transporter, CD133, CD44, cytokeratins 5 and 18 (CK5 and CK18) and negatives for androgen receptor (AR) and prostate-specific antigen (PSA) showed higher clonogenic capacity, holoclone-forming ability, colony-forming capacity in soft agar and lower proliferative and apoptotic rate than control adherent cell cultures. Furthermore, exposing tumorsphere cultures to ABCG2 substrate drugs resulted in a high survival rate compared with control PCa cells. This high drug resistance was decreased using a selective inhibitor of ABCG2. According to these results, tumorspheres from PCa explants showed a functional stem phenotype and a marked drug resistance, probably mediated by high expression of the ABCG2 transporter, which might be considered as a suitable therapeutic target for CSCs.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Resistencia a Medicamentos Antineoplásicos , Proteínas de Neoplasias/metabolismo , Células-Tronco Neoplásicas/metabolismo , Neoplasias da Próstata/metabolismo , Esferoides Celulares/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Antineoplásicos/farmacologia , Biomarcadores Tumorais/metabolismo , Daunorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Humanos , Indóis/farmacologia , Masculino , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/patologia , Topotecan/farmacologia , Células Tumorais Cultivadas
18.
Int J Oncol ; 44(3): 647-54, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24424718

RESUMO

Prostate cancer (PC) is a leading male oncologic malignancy wideworld. During malignant transformation, normal epithelial cells undergo genetic and morphological changes known as epithelial-mesenchymal transition (EMT). Several regulatory genes and specific marker proteins are involved in PC EMT. Recently, syndecans have been associated with malignancy grade and Gleason score in PC. Considering that SNAIL is mainly a gene repressor increased in PC and that syndecan promoters have putative binding sites for this repressor, we propose that SNAIL might regulate syndecan expression during PC EMT. The aim of this study was to analyze immunochemically the expression of SNAIL, syndecans 1 and 2 and other EMT markers in a tissue microarray (TMA) of PC samples and PC cell lines. The TMAs included PC samples of different Gleason grade and benign prostatic hyperplasia (BPH) samples, as non­malignant controls. PC3 and LNCaP cell lines were used as models of PC representing different tumorigenic capacities. Semi-quantitative immunohistochemistry was performed on TMAs and fluorescence immunocytochemistry and western blot analysis were conducted on cell cultures. Results show that SNAIL exhibits increased expression in high Gleason specimens compared to low histological grade and BPH samples. Accordingly, PC3 cells show higher SNAIL expression levels compared to LNCaP cells. Conversely, syndecan 1, similarly to E-cadherin (a known marker of EMT), shows a decreased expression in high Gleason grades samples and PC3 cells. Interestingly, syndecan 2 shows no changes associated to histological grade. It is concluded that increased SNAIL levels in advanced PC are associated with low expression of syndecan 1. The mechanism by which SNAIL regulates the expression of syndecan 1 remains to be investigated.


Assuntos
Neoplasias da Próstata/genética , Sindecana-1/biossíntese , Sindecana-2/biossíntese , Fatores de Transcrição/biossíntese , Animais , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Gradação de Tumores , Hiperplasia Prostática/genética , Hiperplasia Prostática/patologia , Neoplasias da Próstata/patologia , Fatores de Transcrição da Família Snail , Sindecana-1/metabolismo , Sindecana-2/metabolismo , Análise Serial de Tecidos , Fatores de Transcrição/metabolismo
19.
Anticancer Drugs ; 23(9): 959-69, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22713594

RESUMO

Gonadotropin-releasing hormone (GnRH) agonists are widely used for the treatment of advanced prostate cancer (PCa). Agonists activate the GnRH receptor (GnRH-R), triggering apoptosis in PCa cells. In gonadotropes, the amount of GnRH-R in the plasma membrane is regulated by protein folding and endoplasmic reticulum retention, mechanisms that can be overcome by the pharmacoperone IN3. Our aim was to describe the intracellular distribution of GnRH-R in PCa cells and its relation to response to GnRH analog treatments. The expressions of GnRH-R in PCa biopsies were evaluated by immunohistochemistry and the intracellular distribution was determined by immunofluorescence in primary cell cultures from human PCa samples. Cultured cells were pretreated with IN3 and then with leuprolide. Cell survival was evaluated by 1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan (MTT) thiazolyl blue formazan and cell cycle and apoptosis by flow cytometry. We observed that the expression of GnRH-R decreased according to malignant progression. Most GnRH-R are located inside the cell, colocalizing with endoplasmic reticulum markers. The treatment with IN3 decreased cellular GnRH-R retention, increasing plasma membrane expression in approximately 60%. Pretreatment with IN3 decreased PCa cell survival compared with leuprolide-alone treatment, primarily because of an increase in apoptosis. We conclude that the response of PCa cells to leuprolide is related to the amount of GnRH-R in the plasma membrane. Therefore, pretreatment evaluation of the amount of these receptors may be a predictor of the outcome of leuprolide treatment in PCa patients. Assessment of systemic IN3 effect would be necessary to determine its utility as an adjuvant treatment in hormone-resistant tumors.


Assuntos
Apoptose/efeitos dos fármacos , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Membrana Celular/efeitos dos fármacos , Indóis/farmacologia , Leuprolida/farmacologia , Neoplasias da Próstata/patologia , Piridinas/farmacologia , Receptores LHRH/agonistas , Western Blotting , Técnicas de Cultura de Células , Ciclo Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Masculino , Neoplasias da Próstata/metabolismo , Dobramento de Proteína , Receptores LHRH/biossíntese , Células Tumorais Cultivadas
20.
Biol Res ; 45(3): 297-305, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23283439

RESUMO

Prostate cancer (PCa) is the most frequently diagnosed malignancy in men worldwide. Chemotherapy response is very poor and resistance to hormone-based treatments is frequent in advances stages. Recently, tumor-initiating cells or cancer stem cells (CSCs) have been identified in several cancers, including PCa. These cells are thought to be responsible for therapy resistance, relapse and metastasis. In the present work, enriched populations of CSCs were obtained using a mixed procedure that included differential clone-forming ability, sphere growing induction (prostatospheres) and magnetic-associated cell sorting (MACS). Also, stem marker expression was determined in PCa biopsies of different histological grades and metastasis samples. The signature for stem markers of the isolated CSCs was CD133+/CD44+/ABCG2+/ CD24-. Expression of stem markers (CD133, CD44, and ABCG2) was higher in medium Gleason biopsies than in lower and higher grades, and lymph-node and bone metastasis samples. These results suggest that the CSCs in PCa reach an important number in medium Gleason grades, when the tumor is still confined into the gland. At this stage, the surgical treatment is usually with curative intention. However, an important percentage of patients relapse after treatment. Number and signature of CSCs may be a prognosis factor for PCa recurrence.


Assuntos
Antígenos CD/análise , Regulação Neoplásica da Expressão Gênica , Células-Tronco Neoplásicas/patologia , Neoplasias da Próstata/genética , Biomarcadores Tumorais/análise , Biópsia , Neoplasias Ósseas/secundário , Separação Celular , Humanos , Imuno-Histoquímica , Metástase Linfática/patologia , Masculino , Gradação de Tumores , Metástase Neoplásica , Recidiva Local de Neoplasia , Prognóstico , Neoplasias da Próstata/patologia , Ensaio Tumoral de Célula-Tronco
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