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Understanding prostate response to castration and androgen receptor signaling inhibitors (ARSI) is critical to improving long-term prostate cancer (PCa) patient survival. Here, we use a multi-omics approach on 229,794 single cells to create a mouse single-cell reference atlas for interpreting mouse prostate biology and castration response. Our reference atlas refines single-cell annotations and provides a chromatin context, which, when coupled with mouse lineage tracing, demonstrates that castration-resistant luminal cells are distinct from the pre-existent urethra-proximal stem/progenitor cells. Molecular pathway analysis and therapeutic studies further implicate AP1 (JUN/FOS), WNT/ß-catenin, FOXQ1, NF-κB, and JAK/STAT pathways as major drivers of castration-resistant luminal populations with relevance to human PCa. Our datasets, which can be explored through an interactive portal (https://visportal.roswellpark.org/data/tang/), can aid in developing combination treatments with ARSI for advanced PCa patients.
Assuntos
Epigênese Genética , Neoplasias de Próstata Resistentes à Castração , Análise de Célula Única , Masculino , Animais , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Camundongos , Humanos , Próstata/patologia , Próstata/metabolismoRESUMO
Technological advancements in biology and microscopy have empowered a transition from bioimaging as an observational method to a quantitative one. However, as biologists are adopting quantitative bioimaging and these experiments become more complex, researchers need additional expertise to carry out this work in a rigorous and reproducible manner. This Essay provides a navigational guide for experimental biologists to aid understanding of quantitative bioimaging from sample preparation through to image acquisition, image analysis, and data interpretation. We discuss the interconnectedness of these steps, and for each, we provide general recommendations, key questions to consider, and links to high-quality open-access resources for further learning. This synthesis of information will empower biologists to plan and execute rigorous quantitative bioimaging experiments efficiently.
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Processamento de Imagem Assistida por Computador , MicroscopiaRESUMO
Understanding prostate response to castration and androgen receptor signaling inhibitors (ARSI) is critical to improving long-term prostate cancer (PCa) patient survival. Here we use a multi-omics approach on 229,794 single cells to create a mouse single-cell reference atlas better suited to interpreting mouse prostate biology and castration response. Our reference atlas refines single-cell annotations and provides chromatin context, which, when coupled with mouse lineage tracing demonstrates that the castration-resistant luminal cells are distinct from the pre-existent urethra-proximal stem/progenitor cells. Molecular pathway analysis and therapeutic studies further implicate JUN/FOS, WNT/B-Catenin, FOXQ1, NFkB, and JAK/STAT pathways as the major drivers of castration-resistant luminal populations with high relevance to human PCa. Importantly, we demonstrate the utility of our datasets, which can be explored through an interactive portal (https://visportal.roswellpark.org/data/tang/), to aid in developing novel combination treatments with ARSI for advanced PCa patients.
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Tissue clearing for whole organ cell profiling has revolutionized biology and imaging for exploration of organs in three-dimensional space without compromising tissue architecture. But complicated, laborious procedures, or expensive equipment, as well as the use of hazardous, organic solvents prevent the widespread adoption of these methods. Here, we report a simple and rapid tissue clearing method, EZ Clear, that can clear whole adult mouse organs in 48 hr in just three simple steps. Samples stay at room temperature and remain hydrated throughout the clearing process, preserving endogenous and synthetic fluorescence, without altering sample size. After wholemount clearing and imaging, samples processed with EZ Clear can be subjected to downstream applications, such as tissue embedding and cryosectioning followed by standard histology or immunofluorescent staining without loss of fluorescence signal from endogenous or synthetic reporters. Furthermore, we demonstrate that wholemount adult mouse brains processed with EZ Clear can be successfully immunolabeled for fluorescent imaging while still retaining signal from endogenous fluorescent reporters. Overall, the simplicity, speed, and flexibility of EZ Clear make it easy to adapt and implement in diverse imaging modalities in biomedical research.
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Corantes , Imageamento Tridimensional , Animais , Encéfalo/diagnóstico por imagem , Imageamento Tridimensional/métodos , Camundongos , Solventes , Coloração e RotulagemRESUMO
This study addresses the roles of nuclear receptor corepressor 2 (NCOR2) in prostate cancer (PC) progression in response to androgen deprivation therapy (ADT). Reduced NCOR2 expression significantly associates with shorter disease-free survival in patients with PC receiving adjuvant ADT. Utilizing the CWR22 xenograft model, we demonstrate that stably reduced NCOR2 expression accelerates disease recurrence following ADT, associates with gene expression patterns that include neuroendocrine features, and induces DNA hypermethylation. Stably reduced NCOR2 expression in isogenic LNCaP (androgen-sensitive) and LNCaP-C4-2 (androgen-independent) cells revealed that NCOR2 reduction phenocopies the impact of androgen treatment and induces global DNA hypermethylation patterns. NCOR2 genomic binding is greatest in LNCaP-C4-2 cells and most clearly associates with forkhead box (FOX) transcription factor FOXA1 binding. NCOR2 binding significantly associates with transcriptional regulation most when in active enhancer regions. These studies reveal robust roles for NCOR2 in regulating the PC transcriptome and epigenome and underscore recent mutational studies linking NCOR2 loss of function to PC disease progression.
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Antagonistas de Androgênios/farmacologia , Androgênios/deficiência , Biomarcadores Tumorais/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Recidiva Local de Neoplasia/patologia , Correpressor 2 de Receptor Nuclear/antagonistas & inibidores , Neoplasias da Próstata/patologia , Animais , Apoptose , Biomarcadores Tumorais/genética , Proliferação de Células , Humanos , Masculino , Camundongos , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/metabolismo , Correpressor 2 de Receptor Nuclear/genética , Correpressor 2 de Receptor Nuclear/metabolismo , Prognóstico , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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The role of dysregulation of mRNA alternative splicing (AS) in the development and progression of solid tumors remains to be defined. Here we describe the first comprehensive AS landscape in the spectrum of human prostate cancer (PCa) evolution. We find that the severity of splicing dysregulation correlates with disease progression and establish intron retention as a hallmark of PCa stemness and aggressiveness. Systematic interrogation of 274 splicing-regulatory genes (SRGs) uncovers prevalent genomic copy number variations (CNVs), leading to mis-expression of ~68% of SRGs during PCa development and progression. Consequently, many SRGs are prognostic. Surprisingly, androgen receptor controls a splicing program distinct from its transcriptional regulation. The spliceosome modulator, E7107, reverses cancer aggressiveness and inhibits castration-resistant PCa (CRPC) in xenograft and autochthonous PCa models. Altogether, our studies establish aberrant AS landscape caused by dysregulated SRGs as a hallmark of PCa aggressiveness and the spliceosome as a therapeutic vulnerability for CRPC.
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Íntrons/genética , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Spliceossomos/metabolismo , Processamento Alternativo/efeitos dos fármacos , Processamento Alternativo/genética , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Estudos de Coortes , Progressão da Doença , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Compostos de Epóxi/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Estimativa de Kaplan-Meier , Macrolídeos/farmacologia , Masculino , Camundongos , Terapia de Alvo Molecular , Invasividade Neoplásica , Metástase Neoplásica , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Prognóstico , Neoplasias da Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Transcrição Gênica/efeitos dos fármacosRESUMO
LRIG1 has been reported to be a tumor suppressor in gastrointestinal tract and epidermis. However, little is known about the expression, regulation and biological functions of LRIG1 in prostate cancer (PCa). We find that LRIG1 is overexpressed in PCa, but its expression correlates with better patient survival. Functional studies reveal strong tumor-suppressive functions of LRIG1 in both AR+ and AR- xenograft models, and transgenic expression of LRIG1 inhibits tumor development in Hi-Myc and TRAMP models. LRIG1 also inhibits castration-resistant PCa and exhibits therapeutic efficacy in pre-established tumors. We further show that 1) AR directly transactivates LRIG1 through binding to several AR-binding sites in LRIG1 locus, and 2) LRIG1 dampens ERBB expression in a cell type-dependent manner and inhibits ERBB2-driven tumor growth. Collectively, our study indicates that LRIG1 represents a pleiotropic AR-regulated feedback tumor suppressor that functions to restrict oncogenic signaling from AR, Myc, ERBBs, and, likely, other oncogenic drivers.
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Glicoproteínas de Membrana/metabolismo , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Glicoproteínas de Membrana/genética , Camundongos Endogâmicos NOD , Camundongos SCID , Proteína Oncogênica p55(v-myc)/genética , Proteína Oncogênica p55(v-myc)/metabolismo , Neoplasias da Próstata/genética , Ligação Proteica , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Receptores Androgênicos/genética , Transdução de Sinais , Proteínas Supressoras de Tumor/genéticaRESUMO
Cancer cell heterogeneity is a universal feature of human tumors and represents a significant barrier to the efficacy and duration of anticancer therapies, especially targeted therapeutics. Among the heterogeneous cancer cell populations is a subpopulation of relatively quiescent cancer cells, which are in the G0/G1 cell-cycle phase and refractory to anti-mitotic drugs that target proliferative cells. These slow-cycling cells (SCCs) preexist in untreated tumors and frequently become enriched in treatment-failed tumors, raising the possibility that these cells may mediate therapy resistance and tumor relapse. Here we review several general concepts on tumor cell heterogeneity, quiescence, and tumor dormancy. We discuss the potential relationship between SCCs and cancer stem cells (CSCs). We also present our current understanding of how SCCs and cancer dormancy might be regulated. Increasing knowledge of SCCs and tumor dormancy should lead to identification of novel molecular regulators and therapeutic targets of tumor relapse, residual diseases, and metastasis.
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Ciclo Celular , Neoplasias , Ciclo Celular/fisiologia , Humanos , Neoplasias/fisiopatologia , Células-Tronco Neoplásicas/citologiaRESUMO
BACKGROUND: RNA-Seq is currently the most widely used tool to analyze whole-transcriptome profiles. There are numerous commercial kits available to facilitate preparing RNA-Seq libraries; however, it is still not clear how some of these kits perform in terms of: 1) ribosomal RNA removal; 2) read coverage or recovery of exonic vs. intronic sequences; 3) identification of differentially expressed genes (DEGs); and 4) detection of long non-coding RNA (lncRNA). In RNA-Seq analysis, understanding the strengths and limitations of commonly used RNA-Seq library preparation protocols is important, as this technology remains costly and time-consuming. RESULTS: In this study, we present a comprehensive evaluation of four RNA-Seq kits. We used three standard input protocols: Illumina TruSeq Stranded Total RNA and mRNA kits, a modified NuGEN Ovation v2 kit, and the TaKaRa SMARTer Ultra Low RNA Kit v3. Our evaluation of these kits included quality control measures such as overall reproducibility, 5' and 3' end-bias, and the identification of DEGs, lncRNAs, and alternatively spliced transcripts. Overall, we found that the two Illumina kits were most similar in terms of recovering DEGs, and the Illumina, modified NuGEN, and TaKaRa kits allowed identification of a similar set of DEGs. However, we also discovered that the Illumina, NuGEN and TaKaRa kits each enriched for different sets of genes. CONCLUSIONS: At the manufacturers' recommended input RNA levels, all the RNA-Seq library preparation protocols evaluated were suitable for distinguishing between experimental groups, and the TruSeq Stranded mRNA kit was universally applicable to studies focusing on protein-coding gene profiles. The TruSeq protocols tended to capture genes with higher expression and GC content, whereas the modified NuGEN protocol tended to capture longer genes. The SMARTer Ultra Low RNA Kit may be a good choice at the low RNA input level, although it was inferior to the TruSeq mRNA kit at standard input level in terms of rRNA removal, exonic mapping rates and recovered DEGs. Therefore, the choice of RNA-Seq library preparation kit can profoundly affect data outcomes. Consequently, it is a pivotal parameter to consider when designing an RNA-Seq experiment.
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Análise de Sequência de RNA/métodos , Análise de Dados , Perfilação da Expressão Gênica , RNA Mensageiro/genética , Padrões de Referência , Análise de Sequência de RNA/normasRESUMO
Dapagliflozin, a sodium-glucose co-transporter 2 (SGLT2) inhibitor, is indicated to improve glycaemic control in adults of type 2 diabetes. In nonclinical studies, dapagliflozin was neither genotoxic nor carcinogenic. However, in some clinical studies, an increased incidence of bladder cancer was observed in the dapagliflozin group vs. the placebo. Therefore, this study was undertaken to determine if dapagliflozin can act as a promoter in a 2-stage bladder cancer model in rats induced with N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN). Rats given BBN (100 or 400â¯mg/kg, po) twice weekly for 6 weeks in Phase 1 were assigned in Phase 2 to receive daily dose of vehicle, dapagliflozin (0.5â¯mg/kg, po) or uracil (positive control, 3% in diet) from weeks 8-34. All bladders were evaluated by histopathology. Verifying the validity of the model, uracil increased the incidence of bladder cancer, while dapagliflozin had no effect on the incidence or invasiveness of transitional cell carcinoma. The exposure of dapagliflozin at 0.5â¯mg/kg/day in rats was 7 times the clinical exposure at maximal therapeutic dose (10â¯mg). In conclusion, dapagliflozin does not act as promoter or progressor of bladder cancer in a validated bladder cancer model in rats.
Assuntos
Compostos Benzidrílicos/administração & dosagem , Modelos Animais de Doenças , Glucosídeos/administração & dosagem , Neoplasias da Bexiga Urinária/induzido quimicamente , Administração Oral , Animais , Compostos Benzidrílicos/efeitos adversos , Butilidroxibutilnitrosamina/administração & dosagem , Butilidroxibutilnitrosamina/efeitos adversos , Relação Dose-Resposta a Droga , Glucosídeos/efeitos adversos , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
Expression levels of retinoic acid receptor gamma (NR1B3/RARG, encodes RARγ) are commonly reduced in prostate cancer (PCa). Therefore, we sought to establish the cellular and gene regulatory consequences of reduced RARγ expression, and determine RARγ regulatory mechanisms. RARG shRNA approaches in non-malignant (RWPE-1 and HPr1-AR) and malignant (LNCaP) prostate models revealed that reducing RARγ levels, rather than adding exogenous retinoid ligand, had the greatest impact on prostate cell viability and gene expression. ChIP-Seq defined the RARγ cistrome, which was significantly enriched at active enhancers associated with AR binding sites. Reflecting a significant genomic role for RARγ to regulate androgen signaling, RARγ knockdown in HPr1-AR cells significantly regulated the magnitude of the AR transcriptome. RARγ downregulation was explained by increased miR-96 in PCa cell and mouse models, and TCGA PCa cohorts. Biochemical approaches confirmed that miR-96 directly regulated RARγ expression and function. Capture of the miR-96 targetome by biotin-miR-96 identified that RARγ and a number of RARγ interacting co-factors including TACC1 were all targeted by miR-96, and expression of these genes were prominently altered, positively and negatively, in the TCGA-PRAD cohort. Differential gene expression analyses between tumors in the TCGA-PRAD cohort with lower quartile expression levels of RARG and TACC1 and upper quartile miR-96, compared to the reverse, identified a gene network including several RARγ target genes (e.g., SOX15) that significantly associated with worse disease-free survival (hazard ratio 2.23, 95% CI 1.58 to 2.88, p = 0.015). In summary, miR-96 targets a RARγ network to govern AR signaling, PCa progression and disease outcome.
Assuntos
Adenocarcinoma/patologia , Androgênios , MicroRNAs/fisiologia , Proteínas de Neoplasias/fisiologia , Neoplasias Hormônio-Dependentes/patologia , Neoplasias da Próstata/patologia , RNA Neoplásico/fisiologia , Receptores do Ácido Retinoico/fisiologia , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/mortalidade , Animais , Linhagem Celular Tumoral , Progressão da Doença , Elementos Facilitadores Genéticos , Proteínas Fetais/metabolismo , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Estimativa de Kaplan-Meier , Masculino , Camundongos , Proteínas Associadas aos Microtúbulos/metabolismo , Neoplasias Hormônio-Dependentes/genética , Neoplasias Hormônio-Dependentes/metabolismo , Neoplasias Hormônio-Dependentes/mortalidade , Proteínas Nucleares/metabolismo , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/mortalidade , Interferência de RNA , RNA Interferente Pequeno/genética , Receptores Androgênicos/metabolismo , Transdução de Sinais , Receptor gama de Ácido RetinoicoRESUMO
Prostate cancer (PCa) has a predominantly luminal phenotype. Basal cells were previously identified as a cell of origin for PCa, but increasing evidence implicates luminal cells as a preferred cell of origin for PCa, as well as key drivers of tumor development and progression. Prostate luminal cells are understudied compared with basal cells. In this review, we describe the contribution of prostate luminal progenitor (LP) cells to luminal cell development and their role in prostate development, androgen-mediated regeneration of castrated prostate, and tumorigenesis. We also discuss the potential value of LP transcriptomics to identify new targets and therapies to treat aggressive PCa. Finally, we propose future research directions focusing on molecular mechanisms underlying LP cell biology and heterogeneity in normal and diseased prostate.
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Carcinogênese , Próstata/citologia , Neoplasias da Próstata , Células-Tronco , Animais , Humanos , Masculino , Próstata/crescimento & desenvolvimentoRESUMO
Expression of androgen receptor (AR) in prostate cancer (PCa) is heterogeneous but the functional significance of AR heterogeneity remains unclear. Screening ~200 castration-resistant PCa (CRPC) cores and whole-mount sections (from 89 patients) reveals 3 AR expression patterns: nuclear (nuc-AR), mixed nuclear/cytoplasmic (nuc/cyto-AR), and low/no expression (AR-/lo). Xenograft modeling demonstrates that AR+ CRPC is enzalutamide-sensitive but AR-/lo CRPC is resistant. Genome editing-derived AR+ and AR-knockout LNCaP cell clones exhibit distinct biological and tumorigenic properties and contrasting responses to enzalutamide. RNA-Seq and biochemical analyses, coupled with experimental combinatorial therapy, identify BCL-2 as a critical therapeutic target and provide proof-of-concept therapeutic regimens for both AR+/hi and AR-/lo CRPC. Our study links AR expression heterogeneity to distinct castration/enzalutamide responses and has important implications in understanding the cellular basis of prostate tumor responses to AR-targeting therapies and in facilitating development of novel therapeutics to target AR-/lo PCa cells/clones.
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Feniltioidantoína/análogos & derivados , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , Receptores Androgênicos/genética , Animais , Antineoplásicos/farmacologia , Benzamidas , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos Endogâmicos NOD , Camundongos Knockout , Terapia de Alvo Molecular , Nitrilas , Feniltioidantoína/farmacologia , Neoplasias de Próstata Resistentes à Castração/patologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptores Androgênicos/metabolismo , Transdução de Sinais , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Reactivation of apoptotic pathways is an attractive strategy for patients with treatment-resistant B-cell lymphoma. The tumor suppressor, p53 is central for apoptotic response to multiple DNA damaging agents used to treat aggressive B-cell lymphomas, including etoposide. It has been demonstrated that etoposide induced DNA damage and therapeutic efficacy is enhanced by combination with inhibitors of the histone methyltransferase, enhancer of zeste homolog 2 (EZH2). Further, EZH2 was identified to regulate cell fate decisions in response to DNA damage. Using B-cell lymphoma cell lines resistant to etoposide induced cell death; we show that p53 is dramatically down regulated and MDMX, a negative regulator of p53, is significantly up regulated. However, these cell lines remain responsive to etoposide mediated DNA damage and exhibit cell cycle inhibition and induction of senescence. Furthermore, chemical inhibition of EZH2 directs DNA damage to a predominant p53 dependent apoptotic response associated with loss of MDMX and BCL-XL. These data provide confirmation of EZH2 in determining cell fate following DNA damage and propose a novel therapeutic strategy for patients with aggressive treatment-resistant B-cell lymphoma.
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Progression of aggressive prostate cancers (PCa) with androgen receptor splice variants or neuroendrocrine features is currently untreatable in the clinic. Therefore novel therapies are urgently required. We conducted RNA-seq using tumors from a unique murine transplant mouse model which spontaneously progresses to metastatic disease. Differential gene expression analysis revealed a significant increase of topoisomerase IIα, Top2a (Top2a) in metastatic tumors. Interrogation of human data revealed that increased Top2a expression in primary tumors selected patients with more aggressive disease. Further, significant positive correlation was observed between Top2a and the histone methyltransferase, Ezh2. Combination of the Top2 poison etoposide with the Ezh2 inhibitor GSK126 or DZNep significantly increased cell death in vitro in murine and human prostate cancer cell lines. Additionally, combination therapy extended time to progression and increased therapeutic efficacy in vivo. Overall, our studies demonstrate that patients screened for Top2a and Ezh2 expression would exhibit significant response to a combinational treatment involving low dose etoposide combined with Ezh2 inhibition. In addition, our data suggests that this combination therapeutic strategy is beneficial against aggressive PCa, and provides strong rationale for continued clinical development.
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Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Biomarcadores Tumorais/antagonistas & inibidores , Proteínas de Ligação a DNA/antagonistas & inibidores , Epigênese Genética , Neoplasias da Próstata/tratamento farmacológico , Animais , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , DNA Topoisomerases Tipo II/genética , DNA Topoisomerases Tipo II/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Intervalo Livre de Doença , Proteína Potenciadora do Homólogo 2 de Zeste , Etoposídeo/farmacologia , Regulação Neoplásica da Expressão Gênica , Humanos , Indóis/farmacologia , Masculino , Camundongos Endogâmicos C57BL , Proteínas de Ligação a Poli-ADP-Ribose , Complexo Repressor Polycomb 2/antagonistas & inibidores , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Medicina de Precisão , Valor Preditivo dos Testes , Neoplasias da Próstata/enzimologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Piridonas/farmacologia , RNA Mensageiro/metabolismo , Fatores de Tempo , Inibidores da Topoisomerase II/farmacologia , Regulação para Cima , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The active metabolite of vitamin D3, 1,25-dihydroxyvitamin D3 (calcitriol) has antiproliferative effects in non-aggressive prostate cancer, however, its effects in more aggressive model systems are still unclear. In these studies, effects of calcitriol and a less-calcemic vitamin D analog, QW-1624F2-2 (QW), were tested in vivo, using the aggressive autochthonous transgenic adenocarcinoma of mouse prostate (TRAMP) model. To study prevention of androgen-stimulated prostate cancer, vehicle, calcitriol (20 µg/kg), or QW (50 µg/kg) were administered to 4 week-old TRAMP mice intraperitoneal (i.p.) 3×/week on a MWF schedule for 14 weeks. Calcitriol and QW slowed progression of prostate cancer as indicated by reduced urogenital tract (pâ=â0.0022, calcitriol; pâ=â0.0009, QW) and prostate weights (pâ=â0.0178, calcitriol; pâ=â0.0086, QW). However, only calcitriol increased expression of the pro-differentiation marker, cadherin 1 (pâ=â0.0086), and reduced tumor proliferation (pâ=â0.0467). By contrast, neither vitamin D analog had any effect on castration resistant prostate cancer in mice treated pre- or post-castration. Interestingly, although vitamin D showed inhibitory activity against primary tumors in hormone-intact mice, distant organ metastases seemed to be enhanced following treatment (pâ=â0.0823). Therefore, TRAMP mice were treated long-term with calcitriol to further examine effects on metastasis. Calcitriol significantly increased the number of distant organ metastases when mice were treated from 4 weeks-of-age until development of palpable tumors (20-25 weeks-of-age)(pâ=â0.0003). Overall, data suggest that early intervention with vitamin D in TRAMP slowed androgen-stimulated tumor progression, but prolonged treatment resulted in development of a resistant and more aggressive disease associated with increased distant organ metastasis.
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Adenocarcinoma/secundário , Modelos Animais de Doenças , Neoplasias de Próstata Resistentes à Castração/secundário , Neoplasias da Próstata/patologia , Vitamina D/análogos & derivados , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/epidemiologia , Animais , Western Blotting , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Técnicas Imunoenzimáticas , Incidência , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/epidemiologia , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/epidemiologia , Células Tumorais Cultivadas , Vitamina D/farmacologiaRESUMO
Many efficacious cancer treatments cause significant cardiac morbidity, yet biomarkers or functional indices of early damage, which would allow monitoring and intervention, are lacking. In this study, we have utilized a rat model of progressive doxorubicin (DOX)-induced cardiomyopathy, applying multiple approaches, including cardiac magnetic resonance imaging (MRI), to provide the most comprehensive characterization to date of the timecourse of serological, pathological, and functional events underlying this toxicity. Hannover Wistar rats were dosed with 1.25 mg/kg DOX weekly for 8 weeks followed by a 4 week off-dosing "recovery" period. Electron microscopy of the myocardium revealed subcellular degeneration and marked mitochondrial changes after a single dose. Histopathological analysis revealed progressive cardiomyocyte degeneration, hypertrophy/cytomegaly, and extensive vacuolation after two doses. Extensive replacement fibrosis (quantified by Sirius red staining) developed during the off-dosing period. Functional indices assessed by cardiac MRI (including left ventricular ejection fraction (LVEF), cardiac output, and E/A ratio) declined progressively, reaching statistical significance after two doses and culminating in "clinical" LV dysfunction by 12 weeks. Significant increases in peak myocardial contrast enhancement and serological cardiac troponin I (cTnI) emerged after eight doses, importantly preceding the LVEF decline to <50%. Troponin I levels positively correlated with delayed and peak gadolinium contrast enhancement, histopathological grading, and diastolic dysfunction. In summary, subcellular cardiomyocyte degeneration was the earliest marker, followed by progressive functional decline and histopathological manifestations. Myocardial contrast enhancement and elevations in cTnI occurred later. However, all indices predated "clinical" LV dysfunction and thus warrant further evaluation as predictive biomarkers.