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1.
Nat Commun ; 14(1): 283, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36650186

RESUMO

Long-read sequencing has demonstrated great potential for characterizing all types of structural variations (SVs). However, existing algorithms have insufficient sensitivity and precision. To address these limitations, we present DeBreak, a computational method for comprehensive and accurate SV discovery. Based on alignment results, DeBreak employs a density-based approach for clustering SV candidates together with a local de novo assembly approach for reconstructing long insertions. A partial order alignment algorithm ensures precise SV breakpoints with single base-pair resolution, and a k-means clustering method can report multi-allele SV events. DeBreak outperforms existing tools on both simulated and real long-read sequencing data from both PacBio and Nanopore platforms. An important application of DeBreak is analyzing cancer genomes for potentially tumor-driving SVs. DeBreak can also be used for supplementing whole-genome assembly-based SV discovery.


Assuntos
Algoritmos , Genoma Humano , Humanos , Análise de Sequência de DNA/métodos , Genoma Humano/genética , Sequenciamento de Nucleotídeos em Larga Escala
2.
Mol Cancer Res ; 20(6): 883-894, 2022 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-35247910

RESUMO

Recent work has established that SWI-independent-3 (SIN3) chromatin modification complexes play key roles in cancer progression. We previously demonstrated that knockdown of SIN3A expression promotes human breast cancer cell invasion and metastasis; however, the levels of SIN3A in patient breast carcinoma are not known. We therefore examined SIN3A mRNA and protein in patient tissues and determined that SIN3A expression is lower in breast carcinoma relative to normal breast. Given the 3'-untranslated region (UTR) of SIN3A has several conserved binding sites for oncogenic miRNA, we hypothesized that SIN3A is targeted by miRNA and found that ectopic miR-183 results in decreased SIN3A in breast carcinoma cell lines. Functionally, we demonstrate that miR-183 promotes breast cancer cell migration and invasion in a SIN3A-dependent manner and ectopic miR-183 promotes metastasis in vivo. Patients with breast cancer with high levels of miR-183 and low levels of SIN3A have the shortest overall survival. Given the critical link between metastasis and survival in patients with breast cancer, it is of utmost importance to identify clinically relevant genes involved in metastasis. Here, we report for the first time the aberrant expression of the putative metastasis suppressing gene SIN3A in human breast cancers and propose a mechanism of SIN3A suppression by miR-183. IMPLICATIONS: SIN3A expression is decreased in metastatic breast cancer in part due to miR-183.


Assuntos
Neoplasias da Mama , MicroRNAs , Regiões 3' não Traduzidas , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Invasividade Neoplásica/genética , Metástase Neoplásica
3.
PLoS One ; 16(11): e0259128, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34788285

RESUMO

Breast Cancer Metastasis Suppressor 1 (BRMS1) expression is associated with longer patient survival in multiple cancer types. Understanding BRMS1 functionality will provide insights into both mechanism of action and will enhance potential therapeutic development. In this study, we confirmed that the C-terminus of BRMS1 is critical for metastasis suppression and hypothesized that critical protein interactions in this region would explain its function. Phosphorylation status at S237 regulates BRMS1 protein interactions related to a variety of biological processes, phenotypes [cell cycle (e.g., CDKN2A), DNA repair (e.g., BRCA1)], and metastasis [(e.g., TCF2 and POLE2)]. Presence of S237 also directly decreased MDA-MB-231 breast carcinoma migration in vitro and metastases in vivo. The results add significantly to our understanding of how BRMS1 interactions with Sin3/HDAC complexes regulate metastasis and expand insights into BRMS1's molecular role, as they demonstrate BRMS1 C-terminus involvement in distinct protein-protein interactions.


Assuntos
Neoplasias da Mama , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas de Neoplasias , Proteínas Repressoras , Complexo Correpressor Histona Desacetilase e Sin3
4.
Transl Oncol ; 14(8): 101128, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34049151

RESUMO

Lung cancer is the leading cause of cancer-related deaths globally and is histologically defined as either small cell lung cancer (SCLC) or non-small cell lung cancer (NSCLC), with the latter accounting for 80% of all lung cancers. The 5-year overall survival rate for lung cancer patients is low as it is often discovered at advanced stages when potential cure by surgical resection is no longer an option. To identify a biomarker and target for lung cancer, we performed analysis of multiple datasets of lung cancer gene expression data. Our analyses indicated that the collagen-modifying enzyme Prolyl 4-Hydroxylase Subunit Alpha 1 (P4HA1) is overexpressed in NSCLC. Furthermore, our investigation found that overexpression of enzymes involved in this pathway predicts poor outcome for patients with lung adenocarcinoma. Our functional studies using knockdown strategies in lung cancer cell lines in vitro indicated that P4HA1 is critical for lung cancer growth, migration, and invasion. Additionally, diethyl pythiDC (PythiDC), a small molecule inhibitor, decreased the malignant phenotypes of lung cancer cells. Moreover, we found that miR-124 regulates and targets P4HA1 in lung cancer cells. Thus, our study suggests that collagen-modifying enzymes play an important role in lung cancer aggressiveness. Furthermore, our studies showed that P4HA1 is required for lung cancer cell growth and invasion, suggesting its potential as a valid therapeutic target in lung adenocarcinoma.

5.
Cancer Res ; 81(8): 1942-1953, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33558335

RESUMO

miRNA rarely possess pan-oncogenic or tumor-suppressive properties. Most miRNAs function under tissue-specific contexts, acting as either tumor suppressors in one tissue, promoting oncogenesis in another, or having no apparent role in the regulation of processes associated with the hallmarks of cancer. What has been less clear is the role of miRNAs within cell types of the same tissue and the ability within each cell type to contribute to oncogenesis. In this study, we characterize the role of one such tissue-specific miRNA, miR-31, recently identified as the most oncogenic miRNA in lung adenocarcinoma, across the histologic spectrum of human lung cancer. Compared with normal lung tissue, miR-31 was overexpressed in patient lung adenocarcinoma, squamous cell carcinoma, and large-cell neuroendocrine carcinoma, but not small-cell carcinoma or carcinoids. miR-31 promoted tumor growth in mice of xenografted human adenocarcinoma and squamous cell carcinoma cell lines, but not in large- or small-cell carcinoma lines. While miR-31 did not promote primary tumor growth of large- and small-cell carcinoma, it did promote spontaneous metastasis. Mechanistically, miR-31 altered distinct cellular signaling programs within each histologic subtype, resulting in distinct phenotypic differences. This is the first report distinguishing diverse functional roles for this miRNA across the spectrum of lung cancers and suggests that miR-31 has broad clinical value in human lung malignancy. SIGNIFICANCE: These findings demonstrate the oncogenic properties of miR-31 in specific subtypes of lung cancer and highlight it as a potential therapeutic target in these subtypes. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/8/1942/F1.large.jpg.


Assuntos
Adenocarcinoma de Pulmão/metabolismo , Carcinoma Neuroendócrino/metabolismo , Carcinoma de Células Escamosas/metabolismo , Neoplasias Pulmonares/metabolismo , MicroRNAs/metabolismo , Carcinoma de Pequenas Células do Pulmão/metabolismo , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Animais , Carcinoma Adenoescamoso/genética , Carcinoma Adenoescamoso/metabolismo , Carcinoma Adenoescamoso/patologia , Carcinoma de Células Grandes/genética , Carcinoma de Células Grandes/metabolismo , Carcinoma de Células Grandes/secundário , Carcinoma Neuroendócrino/genética , Carcinoma Neuroendócrino/patologia , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Bases de Dados Genéticas , Feminino , Humanos , Neoplasias Hepáticas/secundário , Pulmão/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Masculino , Camundongos , Camundongos Nus , Metástase Neoplásica/genética , Transplante de Neoplasias , Especificidade de Órgãos , Transdução de Sinais/genética , Carcinoma de Pequenas Células do Pulmão/genética , Carcinoma de Pequenas Células do Pulmão/patologia , Carcinoma de Pequenas Células do Pulmão/secundário , Proteínas Supressoras de Tumor/metabolismo
6.
J Vis Exp ; (162)2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32831298

RESUMO

The ability to evaluate lung histology is critical for the fields of lung cancer research and cancer metastasis. It is equally important to perform necropsies rapidly and efficiently from studies without sacrificing the quality of the tissues procured. The goal of this protocol is to present a method to rapidly perfuse, inflate, and fix mouse lungs for downstream histological analysis. This method does not standardize lung inflation; thus, it does not require any special procedures or equipment and instead simply instills fixative directly through the trachea following perfusion through the heart. This allows for sufficient estimation of tumor size, histology, and scoring. This also allows for the collection of frozen tissue prior to lung tissue fixation. This method is limited in that it does not allow for later morphometric quantification of the lung; however, it is more than sufficient for lung tumor analysis from genetically engineered mouse models (GEMMs), syngeneic models, as well as xenograft tumor and metastasis studies.


Assuntos
Neoplasias Pulmonares/patologia , Pulmão/patologia , Perfusão , Animais , Humanos , Camundongos , Coloração e Rotulagem , Fixação de Tecidos , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Mol Cancer Res ; 17(1): 289-298, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30257988

RESUMO

Metastatic lung cancer is common in patients with lung adenocarcinoma, but the molecular mechanisms of metastasis remain incompletely resolved. miRNA regulate gene expression and contribute to cancer development and progression. This report identifies miR-576-3p and its mechanism of action in lung cancer progression. miR-576-3p was determined to be significantly decreased in clinical specimens of late-stage lung adenocarcinoma. Overexpression of miR-576-3p in lung adenocarcinoma cells decreased mesenchymal marker expression and inhibited migration and invasion. Inhibition of miR-576-3p in nonmalignant lung epithelial cells increased migration and invasion as well as mesenchymal markers. Serum/glucocorticoid-regulated kinase 1 (SGK1) was a direct target of miR-576-3p, and modulation of miR-576-3p levels led to alterations in SGK1 protein and mRNA as well as changes in activation of its downstream target linked to metastasis, N-myc downstream regulated 1 (NDRG1). Loss of the ability of miR-576-3p to bind the 3'-UTR of SGK1 rescued the inhibition in migration and invasion observed with miR-576-3p overexpression. In addition, increased SGK1 levels were detected in lung adenocarcinoma patient samples expressing mesenchymal markers, and pharmacologic inhibition of SGK1 resulted in a similar inhibition of migration and invasion of lung adenocarcinoma cells as observed with miR-576-3p overexpression. Together, these results reveal miR-576-3p downregulation is selected for in late-stage lung adenocarcinoma due to its ability to inhibit migration and invasion by targeting SGK1. Furthermore, these results also support targeting SGK1 as a potential therapeutic for lung adenocarcinoma. IMPLICATIONS: This study reveals SGK1 inhibition with miR-576-3p or pharmacologically inhibits migration and invasion of lung adenocarcinoma, providing mechanistic insights into late-stage lung adenocarcinoma and a potential new treatment avenue.


Assuntos
Adenocarcinoma de Pulmão/genética , Proteínas Imediatamente Precoces/antagonistas & inibidores , Neoplasias Pulmonares/genética , MicroRNAs/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/patologia , Movimento Celular/fisiologia , Humanos , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , MicroRNAs/genética , Invasividade Neoplásica , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transfecção
8.
Cancer Res ; 78(9): 2149-2158, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29632135

RESUMO

At the time of its construction in the 1950s, the central dogma of molecular biology was a useful model that represented the current state of knowledge for the flow of genetic information after a period of prolific scientific discovery. Unknowingly, it also biased many of our assumptions going forward. Whether intentional or not, genomic elements not fitting into this paradigm were deemed unimportant and emphasis on the study of protein-coding genes prevailed for decades. The phrase "Junk DNA," first popularized in the 1960s, is still used with alarming frequency to describe the entirety of noncoding DNA. It has since become apparent that RNA molecules not coding for protein are vitally important in both normal development and human malignancy. Cancer researchers have been pioneers in determining noncoding RNA function and developing new technologies to study these molecules. In this review, we will discuss well known and newly emerging species of noncoding RNAs, their functions in cancer, and new technologies being utilized to understand their mechanisms of action in cancer. Cancer Res; 78(9); 2149-58. ©2018 AACR.


Assuntos
MicroRNAs/genética , Neoplasias/genética , RNA Longo não Codificante/genética , Humanos , Neoplasias/patologia
9.
Hum Pathol ; 50: 118-26, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26997445

RESUMO

The 30% of patients whose indolent follicular lymphoma transforms to aggressive diffuse large B-cell lymphoma (DLBCL) have poor survival. Reliable predictors of follicular B-cell lymphoma transformation to DLBCL are lacking, and diagnosis of those that will progress is challenging. MicroRNA, which regulates gene expression, has critical functions in the growth and progression of many cancers and contributes to the pathogenesis of lymphoma. Using 5 paired samples from patients who presented with follicular lymphoma and progressed to DLBCL, we identified specific microRNA differentially expressed between the two. Specifically, miR-17-5p levels were low in follicular lymphoma and increased as the disease transformed. In contrast, miR-31 expression was high in follicular lymphoma and decreased as the lymphoma progressed. These results were confirmed in additional unpaired cases of low-grade follicular lymphoma (n = 13) and high-grade follicular lymphoma grade 3 or DLBCL (n = 17). Loss of miR-31 expression in DLBCL was not due to deletion of the locus. Changes in miR-17-5p and miR-31 were not correlated with immunophenotype, genetics, or status of the MYC oncogene. However, increased miR-17-5p expression did significantly correlate with increased expression of p53 protein, which is indicative of mutant TP53. Two pro-proliferative genes, E2F2 and PI3KC2A, were identified as direct messenger RNA targets of miR-31, suggesting that these may contribute to follicular lymphoma transformation. Our results indicate that changes in miR-31 and miR-17-5p reflect the transformation of follicular lymphoma to an aggressive large B-cell lymphoma and may, along with their targets, be viable markers for this process.


Assuntos
Biomarcadores Tumorais/genética , Transformação Celular Neoplásica/genética , Linfoma Folicular/genética , Linfoma Difuso de Grandes Células B/genética , MicroRNAs/genética , Regiões 3' não Traduzidas , Adulto , Idoso , Idoso de 80 Anos ou mais , Sítios de Ligação , Biomarcadores Tumorais/metabolismo , Linhagem Celular , Proliferação de Células , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Criança , Classe I de Fosfatidilinositol 3-Quinases , Progressão da Doença , Fator de Transcrição E2F2/genética , Fator de Transcrição E2F2/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Humanos , Linfoma Folicular/metabolismo , Linfoma Folicular/patologia , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/patologia , Masculino , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Gradação de Tumores , Fenótipo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Transfecção
10.
J Clin Invest ; 126(1): 349-64, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26657862

RESUMO

MicroRNA (miR) are important regulators of gene expression, and aberrant miR expression has been linked to oncogenesis; however, little is understood about their contribution to lung tumorigenesis. Here, we determined that miR-31 is overexpressed in human lung adenocarcinoma and this overexpression independently correlates with decreased patient survival. We developed a transgenic mouse model that allows for lung-specific expression of miR-31 to test the oncogenic potential of miR-31 in the lung. Using this model, we observed that miR-31 induction results in lung hyperplasia, followed by adenoma formation and later adenocarcinoma development. Moreover, induced expression of miR-31 in mice cooperated with mutant KRAS to accelerate lung tumorigenesis. We determined that miR-31 regulates lung epithelial cell growth and identified 6 negative regulators of RAS/MAPK signaling as direct targets of miR-31. Our study distinguishes miR-31 as a driver of lung tumorigenesis that promotes mutant KRAS-mediated oncogenesis and reveals that miR-31 directly targets and reduces expression of negative regulators of RAS/MAPK signaling.


Assuntos
Adenocarcinoma/etiologia , Neoplasias Pulmonares/etiologia , MicroRNAs/fisiologia , Mutação , Proteínas Proto-Oncogênicas p21(ras)/genética , Adenocarcinoma/genética , Adenocarcinoma/mortalidade , Adenocarcinoma de Pulmão , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidade , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos , Células NIH 3T3 , Proteínas ras/fisiologia
11.
RNA ; 20(9): 1356-68, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25024357

RESUMO

While previous studies reported aberrant expression of microRNAs (miRNAs) in non-small cell lung cancer (NSCLC), little is known about which miRNAs play central roles in NSCLC's pathogenesis and its regulatory mechanisms. To address this issue, we presented a robust computational framework that integrated matched miRNA and mRNA expression profiles in NSCLC using feed-forward loops. The network consists of miRNAs, transcription factors (TFs), and their common predicted target genes. To discern the biological meaning of their associations, we introduced the direction of regulation. A network edge validation strategy using three independent NSCLC expression profiling data sets pinpointed reproducible biological regulations. Reproducible regulation, which may reflect the true molecular interaction, has not been applied to miRNA-TF co-regulatory network analyses in cancer or other diseases yet. We revealed eight hub miRNAs that connected to a higher proportion of targets validated by independent data sets. Network analyses showed that these miRNAs might have strong oncogenic characteristics. Furthermore, we identified a novel miRNA-TF co-regulatory module that potentially suppresses the tumor suppressor activity of the TGF-ß pathway by targeting a core pathway molecule (TGFBR2). Follow-up experiments showed two miRNAs (miR-9-5p and miR-130b-3p) in this module had increased expression while their target gene TGFBR2 had decreased expression in a cohort of human NSCLC. Moreover, we demonstrated these two miRNAs directly bind to the 3' untranslated region of TGFBR2. This study enhanced our understanding of miRNA-TF co-regulatory mechanisms in NSCLC. The combined bioinformatics and validation approach we described can be applied to study other types of diseases.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Redes Reguladoras de Genes , Neoplasias Pulmonares/genética , MicroRNAs/genética , Oncogenes , Biologia Computacional/métodos , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Genes Neoplásicos , Humanos , Oncogenes/genética , Reprodutibilidade dos Testes , Integração de Sistemas , Fatores de Transcrição/genética
12.
PLoS One ; 9(7): e101802, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25028925

RESUMO

Relapse of adenocarcinoma, the most common non-small cell lung cancer (NSCLC), is a major clinical challenge to improving survival. To gain insight into the early molecular events that contribute to lung adenocarcinoma relapse, and taking into consideration potential cell type specificity, we used stringent criteria for sample selection. We measured miRNA expression only from flash frozen stage I lung adenocarcinomas, excluding other NSCLC subtypes. We compared miRNA expression in lung adenocarcinomas that relapsed within two years to those that did not relapse within three years after surgical resection prior to adjuvant therapy. The most significant differences in mRNA expression for recurrent tumors compared to non-recurrent tumors were decreases in miR-106b*, -187, -205, -449b, -774* and increases in miR-151-3p, let-7b, miR-215, -520b, and -512-3p. A unique comparison between adjacent normal lung tissue from relapse and non-relapse groups revealed dramatically different miRNA expression, suggesting dysregulation of miRNA in the environment around the tumor. To assess patient-to-patient variability, miRNA levels in the tumors were normalized to levels in matched adjacent normal lung tissue. This analysis revealed a different set of significantly altered miRNA in tumors that recurred compared to tumors that did not. Together our analyses elucidated miRNA not previously linked to lung adenocarcinoma that likely have important roles in its development and progression. Our results also highlight the differences in miRNA expression in normal lung tissue in adenocarcinomas that do and do not recur. Most notably, our data identified those miRNA that distinguish early stage tumors likely to relapse prior to treatment and miRNA that could be further studied for use as biomarkers for prognosis, patient monitoring, and/or treatment decisions.


Assuntos
Adenocarcinoma/genética , Adenocarcinoma/patologia , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , MicroRNAs/genética , Adenocarcinoma/diagnóstico , Adenocarcinoma/terapia , Adenocarcinoma de Pulmão , Idoso , Idoso de 80 Anos ou mais , Carcinogênese , Estudos de Coortes , Feminino , Predisposição Genética para Doença , Humanos , Pulmão/citologia , Pulmão/metabolismo , Pulmão/patologia , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/terapia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Recidiva
13.
PLoS One ; 8(2): e55966, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23390556

RESUMO

Breast cancer metastasis suppressor 1 (BRMS1) is a predominantly nuclear protein that suppresses metastasis in multiple human and murine carcinoma cell lines. BRMS1 interacts with several nuclear proteins including SIN3:HDAC chromatin remodeling complexes that are involved in repressing transcription. However, recent reports suggest BRMS1 may function in the cytoplasm. BRMS1 has two predicted nuclear localization sequences (NLS) that are located near the C-terminus (amino acids 198-205 and 238-244, NLS1 and NLS2 respectively). We hypothesized that nuclear localization sequences of BRMS1 were essential for BRMS1 mediated metastasis suppression. Replacement of NLS2 with NLS1 (BRMS1(NLS1,1)), truncation at 238 (BRMS1(ΔNLS2)), or switching the location of NLS1 and NLS2 (BRMS1(NLS2,1)) did not affect nuclear localization; but, replacement of NLS1 with NLS2 (BRMS1(NLS2,2)) or truncation at 197 (BRMS1(ΔNLS) which removes both NLS) promoted cytoplasmic localization. MDA-MB-231 human metastatic breast cancer cells transduced with BRMS1(NLS1,1), BRMS1(NLS2,2) or BRMS1(NLS2,1) were evaluated for metastasis suppression in an experimental xenograft mouse model. Interestingly, while NLS2 was not necessary for nuclear localization, it was found to be important for metastasis suppression since BRMS1(NLS2,2) suppressed metastasis by 85%. In contrast, BRMS1(NLS2,1) and BRMS1(NLS1,1) did not significantly suppress metastasis. Both BRMS1 and BRMS1(NLS2,2) co-immunoprecipitated with SIN3A in the nucleus and cytoplasm; however, BRMS1(NLS1,1) and BRMS1(NLS2,1) were associated with SIN3A in the nucleus only. Moreover, BRMS1 and BRMS1(NLS2,2), but not BRMS1(NLS1,1) and BRMS1(NLS2,1), down-regulated the pro-metastatic microRNA, miR-10b. Together, these data demonstrate an important role for NLS2 in the cytoplasm that is critical for metastasis suppression and is distinct from nuclear localization.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Regulação Neoplásica da Expressão Gênica , Metástase Neoplásica , Proteínas de Neoplasias/genética , Sinais de Localização Nuclear/genética , Animais , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Núcleo Celular/genética , Núcleo Celular/metabolismo , Citoplasma/genética , Citoplasma/metabolismo , Feminino , Humanos , Camundongos , Camundongos Nus , MicroRNAs/genética , MicroRNAs/metabolismo , Mutação , Proteínas de Neoplasias/química , Sinais de Localização Nuclear/química , Proteínas Nucleares/química , Proteínas Nucleares/genética , Ligação Proteica , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Complexo Correpressor Histona Desacetilase e Sin3 , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Clin Exp Metastasis ; 29(4): 315-25, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22241150

RESUMO

Morbidity and mortality of breast cancer patients are drastically increased when primary tumor cells are able to spread to distant sites and proliferate to become secondary lesions. Effective treatment of metastatic disease has been limited; therefore, an increased molecular understanding to identify biomarkers and therapeutic targets is needed. Breast cancer metastasis suppressor 1 (BRMS1) suppresses development of pulmonary metastases when expressed in a variety of cancer types, including metastatic mammary carcinoma. Little is known of Brms1 function throughout the initiation and progression of mammary carcinoma. The goal of this study was to investigate mechanisms of Brms1-mediated metastasis suppression in transgenic mice that express Brms1 using polyoma middle T oncogene-induced models. Brms1 expression did not significantly alter growth of the primary tumors. When expressed ubiquitously using a ß-actin promoter, Brms1 suppressed pulmonary metastasis and promoted apoptosis of tumor cells located in the lungs but not in the mammary glands. Surprisingly, selective expression of Brms1 in the mammary gland using the MMTV promoter did not significantly block metastasis nor did it promote apoptosis in the mammary glands or lung, despite MMTV-induced expression within the lungs. These results strongly suggest that cell type-specific over-expression of Brms1 is important for Brms1-mediated metastasis suppression.


Assuntos
Apoptose/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Mamárias Animais/genética , Neoplasias Mamárias Animais/patologia , Metástase Neoplásica/genética , Proteínas Repressoras/genética , Animais , Feminino , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Metástase Neoplásica/patologia , Regiões Promotoras Genéticas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
15.
FEBS Lett ; 586(1): 27-31, 2012 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-22119728

RESUMO

Gap junctional intercellular communication (GJIC) regulates cellular homeostasis by propagating signaling molecules, exchanging cellular metabolites, and coupling electrical signals. In cancer, cells exhibit altered rates of GJIC which may play a role in neoplastic progression. K(ATP) channels help maintain membrane polarity and linkages between K(ATP) channel activity and rates of GJIC have been established. The mechanistic relationship has not been fully elucidated. We report the effects of treatment with multiple K(ATP) antagonist compounds on GJIC in metastatic cell lines demonstrating an increase in communication rates following treatment with compounds possessing specificities towards the SUR2 subunit of K(ATP). These effects remained consistent using cell lines with different expression levels of SUR1 and SUR2, suggesting possible off target effects on GJIC by these compounds.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Canais KATP/antagonistas & inibidores , Complexo Mediador/metabolismo , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Potássio Corretores do Fluxo de Internalização/metabolismo , Receptores de Droga/metabolismo , Comunicação Celular/efeitos dos fármacos , Linhagem Celular Tumoral/patologia , Junções Comunicantes/metabolismo , Humanos , Metástase Neoplásica , Receptores de Sulfonilureias
16.
Cancer Res ; 69(19): 7495-8, 2009 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-19773429

RESUMO

Despite advancements in knowledge from more than a century of metastasis research, the genetic programs and molecular mechanisms required for cancer metastasis are still incompletely understood. Genes that specifically regulate the process of metastasis are useful tools to elucidate molecular mechanisms and may become markers and/or targets for antimetastatic therapy. Recently, several noncoding regulatory RNA genes, microRNA (miRNA), were identified, which play roles in various steps of metastasis, some without obvious roles in tumorigenesis. Understanding how these metastasis-associated miRNA, which we term metastamir, are involved in metastasis will help identify possible biomarkers or targets for the most lethal attribute of cancer: metastasis.


Assuntos
MicroRNAs/biossíntese , Metástase Neoplásica/genética , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Humanos , MicroRNAs/genética
18.
Tumour Biol ; 30(3): 148-59, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19609101

RESUMO

BACKGROUND/AIMS: To determine breast cancer metastasis suppressor 1 (BRMS1) expression in breast cancers and the efficacy of BRMS1 as a prognostic indicator, BRMS1 expression was assessed in two sets of breast cancer tissues. METHODS: Epithelial cells from 36 frozen samples of breast cancers and corresponding normal breast were collected by laser capture microdissection and assessed for BRMS1 by quantitative RT-PCR and immunohistochemistry. BRMS1 was also evaluated by immunohistochemistry in a tissue microarray of 209 breast cancers and correlated with indicators of prognosis [estrogen receptor (ER), progesterone receptor (PR), ErbB2, p53, p27(Kip1), Bcl2 and Ki-67]. RESULTS: BRMS1 mRNA and protein were higher in 94 and 81%, respectively, of breast cancers than in corresponding normal epithelium. BRMS1 localization was predominantly nuclear, but 60-70% of cancers also exhibited cytoplasmic immunostaining. Breast cancers with lower nuclear than cytoplasmic BRMS1 (nuclear score - cytoplasmic score < or =0; 11% of cancers) had lower ER, lower PR and higher Ki-67 expression. There was also a trend toward poorer overall survival in this group of cancers, but this was only of borderline significance (p = 0.073). In Cox proportional hazards models, loss of nuclear BRMS1 was not a significant predictor of overall survival. CONCLUSIONS: Loss of nuclear BRMS1 was associated with ER-negative cancers and a high rate of proliferation, but was not an independent indicator of prognosis.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/metabolismo , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Proteínas de Neoplasias/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proliferação de Células , Feminino , Expressão Gênica , Humanos , Imuno-Histoquímica , Lasers , Microdissecção , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Estadiamento de Neoplasias , Prognóstico , Receptores de Estrogênio/biossíntese , Receptores de Estrogênio/genética , Proteínas Repressoras , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise Serial de Tecidos
19.
Int J Cancer ; 125(8): 1778-85, 2009 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-19585508

RESUMO

Breast cancer metastasis suppressor 1 (BRMS1) suppresses metastasis of multiple tumor types without blocking tumorigenesis. BRMS1 forms complexes with SIN3, histone deacetylases and selected transcription factors that modify metastasis-associated gene expression (e.g., EGFR, OPN, PI4P5K1A, PLAU). microRNA (miRNA) are a recently discovered class of regulatory, noncoding RNA, some of which are involved in neoplastic progression. Based on these data, we hypothesized that BRMS1 may also exert some of its antimetastatic effects by regulating miRNA expression. MicroRNA arrays were done comparing small RNAs that were purified from metastatic MDA-MB-231 and MDA-MB-435 and their nonmetastatic BRMS1-transfected counterparts. miRNA expression changed by BRMS1 were validated using SYBR Green RT-PCR. BRMS1 decreased metastasis-promoting (miR-10b, -373 and -520c) miRNA, with corresponding reduction of their downstream targets (e.g., RhoC which is downstream of miR-10b). Concurrently, BRMS1 increased expression of metastasis suppressing miRNA (miR-146a, -146b and -335). Collectively, these data show that BRMS1 coordinately regulates expression of multiple metastasis-associated miRNA and suggests that recruitment of BRMS1-containing SIN3:HDAC complexes to, as yet undefined, miRNA promoters might be involved in the regulation of cancer metastasis.


Assuntos
Neoplasias da Mama/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Proteínas de Neoplasias/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Perfilação da Expressão Gênica , Humanos , MicroRNAs/metabolismo , Proteínas de Neoplasias/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Repressoras , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas
20.
Cancer Res ; 69(4): 1279-83, 2009 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-19190326

RESUMO

Breast cancer metastasis suppressor 1 (BRMS1) is a predominantly nuclear protein that differentially regulates expression of multiple genes, leading to suppression of metastasis without blocking orthotopic tumor growth in multiple human and murine cancer cells of diverse origins. We hypothesized that miR-146 may be involved in the ability of BRMS1 to supress metastasis because miR-146 expression is altered by BRMS1 and because BRMS1 and miR-146 are both associated with decreased signaling through the nuclear factor-kappaB pathway. BRMS1 significantly up-regulates miR-146a by 6- to 60-fold in metastatic MDA-MB-231 and MDA-MB-435 cells, respectively, and miR-146b by 40-fold in MDA-MB-435 as measured by real-time quantitative reverse transcription-PCR. Transduction of miR-146a or miR-146b into MDA-MB-231 down-regulated expression of epidermal growth factor receptor, inhibited invasion and migration in vitro, and suppressed experimental lung metastasis by 69% and 84%, respectively (mean +/- SE: empty vector = 39 +/- 6, miR-146a = 12 +/- 1, miR-146b = 6 +/- 1). These results further support the recent notion that modulating the levels of miR-146a or miR-146b could have a therapeutic potential to suppress breast cancer metastasis.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Metástase Neoplásica/prevenção & controle , Proteínas de Neoplasias/fisiologia , RNA Neoplásico/genética , Divisão Celular , Linhagem Celular Tumoral , Feminino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/secundário , NF-kappa B/fisiologia , Proteínas Repressoras , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Regulação para Cima
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