RESUMO
Multiple pterygium syndrome (MPS) disorders are a phenotypically and genetically heterogeneous group of conditions characterized by multiple joint contractures (arthrogryposis), pterygia (joint webbing) and other developmental defects. MPS is most frequently inherited in an autosomal recessive fashion but X-linked and autosomal dominant forms also occur. Advances in genomic technologies have identified many genetic causes of MPS-related disorders and genetic diagnosis requires large targeted next generation sequencing gene panels or genome-wide sequencing approaches. Using the Illumina TruSightOne clinical exome assay, we identified a recurrent heterozygous missense substitution in TPM2 (encoding beta tropomyosin) in three unrelated individuals. This was confirmed to have arisen as a de novo event in the two patients with parental samples. TPM2 mutations have previously been described in association with a variety of dominantly inherited neuromuscular phenotypes including nemaline myopathy, congenital fibre-type disproportion, distal arthrogryposis and trismus pseudocamptodactyly, and in a patient with autosomal recessive Escobar syndrome and a nemaline myopathy. The three cases reported here had overlapping but variable features. Our findings expand the range of TMP2-related phenotypes and indicate that de novo TMP2 mutations should be considered in isolated cases of MPS-related conditions.
Assuntos
Anormalidades Múltiplas/genética , Artrogripose/genética , Heterogeneidade Genética , Hipertermia Maligna/genética , Anormalidades da Pele/genética , Tropomiosina/genética , Anormalidades Múltiplas/patologia , Adolescente , Artrogripose/patologia , Criança , Pré-Escolar , Bases de Dados Genéticas , Exoma/genética , Feminino , Predisposição Genética para Doença , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lactente , Masculino , Hipertermia Maligna/patologia , Mutação , Fenótipo , Anormalidades da Pele/patologiaRESUMO
Lipid rafts are dynamic membrane microdomains that orchestrate molecular interactions and are implicated in cancer development. To understand the functions of lipid rafts in cancer, we performed an integrated analysis of quantitative lipid raft proteomics data sets modeling progression in breast cancer, melanoma, and renal cell carcinoma. This analysis revealed that cancer development is associated with increased membrane raft-cytoskeleton interactions, with â¼40% of elevated lipid raft proteins being cytoskeletal components. Previous studies suggest a potential functional role for the raft-cytoskeleton in the action of the putative tumor suppressors PTRF/Cavin-1 and Merlin. To extend the observation, we examined lipid raft proteome modulation by an unrelated tumor suppressor opioid binding protein cell-adhesion molecule (OPCML) in ovarian cancer SKOV3 cells. In agreement with the other model systems, quantitative proteomics revealed that 39% of OPCML-depleted lipid raft proteins are cytoskeletal components, with microfilaments and intermediate filaments specifically down-regulated. Furthermore, protein-protein interaction network and simulation analysis showed significantly higher interactions among cancer raft proteins compared with general human raft proteins. Collectively, these results suggest increased cytoskeleton-mediated stabilization of lipid raft domains with greater molecular interactions as a common, functional, and reversible feature of cancer cells.
Assuntos
Citoesqueleto/metabolismo , Microdomínios da Membrana/química , Neoplasias/ultraestrutura , Proteoma/análise , Proteômica/métodos , Moléculas de Adesão Celular , Linhagem Celular Tumoral , Membrana Celular , Simulação por Computador , Citoesqueleto/química , Progressão da Doença , Feminino , Proteínas Ligadas por GPI , Humanos , Microdomínios da Membrana/metabolismo , Neoplasias/patologia , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/ultraestrutura , Domínios e Motivos de Interação entre ProteínasRESUMO
The Sprouty proteins are increasingly being recognized to be deregulated in various types of cancers. This deregulation is often associated with aberrant signaling of receptor tyrosine kinases and its downstream effectors, leading to the mitogen-activated protein kinase (MAPK) signaling pathway. In human hepatocellular carcinoma, where the MAPK activity is enhanced via multiple hepatocarcinogenic factors, we observed a consistent reduced expression of the sprouty 2 (Spry2) transcript and protein in malignant hepatocytes compared with normal or cirrhotic hepatocytes. The expression pattern of Spry2 in hepatocellular carcinoma resembles that of several potential tumor markers of hepatocellular carcinoma and also that of several angiogenic factors and growth factor receptors. In contrast to previous studies of Spry2 down-regulation in other cancers, we have ruled out loss of heterozygosity or the methylation of promoter sites, two common mechanisms responsible for the silencing of genes with tumor suppressor properties. Functionally, we show that Spry2 inhibits both extracellular signal-regulated kinase signaling as well as proliferation in hepatocellular carcinoma cell lines, whereas knocking down Spry2 levels in NIH3T3 cells causes mild transformation. Our study clearly indicates a role for Spry2 in hepatocellular carcinoma, and an understanding of the regulatory controls of its expression could provide new means of regulating the angiogenic switch in this hypervascular tumor, thereby potentially controlling tumor growth.
Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas/fisiologia , Proteínas Adaptadoras de Transdução de Sinal , Animais , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Metilação de DNA , Regulação para Baixo , Fatores de Crescimento de Fibroblastos/farmacologia , Perfilação da Expressão Gênica , Genes Supressores de Tumor , Fator de Crescimento de Hepatócito/farmacologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Cirrose Hepática/genética , Cirrose Hepática/metabolismo , Neoplasias Hepáticas/genética , Perda de Heterozigosidade , Sistema de Sinalização das MAP Quinases/fisiologia , Proteínas de Membrana , Camundongos , Células NIH 3T3 , Regiões Promotoras Genéticas , Proteínas Serina-Treonina Quinases , Proteínas/genética , Proteínas/metabolismo , RNA Mensageiro/biossíntese , RNA Mensageiro/genéticaRESUMO
Opioid-binding protein/cell adhesion molecule-like (OPCML) is a tumor-suppressor gene that is frequently inactivated in ovarian cancer and many other cancers by somatic methylation. We have previously shown that OPCML exerts its suppressor function by negatively regulating a spectrum of receptor tyrosine kinases (RTK), such as ErbB2/HER2, FGFR1, and EphA2, thus attenuating their related downstream signaling. The physical interaction of OPCML with this defined group of RTKs is a prerequisite for their downregulation. Overexpression/gene amplification of EGFR and HER2 is a frequent event in multiple cancers, including ovarian and breast cancers. Molecular therapeutics against EGFR/HER2 or EGFR only, such as lapatinib and erlotinib, respectively, were developed to target these receptors, but resistance often occurs in relapsing cancers. Here we show that, though OPCML interacts only with HER2 and not with EGFR, the interaction of OPCML with HER2 disrupts the formation of the HER2-EGFR heterodimer, and this translates into a better response to both lapatinib and erlotinib in HER2-expressing ovarian and breast cancer cell lines. Also, we show that high OPCML expression is associated with better response to lapatinib therapy in breast cancer patients and better survival in HER2-overexpressing ovarian cancer patients, suggesting that OPCML co-therapy could be a valuable sensitizing approach to RTK inhibitors. Mol Cancer Ther; 16(10); 2246-56. ©2017 AACR.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Moléculas de Adesão Celular/genética , Receptores ErbB/genética , Neoplasias Ovarianas/tratamento farmacológico , Receptor ErbB-2/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Receptores ErbB/antagonistas & inibidores , Cloridrato de Erlotinib/administração & dosagem , Feminino , Proteínas Ligadas por GPI/genética , Amplificação de Genes/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Lapatinib , Terapia de Alvo Molecular , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Inibidores de Proteínas Quinases/administração & dosagem , Quinazolinas/administração & dosagem , Receptor ErbB-2/antagonistas & inibidores , Trastuzumab/administração & dosagemRESUMO
Abnormal signalling events mediated by receptor tyrosine kinases (RTKs) contribute to human carcinogenesis. Sprouty2 (Spry2) is a key antagonistic regulator of RTK signalling and suppression of its expression or function may facilitate proliferation and angiogenesis. Using prostate cancer (CaP) as a model, we investigated the significance of Spry2 in human malignancy. We observed downregulated Spry2 expression in invasive CaP cell lines and high-grade clinical CaP (compared to benign prostatic hyperplasia (BPH) and well-differentiated tumours, P=0.041). A large CpG island is associated with hSPRY2, and extensive hypermethylation of this CpG island was observed in 76-82% of high-grade CaP, while control BPH tissues were predominantly unmethylated (P=0.0005). Furthermore, suppressed Spry2 expression correlated with methylation of the CpG region in clinical samples (P=0.004) and treatment with 5-aza-2'-deoxycytidine reactivated Spry2 expression in LNCaP and PC-3M cells. hSPRY2 maps to the long arm of chromosome 13 (13q31.1), where loss of heterozygosity (LOH) has been reported. We found no evidence of mutation; however, we demonstrated 27-40% LOH using flanking markers to hSPRY2. Hence, while biallelic epigenetic inactivation of hSPRY2 represents the main genetic event in prostate carcinogenesis, the observed 27-40% LOH presents evidence of hemizygous deletion with the remaining allele hypermethylated. We therefore propose hSPRY2 as a potential tumour suppressor locus in CaP.
Assuntos
Cromossomos Humanos Par 3 , Genes Supressores de Tumor , Perda de Heterozigosidade , Neoplasias da Próstata/genética , Proteínas/genética , Sequência de Bases , Linhagem Celular Tumoral , Metilação de DNA , Primers do DNA , Regulação Neoplásica da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Proteínas de Membrana , Regiões Promotoras Genéticas/genéticaRESUMO
The Ras/Erk signaling pathway has a central role in development of multi-cellular organisms as well as in signal transmission in the mature individual. Recently, a family of genes, designated Sprouty, induced by the Ras/Erk pathway was found to specify proteins that inhibited the upstream pathway. Being in a position that is likely to control well-characterized oncogene products suggested that the expression levels of the Sprouty genes may be relevant in human carcinogenesis. Early data on the deregulation of Sprouty expression in breast, prostate and liver cancers is discussed along with the notion that some of them might have potential as tumour markers or that the derived proteins may act as tumour suppressors.
Assuntos
Neoplasias da Mama/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/metabolismo , Proteínas de Membrana/fisiologia , Fosfoproteínas/fisiologia , Neoplasias da Próstata/metabolismo , Animais , Biomarcadores Tumorais , Feminino , Humanos , Masculino , Neoplasias Mamárias Animais/metabolismo , Proteínas de Membrana/biossíntese , Camundongos , Modelos Biológicos , Fosfoproteínas/biossíntese , Transdução de Sinais , Distribuição TecidualRESUMO
The RP9 form of autosomal dominant retinitis pigmentosa (adRP) maps to a locus on human chromosome 7p14. We now report two different disease associated mutations in a previously unidentified human gene, the mouse orthologue of which has been characterised by its interaction with the Pim-1 oncogene. In the original linked family we identified the missense mutation H137L. A second missense mutation, D170G, was found in a single RP patient. The putative RP9 gene appears to be expressed in a wide range of tissues, but its function is unknown and a pathogenic mechanism remains to be determined.
Assuntos
Genes Dominantes , Mutação de Sentido Incorreto , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas/genética , Proteínas Proto-Oncogênicas/metabolismo , Retinose Pigmentar/genética , Sequência de Aminoácidos , Sequência de Bases , Éxons , Humanos , Dados de Sequência Molecular , Polimorfismo Conformacional de Fita Simples , Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-pim-1 , Fatores de Processamento de RNA , Análise de Sequência de DNARESUMO
INTRODUCTION: Foetal akinesia deformation sequence syndrome (FADS) is a genetically heterogeneous disorder characterised by the combination of foetal akinesia and developmental defects which may include pterygia (joint webbing). Traditionally multiple pterygium syndrome (MPS) has been divided into two forms: prenatally lethal (LMPS) and non-lethal Escobar type (EVMPS) types. Interestingly, FADS, LMPS and EVMPS may be allelic e.g. each of these phenotypes may result from mutations in the foetal acetylcholine receptor gamma subunit gene (CHRNG). Many cases of FADS and MPS do not have a mutation in a known FADS/MPS gene and we undertook molecular genetic studies to identify novel causes of these phenotypes. RESULTS: After mapping a novel locus for FADS/LMPS to chromosome 19, we identified a homozygous null mutation in the RYR1 gene in a consanguineous kindred with recurrent LMPS pregnancies. Resequencing of RYR1 in a cohort of 66 unrelated probands with FADS/LMPS/EVMPS (36 with FADS/LMPS and 30 with EVMPS) revealed two additional homozygous mutations (in frame deletions). The overall frequency of RYR1 mutations in probands with FADS/LMPS was 8.3%. CONCLUSIONS: Our findings report, for the first time, a homozygous RYR1 null mutation and expand the range of RYR1-related phenotypes to include early lethal FADS/LMPS. We suggest that RYR1 mutation analysis should be performed in cases of severe FADS/LMPS even in the absence of specific histopathological indicators of RYR1-related disease.
Assuntos
Anormalidades Múltiplas/genética , Mutação em Linhagem Germinativa , Hipertermia Maligna/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Anormalidades da Pele/genética , Anormalidades Múltiplas/patologia , Códon sem Sentido , Estudos de Coortes , Análise Mutacional de DNA , Família , Feto , Ligação Genética , Humanos , Hipertermia Maligna/patologia , Repetições de Microssatélites , Músculo Esquelético/embriologia , Músculo Esquelético/patologia , Deleção de Sequência , Anormalidades da Pele/patologiaRESUMO
Concurrent activation of RAS/ERK and PI3K/AKT pathways is implicated in prostate cancer progression. The negative regulators of these pathways, including sprouty2 (SPRY2), protein phosphatase 2A (PP2A), and phosphatase and tensin homolog (PTEN), are commonly inactivated in prostate cancer. The molecular basis of cooperation between these genetic alterations is unknown. Here, we show that SPRY2 deficiency alone triggers activation of AKT and ERK, but this is insufficient to drive tumorigenesis. In addition to AKT and ERK activation, SPRY2 loss also activates a PP2A-dependent tumor suppressor checkpoint. Mechanistically, the PP2A-mediated growth arrest depends on GSK3ß and is ultimately mediated by nuclear PTEN. In murine prostate cancer models, Pten haploinsufficiency synergized with Spry2 deficiency to drive tumorigenesis, including metastasis. Together, these results show that loss of Pten cooperates with Spry2 deficiency by bypassing a novel tumor suppressor checkpoint. Furthermore, loss of SPRY2 expression correlates strongly with loss of PTEN and/or PP2A subunits in human prostate cancer. This underlines the cooperation between SPRY2 deficiency and PTEN or PP2A inactivation in promoting tumorigenesis. Overall, we propose SPRY2, PTEN, and PP2A status as an important determinant of prostate cancer progression. Characterization of this trio may facilitate patient stratification for targeted therapies and chemopreventive interventions.
Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Neoplasias da Próstata/metabolismo , Proteína Fosfatase 2/metabolismo , Animais , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Proliferação de Células , Transformação Celular Neoplásica/metabolismo , Progressão da Doença , Ativação Enzimática , Pontos de Checagem da Fase G1 do Ciclo Celular , Técnicas de Silenciamento de Genes , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Proteínas de Membrana , Camundongos , Camundongos Nus , Camundongos Transgênicos , Transplante de Neoplasias , Fosforilação , Próstata/metabolismo , Próstata/patologia , Neoplasias da Próstata/patologia , Processamento de Proteína Pós-Traducional , Transporte Proteico , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Análise Serial de Tecidos , Carga TumoralRESUMO
UNLABELLED: Epithelial ovarian cancer is the leading cause of death from gynecologic malignancy, and its molecular basis is poorly understood. We previously demonstrated that opioid binding protein cell adhesion molecule (OPCML) was frequently epigenetically inactivated in epithelial ovarian cancers, with tumor suppressor function in vitro and in vivo. Here, we further show the clinical relevance of OPCML and demonstrate that OPCML functions by a novel mechanism in epithelial ovarian cancer cell lines and normal ovarian surface epithelial cells by regulating a specific repertoire of receptor tyrosine kinases: EPHA2, FGFR1, FGFR3, HER2, and HER4. OPCML negatively regulates receptor tyrosine kinases by binding their extracellular domains, altering trafficking via nonclathrin-dependent endocytosis, and promoting their degradation via a polyubiquitination-associated proteasomal mechanism leading to signaling and growth inhibition. Exogenous recombinant OPCML domain 1-3 protein inhibited the cell growth of epithelial ovarian cancers cell in vitro and in vivo in 2 murine ovarian cancer intraperitoneal models that used an identical mechanism. These findings demonstrate a novel mechanism of OPCML-mediated tumor suppression and provide a proof-of-concept for recombinant OPCML protein therapy in epithelial ovarian cancers. SIGNIFICANCE: The OPCML tumor suppressor negatively regulates a specific spectrum of receptor tyrosine kinases in ovarian cancer cells by binding to their extracellular domain and altering trafficking to a nonclathrin, caveolin-1associated endosomal pathway that results in receptor tyrosine kinase polyubiquitination and proteasomal degradation. Recombinant OPCML domain 1-3 recapitulates this mechanism and may allow for the implementation of an extracellular tumor-suppressor replacement strategy.