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1.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 51(4): 521-525, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32691561

RESUMO

Objective: To quantitatively detect GNAQ/11 mutations in uveal melanoma (UM) by droplet digital PCR (ddPCR). Methods: Formaldehyde-fixed paraffin-embedded (FFPE) tumor samples were taken from 78 UM patients with enucleation in West China Hospital between 2009 and 2015. None of the patients received radiotherapy or chemotherapy before enucleation. A retrospective study was conducted to detect GNAQ/11 mutation in UM by ddPCR. To compare the consistency of the results of the two detection methods, DNA sequencing was performed on the target gene by Sanger sequencing. 78 patients with UM were studied retrospectively. GNAQ/11 mutations in uveal melanoma was detected by ddPCR. The consistency of the results of the two detection methods was analyzed. Results: GNAQ/11 mutations frequency was 91.9%. The consistency test between Sanger sequencing and ddPCR of GNAQ/11 mutations in 74 patients with UM was conducted. Kappa coefficient=0.436, P=0.001. The error rate of Sanger sequencing results was significantly higher in the heterogeneous group than in the homogeneous group (12/37 vs. 3/16, P=0.53), but the difference was not statistically significant. Conclusion: The results of ddPCR and Sanger sequencing showed good consistency, and the mutation ratio of GNAQ/11 in UM was significantly different. GNAQ/11 mutation frequency in UM patients detected by ddPCR was close to the reported frequency. It is more recommended to use ddPCR with high sensitivity to detect gene mutations in samples of tumor tissue DNA derived from FFPE. Sanger sequencing is prone to false negative results.


Assuntos
Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP , Subunidades alfa de Proteínas de Ligação ao GTP , Melanoma , Mutação , Reação em Cadeia da Polimerase , Neoplasias Uveais , China , DNA/química , Análise Mutacional de DNA , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Humanos , Melanoma/diagnóstico , Melanoma/genética , Estudos Retrospectivos , Neoplasias Uveais/diagnóstico , Neoplasias Uveais/genética
2.
Nat Commun ; 11(1): 312, 2020 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-31949161

RESUMO

Identifying the underlying genetic drivers of the heritability of breast cancer prognosis remains elusive. We adapt a network-based approach to handle underpowered complex datasets to provide new insights into the potential function of germline variants in breast cancer prognosis. This network-based analysis studies ~7.3 million variants in 84,457 breast cancer patients in relation to breast cancer survival and confirms the results on 12,381 independent patients. Aggregating the prognostic effects of genetic variants across multiple genes, we identify four gene modules associated with survival in estrogen receptor (ER)-negative and one in ER-positive disease. The modules show biological enrichment for cancer-related processes such as G-alpha signaling, circadian clock, angiogenesis, and Rho-GTPases in apoptosis.


Assuntos
Neoplasias da Mama/genética , Variação Genética , Estudo de Associação Genômica Ampla , Células Germinativas , Apoptose , Relógios Circadianos , Biologia Computacional , Feminino , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Redes Reguladoras de Genes , Genótipo , Humanos , Prognóstico , Receptores Estrogênicos/genética , Transdução de Sinais
3.
PLoS Pathog ; 16(1): e1008138, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31961913

RESUMO

Eukaryotic heterotrimeric guanine nucleotide-binding proteins consist of α, ß, and γ subunits, which act as molecular switches to regulate a number of fundamental cellular processes. In the oomycete pathogen Phytophthora sojae, the sole G protein α subunit (Gα; encoded by PsGPA1) has been found to be involved in zoospore mobility and virulence, but how it functions remains unclear. In this study, we show that the Gα subunit PsGPA1 directly interacts with PsYPK1, a serine/threonine protein kinase that consists of an N-terminal region with unknown function and a C-terminal region with a conserved catalytic kinase domain. We generated knockout and knockout-complemented strains of PsYPK1 and found that deletion of PsYPK1 resulted in a pronounced reduction in the production of sporangia and oospores, in mycelial growth on nutrient poor medium, and in virulence. PsYPK1 exhibits a cytoplasmic-nuclear localization pattern that is essential for sporangium formation and virulence of P. sojae. Interestingly, PsGPA1 overexpression was found to prevent nuclear localization of PsYPK1 by exclusively binding to the N-terminal region of PsYPK1, therefore accounting for its negative role in sporangium formation. Our data demonstrate that PsGPA1 negatively regulates sporangium formation by repressing the nuclear localization of its downstream kinase PsYPK1.


Assuntos
Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Phytophthora/enzimologia , Proteínas Serina-Treonina Quinases/metabolismo , Esporos/crescimento & desenvolvimento , Núcleo Celular/genética , Núcleo Celular/metabolismo , Subunidades alfa de Proteínas de Ligação ao GTP/química , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Phytophthora/genética , Phytophthora/crescimento & desenvolvimento , Phytophthora/patogenicidade , Doenças das Plantas/parasitologia , Ligação Proteica , Domínios Proteicos , Transporte Proteico , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética , Soja/parasitologia , Esporos/enzimologia , Esporos/genética , Esporos/metabolismo , Virulência
4.
Am J Surg Pathol ; 44(2): 255-262, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31633489

RESUMO

In this study, we aimed to present the clinicopathologic and molecular features of a distinct group of hemangioma with GNA mutations that exhibited prominent thrombosis and organization changes with florid intravascular endothelial cell proliferation that we provisionally termed "thrombotic hemangioma with organizing/anastomosing features." Twenty-six cases were included. No sex predilection was seen (male:female=13:13). Patients' age ranged from 17 to 89 years (median: 51 y). All but 1 occurred in the skin whereas the remaining tumor involved the neck soft tissue. Remarkably, the majority (18) occurred in the lower abdominal/inguinal regions. Histologically, thrombotic hemangioma with organizing/anastomosing features were circumscribed tumors composed of variably sized and congested thin-walled vessels. The most striking features were prominent thrombosis and organization with florid intravascular endothelial cell proliferation. The proliferating endothelial cells exhibit a streaming pattern with focal anastomosing-like feature resembling anastomosing hemangioma. The stroma was sclerotic or hyalinized but could also be myxoid/edematous. Other features included vessels with nuclear hobnailing and perivascular hyalinization, cherry hemangioma-like component, cavernous-like or sinusoidal hemangioma-like areas, Masson hemangioma-like feature, and spindle cell fascicular pattern. Mitotic activity was usually low and nuclei were bland but 2 tumors exhibited moderate nuclear atypia and higher mitotic activity. Extramedullary hematopoiesis and hyaline globules were not identified. Genetically, by Sanger sequencing and MassARRAY analysis, mutually exclusive GNAQ, GNA11, and GNA14 exon 5 mutations were identified in 15, 5, and 2 tumors, respectively, with a combined mutation rate of 85% (22/26). In conclusion, we described a distinct group of hemangioma and expanded the clinicopathologic features of GNA-mutated hemangiomas.


Assuntos
Biomarcadores Tumorais/genética , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Hemangioma/patologia , Neoplasias Cutâneas/patologia , Trombose/etiologia , Abdome , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Hemangioma/complicações , Hemangioma/diagnóstico , Hemangioma/genética , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Pele/patologia , Neoplasias Cutâneas/complicações , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/genética , Adulto Jovem
6.
Virchows Arch ; 476(3): 475-481, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31707589

RESUMO

Anastomosing hemangioma (AH) is a distinct benign vascular tumor that may be histologically confused with an angiosarcoma. Recently, recurrent GNAQ and GNA14 mutations were identified in AH. GNA11, another paralogue of GNAQ and the one that shows the highest degree of homology to GNAQ, has not yet been found to be mutated in AH. In this study, we investigated the clinicopathological and molecular features of 26 AHs. By Sanger sequencing and MassARRAY analysis, mutually exclusive mutations in exon 5 of GNAQ, GNA11, and GNA14 were identified in 10, 5, and 5 tumors, respectively, of the 22 investigated tumors, with an overall mutation rate of 91%. No notable differences in the clinicopathological features were observed between GNAQ-, GNA11-, or GNA14-mutated tumors. Our results implicated GNA11 mutations, as well as previously known mutations of its paralogues GNAQ and GNA14, as essential drivers in the pathogenesis of AH.


Assuntos
Subunidades alfa de Proteínas de Ligação ao GTP/genética , Hemangioma/genética , Adulto , Idoso , Feminino , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Humanos , Masculino , Pessoa de Meia-Idade , Mutação
7.
Virchows Arch ; 476(3): 439-443, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31754815

RESUMO

We report a series of 21 compound blue nevi, a rare variant in the vast clinical and morphological spectrum of blue melanocytic proliferations. Clinically, they presented in young adults, with a slight female predominance. One-third were located on the dorsum of the foot. Morphologically, all cases displayed large dendritic melanocytes restricted to the deep layers of the epidermis. The compound component was central and evenly distributed. Melanocytic density ranged from scarce isolated cells to a confluent lentiginous architecture. In 12 of the 21 cases, junctional nests of small, bland, weakly pigmented melanocytes were associated. These nests became confluent in the most cellular cases. In all cases, a dermal component was immediately present underneath, mainly of cellular blue nevus-type. All cases were genetically confirmed to harbor either a GNAQ or GNA11 hotspot mutation. This study expands the morphological spectrum of blue nevi that should not be restricted to a strictly intradermal melanocytic proliferation.


Assuntos
Nevo Azul/genética , Nevo Azul/patologia , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Humanos , Masculino , Melanócitos/patologia , Pessoa de Meia-Idade , Mutação , Adulto Jovem
8.
Zhonghua Nei Ke Za Zhi ; 59(1): 23-28, 2020 Jan 01.
Artigo em Chinês | MEDLINE | ID: mdl-31887832

RESUMO

Objective: To investigate the association of GNA11 gene polymorphisms with the risk of adult-onset non-surgical hypoparathyroidism (Ns-HypoPT). Methods: Genotyping of GNA11 single nucleotide polymorphisms (SNPs) (rs28685098, rs4806907, rs11084997 and rs78003011) was carried out in 203 patients and 209 healthy participants by sequenom MassArray iPLEX System. These SNPs are located in promoter and 3'untranslated region (3'UTR) of GNA11 gene, respectively. Results: Allele and genotype frequencies of rs11084997 in patients were significantly different from those of controls (genotype GG:60.5% vs. 49.8%, GC: 35.5% vs. 41.6%, CC: 4.0% vs. 8.6%, P=0.038; G allele 78.3% vs. 70.6%, C allele 21.7% vs. 29.4%, P=0.012), and the C allele of rs11084997 carriers had a lower risk to develops Ns-HypoPT in additive and dominant genetic models [OR=0.382 (0.160-0.915), 0.647 (0.437-0.957)]. CC-Haplotype formed by the minor alleles of rs4806907 and rs11084997 was associated with a decreased risk of Ns-HypoPT in additive, dominant and recessive genetic model [OR=0.317 (0.126-0.801), 0.640 (0.430-0.952), 0.367 (0.148-0.912)]. Conclusion: The minor allele C of rs11084997 in GNA11 gene promoter was associated with decreased risk of Ns-HypoPT in Chinese population.


Assuntos
Subunidades alfa de Proteínas de Ligação ao GTP/genética , Predisposição Genética para Doença , Hipoparatireoidismo/genética , Adulto , Alelos , Grupo com Ancestrais do Continente Asiático , Estudos de Casos e Controles , China , Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Frequência do Gene , Genótipo , Humanos , Hipoparatireoidismo/diagnóstico , Polimorfismo de Nucleotídeo Único
9.
J Biol Chem ; 294(49): 18836-18845, 2019 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-31690628

RESUMO

Heterotrimeric G proteins are important molecular switches that facilitate transmission of a variety of signals from the outside to the inside of cells. G proteins are highly conserved, enabling study of their regulatory mechanisms in model organisms such as the budding yeast Saccharomyces cerevisiae Gpa2 is a yeast Gα protein that functions in the nutrient signaling pathway. Using Phos-tag, a highly specific phosphate binding tag for separating phosphorylated proteins, we found that Gpa2 undergoes phosphorylation and that its level of phosphorylation is markedly increased upon nitrogen starvation. We also observed that phosphorylation of Gpa2 depends on glycogen synthase kinase (GSK). Disrupting GSK activity diminishes Gpa2 phosphorylation levels in vivo, and the purified GSK isoforms Mck1 and Ygk3 are capable of phosphorylating Gpa2 in vitro Functionally, phosphorylation enhanced plasma membrane localization of Gpa2 and promoted nitrogen starvation-induced activation of protein kinase A. Together, the findings of our study reveal a mechanism by which GSK- and nutrient-dependent phosphorylation regulates subcellular localization of Gpa2 and its ability to activate downstream signaling.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Membrana Celular/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/genética , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Regulação Fúngica da Expressão Gênica , Quinases da Glicogênio Sintase/genética , Quinases da Glicogênio Sintase/metabolismo , Fosforilação , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Transdução de Sinais
10.
Am J Dermatopathol ; 41(9): 623-629, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31433323

RESUMO

Studies on the genomic aberrations in melanocytic neoplasms have shown a complex genomic landscape. In nevi and melanomas, a MAP-kinase pathway activation was generally found, produced by different chromosomal aberrations, including BRAF, NRAS, HRAS, GNAQ, GNA11, BAP1, CTNNB1, MAP2K1, PRKAR1A, and NF1 mutations, and ALK, ROS1, NTRK1, RET, MET, BRAF, NTRK3, and PRKCA fusions. Melanomas also showed a variable number of additional mutations ablating tumor-suppression mechanisms and activating other oncogenic pathways, including CDKN2A loss, PTEN loss, as well as TP53 and TERT-promoter mutations. Moreover, borderline melanocytic tumors displayed the same chromosomal aberrations, but more mutations than nevi and fewer than melanomas. In this context, the notion that melanocytic neoplasms can be classified as benign/malignant is hardly supportable, because all neoplasms harbor a certain number of mutations and the progression risk, that is, the malignant potential, is related and proportional to the burden of pathogenic mutations. Moreover, from the genomic analysis, in parallel to the current diagnostic categories of "nevi," "melanomas," and "melanocytomas," some aggregations or classes of tumors based on the characteristic types of driver mutations/fusions emerge as possible and more rationale, including Spitzoid neoplasms, blue neoplasms, BAP1-inactivated melanocytic neoplasms, deep penetrating melanocytic neoplasms, pigment-synthesizing melanocytic neoplasms, and "common" melanocytic neoplasms. Each of these classes, showing the same driver mutations/fusions, demonstrates to have the same pathogenesis and may be genetically considered as a single tumor, although with a variable amount of progression risk. Histologic features, being an expression of the mutational state, could be used to obtain an approximate risk assessment in each single tumor.


Assuntos
Aberrações Cromossômicas , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Melanoma/genética , Nevo de Células Epitelioides e Fusiformes/genética , Neoplasias Cutâneas/genética , beta Catenina/genética , Biópsia por Agulha , Educação Médica Continuada , Feminino , Predisposição Genética para Doença/epidemiologia , Estudo de Associação Genômica Ampla , Genômica , Humanos , Imuno-Histoquímica , Masculino , Melanoma/patologia , Mutação , Nevo de Células Epitelioides e Fusiformes/patologia , Sensibilidade e Especificidade , Neoplasias Cutâneas/patologia
11.
J Proteomics ; 207: 103467, 2019 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-31351147

RESUMO

The mating-specific yeast Gα controls pheromone signaling by sequestering Gßγ and by regulating the Fus3 MAP kinase. Disrupting Gα-Fus3 interaction leads to severe defects in chemotropism. Because Gα concentrates at the chemotropic growth site where Fus3 is required for the phosphorylation of two known targets, we screened for additional proteins whose phosphorylation depends on pheromone stimulation and Gα-Fus3 interaction. Using a mutant form of Gα severely defective in Fus3-binding, GαDSD, and quantitative mass spectrometry, fourteen proteins were identified as potential targets of Gα-recruited Fus3, ten of which were previously implicated in cell polarity and morphogenesis. To explore the biological relevance of these findings, we focused on the Spa2 polarisome protein, which was hypophosphorylated on multiple serine residues in pheromone-treated GαDSD cells. Six sites were mutagenized to create the Spa26XSA mutant protein. Spa26XSA exhibited increased affinity for Fus3, consistent with a kinase-substrate interaction, and Spa26XSA cells exhibited dramatic defects in gradient sensing and zygote formation. These results suggest that Gα promotes the phosphorylation of Spa2 by Fus3 at the cortex of pheromone-stimulated cells, and that this mechanism plays a role in chemotropism. How the Gα-Fus3 signaling hub affects the other putative targets identified here has yet to be determined. SIGNIFICANCE: Previously, interaction between the G alpha protein, Gpa1, and the MAPK of the pheromone response pathway, Fus3, was shown to be important for efficient sensing of the pheromone gradient and for the maintenance of cell polarity during mating. Here we show that the underlying molecular mechanisms involve the phosphorylation of specific cortical targets of Gpa1/Fus3. These have been identified by quantitative phosphoproteomics using a mutant of Gpa1, which is defective in interacting with Fus3. One of these targets is the polarisome protein Spa2. Alanine substitution of the Spa2 phosphorylation sites targeted by Gpa1/Fus3 lead to a dramatic defect in pheromone gradient sensing and zygote formation. These results reveal how the G alpha protein and the MAPK control cell polarity in a prototypical model system. Our results have wider significance as similar mechanisms exist in higher eukaryotes and are involved in important biological such as neuron development, immunity, and cancer cell metastasis.


Assuntos
Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Sistema de Sinalização das MAP Quinases , Fator de Acasalamento/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Substituição de Aminoácidos , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Fator de Acasalamento/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Mutação de Sentido Incorreto , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
12.
Mod Pathol ; 32(11): 1657-1665, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31189994

RESUMO

Cherry hemangioma is the most common hemangioma in adult life. Neoplastic and non-neoplastic theories had both been proposed for its pathogenesis, but its nature is still poorly understood. We noted a significant subset of anastomosing hemangiomas and congenital hemangiomas harbored a population of small capillaries surrounded by a perivascular hyaline layer, reminiscent of the vessels seen in cherry hemangioma. Both anastomosing hemangioma and congenital hemangioma harbor recurrent mutations in exon 5 of GNAQ and its paralogues. In this study, we analyzed 68 cherry hemangiomas and 17 cherry hemangioma-like hemangiomas exhibiting additional non-classical features including markedly dilated, cavernous vessels, and/or a deep component extending to the deep dermis. By Sanger sequencing, GNAQ, GNA11, and GNA14 exon 5 mutations were identified in 12, 4, and 32 cherry hemangiomas, respectively, and 5, 3, and 3 cherry hemangioma-like hemangiomas, respectively. MassARRAY analysis detected mutations (including exon 2 GNAQG48V mutations) in additional 8 cherry hemangiomas and 3 cherry hemangioma-like hemangiomas. Overall, the cherry hemangiomas and cherry hemangioma-like hemangiomas had equal GNA mutation rates (82%), and GNA14 and GNAQ mutations were present in approximately half of cherry hemangiomas and cherry hemangioma-like hemangiomas, respectively. All mutations were mutually exclusive. KRASG12V mutation was also detected in one cherry hemangioma-like hemangioma without GNA mutations. In summary, our study demonstrated recurrent GNA14/GNAQ/GNA11 mutations were present in the majority of this very common hemangioma and established its neoplastic nature. Our results also expanded the morphological spectrum of GNA-mutated hemangiomas to include tumors composed of cavernous-like vessels and indicated GNA14 was the most commonly mutated gene in vascular tumors.


Assuntos
Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Hemangioma Capilar/genética , Neoplasias Cutâneas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise Mutacional de DNA , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Adulto Jovem
13.
Invest Ophthalmol Vis Sci ; 60(7): 2474-2480, 2019 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-31173078

RESUMO

Purpose: The activation of the mitogen-activated protein kinase (MAPK) pathway has been suggested as the major downstream target when GNAQ and GNA11 (GNAQ/11) are mutated in uveal melanoma (UM). However, clinical trials with single agent MEK inhibitor showed no clinical significance in altering the overall outcome of the disease in UM; therefore, we investigated the correlation between naturally occurring mutations in GNAQ/11 and activation of MAPK pathway in vivo in primary UM. Methods: Screening for activating mutations in codons 183 and 209 of GNAQ/11 was carried out by sequencing and restriction fragment length polymorphism (RFLP) in a cohort of 42 primary UM. Activation of the MAPK pathway and other potential downstream signals was assessed by immunohistochemistry and/or Western blot analysis. Potential downstream signaling of mutant and wild type GNAQ/11 was studied by transient transfection assay in nonmutant cell lines. Results: Somatic mutations in GNAQ/11 were observed in 35/42 (83.3%) of primary UM. Tumors with GNAQ/11 mutations showed variations in the activation of ERK1/2 with significant tumor heterogeneity. Weak and undetectable ERK1/2 activation was observed in 4/35 (11.4%) and 8/35 (22.9%) of the GNAQ/11 mutant UM, respectively. Tumor heterogeneity of GNAQ/11 mutations was also observed in a subset of tumors. Conclusions: Our results indicate that there is marked variation in MAPK activation in UM with GNAQ/11 mutations. Thus, GNAQ/11 mutational status is not a sufficient biomarker to adequately predict UM patient responses to single-agent selective MEK inhibitor therapy.


Assuntos
Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Melanoma/enzimologia , Melanoma/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mutação , Neoplasias Uveais/enzimologia , Neoplasias Uveais/genética , Western Blotting , Linhagem Celular Tumoral , Estudos de Coortes , Análise Mutacional de DNA , Humanos , Imuno-Histoquímica , Plasmídeos , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNA , Transdução de Sinais , Transfecção
14.
Cancer Chemother Pharmacol ; 84(1): 15-32, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31079217

RESUMO

Uveal melanoma is the most common primary intraocular tumor in adults. It can arise from melanocytes in the anterior (iris) or posterior uveal tract (choroid and ciliary body). Uveal melanoma has a particular molecular pathogenesis, being characterized by specific chromosome alterations and gene mutations (e.g., GNAQ/GNA11; BAP1), which are considered promising targets for molecular therapy. Primary treatment of uveal melanoma includes radiotherapy (brachytherapy and charged-particle therapy), phototherapy (photocoagulation, transpupillary thermal therapy, and photodynamic therapy) and surgery (local resection, enucleation and exenteration). Approximately half of patients with uveal melanoma will, however, develop metastasis, especially in the liver. The treatment of metastatic uveal melanoma includes systemic chemotherapy, immunotherapy and molecular targeted therapy. Liver-directed therapies, such as resection, chemoembolization, immunoembolization, radioembolization, isolated hepatic perfusion and percutaneous hepatic perfusion, are also available to treat metastatic uveal melanoma. Several clinical trials are being developed to study new therapeutic options to treat uveal melanoma, mainly for those with identified liver metastases. The present work discusses the physiopathology and new in situ-specific therapies for the treatment of uveal melanoma.


Assuntos
Neoplasias Hepáticas/terapia , Melanoma/patologia , Neoplasias Uveais/patologia , Adulto , Aberrações Cromossômicas , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Humanos , Neoplasias Hepáticas/secundário , Melanoma/genética , Melanoma/terapia , Mutação , Proteínas Supressoras de Tumor/genética , Ubiquitina Tiolesterase/genética , Neoplasias Uveais/genética , Neoplasias Uveais/terapia
15.
Sci Rep ; 9(1): 5838, 2019 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-30967583

RESUMO

G-protein signaling components have been attributed many biological roles in plants, but the extent of involvement of G-protein coupled receptor 1 (GCR1) with the Gα (GPA1) remained unknown. To address this, we have performed transcriptomic analyses on Arabidopsis gpa1-5gcr1-5 double mutant and identified 656 differentially expressed genes (DEGs). MapMan and Gene Ontology analyses revealed global transcriptional changes associated with external stimulus, cell wall organization/biogenesis and secondary metabolite process among others. Comparative transcriptomic analyses using the single and double mutants of gcr1-5 and gpa1-5 identified 194, 139 and 391 exclusive DEGs respectively, whereas 64 DEGs were common to all three mutants. Further, pair wise comparison of DEGs of double mutant with single mutants of gcr1-5 or gpa1-5 showed about one-third and over half common DEGs, respectively. Further analysis of the DEGs exclusive to the double mutant using protein-protein interaction networks revealed molecular complexes associated with nitrate and light signaling and plant-pathogen interactions among others. Physiological and molecular validation of nitrate-response revealed the sensitivity of germination to low N in the double mutant and differential expression of nitrate transporter (and nitrate reductase in all three mutants). Taken together, GCR1 and GPA1 work in partnership as well as independently to regulate different pathways.


Assuntos
Proteínas de Arabidopsis/metabolismo , Parede Celular/metabolismo , Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Regulação da Expressão Gênica de Plantas , Nitratos/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Arabidopsis , Proteínas de Arabidopsis/genética , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Germinação/fisiologia , Receptores Acoplados a Proteínas-G/genética
17.
J Biol Chem ; 294(20): 8148-8160, 2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-30940727

RESUMO

Regulator of G protein signaling (RGS) proteins are negative regulators of G protein-coupled receptor (GPCR) signaling through their ability to act as GTPase-activating proteins (GAPs) for activated Gα subunits. Members of the RZ subfamily of RGS proteins bind to activated Gαo, Gαz, and Gαi1-3 proteins in the nervous system and thereby inhibit downstream pathways, including those involved in Ca2+-dependent signaling. In contrast to other RGS proteins, little is known about RZ subfamily structure and regulation. Herein, we present the 1.5-Å crystal structure of RGS17, the most complete and highest-resolution structure of an RZ subfamily member to date. RGS17 cocrystallized with Ca2+ bound to conserved positions on the predicted Gα-binding surface of the protein. Using NMR chemical shift perturbations, we confirmed that Ca2+ binds in solution to the same site. Furthermore, RGS17 had greater than 55-fold higher affinity for Ca2+ than for Mg2+ Finally, we found that Ca2+ promotes interactions between RGS17 and activated Gα and decreases the Km for GTP hydrolysis, potentially by altering the binding mechanism between these proteins. Taken together, these findings suggest that Ca2+ positively regulates RGS17, which may represent a general mechanism by which increased Ca2+ concentration promotes the GAP activity of the RZ subfamily, leading to RZ-mediated inhibition of Ca2+ signaling.


Assuntos
Sinalização do Cálcio , Cálcio/química , Proteínas RGS/química , Cálcio/metabolismo , Cristalografia por Raios X , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Guanosina Trifosfato/química , Guanosina Trifosfato/genética , Guanosina Trifosfato/metabolismo , Humanos , Hidrólise , Magnésio/química , Magnésio/metabolismo , Proteínas RGS/genética , Proteínas RGS/metabolismo
18.
Invest Ophthalmol Vis Sci ; 60(5): 1538-1546, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30994864

RESUMO

Purpose: Recent evidence suggests that retinal photoreceptor cells have an important role in the pathogenesis of retinal microvascular lesions in diabetes. We investigated the role of rod cell phototransduction on the pathogenesis of early diabetic retinopathy (DR) using Gnat1-/- mice (which causes permanent inhibition of phototransduction in rod cells without degeneration). Methods: Retinal thickness, oxidative stress, expression of inflammatory proteins, electroretinograms (ERG) and optokinetic responses, and capillary permeability and degeneration were evaluated at up to 8 months of diabetes. Results: The diabetes-induced degeneration of retinal capillaries was significantly inhibited in the Gnat1-/- diabetics. The effect of the Gnat1 deletion on the diabetes-induced increase in permeability showed a nonuniform accumulation of albumin in the neural retina; the defect was inhibited in diabetic Gnat1-/- mice in the inner plexiform layer (IPL), but neither in the outer plexiform (OPL) nor inner nuclear (INL) layers. In Gnat1-deficient animals, the diabetes-induced increase in expression of inflammatory associated proteins (iNOS and ICAM-1, and phosphorylation of IĸB) in the retina, and the leukocyte mediated killing of retinal endothelial cells were inhibited, however the diabetes-mediated induction of oxidative stress was not inhibited. Conclusions: In conclusion, deletion of transducin1 (and the resulting inhibition of phototransduction in rod cells) inhibits the development of retinal vascular pathology in early DR.


Assuntos
Diabetes Mellitus Experimental/fisiopatologia , Retinopatia Diabética/etiologia , Retinopatia Diabética/fisiopatologia , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Deleção de Genes , Células Fotorreceptoras Retinianas Bastonetes/fisiologia , Transducina/genética , Visão Ocular/fisiologia , Animais , Permeabilidade Capilar , Retinopatia Diabética/metabolismo , Eletrorretinografia , Proteínas I-kappa B/metabolismo , Immunoblotting , Molécula 1 de Adesão Intercelular/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Óxido Nítrico Sintase Tipo II/metabolismo , Nistagmo Optocinético/fisiologia , Estresse Oxidativo , Fosforilação , Vasos Retinianos/patologia , Estreptozocina , Tomografia de Coerência Óptica
19.
Exp Neurol ; 318: 61-70, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31034808

RESUMO

GNAL encodes guanine nucleotide-binding protein subunit Gα(olf) which plays a key role in striatal medium spiny neuron (MSN)-dopamine signaling. GNAL loss-of-function mutations are causally-associated with isolated dystonia, a movement disorder characterized by involuntary muscle contractions leading to abnormal postures. Dopamine D2 receptor (D2R) blockers such as haloperidol are mainstays in the treatment of psychosis but may contribute to the development of secondary acute and tardive dystonia. Administration of haloperidol promotes cAMP-dependent signaling in D2R-expressing indirect pathway MSNs. At present, little is known about the cellular relationships among isolated, acute, and tardive dystonia. Herein, we report the effects of acute D2R blockade on motor behavior, DNA repair, cAMP-mediated histone H3 phosphorylation (Ser10), and cell death in Gnal+/- mice and their isogenic Gnal+/+ littermates. In comparison to Gnal+/+ littermates, Gnal+/- mice exhibited increased catalepsy responses, persistent DNA breaks, decreased cAMP-dependent histone H3 phosphorylation (Ser10), and increased cell death in response to haloperidol. In striatum, aged Gnal+/- mice exhibited increased global DNA methylation, increased euchromatin, and dendritic structural abnormalities. Our results provide evidence that Gα(olf) deficiency intensifies the effects of D2R antagonism and suggests that loss-of-function variants in GNAL may increase risk for movement disorders associated with D2R blockers. We hypothesize that the effects of Gα(olf) dysfunction and/or long-term D2R antagonism may lead to epigenetic silencing, transcriptional dysregulation, and, ultimately, cellular senescence and/or apoptosis in human brain.


Assuntos
Antagonistas de Dopamina/farmacologia , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Instabilidade Genômica/efeitos dos fármacos , Haloperidol/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Feminino , Haploinsuficiência , Masculino , Camundongos , Discinesia Tardia/genética
20.
Am J Med Genet A ; 179(6): 966-977, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30920161

RESUMO

Phacomatosis pigmentovascularis (PPV) comprises a family of rare conditions that feature vascular abnormalities and melanocytic lesions that can be solely cutaneous or multisystem in nature. Recently published work has demonstrated that both vascular and melanocytic abnormalities in PPV of the cesioflammea and cesiomarmorata subtypes can result from identical somatic mosaic activating mutations in the genes GNAQ and GNA11. Here, we present three new cases of PPV with features of the cesioflammea and/or cesiomarmorata subtypes and mosaic mutations in GNAQ or GNA11. To better understand the risk of potentially occult complications faced by such patients we additionally reviewed 176 cases published in the literature. We report the frequency of clinical findings, their patterns of co-occurrence as well as published recommendations for surveillance after diagnosis. Features assessed include: capillary malformation; dermal and ocular melanocytosis; glaucoma; limb asymmetry; venous malformations; and central nervous system (CNS) anomalies, such as ventriculomegaly and calcifications. We found that ocular findings are common in patients with phacomatosis cesioflammea and cesiomarmorata. Facial vascular involvement correlates with a higher risk of seizures (p = .0066). Our genetic results confirm the role of mosaic somatic mutations in GNAQ and GNA11 in phacomatosis cesioflammea and cesiomarmorata. Their clinical and molecular findings place these conditions on a clinical spectrum encompassing other GNAQ and GNA11 related disorders and inform recommendations for their management.


Assuntos
Síndromes Neurocutâneas/diagnóstico , Fenótipo , Alelos , Criança , Diagnóstico Diferencial , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Genótipo , Humanos , Lactente , Angiografia por Ressonância Magnética , Imagem por Ressonância Magnética , Masculino , Mutação , Síndromes Neurocutâneas/genética , Pele/patologia , Sequenciamento Completo do Exoma
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