RESUMO
Ovarian cancer is one of the deadliest types of gynaecological cancers and more than half of the patients die within 5 years after diagnosis. Recurrence in advanced staged patients after chemotherapy is associated with increased chemoresistance, which results in poor prognosis. Regulator of G-protein signalling 10 (RGS10) negatively regulates cell proliferation, migration and survival by attenuating G-protein coupled-receptors mediated signalling pathways. Recent studies have shown that loss of RGS10 expression is significantly associated with proliferation and cisplatin resistance in ovarian cancer cells. SIGNIFICANCE OF THE STUDY: In this study, we analysed differential RGS10 expression levels using public microarray datasets from clinical and in vitro ovarian cancer samples. We validated that cancer progression and chemotherapy exposure change RGS10 expression. We enriched our study to evaluate the relationship between chemoresistance and differential RGS10 expression against ovarian cancer potential chemotherapeutic agent, palbociclib. Results showed that palbociclib treatment reduced cell viability, despite significantly decreased RGS10 expression in chemoresistant cells. Overall, the results confirmed that cancer progression and chemoresistance are significantly associated with the down-regulation of RGS10 while some chemotherapeutics seem to be beneficial in decreasing chemoresistance in ovarian cancer.
Assuntos
Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias/biossíntese , Neoplasias Ovarianas/metabolismo , Proteínas RGS/biossíntese , Linhagem Celular Tumoral , Feminino , Humanos , Neoplasias Ovarianas/patologiaRESUMO
BACKGROUND: Regulator of G-protein signaling 2 (RGS2) is a multifaceted protein with a prognostic value in hormone-naïve prostate cancer (PC). It has previously been associated with the development of castration resistance. However, RGS2 expression in clinical specimens of castration-resistant prostate cancer (CRPC) and its clinical relevance has not been explored. In the present study, RGS2 was assessed in CRPC and in relation to the development of castration resistance. METHODS: In the present study, RGS2 expression was evaluated with immunohistochemistry in patient materials of hormone-naïve and castration-resistant primary tumors, also in matched specimens before and after 3 months of androgen deprivation therapy (ADT). Cox regression and Kaplan-Meier curves were used to evaluate the clinical significance of RGS2 expression. RGS2 expression in association to castration-resistant growth was assessed experimentally in an orthotopic xenograft mouse model of CRPC. In vitro, hormone depletion of LNCaP and enzalutamide treatment of LNCaP, 22Rv1, and VCaP was performed to evaluate the association between RGS2 and the androgen receptor (AR). Stable RGS2 knockdown was used to evaluate the impact of RGS2 in association to PC cell growth under hormone-reduced conditions. Gene and protein expression were evaluated with quantitative polymerase chain reaction and Western blot analysis, respectively. RESULTS: RGS2 expression is increased in CRPC and enriched under ADT. Furthermore, a high RGS2 level is prognostic for poor cancer-specific survival for CRPC patients and significantly reduced failure-free survival (FFS) after an initiated ADT. Additionally, the prognostic value of RGS2 outperforms prostate-specific antigen (PSA) in terms of FFS. The present study furthermore suggests that RGS2 expression is reflective of AR activity. Moreover, low RGS2-expressing cells display hampered growth under hormone-reduced conditions, in line with the poor prognosis associated with high RGS2 expression. CONCLUSIONS: High levels of RGS2 are associated with aggressive forms of castration-resistant PC. The results demonstrate that a high level of RGS2 is associated with poor prognosis in association with castration-resistant PC growth. RGS2 alone, or in association with PSA, has the potential to identify patients that require additional treatment at an early stage during ADT.
Assuntos
Neoplasias de Próstata Resistentes à Castração/metabolismo , Proteínas RGS/biossíntese , Idoso , Idoso de 80 Anos ou mais , Antagonistas de Androgênios/uso terapêutico , Animais , Linhagem Celular Tumoral , Estudos de Coortes , Xenoenxertos , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Prognóstico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Proteínas RGS/genética , Proteínas RGS/metabolismo , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Taxa de Sobrevida , Regulação para CimaRESUMO
BACKGROUND: RGS protein family members have recently became new potentially promising therapeutic targets in many cancers. However, as a key member of RGS family, RGS16 has seldom been studied in glioma. The present study was designed to investigate the prognostic value and biological function of RGS16 based on large-scale databases and functional assays in vitro. METHODS: Here, we performed comprehensive analysis for the expression characteristic of RGS16 in Chinese Glioma Genome Atlas (CGGA) microarray database with 301 patients and validated in The Cancer Genome Atlas (TCGA) microarray and RNA sequencing database. Student's t-test, one-way ANOVA test and long-rank test were used to assess differences between groups. Kaplan-Meier survival, univariate and multivariate Cox analysis and ROC curve were used to estimate the survival distributions. Biological implication of abnormal expression of RGS16 in glioma was also explored. Functional analysis of RGS16 was performed in several glioblastoma (GBM) cell lines. R language and SPSS were used for statistical analysis and graphical work. RESULTS: We found that the expression of RGS16 was positively related to the grade of glioma. High level of RGS16 commonly gathered in glioma of mesenchymal subtype and wild-type IDH1. Moreover, higher expression level of RGS16 was found to be significantly correlated with poor prognosis. The univariate and multivariate Cox regression analysis and ROC curve showed that RGS16 was an independent prognostic factor for glioma patients. Gene ontology analysis, gene set enrichment analysis, and gene set variation analysis suggested that the overexpression of RGS16 tightly related to cell proliferation, migration, epithelial-mesenchymal transition (EMT), immune and inflammatory response of glioma. Knockdown of RGS16 in glioma cell lines also showed that RGS16 promoted the malignant progress of glioma cell lines. CONCLUSIONS: RGS16 plays an important role in glioma progression and serves as an independent prognostic factor, especially in GBM patients.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Bases de Dados Genéticas/tendências , Progressão da Doença , Glioma/genética , Proteínas RGS/genética , Biomarcadores Tumorais/biossíntese , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/metabolismo , Linhagem Celular , Feminino , Glioma/diagnóstico , Glioma/metabolismo , Humanos , Masculino , Gradação de Tumores/métodos , Gradação de Tumores/tendências , Prognóstico , Proteínas RGS/biossíntese , Transcriptoma/genéticaRESUMO
Triplenegative breast cancer (TNBC) is characterized by fast progression with high potential for metastasis, and poor prognosis. The dysregulation of microRNAs (miRNAs) occurring in the initiation or progression of cancers often leads to aberrant gene expression. The aim of the present study was to explore the function of miR126 in TNBC cells. Expression levels of miR1263p were determined by quantitative realtime PCR. Then, the effects of miR1263p on migration, proliferation, invasion, and angiogenesis were assessed through in vitro experiments including Cell Counting Kit8, colony formation, Transwell invasion and vasculogenic mimicry formation assays. One of the target genes for miR1263p predicted by TargetScan was confirmed by luciferase activity assay. Results indicated that miR1263p expression was reduced in TNBC cell lines. Functional assays revealed that miR1263p overexpression inhibited cell proliferation, migration, invasion, colony formation capacity and vasculogenesis by 1.2, 1.8, 2.3, 2.0 and 3.3fold, respectively, compared to the miRNAnegative control group of MDAMB231 cells (P<0.001, respectively). In addition, the regulator of Gprotein signaling 3 (RGS3) was hypothesized and validated as a direct target of miR1263p in TNBC. The proliferation, migration, invasion, colony formation capacity and vasculogenesis of MDAMB231 cells were significantly increased by 1.4, 2.0, 1.8, 1.4 and 3.2fold, respectively, in cells transfected with pcDNA3.0RGS3 compared to pcDNA3.0negative control groups (P<0.001, respectively). The influence of miR1263p expression was reversed by RGS3 restoration. Collectively, the present study revealed that miR1263p plays a role as a tumor suppressor in regulating TNBC cell activities by targeting RGS3, indicating that the miR1263p/RGS3 axis may be a potential treatment target.
Assuntos
MicroRNAs/genética , Proteínas RGS/genética , Neoplasias de Mama Triplo Negativas/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Humanos , MicroRNAs/biossíntese , Invasividade Neoplásica , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Proteínas RGS/biossíntese , Proteínas RGS/metabolismo , Neoplasias de Mama Triplo Negativas/irrigação sanguínea , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
The relationship between impaired calcium sensing, dysregulated parathyroid hormone (PTH) secretion, and parathyroid cell proliferation in parathyroid neoplasia is not understood. We previously reported that a GTPase activating protein, regulator of G-protein signaling 5 (RGS5) is overexpressed in a subset of parathyroid tumors associated with primary hyperparathyroidism (PHPT) and that RGS5 can inhibit signaling from the calcium-sensing receptor (CASR). In vivo, we found that RGS5-null mice have abnormally low PTH levels. To gain a better understanding of the potential role of RGS5 overexpression in parathyroid neoplasia and PHPT and to investigate whether inhibition of CASR signaling can lead to parathyroid neoplasia, we created and characterized a transgenic mouse strain overexpressing RGS5 specifically in the parathyroid gland. These mice develop hyperparathyroidism, bone changes reflective of elevated PTH, and parathyroid neoplasia. Further, expression of exogenous RGS5 in normal human parathyroid cells results in impaired signaling from CASR and negative feedback on PTH secretion. These results provide evidence that RGS5 can modulate signaling from CASR and support a role for RGS5 in the pathogenesis of PHPT through inhibition of CASR signaling. © 2019 American Society for Bone and Mineral Research.
Assuntos
Regulação da Expressão Gênica , Hiperparatireoidismo/metabolismo , Proteínas RGS/biossíntese , Receptores de Detecção de Cálcio/metabolismo , Transdução de Sinais , Animais , Hiperparatireoidismo/genética , Hiperparatireoidismo/patologia , Camundongos , Camundongos Transgênicos , Proteínas RGS/genética , Receptores de Detecção de Cálcio/genéticaRESUMO
Embryo implantation is a complicated event that relies on two critical factors: the competent blastocyst and the receptive uterus. Successful implantation results from tight coordination of these two factors. The maternal hormone environment of the uterus and molecular cross-talk between the embryo and uterine tissue play pivotal roles in implantation. Here we showed that regulator of G-protein signaling 2 (RGS2), a member of ubiquitous family of proteins that regulate G-protein activation, plays an important role in embryo implantation by interfering in the cross-talk between the embryo and uterine tissue. RGS2 expression increased during the implantation process, and was higher in the implant site than at the nonimplantation site. Meanwhile, ovariectomized (OVX) mice exhibited higher expression of RGS2 in the uterus. Exogenous 17ß-estradiol and progesterone in OVX mice downregulated the expression of RGS2. Treatment with exogenous 17ß-estradiol alone caused uterine RGS2 messenger RNA levels of OVX mice to return to those of normal female mice; when these mice were treated with progesterone or 17ß-estradiol plus progesterone, RGS2 levels rose. Downregulation of Rgs2 by small interfering RNA in an in vitro coculture system of decidualized endometrial stromal cells and blastocysts inhibited blastocyst outgrowth by restricting trophoblast spreading, suggesting a mechanism by which RGS2 regulates embryo implantation.
Assuntos
Regulação para Baixo/efeitos dos fármacos , Endométrio/metabolismo , Estrogênios/farmacologia , Progesterona/farmacologia , Proteínas RGS/biossíntese , Trofoblastos/metabolismo , Animais , Blastocisto/citologia , Blastocisto/metabolismo , Endométrio/citologia , Feminino , Camundongos , Ovariectomia , Gravidez , Células Estromais/citologia , Células Estromais/metabolismo , Trofoblastos/citologiaRESUMO
BACKGROUND: Regulators of G-protein signaling (RGS) are major physiological modulators of G-protein-coupled receptors (GPCR) signaling. Several GPCRs expressed in both neurons and astrocytes participate in the central control of pain processing, and the reduced efficacy of analgesics in neuropathic pain conditions may rely on alterations in RGS function. The expression and the regulation of RGS in astrocytes is poorly documented, and we herein hypothesized that neuroinflammation which is commonly observed in neuropathic pain could influence RGS expression in astrocytes. METHODS: In a validated model of neuropathic pain, the spared nerve injury (SNI), the regulation of RGS2, RGS3, RGS4, and RGS7 messenger RNA (mRNA) was examined up to 3 weeks after the lesion. Changes in the expression of the same RGS were also studied in cultured astrocytes exposed to defined activation protocols or to inflammatory cytokines. RESULTS: We evidenced a differential regulation of these RGS in the lumbar spinal cord of animals undergoing SNI. In particular, RGS3 appeared upregulated at early stages after the lesion whereas expression of RGS2 and RGS4 was decreased at later stages. Decrease in RGS7 expression was already observed after 3 days and outlasted until 21 days after the lesion. In cultured astrocytes, we observed that changes in the culture conditions distinctly influenced the constitutive expression of these RGS. Also, brief exposures (4 to 8 h) to either interleukin-1ß, interleukin-6, or tumor necrosis factor α caused rapid changes in the mRNA levels of the RGS, which however did not strictly recapitulate the regulations observed in the spinal cord of lesioned animals. Longer exposure (48 h) to inflammatory cytokines barely influenced RGS expression, confirming the rapid but transient regulation of these cell signaling modulators. CONCLUSION: Changes in the environment of astrocytes mimicking the inflammation observed in the model of neuropathic pain can affect RGS expression. Considering the role of astrocytes in the onset and progression of neuropathic pain, we propose that the inflammation-mediated modulation of RGS in astrocytes constitutes an adaptive mechanism in a context of neuroinflammation and may participate in the regulation of nociception.
Assuntos
Astrócitos/metabolismo , Mediadores da Inflamação/metabolismo , Neuralgia/metabolismo , Proteínas RGS/biossíntese , Animais , Astrócitos/patologia , Células Cultivadas , Feminino , Inflamação/metabolismo , Inflamação/patologia , Neuralgia/patologia , Distribuição Aleatória , Ratos , Ratos Sprague-DawleyRESUMO
Involvement of the RGS17 oncogene in the promotion of non-small-cell lung cancer (NSCLC) has been reported, but the regulation mechanism in NSCLC remains unclear. MicroRNAs (miRNAs) negatively regulate gene expression, and their dysregulation has been implicated in tumorigenesis. To understand the role of miRNAs in Regulator of G Protein Signaling 17 (RGS17)-induced NSCLC, we showed that miR-203 was downregulated during tumorigenesis, and inhibited the proliferation and invasion of lung cancer cells. We then determined whether miR-203 regulated NSCLC by targeting RGS17. To characterize the regulatory effect of miR-203 on RGS17, we used lung cancer cell lines, A549 and Calu-1, and the constructed miR-203 and RGS17 overexpression vectors. The CCK8 kit was used to determine cell proliferation, and the Transwell® assay was used to measure cell invasion and migration. RT-PCR, western blots, and immunofluorescence were used to analyze expression of miR-203 and RGS17, and the luciferase reporter assay was used to examine the interaction between miR-203 and RGS17. Nude mice were used to characterize in vivo tumor growth regulation. Expression of miR-203 inhibited proliferation, invasion, and migration of lung cancer cell lines A549 and Calu-1 by targeting RGS17. The regulatory effect of miR-203 was inhibited after overexpression of RGS17. The luciferase reporter assay showed that miR-203 downregulated RGS17 by direct integration into the 3'-UTR of RGS17 mRNA. In vivo studies showed that expression of miR-203 significantly inhibited growth of tumors. Taken together, the results suggested that expression of miR-203 inhibited tumor growth and metastasis by targeting RGS17.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias Pulmonares/patologia , MicroRNAs/genética , Proteínas RGS/biossíntese , Células A549 , Animais , Carcinoma Pulmonar de Células não Pequenas/genética , Movimento Celular/genética , Proliferação de Células/genética , Regulação para Baixo , Xenoenxertos , Humanos , Neoplasias Pulmonares/genética , Camundongos , Camundongos Nus , Invasividade Neoplásica/genética , Proteínas RGS/genéticaRESUMO
Triple-negative breast cancer (TNBC) is a highly aggressive tumor subtype lacking effective prognostic indicators or therapeutic targets. Therefore, finding a novel molecular biomarker for TNBC to achieve target therapy and predict its prognosis is crucial in preventing inappropriate treatment. Regulator of G-protein signaling (RGS) families of protein can negatively regulate signaling of heterotrimeric G proteins and are known to be upregulated in various tumors. In this study, we demonstrated that RGS20 was more highly expressed in TNBC tumor tissue than in adjacent normal tissue by analyzing the cancer genome atlas (TCGA) database. However, RGS20 expression was low in all breast cancer and luminal breast cancer patients. Validated by the TCGA cohort, RGS20 was upregulated in lymph node-positive TNBC compared with that in lymph node-negative breast cancer. High expression of RGS20 had a risk of lymph node metastasis, ki-67 > 14%, poor N stage, and poor clinical stage in the immunohistochemistry of tissue microarrays. Moreover, K-M plot analysis showed that TNBC patients with high RGS20 expression had poor relapse-free survival. In summary, the findings revealed that RGS20 was a special TNBC oncogene that promoted tumor progression and influenced TNBC prognosis. This study is the first to show that RGS20 was a special oncogene, and its high expression was significantly associated with the progression and prognosis of TNBC. RGS20 may be a novel molecular biomarker for the targeted therapy and prognosis of TNBC.
Assuntos
Biomarcadores Tumorais/biossíntese , Proteínas RGS/biossíntese , Neoplasias de Mama Triplo Negativas/metabolismo , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Metástase Linfática , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Prognóstico , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
AIMS: Multiple myeloma (MM) is an invariably fatal disease with highly heterogeneous outcome. Because of this heterogeneity of MM, risk stratification is crucial for therapeutic decision-making. However, no immunohistochemical prognostic or predictive markers have been established yet. The expression of regulator of G-protein signalling (RGS) proteins, which desensitise G-protein-coupled receptor signalling, has been reported to be associated with the prognosis of various malignancies. Recently, our group demonstrated the importance of RGS1 in chemokine signalling in a human MM cell line and normal plasmablasts. In the present study, we explored the prognostic value of RGS1 expression in patients with MM using immunohistochemistry. METHODS: We evaluated RGS1 protein expression in 79 bone marrow biopsies obtained from patients with MM between 2008 and 2010 at Asan Medical Center. Correlations between RGS1 expression and clinicopathological factors were analysed. RESULTS: High RGS1 protein expression was significantly associated with poor overall survival (p=0.005). After an adjusted multivariable analysis, high RGS1 protein expression (p=0.010), high International Myeloma Working Group risk (p=0.003) and high serum lactate dehydrogenase levels (p=0.040) were significantly associated with poor outcomes. CONCLUSIONS: RGS1 expression may be a prognostic marker for risk stratification and a promising target for the development of a new MM therapy.
Assuntos
Biomarcadores Tumorais/análise , Mieloma Múltiplo/patologia , Proteínas RGS/biossíntese , Adulto , Idoso , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/mortalidade , Prognóstico , Modelos de Riscos Proporcionais , Proteínas RGS/análiseRESUMO
The Wnt/ß-catenin signaling pathway dominates numerous cellular processes including cell proliferation, differentiation, and epithelial-mesenchymal transition, which play a crucial role in human cancer malignancies. Regulator of G-protein signaling 3 (RGS3) is a pivotal molecule involved in the Wnt/ß-catenin signaling pathway, which is worthy of intensive research as a potential target in cancer treatment. In this study, we found that RGS3 is significantly upregulated in gastric cancer (GC) tumor samples compared with normal samples from the analysis of two independent GC mRNA microarray datasets in the NCBI public database. Further immunohistochemistry assay and western-blot experiments confirmed this finding on the basis of the results of our own 102 paired GC specimens and three GC cell lines. We found that a high expression of RGS3 is associated with advanced TNM stages and more aggressive malignant behaviors. In addition, the association of overexpression of RGS3 and poor overall survival and progression-free survival outcomes suggests that RGS3 has the potential to serve as a molecular therapy target for GC. Interestingly, our pathways analysis and the follow-up dual-luciferase reporter assay showed that there is a direct 3'-untranslated region binding site between RGS3 mRNA and microRNA-126, a GC inhibitor. On the basis of all the above evidences, our findings suggest that overexpressed RGS3 regulated by microRNA-126 through the post-transcriptional modulation is associated significantly with a poor prognosis of GC patients.
Assuntos
MicroRNAs/genética , Proteínas RGS/genética , Neoplasias Gástricas/genética , Humanos , Imuno-Histoquímica , MicroRNAs/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Prognóstico , Proteínas RGS/biossíntese , Proteínas RGS/metabolismo , Processamento Pós-Transcricional do RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Neoplasias Gástricas/metabolismo , Regulação para CimaRESUMO
Regulator of G protein signaling 11 (RGS11), a member of the R7 subfamily of RGS proteins, is a well-characterized GTPase-accelerating protein that is involved in the heterotrimeric G protein regulation of the amplitude and kinetics of receptor-promoted signaling in retinal bipolar and nerve cells. However, the role of RGS11 in cancer is completely unclear. Using subtractive hybridization analysis, we found that RGS11 was highly expressed in the lymph-node metastatic tissues and bone-metastatic tumors obtained from patients with lung adenocarcinoma. Characterization of the clinicopathological features of 91 patients showed that around 57.1% of the tumor samples displayed RGS11 overexpression that was associated with primary tumor status, nodal metastasis and increased disease stages. Its high expression was an independent predictive factor for poor prognosis of these patients. Cotransfection of guanine nucleotide-binding protein beta-5 (GNB5) markedly increased RGS11 expression. Enhancement or attenuation of RGS11 expression pinpointed its specific role in cell migration, but not in cell invasion and proliferation. Signaling events initiated by the RGS11-GNB5 coexpression activated the c-Raf/ERK/FAK-mediated pathway through upregulation of the Rac1 activity. Consistently, increasing the cell invasiveness of the transfectants by additional cotransfection of the exogenous urokinase-plasminogen activator gene caused a significant promotion in cell invasion in vitro and in vivo, confirming that RGS11 functions in cell migration, but requires additional proteolytic activity for cell and tissue invasion. Collectively, overexpression of RGS11 promotes cell migration, participates in tumor metastasis, and correlates the clinicopathological conditions of patients with lung adenocarcinoma.
Assuntos
Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Movimento Celular/fisiologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Proteínas RGS/biossíntese , Adenocarcinoma/genética , Adenocarcinoma de Pulmão , Animais , Linhagem Celular Tumoral , Feminino , Xenoenxertos , Humanos , Neoplasias Pulmonares/genética , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Inclusão em Parafina , Proteínas RGS/genética , Análise de Sobrevida , Transfecção , Regulação para CimaRESUMO
Regulator of G protein signaling (RGS) proteins have emerged as novel drug targets since their discovery almost two decades ago. RGS2 has received particular interest in cardiovascular research due to its role in regulating Gqsignaling in the heart and vascular smooth muscle. RGS2(-/-)mice are hypertensive, prone to heart failure, and display accelerated kidney fibrosis. RGS2 is rapidly degraded through the proteasome, and human mutations leading to accelerated RGS2 protein degradation correlate with hypertension. Hence, stabilizing RGS2 protein expression could be a novel route in treating cardiovascular disease. We previously identified cardiotonic steroids, including digoxin, as selective stabilizers of RGS2 protein in vitro. In the current study we investigated the functional effects of digoxin-mediated RGS2 protein stabilization in vivo. Using freshly isolated myocytes from wild-type and RGS2(-/-)mice treated with vehicle or low-dose digoxin (2µg/kg/day for 7 days) we demonstrated that agonist-induced cAMP levels and cardiomyocyte contractility was inhibited by digoxin in wild-type but not in RGS2(-/-)mice. This inhibition was accompanied by an increase in RGS2 protein levels in cardiomyocytes as well as in whole heart tissue. Furthermore, digoxin had protective effects in a model of cardiac injury in wild-type mice and this protection was lost in RGS2(-/-)mice. Digoxin is the oldest known therapy for heart failure; however, beyond its activity at the Na(+)/K(+)-ATPase, the exact mechanism of action is not known. The current study adds a novel mechanism, whereby through stabilizing RGS2 protein levels digoxin could exert its protective effects in the failing heart.
Assuntos
Cardiotônicos/farmacologia , Digoxina/farmacologia , Cardiopatias/prevenção & controle , Proteínas RGS/biossíntese , Animais , AMP Cíclico/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Contração Miocárdica/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Proteínas RGS/efeitos dos fármacos , Receptores Acoplados a Proteínas G/efeitos dos fármacos , Receptores Acoplados a Proteínas G/metabolismo , ATPase Trocadora de Sódio-Potássio/genética , ATPase Trocadora de Sódio-Potássio/metabolismo , Regulação para Cima/efeitos dos fármacosRESUMO
Glioblastoma multiforme (GBM) is the most aggressive malignant brain tumor. Since differentiation can attenuate or halt the growth of tumor cells, an image-based phenotypic screening was performed to find out drugs inducing morphological differentiation of GBMs. Bexarotene, a selective retinoid X receptor agonist, showed strong inhibition of neurospheroidal colony formation and migration of cultured primary GBM cells. Bexarotene treatment reduced nestin expression, while significantly increasing glial fibrillary acidic protein (GFAP) expression. The effect of bexarotene on gene expression profile was compared with the activity of all-trans retinoic acid (ATRA), a well-known differentiation inducer. Both drugs largely altered the gene expression pattern into a tumor-ameliorating direction. These drugs increased the gene expression levels of Krüppel-like factor 9 (KLF9), regulator of G-protein signaling 4 (RGS4), growth differentiation factor 15 (GDF15), angiopoietin-like protein 4 (ANGPTL4), and lowered the level of chemokine receptor type 4 (CXCR4). However, transglutaminase 2 (TG2) induction, an adverse effect of ATRA, was much weaker in bexarotene treated primary GBM cells. Consistently, the TG2 enzymatic activity was negligibly affected by bexarotene treatment. It is important to control TG2 overexpression since its upregulation is correlated with tumor transformation and drug resistance. Bexarotene also showed in vivo tumoricidal effects in a GBM xenograft mouse model. Therefore, we suggest bexarotene as a more beneficial differentiation agent than ATRA for GBM.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Proteínas de Ligação ao GTP/genética , Glioblastoma/tratamento farmacológico , Tetra-Hidronaftalenos/administração & dosagem , Transglutaminases/genética , Proteína 4 Semelhante a Angiopoietina , Angiopoietinas/biossíntese , Animais , Bexaroteno , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proteínas de Ligação ao GTP/biossíntese , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/diagnóstico por imagem , Glioblastoma/genética , Glioblastoma/patologia , Fator 15 de Diferenciação de Crescimento/biossíntese , Humanos , Fatores de Transcrição Kruppel-Like/biossíntese , Camundongos , Proteína 2 Glutamina gama-Glutamiltransferase , Proteínas RGS/biossíntese , Receptores CXCR4/biossíntese , Receptores X de Retinoides/agonistas , Transdução de Sinais/efeitos dos fármacos , Transglutaminases/biossíntese , Tretinoína/administração & dosagem , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The non-small-cell lung cancer (NSCLC) is the most common type of lung cancer that affects the human health. But, the underlying mechanisms and effective therapy are still absent. MicroRNAs (miRNAs) are small RNAs that specifically bind to the 3' untranslated region (3'UTR) of its target and regulate the protein level of the target at post-transcriptional level. A lot of miRNAs had been found abnormally regulated in the NSCLC patients, and understanding their specific roles in the pathogenesis of NSCLC will help us to develop novel therapeutic approaches. Here, we reported that miR-25 is dramatically upregulated in NSCLC tissues and negatively correlated with RGS3 protein. A conserved binding sequence in the 3'UTR of RGS3 gene to miR-25 was identified, and overexpression of miR-25 induces the RGS3 inhibition. Importantly, suppression of miR-25 facilitates the cell apoptosis and retards the cell proliferation in A549 and H520 cell lines. Our data provide a novel miR-25/RGS3 signal in the development of lung cancer.
Assuntos
Apoptose/genética , Carcinoma Pulmonar de Células não Pequenas/genética , MicroRNAs/biossíntese , Proteínas RGS/genética , Regiões 3' não Traduzidas , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/genética , Proteínas RGS/biossíntese , Transdução de SinaisRESUMO
Cell lifespan is partially regulated by a balance between survival signals via constitutively active G protein-coupled receptors (GPCRs) and death signals via death receptors. We have demonstrated that neutrophils produce a mimic ligand of G protein-coupled C5a receptor (C5aR), ribosomal protein S19 (RP S19) polymer. In contrast to an original ligand C5a, RP S19 polymer induces not only inhibition of the guanine nucleotide exchange factor activity but also initiation of the regulator of G protein signaling 3 (RGS3) promoter in a RP S19 C-terminus dependent manner. To examine an antagonistic effect of the RP S19 C-terminus on G proteins, His-S-tagged C5a or C5a/RP S19, in which an RP S19 C-terminus is bound to the C5a C-terminus, was incubated with neutrophils, and a transcription factor delta lactoferrin (δLf) was identified as a specific binding protein via pull-down experiments. The S-tagged C5a-induced agonistic effects on chemotaxis, cytoplasmic Ca(2+) influx and p38 mitogen-activated protein kinase phosphorylation were not changed by Lf knockdown and δLf overexpression in neutrophil-like or macrophage-like cells, which were differentiated into mature cells from human promyelocytic leukemia HL-60 cells by dimethyl sulfoxide and phorbol-12-myristate-13-acetate, respectively. While, the S-tagged C5a/RP S19-induced antagonistic or agonistic effects on mature HL-60 neutrophil-like or macrophage-like cells were reversed by Lf knockdown and δLf overexpression, respectively. Moreover, RGS3 expression was increased in another HL-60 neutrophil-like cells under spontaneous apoptosis induced by an apoptotic inducer MnCl2. The RGS3 expression in apoptotic neutrophil-like cells was delayed not only by Lf knockdown but also by neutralization of the RP S19 polymer or C5aR. The inhibitory extension from G protein of C5aR to Gα subsets of constitutively active GPCRs along with the RP S19 polymer-induced translocation of δLf from the cytoplasmic face of the plasma membrane to the nucleus seems to shorten the neutrophil cell lifespan.
Assuntos
Lactoferrina/metabolismo , Longevidade/imunologia , Neutrófilos/imunologia , Proteínas RGS/biossíntese , Receptores Acoplados a Proteínas G/genética , Proteínas Ribossômicas/genética , Apoptose/imunologia , Cálcio/metabolismo , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Quimiotaxia/imunologia , Células HL-60 , Humanos , Transporte de Íons/imunologia , Lactoferrina/genética , Macrófagos/imunologia , Fosforilação , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Regulator of G protein signaling 5 (RGS5) belongs to the R4 subfamily of RGS proteins, a family of GTPase activating proteins, which is dynamically regulated in various biological processes including blood pressure regulation, smooth muscle cell pathology, fat metabolism and tumor angiogenesis. Low-expression of RGS5 was reported to be associated with tumor progression in lung cancer. In the present study, we examined the potential roles of RGS5 in human lung cancer cells by overexpressing RGS5 in the cancer cells and further explored the underlying molecular mechanisms. The RGS5 gene was cloned and transfected into the human lung cancer cell lines A549 and Calu-3. The cells were tested for apoptosis with flow cytometry, for viability with MTT, for mobility and adhesion capacity. The radiosensitization effect of RGS5 was measured by a colony formation assay. The mechanisms of RGS5 functioning was also investigated by detection of protein expression with western blot analysis, including PARP, caspase 3 and 9, bax, bcl2, Rock1, Rock2, CDC42, phospho-p53 (Serine 15) and p53. The present study demonstrated that RGS5 overexpression remarkably induced apoptosis in human lung cancer cells, which was suggested to be through mitochondrial mechanisms. Overexpression of RGS5 resulted in significantly lower adhesion and migration abilities of the lung cancer cells (P<0.01). Furthermore, overexpression of RGS5 sensitized the lung cancer cells to radiation. In conclusion, the present study showed that RGS5 played an inhibitory role in human lung cancer cells through induction of apoptosis. Furthermore, RGS5 enhanced the cytotoxic effect of radiation in the human lung cancer cells. Our results indicated that RGS5 may be a potential target for cancer therapy.
Assuntos
Neoplasias Pulmonares/genética , Proteínas de Neoplasias/biossíntese , Proteínas RGS/biossíntese , Tolerância a Radiação/genética , Apoptose/genética , Adesão Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Sobrevivência Celular/genética , Sobrevivência Celular/efeitos da radiação , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/radioterapia , Proteínas RGS/genética , Transdução de Sinais/genéticaRESUMO
The entomopathogenic fungus Beauveria bassiana is widely used in pest biocontrol strategies. We evaluated both the antioxidant response mediated by compatible solutes, trehalose or mannitol, and the expression of related genes using oxygen pulses at three oxygen concentrations in solid state culture (SSC): normal atmosphere (21% O2), low oxygen (16% O2) and enriched oxygen (26% O2). Trehalose concentration decreased 75% after atmospheric modifications in the cultures, whereas mannitol synthesis was three-fold higher under the 16% O2 pulses relative to normal atmosphere (100 and 30 µg mannitol mg(-1) biomass, respectively). Confirming this result, expression of the mpd gene, coding for mannitol-1-P dehydrogenase (MPD), increased up to 1.4 times after O2 pulses. The expression of the bbrgs1 gene, encoding a regulatory G protein related to conidiation, was analysed to explain previously reported differences in conidial production. Surprisingly, expression of bbrgs1 decreased after atmospheric modification. Finally, principal component analysis (PCA) indicated that 83.39% of the variability in the data could be explained by two components. This analysis corroborated the positive correlation between mannitol concentration and mpd gene expression, as well as the negative correlation between conidial production and bbrgs1 gene expression. This study contributes to understanding of antioxidant and molecular response of B. bassiana induced under oxidant conditions.
Assuntos
Antioxidantes/metabolismo , Beauveria/efeitos dos fármacos , Beauveria/metabolismo , Oxigênio/metabolismo , Estresse Fisiológico , Beauveria/genética , Beauveria/crescimento & desenvolvimento , Meios de Cultura/química , Perfilação da Expressão Gênica , Manitol/metabolismo , Proteínas RGS/biossíntese , Proteínas RGS/genética , Esporos Fúngicos/crescimento & desenvolvimento , Desidrogenase do Álcool de Açúcar/biossíntese , Desidrogenase do Álcool de Açúcar/genética , Trealose/metabolismoRESUMO
Mouse embryonic stem cells (ESCs) are self-renewing, pluripotent, and have the ability to differentiate into the three germ layers required to form all embryonic tissues. These properties are maintained by both intrinsic and extrinsic factors. Many studies have contributed to the understanding of the molecular signal transduction required for pluripotency and controlled differentiation. Such an understanding is important in the potential application of stem cells to cell therapy for disease, and thus there is an interest in understanding the cell cycle regulation, pluripotency, and differentiation of ESCs. The regulator of G protein signaling (RGS) family consists of over 20 members. Rgs19, one such protein, specifically interacts with Gαi to enhance its GTPase activity. Growth factor receptors use Gi proteins for signal transduction, and Rgs19 may thus be involved in the regulation of cell proliferation. In a previous gain-of-function study, Rgs19 overexpression was found to enhance proliferation in various cell types. Our data demonstrate a role for Rgs19 in the regulation of ESC differentiation. Based on the presence of Rgs19 in ESCs, the morphological and molecular properties of wild-type and Rgs19 +/- ESCs during LIF withdrawal, in vitro differentiation, and teratoma formation were compared. Our findings provide insight for the first time into the mechanisms involved in Rgs19 regulation of mouse ESC proliferation and differentiation.
Assuntos
Diferenciação Celular/genética , Proliferação de Células/genética , Células-Tronco Embrionárias Murinas , Proteínas RGS/genética , Animais , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Proteínas RGS/biossíntese , Transdução de SinaisRESUMO
Immune cells express powerful and harmful effectors that require tight regulation. Heterotrimeric G proteins are critical mediators in translating extracellular signals into cell responses, which need a fine-tuned regulation for the control of cell activation. Regulator of G-protein signalling 16 (RGS16) has been identified as a key factor of G protein-mediated activation in lymphocytes, modulating inflammatory and survival responses of various cell types. However, data about the expression of this regulatory protein in monocytes are scarce, and it has remained unclear whether activation and migration of these cells are regulated by RGS16. In this study, the impact of RGS16 on the production of inflammatory cytokines by activated human monocytes was investigated in vitro using the human promonocytic cell line THP-1 as a model. Gain and loss of function experiments showed that RGS16 overexpression reduces the expression of pro-inflammatory cytokines IL-1ß, IL-6, IL-8 and TNFα, while RGS16 knockdown by RNAi upregulates IL-1ß, IL-6 and TNFα but not IL-8. RGS16 knockdown was also shown to enhance Pam3-mediated induction of the anti-inflammatory cytokine IL-10. Our results indicate that RGS16 restricts the activation-induced pro-inflammatory profile in myeloid cells.