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1.
Aging (Albany NY) ; 15(24): 14930-14944, 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38112616

RESUMO

OBJECTIVE: Papillary thyroid cancer (PTC) is one of the most serious diseases of the endocrine system. In view of the limited therapeutic effects of current medical methods, this study starts from the molecular level and looks for potential treatments. The interaction between HAGLROS/miR-206/HMGA2 was studied using multi-omics methods, which provided new ideas and methods for future treatments. METHOD: Microarray analysis and R language were used for differential analysis to screening experimental targets of lncRNA, miRNA, and mRNA. qRT-PCR was used to detect RNA expression in tissues and cells. Double luciferase reporter assays analyzed and validated binding relationships between different RNAs. Colony formation, flow cytometry, and transwell assays were used to measure the effect of them on cell proliferation, apoptosis, and migration. RESULT: Microarray analysis identified lncRNAs, miRNAs, and mRNAs differentially expressed in PTC and normal cells, and selected lncRNA HAGLROS, miR-206, and mRNA HMGA2 as study subjects. LncRNA HAGLROS and mRNA HMGA2 were highly expressed in PTC cells while miR-206 was lowly expressed in PTC cells. LncRNA HAGLROS/HMGA2 can inhibit apoptosis of PTC cells, promote proliferation and migration, and miR-206 promotes the above process. HAGLROS and HMGA2 were negatively correlated with miR-206. shHAGLROS promoted miR-206 expression, inhibited HMGA2 expression and repressed PTC tumor growth in mice. CONCLUSIONS: HAGLROS promotes the growth of PTC by competitively binding to miR-206 to promote HMGA2 expression.


Assuntos
Proteína HMGA2 , MicroRNAs , RNA Longo não Codificante , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide , Animais , Humanos , Camundongos , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , RNA Mensageiro , Câncer Papilífero da Tireoide/genética , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , Proteína HMGA2/genética , Proteína HMGA2/metabolismo
2.
Funct Integr Genomics ; 23(4): 313, 2023 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-37776372

RESUMO

Both circular RNA eukaryotic translation initiation factor 6 (circEIF6) and microRNA (miR)-138-5p participate in thyroid cancer (TC) progression. Nevertheless, the relationship between them remains under-explored. Hence, this research ascertained the mechanism of circEIF6 in TC via miR-138-5p. After TC tissues and cells were harvested, circEIF6, miR-138-5p, and lipase H (LIPH) levels were assessed. The binding relationships among circEIF6, miR-138-5p, and LIPH were analyzed. The impacts of circEIF6, miR-138-5p, and LIPH on the invasive and proliferative abilities of TPC-1 cells were examined by Transwell and EdU assays. Tumor xenograft in nude mice was established for in vivo validation of the impact of circEIF6. CircEIF6 expression was high in TC cells and tissues. Additionally, miR-138-5p was poor and LIPH level was high in TC tissues. Mechanistically, circEIF6 competitively bound to miR-138-5p to elevate LIPH via a competitive endogenous RNA mechanism. Silencing of circEIF6 reduced TPC-1 cell proliferative and invasive properties, which was annulled by further inhibiting miR-138-5p or overexpressing LIPH. Likewise, circEIF6 silencing repressed the growth of transplanted tumors, augmented miR-138-5p expression, and diminished LIPH expression in nude mice. Conclusively, circEIF6 silencing reduced LIPH level by competitive binding to miR-138-5p, thus subduing the proliferation and invasion of TPC-1 cells.


Assuntos
MicroRNAs , RNA Circular , Neoplasias da Glândula Tireoide , Animais , Humanos , Camundongos , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Lipase/genética , Lipase/metabolismo , Camundongos Nus , MicroRNAs/genética , MicroRNAs/metabolismo , Fatores de Iniciação de Peptídeos/genética , Fatores de Iniciação de Peptídeos/metabolismo , RNA Circular/genética , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/patologia
3.
Orthop Surg ; 14(11): 2871-2877, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36125199

RESUMO

OBJECTIVE: Neuropathic pain (NP) plays an important role in patients with knee osteoarthritis (KOA). However, the prevalence of NP at different treatment stages including outpatient, awaiting and after total knee arthroplasty (TKA) have not been compared. The understanding of this issue and identify risk factors can help physicians develop individualized strategies to manage the pain of KOA. Therefore, the aim of the study is to investigate the prevalence and risk factors of NP at different treatment stages of KOA. METHODS: Patients diagnosed as KOA between August 2016 and August 2020 were enrolled in this cross-sectional study and divided into three groups according to treatment stage, including outpatient stage, awaiting TKA stage (pre-TKA) and after TKA stage (post-TKA). A numeric rating scale (NRS) and PainDETECT questionnaire were used to evaluate nociceptive pain and NP. Patient demographics, radiological assessments using Kellgren-Lawrence (K-L) grade, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were analyzed. Data analysis and statistics were processed using SPSS 20.0 and examined by ANOVA with/without Bonferroni correction or Kruskal-Wallis test. A chi-square test was used to determine cross-table data and calculate the odds ratio (OR) value. RESULTS: Of the 921 patients, the prevalence of possible and likely NP was 17.5% (56/320) and 2.5% (8/320) in the pre-TKA group compared with 3.4% (8/233) and 0.4% (1/233) in the outpatient group and 1.4% (5/368) and 0.5% (2/368) in the post-TKA group, respectively. In the pre-TKA group, higher NRS (NRS >3; OR = 10.65, 95% CI: 3.25-34.92, P < 0.001) and WOMAC pain score (score > 10; OR = 4.88, 95% CI: 2.38-10.01, P < 0.001) conferred an increased risk of unclear pain. Age, gender, BMI and K-L grade showed no significant differences among the unlikely, possible and likely NP groups. CONCLUSION: Prevalence of NP is different at stages of out-patient, awaiting and after TKA in patients with KOA. Patients awaiting TKA have the highest prevalence of NP compared with patients in outpatient and post-TKA groups. In the patients waiting for TKA, higher NRS (NRS >3) and WOMAC pain scores (score > 10) are risk factors of NP.


Assuntos
Artroplastia do Joelho , Neuralgia , Osteoartrite do Joelho , Humanos , Osteoartrite do Joelho/cirurgia , Pacientes Ambulatoriais , Prevalência , Estudos Transversais , Neuralgia/cirurgia , Fatores de Risco , Articulação do Joelho/cirurgia , Resultado do Tratamento
4.
Endocrinology ; 163(7)2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35579981

RESUMO

CONTEXT: microRNA (miR/miRNA)-144-3p has been implicated in thyroid cancer (TC) progression with poorly identified mechanisms. Furthermore, E2F2 has been documented to assume a role in the development of various cancers. OBJECTIVE: This research sought to ascertain the role of miR-144-3p in growth and epithelial-mesenchymal transition (EMT) in TC in cells and male BALB/c nude mice. METHODS: In the obtained TC cells, miR-144-3p expression was detected by quantitative reverse transcription polymerase chain reaction, and E2F2 and TNIK expression by Western blot analysis. After gain- and loss-of-function assays, cell viability, clone formation, migration, and invasion were assessed by cell counting kit-8, clone formation, scratch, and Transwell assays. The expression of EMT-related proteins (Snail, Vimentin, N-cadherin, and E-cadherin) was tested by Western blot analysis. The targeting relationship between miR-144-3p and E2F2 was evaluated by dual-luciferase reporter and radioimmunoprecipitation assays, and the binding relationship between E2F2 and TNIK by dual-luciferase reporter and chromatin immunoprecipitation assays. TC cell growth in vivo was determined by subcutaneous tumorigenesis assays in nude mice. RESULTS: miR-144-3p was downregulated, whereas E2F2 and TNIK were upregulated in TC cells. Mechanistically, miR-144-3p inversely targeted E2F2, which increased TNIK expression by binding to TNIK promoter in TC cells. Overexpression of miR-144-3p reduced proliferation, migration, invasion, and EMT of FRO and KTC3 cells, which was nullified by overexpressing E2F2 or TNIK expression. Upregulation of miR-144-3p diminished FRO cell growth and EMT in nude mice, which was abrogated by overexpressing TNIK. CONCLUSION: miR-144-3p inhibits cell growth and EMT in TC through E2F2/TNIK axis inactivation in cells and male BALB/c nude mice.


Assuntos
MicroRNAs , Neoplasias da Glândula Tireoide , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Masculino , Camundongos , Camundongos Nus , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias da Glândula Tireoide/genética
5.
Cancer Cell Int ; 21(1): 322, 2021 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-34176471

RESUMO

BACKGROUND: It have been proven that long non-coding RNAs (lncRNAs) serve as regulators in carcinogenesis. Interleukin enhancer binding factor 3 antisense RNA 1 (ILF3-AS1) has been illuminated as a prognostic factor in some cancers. Nevertheless, its expression pattern and possible functions in papillary thyroid carcinoma (PTC) have not been studied. METHODS: The expression of ILF3-AS1 was measured by RT-qPCR and ISH. Colony formation assay and EdU assay were used to probe cell proliferation. TUNEL assay was used for analysis of cell apoptosis. Immunofluorescence and western blot were conducted to evaluate the expression change of E-cadherin and N-cadherin. The RNA interaction was demonstrated by mechanism experiments, including pull down assay and dual luciferase reporter assay. RESULTS: ILF3-AS1 expression was evidently upregulated in PTC cell lines. ILF3-AS1 knockdown restrained the proliferation, migration and invasion of PTC cells. Mechanical investigation revealed that miR-4306 could interact with ILF3-AS1. PLAGL2 was a downstream target of miR-4306. The effects of ILF3-AS1 knockdown on the cellular processes were abrogated by miR-4306 downregulation or pleiomorphic adenoma gene-like 2 (PLAGL2) overexpression. CONCLUSION: ILF3-AS1 plays tumor-promoting role in PTC via targeting miR-4306/PLAGL2 axis.

6.
Exp Clin Endocrinol Diabetes ; 125(9): 610-617, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28472825

RESUMO

In the past few years, metabolic disorders, such as type 2 diabetes and metabolic syndrome, have reached global prevalence. Lycopene is one of the major carotenoids in tomatoes, watermelons, red grapefruits, and guava. In the current study, using high fat diet (HFD)-fed mice, we investigated the effect of Lycopene on insulin resistance. We showed that diet containing Lycopene significantly prevented HFD-induced increase of fasting blood glucose and insulin level, glucose and insulin intolerance, and decrease of hepatic glycogen content. We found that Lycopene notably prevented the increase of IL-1ß, TNFα and CRP levels in mice fed HFD. We showed that Lycopene improved the lipid profiles in HFD-fed mice, as evidenced by decrease of systemic and hepatic TC, TG and LDL, and increase of HDL. Lycopene suppressed the increase of the expression of Srebp-1c, FAS and ACC-1 in mice fed HFD. The administration of Lycopene notably prevented the expression and phosphorylation of STAT3 in livers of mice induced by HFD. The treatment of adenovirus carrying STAT3 significantly suppressed the decrease of Srebp-1c expression induced by Lycopene. Furthermore, enhancement of STAT3 signaling by adenovirus markedly blocked the reduction of fasting blood glucose and insulin level. In conclusion, in the current study, we found that Lycopene prevented STAT3 signaling and inhibited Srebp-1c and downstream gene expression, resulting in inhibition of lipid accumulation, inflammation, insulin resistance and metabolic dysfunction. Overall, the data in the study provide better understanding of the beneficial effects of Lycopene against insulin resistance and metabolic disorder.


Assuntos
Carotenoides/uso terapêutico , Dieta Hiperlipídica , Intolerância à Glucose/tratamento farmacológico , Inflamação/prevenção & controle , Resistência à Insulina , Metabolismo dos Lipídeos/efeitos dos fármacos , Síndrome Metabólica/tratamento farmacológico , Animais , Dieta Hiperlipídica/efeitos adversos , Intolerância à Glucose/metabolismo , Inflamação/metabolismo , Licopeno , Síndrome Metabólica/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo
7.
Oncol Lett ; 10(1): 71-76, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26170979

RESUMO

The aim of the present study was to determine the antitumor effects of hyperthermic CO2 (HT-CO2)-treated dendritic cell (DC)-derived exosomes (Dex) on human gastric cancer AGS cells. Mouse-derived DCs were incubated in HT-CO2 at 43°C for 4 h. The exosomes in the cell culture supernatant were then isolated. Cell proliferation was analyzed using the cell counting kit-8 (CCK-8) assay. Cell apoptosis was observed using flow cytometry, Hoechst 33258 staining and the analysis of caspase-3 activity. In addition, the proliferation of tumor cells was evaluated in xenotransplant nude mice. HT-CO2 markedly inhibited cell proliferation, as assessed by the CCK-8 assay, and also induced apoptosis in a time-dependent manner, as demonstrated by Annexin V/propidium iodide flow cytometry, caspase-3 activity and morphological analysis using Hoechst fluorescent dye. It was also revealed that HT-CO2-treated Dex decreased the expression of heat shock protein 70 and inhibited tumor growth in nude mice. In conclusion, HT-CO2 exerted an efficacious immune-enhancing effect on DCs. These findings may provide a novel strategy for the elimination of free cancer cells during laparoscopic resection. However, the potential cellular mechanisms underlying this process require further investigation.

8.
Mol Cancer Ther ; 8(9): 2746-53, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19723878

RESUMO

Malignant gliomas manifest frequent tumor recurrence after surgical resection and/or other treatment because of their nature of invasiveness and dissemination. The recognized brain tumor-tracking property of neural progenitor/stem cells opened the possibility of targeting malignant brain tumors using neural progenitor/stem cells. We and others have previously shown that fetal neural progenitor/stem cells can be used to deliver therapeutic molecules to brain tumors. Our recent work has further shown that gene delivery by bone marrow-derived neural progenitor/stem cells achieves therapeutic effects in a glioma model. In this study, we isolate and characterize bone marrow-derived neural progenitor/stem cells, which also express the chemokine receptor chemokine CXC receptor 4 (CXCR4). We show that CXCR4 is required for their chemotaxis and extracellular matrix invasion against a gradient of glioma soluble factors. Furthermore, beta-galactosidase-labeled bone marrow-derived neural progenitor/stem cells implanted in the contralateral side of the brain were shown to track gliomas as early as day 1 and increased through days 3 and 7. Intracranial glioma tracking by bone marrow-derived neural progenitor/stem cells is significantly inhibited by preincubation of bone marrow-derived neural progenitor/stem cells with a blocking anti-CXCR4 antibody, suggesting a CXCR4-dependent tracking mechanism. Glioma tracking bone marrow-derived neural progenitor/stem cells were found to express progenitor/stem cell markers, as well as CXCR4. Although bromodeoxyuridine incorporation assays and proliferating antigen staining indicated that tumor tracking bone marrow-derived neural progenitor/stem cells were mostly nonproliferating, these cells survive in the local tumor environment with little apoptosis. Elucidating the molecular mechanism of brain tumor tracking by adult source stem cells may provide basis for the development of future targeted therapy for malignant brain tumors.


Assuntos
Células da Medula Óssea/metabolismo , Neoplasias Encefálicas/metabolismo , Glioma/metabolismo , Neurônios/metabolismo , Receptores CXCR4/metabolismo , Células-Tronco/metabolismo , Animais , Linhagem Celular Tumoral , Ensaio de Imunoadsorção Enzimática , Imuno-Histoquímica , Ratos , Ratos Endogâmicos F344
9.
Blood ; 113(9): 1992-2002, 2009 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-19060246

RESUMO

Enhanced angiogenesis is a hallmark of cancer. Pleiotrophin (PTN) is an angiogenic factor that is produced by many different human cancers and stimulates tumor blood vessel formation when it is expressed in malignant cancer cells. Recent studies show that monocytes may give rise to vascular endothelium. In these studies, we show that PTN combined with macrophage colony-stimulating factor (M-CSF) induces expression of vascular endothelial cell (VEC) genes and proteins in human monocyte cell lines and monocytes from human peripheral blood (PB). Monocytes induce VEC gene expression and develop tube-like structures when they are exposed to serum or cultured with bone marrow (BM) from patients with multiple myeloma (MM) that express PTN, effects specifically blocked with antiPTN antibodies. When coinjected with human MM cells into severe combined immunodeficient (SCID) mice, green fluorescent protein (GFP)-marked human monocytes were found incorporated into tumor blood vessels and expressed human VEC protein markers and genes that were blocked by anti-PTN antibody. Our results suggest that vasculogenesis in human MM may develop from tumoral production of PTN, which orchestrates the transdifferentiation of monocytes into VECs.


Assuntos
Proteínas de Transporte/farmacologia , Transdiferenciação Celular/efeitos dos fármacos , Citocinas/farmacologia , Células Endoteliais/fisiologia , Monócitos/efeitos dos fármacos , Mieloma Múltiplo/metabolismo , Neovascularização Patológica/etiologia , Animais , Proteínas de Transporte/administração & dosagem , Proteínas de Transporte/metabolismo , Células Cultivadas , Citocinas/administração & dosagem , Citocinas/metabolismo , Combinação de Medicamentos , Células Endoteliais/efeitos dos fármacos , Proteínas de Fluorescência Verde/genética , Humanos , Fator Estimulador de Colônias de Macrófagos/administração & dosagem , Fator Estimulador de Colônias de Macrófagos/farmacologia , Masculino , Camundongos , Camundongos SCID , Camundongos Transgênicos , Monócitos/patologia , Monócitos/fisiologia , Mieloma Múltiplo/patologia , Neovascularização Patológica/induzido quimicamente , Transplante Heterólogo , Células U937
10.
J Neurosci Res ; 85(2): 310-20, 2007 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-17131390

RESUMO

Recent evidence has demonstrated that neural stem cells (NSC) can be expanded from a variety of sources, including embryos, fetuses, and adult bone marrow and brain tissue. We have previously reported the generation of adult rat bone marrow-derived cellular spheres that are morphologically and phenotypically similar to neurospheres derived from brain NSC. Here we show that adult human bone marrow-derived neural stem cells (HBM-NSC) are capable of generating spheres that are similar to brain neural-derived neurospheres. Additionally, we sought to promote proliferation and differentiation of HBM-NSC through transduction with nonreplicative recombinant adenovirus encoding the cDNA sequence for Gli, rADV-Gli-1; sonic hedgehog, rADV-Shh; or Nurr1, rADV-Nurr1. Immunocytochemistry and RT-PCR analysis showed that HBM-NSC could be efficiently expanded and differentiated in vitro and that HBM-NSC transduced with rADV-Gli-1 or rADV-Shh dramatically increased NSC time-related proliferation; however, Nurr1 had no effect on proliferation. We also transplanted HBM-NSC into chicken embryos to examine their potential function in vivo. We found that transduction of HBM-NSC with rADV-Gli-1 or rADV-Shh and subsequent transplantation into chicken embryos increased HBM-NSC proliferation, whereas rADV-Nurr1 promoted migration and differentiation in vivo. Our findings suggest that HBM-NSC can be efficiently expanded and differentiated in vitro and in vivo by overexpressing Gli-1, Shh or Nurr1.


Assuntos
Células da Medula Óssea/citologia , Diferenciação Celular/fisiologia , Proliferação de Células , Células-Tronco Hematopoéticas/citologia , Neurônios/citologia , Animais , Células Cultivadas , Embrião de Galinha , Citometria de Fluxo , Células-Tronco Hematopoéticas/fisiologia , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Potenciais da Membrana/fisiologia , Técnicas de Patch-Clamp , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução Genética
11.
Mol Cancer ; 5: 67, 2006 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-17140455

RESUMO

BACKGROUND: Recently, a small population of cancer stem cells in adult and pediatric brain tumors has been identified. Some evidence has suggested that CD133 is a marker for a subset of leukemia and glioblastoma cancer stem cells. Especially, CD133 positive cells isolated from human glioblastoma may initiate tumors and represent novel targets for therapeutics. The gene expression and the drug resistance property of CD133 positive cancer stem cells, however, are still unknown. RESULTS: In this study, by FACS analysis we determined the percentage of CD133 positive cells in three primary cultured cell lines established from glioblastoma patients 10.2%, 69.7% and 27.5%, respectively. We also determined the average mRNA levels of markers associated with neural precursors. For example, CD90, CD44, CXCR4, Nestin, Msi1 and MELK mRNA on CD133 positive cells increased to 15.6, 5.7, 337.8, 21.4, 84 and 1351 times, respectively, compared to autologous CD133 negative cells derived from cell line No. 66. Additionally, CD133 positive cells express higher levels of BCRP1 and MGMT mRNA, as well as higher mRNA levels of genes that inhibit apoptosis. Furthermore, CD133 positive cells were significantly resistant to chemotherapeutic agents including temozolomide, carboplatin, paclitaxel (Taxol) and etoposide (VP16) compared to autologous CD133 negative cells. Finally, CD133 expression was significantly higher in recurrent GBM tissue obtained from five patients as compared to their respective newly diagnosed tumors. CONCLUSION: Our study for the first time provided evidence that CD133 positive cancer stem cells display strong capability on tumor's resistance to chemotherapy. This resistance is probably contributed by the CD133 positive cell with higher expression of on BCRP1 and MGMT, as well as the anti-apoptosis protein and inhibitors of apoptosis protein families. Future treatment should target this small population of CD133 positive cancer stem cells in tumors to improve the survival of brain tumor patients.


Assuntos
Antígenos CD/biossíntese , Antineoplásicos/farmacologia , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Glicoproteínas/biossíntese , Células-Tronco Neoplásicas/fisiologia , Antígeno AC133 , Antígenos CD/genética , Apoptose/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais , Expressão Gênica , Glioblastoma/imunologia , Glioblastoma/patologia , Glicoproteínas/genética , Humanos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/imunologia , Peptídeos/genética , RNA Mensageiro/biossíntese , RNA Mensageiro/genética
12.
J Biol Chem ; 281(10): 6165-74, 2006 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-16319070

RESUMO

Despite dramatic advances in adjuvant therapies, patients with malignant glioma face a bleak prognosis. Because many adjuvant therapies seek to induce glioma apoptosis, strategies that lower thresholds for the induction of apoptosis may improve patient outcomes. Therefore, elucidation of the biological mechanisms that underlie resistance to current therapies is needed to develop new therapeutic strategies. Here we proposed a novel mechanism of proapoptotic effect induced by a pharmacological peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist, troglitazone, that facilitates caspase signaling in human glioma cells. Troglitazone activates protein-tyrosine phosphatase (PTP)-1B, which subsequently reduces phosphotyrosine 705 STAT3 (pY705-STAT3) via a PPARgamma-independent pathway. Reduction of pY705-STAT3 in glioma cells caused down-regulation of FLIP (FADD-like IL-1beta-converting enzyme-inhibitory protein) and Bcl-2. Furthermore, troglitazone induced Ser-392 phosphorylation of p53 via a PPARgamma-dependent pathway and up-regulation of Bax in a p53 wild-type glioma. When given with tumor necrosis factor-related apoptosis-inducing ligand or caspase-dependent chemotherapeutic agents, such as etoposide and paclitaxel, troglitazone exhibited a synergistic effect by facilitating caspase-8/9 activities. A PPARgamma antagonist, GW9662, did not block this effect, although a PTP inhibitor abrogated it. Knockdown of STAT3 by STAT3-small interfering RNA negated the inhibitory effect of PTP inhibitor on troglitazone, indicating that troglitazone uses a STAT3 inactivation mechanism that makes caspase-8/9 activities susceptible to cytotoxic agents in glioma cells and that PTP1B plays a critical role in the down-regulation of activated STAT3, as well as FLIP and Bcl-2. When taken with caspase-dependent anti-neoplastic agents, troglitazone may be a promising drug for use against malignant gliomas because it facilitates the caspase cascade, thereby lowering thresholds for the apoptosis induction of glioma cells.


Assuntos
Antineoplásicos/farmacologia , Caspases/metabolismo , Cromanos/farmacologia , Glioma/enzimologia , PPAR gama/agonistas , Proteínas Tirosina Fosfatases/metabolismo , Tiazolidinedionas/farmacologia , Regulação para Cima/efeitos dos fármacos , Apoptose/fisiologia , Proteínas Reguladoras de Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/fisiologia , Caspase 8 , Caspase 9 , Sinergismo Farmacológico , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Glioma/tratamento farmacológico , Glioma/patologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Glicoproteínas de Membrana/efeitos dos fármacos , Glicoproteínas de Membrana/fisiologia , Proteína Tirosina Fosfatase não Receptora Tipo 1 , Proteína Tirosina Fosfatase não Receptora Tipo 6 , Proteínas Tirosina Fosfatases/biossíntese , Proteínas Tirosina Fosfatases/genética , Fator de Transcrição STAT3/fisiologia , Ligante Indutor de Apoptose Relacionado a TNF , Troglitazona , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/efeitos dos fármacos , Fator de Necrose Tumoral alfa/fisiologia , Regulação para Cima/fisiologia
13.
Curr Stem Cell Res Ther ; 1(1): 79-84, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18220856

RESUMO

Brain tumors can be highly aggressive and debilitating for many patients and lead to an untimely death in just a few months. Unfortunately, due to the location of many brain tumors, therapy with ionizing radiation, chemotherapeutic agents and/or surgery has limited rewards. In addition, the probability of totally removing highly infiltrative tumors, particularly gliomas, is extremely low and rarely provides a cure. The need for directed targeting and ablation of tumors with minimal damage to nearby healthy tissue has lead to the most recent findings and uses of neural stem cells for therapeutic treatment of brain tumors. Recently, some very promising studies have demonstrated that exogenous neural stem cells have the remarkable ability to migrate very long distances towards sites of metastasis after transplantation. These studies also show that intravascular injections of neural stem cells may lead to preferential migration towards central nervous system tumors. It has also been demonstrated that genetically modified neural stem cells, engineered to produce anti-tumor molecules, upon transplantation, have the ability to migrate towards tumors and reduce tumor mass directly or through a "bystander" effect. Here we review the current literature examining the promise of utilizing genetically modified neural stem cells as vehicles for CNS tumor therapy.


Assuntos
Neoplasias Encefálicas/terapia , Neurônios/transplante , Movimento Celular , Humanos , Neurônios/citologia , Neurônios/fisiologia , Transdução de Sinais , Transplante de Células-Tronco/efeitos adversos
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