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1.
Indian J Clin Biochem ; 39(1): 47-59, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38223000

RESUMO

Meningioma is a common brain tumour which has neither a specific detection nor treatment method. The Sonic hedgehog (Shh) cell signaling pathway is a crucial regulatory pathway of mammalian organogenesis and tumorigenesis including meningioma. Shh cell signalling pathway cascade function by main transcription factor Gli1 and which further regulates in its downstream to Pax6 and Nkx2.2. This current study is aimed to explore the regulation of the Sonic hedgehog-Gli1 cell signaling pathway and its potential downstream targets in meningioma samples. A total of 24 surgically resected meningioma samples were used in this current study.Cytological changes were assessed using electron microscopic techniques as well as hematoxylin & eosin and DAPI staining. The expression pattern of Gli1, Nkx2.2 and Pax6 transcription factors were determined by using immunohistochemistry. The mRNA expression was assessed using RT-qPCR assays. Later, the whole transcriptome analysis of samples was performed with the amploseq technique. Results were compared with those obtained in normal human brain tissue (or normal meninges). Compared to the normal human brain tissue, meningioma samples showed crowded nuclei with morphological changes. Transcription factor Nkx2.2 expressed highly in all samples (24/24, 100%). Twenty-one of the 24 meningiomas (88%) showed high Gli1 and Pax6 expression. Whole transcriptome analysis of two meningioma samples also exhibited a very high increase in Gli1 expression signal in meningioma samples as compare to normal control. Hence, we may conclude that the Shh-Gli1 pathway is aberrantly activated in meningioma cells and is canonically upregulating the expression of transcription factors Pax6 and Nkx2.2. Supplementary Information: The online version contains supplementary material available at 10.1007/s12291-022-01085-1.

2.
Mol Carcinog ; 62(12): 1817-1831, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37606187

RESUMO

The atypical cadherin FAT1 function either as a pro or antitumorigenic in tumors of different tissue origins. Our group previously demonstrated the protumorigenic nature of FAT1 signaling in glioblastoma (GBM). In this study, we investigated how FAT1 influences the expression of clustered oncomiRs (miR-221-3p/miR-222-3p) and their downstream effects in GBM. Through several experiments involving the measurement of specific gene/microRNA expression, gene knockdowns, protein and cellular assays, we have demonstrated a novel oncogenic signaling pathway mediated by FAT1 in glioma. These results have been verified using antimiRs and miR-mimic assays. Initially, in glioma-derived cell lines (U87MG and LN229), we observed FAT1 as a novel up-regulator of the transcription factor NFκB-RelA. RelA then promotes the expression of the clustered-oncomiRs, miR-221-3p/miR-222-3p, which in turn suppresses the expression of the tumor suppressor gene (TSG), PDCD10 (Programmed cell death protein10). The suppression of PDCD10, and other known TSG targets (PTEN/PUMA), by miR-221-3p/miR-222-3p, leads to increased clonogenicity, migration, and invasion of glioma cells. Consistent with our in-vitro findings, we observed a positive expression correlation of FAT1 and miR-221-3p, and an inverse correlation of FAT1 and the miR-targets (PDCD10/PTEN/PUMA), in GBM tissue-samples. These findings were also supported by publicly available GBM databases (The Cancer Genome Atlas [TCGA] and The Repository of Molecular Brain Neoplasia Data [Rembrandt]). Patients with tumors displaying high levels of FAT1 and miR-221-3p expression (50% and 65% respectively) experienced shorter overall survival. Similar results were observed in the TCGA-GBM database. Thus, our findings show a novel FAT1/RelA/miR-221/miR-222 oncogenic-effector pathway that downregulates the TSG, PDCD10, in GBM, which could be targeted therapeutically in a specific manner.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioma , MicroRNAs , Humanos , Glioblastoma/metabolismo , Caderinas/genética , Caderinas/metabolismo , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Glioma/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Proliferação de Células/genética , Movimento Celular/genética , Proteínas de Membrana/genética , Proteínas Proto-Oncogênicas/genética
3.
J Biochem Mol Toxicol ; 37(2): e23241, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36205257

RESUMO

Glioma is a major brain tumor, and the associated mortality rate is very high. Contemporary therapies provide a chance of survival for 9-12 months. Therefore, a novel approach is essential to improve the survival rate. Sonic hedgehog (Shh) cell signaling is critical for early development in various tumors. This investigation attempted to explore the potential interaction and regulation of Shh-Gli1 cell signaling in association with paired box 6 (Pax6) and isocitrate dehydrogenase 2 (IDH2). The expression pattern of Shh, Gli1, Pax6, and IDH2 was examined by transcriptome analysis, immunohistochemistry, and confocal images. The results suggest the interaction of Shh-Gli1 cell signaling pathway with Pax6 and IDH2 and potential regulation. Thereafter, we performed protein-protein docking and molecular dynamic simulations (MDS) of Gli1 with Pax6 and IDH2. The results suggest differential dynamic interactions of Gli1-IDH2 and Gli1-Pax6. Gli1 knockdown downregulated the expression of Pax6 and upregulated the expression of IDH2. Moreover, Gli1 knockdown decreased the expression of the drug resistance gene MRP1. The knockdown of Pax6 gene in glioma cells downregulated the expression of Gli1 and IDH2 and promoted cell proliferation. Moreover, the efficacy of the treatment of glioma cells with temozolomide (TMZ) and Gli1 inhibitor GANT61 was higher than that of TMZ alone. MDS results revealed that the interactions of Gli1 with IDH2 were stronger and more stable than those with Pax6. Intriguingly, inhibition of Pax6 promoted glioma growth even in the presence of TMZ. However, the tumor-suppressive nature of Pax6 was altered when Gli1 was inhibited by GANT61, and it showed potential oncogenic character, as observed in other cancers. Therefore, we conclude that Pax6 interacted with IDH2 and Gli1 in glioma. Moreover, the Shh-Gli1-IDH2/Pax6 cell signaling axis provides a new therapeutic approach for inhibiting the progression of the disease and mitigating drug resistance in glioma.


Assuntos
Neoplasias Encefálicas , Glioma , Humanos , Proteína GLI1 em Dedos de Zinco/genética , Proteína GLI1 em Dedos de Zinco/metabolismo , Proteína GLI1 em Dedos de Zinco/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Proteínas Hedgehog/metabolismo , Glioma/tratamento farmacológico , Glioma/metabolismo , Neoplasias Encefálicas/metabolismo , Temozolomida/farmacologia , Fator de Transcrição PAX6/genética
4.
Ann Diagn Pathol ; 56: 151846, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34749048

RESUMO

PURPOSE: VEGF and HIF-1α are important regulators of angiogenesis, overexpressed in various tumors. Lacrimal gland Adenoid cystic carcinoma (ACC) is a malignant tumor whose angiogenic properties remain unexplored. This study was designed to evaluate the expression of HIF-1α and VEGF in lacrimal gland ACC. METHODS: VEGF and HIF-1α immunoexpression was undertaken in 30 lacrimal gland ACC cases. mRNA expression of VEGF and HIF-1α was analysed in 17 cases by quantitative real time PCR. The results obtained were correlated with clinicopathological features and survival of the patients to determine the prognostic significance. RESULTS: Immunoexpression of HIF-1α and VEGF was seen in 36.6% and 46.6% ACC cases. HIF-1α expression showed significant association with advanced T-stage (P = 0.001) and VEGF with intracranial extension (P = 0.014) and solid histological pattern (P = 0.045). HIF-1α mRNA expression was seen in 29.4% cases and showed significant association with perineural invasion (P = 0.027). Recurrence occurred in 60%, distant metastasis in 20% and death in 20% cases. Survival analysis revealed that patients with HIF-1α, VEGF immunoexpression, solid histological pattern, perineural invasion, bone erosion, intracranial extension, metastasis, advanced T-stage, and exenteration had poor survival. On multivariate analysis VEGF immunoexpression (hazard ratio, 16.785; 95% confidence interval, 1.872-150.495; P = 0.012) was the most significant poor prognostic factor. CONCLUSIONS: This study demonstrates that VEGF is a potential predictor for poor clinical outcome in lacrimal gland Adenoid cystic carcinoma.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma Adenoide Cístico/metabolismo , Neoplasias Oculares/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Doenças do Aparelho Lacrimal/metabolismo , Aparelho Lacrimal/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Adolescente , Adulto , Idoso , Carcinoma Adenoide Cístico/diagnóstico , Carcinoma Adenoide Cístico/mortalidade , Neoplasias Oculares/diagnóstico , Neoplasias Oculares/mortalidade , Feminino , Seguimentos , Humanos , Doenças do Aparelho Lacrimal/diagnóstico , Doenças do Aparelho Lacrimal/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida , Adulto Jovem
5.
BMC Cancer ; 20(1): 62, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992226

RESUMO

BACKGROUND: Overexpression of FAT1 gene and its oncogenic effects have been reported in several cancers. Previously, we have documented upregulation of FAT1 gene in glioblastoma (GBM) tumors which was found to increase the expression of proinflammatory markers, HIF-1α, stemness genes and EMT markers in glioma cells. Here, we reveal NFкB (RelA)/RelA/p65 as the transcriptional regulator of FAT1 gene in GBM cells. METHODS: In-silico analysis of FAT1 gene promoter was performed using online bioinformatics tool Promo alggen (Transfac 8.3) to identify putative transcription factor(s) binding motifs. A 4.0 kb FAT1 promoter (- 3220 bp to + 848 bp w.r.t. TSS + 1) was cloned into promoter less pGL3Basic reporter vector. Characterization of FAT1 promoter for transcriptional regulation was performed by in-vitro functional assays using promoter deletion constructs, site directed mutagenesis and ChIP in GBM cells. RESULTS: Expression levels of NFкB (RelA) and FAT1 were found to be increased and positively correlated in GBM tumors (n = 16), REMBRANDT GBM-database (n = 214) and TCGA GBM-database (n = 153). In addition to glioma, positive correlation between NFкB (RelA) and FAT1 expression was also observed in other tumors like pancreatic, hepatocellular, lung and stomach cancers (data extracted from TCGA tumor data). A 4.0 kb FAT1-promoter-construct [- 3220 bp/+ 848 bp, transcription start site (TSS) + 1, having 17 NFкB (RelA) motifs] showed high FAT1 promoter luciferase-activity in GBM cells (U87MG/A172/U373MG). FAT1 promoter deletion-construct pGL3F1 [- 200 bp/+ 848 bp, with 3-NFкB (RelA)-motifs] showed the highest promoter activity. Exposure of GBM cells to known NFкB (RelA)-activators [severe-hypoxia/TNF-α/ectopic-NFкB (RelA) + IKBK vectors] led to increased pGL3F1-promoter activity and increased endogenous-FAT1 expression. Conversely, siRNA-mediated NFкB (RelA) knockdown led to decreased pGL3F1-promoter activity and decreased endogenous-FAT1 expression. Deletion of NFкB (RelA)-motif at - 90 bp/- 80 bp [pGL3F1δ1-construct] showed significant decrease in promoter activity. Site directed mutagenesis at -90 bp/- 80 bp and ChIP assay for endogenous-NFкB (RelA) confirmed the importance of this motif in FAT1 expression regulation. Significant reduction in the migration, invasion as well as colony forming capacity of the U87MG glioma cells was observed on siRNA-mediated knockdown of NFкB (RelA). CONCLUSION: Since FAT1 and NFкB (RelA) are independently known to promote pro-tumorigenic inflammation and upregulate the expression of HIF-1α/EMT/stemness in tumors, targeting the NFкB (RelA)-FAT1 axis may attenuate an important tumor-promoting pathway in GBM. This may also be applicable to other tumors.


Assuntos
Neoplasias Encefálicas/metabolismo , Caderinas/genética , Glioma/metabolismo , Fator de Transcrição RelA/metabolismo , Sítios de Ligação , Neoplasias Encefálicas/genética , Caderinas/química , Caderinas/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Clonagem Molecular , Simulação por Computador , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Humanos , Mutagênese Sítio-Dirigida , Regiões Promotoras Genéticas , Transdução de Sinais
6.
J Vector Borne Dis ; 57(4): 285-294, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-34856707

RESUMO

BACKGROUND & OBJECTIVES: Malaria continues to be a significant public health problem in tropical countries including India; however, there are limited tools to predict occurrence of severe disease due to malaria. This study was designed to evaluate the role of Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2), Vascular endothelial growth factor (VEGF) and Asymmetric Dimethylarginine (ADMA)as disease biomarkers in uncomplicated malaria (UM) and severe malaria (SM). METHODS: This is a prospective observational study carried out at All India Institute of Medical Sciences (AIIMS), tertiary referral hospital in New Delhi, India. The study population included patients diagnosed with malaria (Plasmodium falciparum or Plasmodium vivax) either by rapid diagnostic kit test or positive peripheral smear and age more than 12 years. Forty-nine patients (25 with SM, 24 with UM) and 22 controls were recruited. In addition to routine investigations, serum concentrations of Ang-1, Ang-2, VEGF and ADMA were measured using ELISA technique. RESULTS: We observed Ang-1 serum levels to be significantly lower in patients with severe malaria (7775 pg/ml) compared to uncomplicated malaria (17629 pg/ml) and healthy controls (43472 pg/ml) [p <0.001]. Ang-2 levels were significantly higher in severe malaria (11100 pg/ml) compared to uncomplicated malaria (7315 pg/ml) and healthy controls (3679 pg/ml) (p <0.001). The ratio of Ang-2/Ang-1 was significantly higher in patients with severe malaria. VEGF serum levels was significantly lower in severe malaria (130.36 pg/ml) compared to uncomplicated malaria (317.3 pg/ml). The Ang-1, Ang-2 and VEGF levels were able to differentiate severe malaria from uncomplicated malaria caused by P. vivax but not with P. falciparum. INTERPRETATION & CONCLUSION: We conclude that Ang-1, Ang-2 and VEGF are markers of disease severity in vivax malaria.


Assuntos
Malária Falciparum , Malária Vivax , Angiopoietina-1 , Criança , Humanos , Malária Falciparum/diagnóstico , Malária Vivax/diagnóstico , Plasmodium vivax , Fator A de Crescimento do Endotélio Vascular , Proteínas de Transporte Vesicular
7.
Exp Mol Pathol ; 111: 104313, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31533021

RESUMO

PURPOSE: To analyze the activation of NFκB1/p50 in the inflammatory and non-inflammatory environment of uveal melanoma and its association with clinicopathological factors and patient outcome. METHODS: Activation of NFκB1/p50 was evaluated in 75 cases of uveal melanoma by immunohistochemistry. mRNA expression in 58 fresh UM specimen was measured by quantitative reverse-transcriptase PCR (qRT-PCR). Western blotting was performed to validate the immunohistochemistry results in representative cases. RESULTS: Forty-five cases showed both cytoplasmic and nuclear immunoreactivity of NFκB1/p50. Increased level of NFκB1/p50 activation was more frequent in the inflammatory environment group as compared to non-inflammatory environment group at both transcriptional and translational level. In multivariate analysis, infiltrating macrophages and nuclear immunoreactivity of NFκB1/p50 (p < .05) in tumor cells were found to be an independent prognostic factor for poor survival. CONCLUSION: Our results suggest that nuclear immunoreactivity NFκB1/p50 may serve as a useful marker in assessing the prognosis of uveal melanoma patients.


Assuntos
Núcleo Celular/metabolismo , Inflamação/patologia , Melanoma/patologia , Subunidade p50 de NF-kappa B/metabolismo , Neoplasias Uveais/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Núcleo Celular/genética , Feminino , Humanos , Inflamação/imunologia , Inflamação/metabolismo , Masculino , Melanoma/imunologia , Melanoma/metabolismo , Pessoa de Meia-Idade , Subunidade p50 de NF-kappa B/genética , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida , Neoplasias Uveais/imunologia , Neoplasias Uveais/metabolismo , Adulto Jovem
8.
Int J Cancer ; 142(4): 805-812, 2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-28994107

RESUMO

Glioblastoma (GBM) is characterized by the presence of hypoxia, stemness and local invasiveness. We have earlier demonstrated that FAT1 promotes invasiveness, inflammation and upregulates HIF-1α expression and its signaling in hypoxic GBM. Here, we have identified the role of FAT1 in regulating EMT (epithelial-mesenchymal transition) and stemness characteristics in GBM. The expression of FAT1, EMT (Snail/LOX/Vimentin/N-cad), stemness (SOX2/OCT4/Nestin/REST) and hypoxia markers (HIF-1α/VEGF/PGK1/CA9) was upregulated in ≥39% of GBM tumors (n = 31) with significant positive correlation (p ≤ 0.05) of the expression of FAT1 with LOX/Vimentin/SOX2/HIF-1α/PGK1/VEGF/CA9. Furthermore, positive correlation (p ≤ 0.01) of FAT1 with Vimentin/N-cad/SOX2/REST/HIF-1α has been observed in TCGA GBM-dataset (n = 430). Analysis of cells (U87MG/A172) exposed to severe hypoxia (0.2%O2 ) revealed elevated mRNA expression of FAT1, EMT (Snail/LOX/Vimentin/N-cad), stemness (SOX2/OCT4/Nestin/REST) and hypoxia markers (HIF-1α/PGK1/VEGF/CA9) as compared to their normoxic (20%O2 ) counterparts. FAT1 knockdown in U87MG/A172 maintained in severe hypoxia and in normoxic primary glioma cultures led to significant reduction of EMT/stemness markers as compared to controls. HIF-1α knockdown in U87MG cells markedly reduced the expression of all the EMT/stemness markers studied except for Nestin and SOX2 which were more under the influence of FAT1. This indicates FAT1 has a novel regulatory effect on EMT/stemness markers both via or independent of HIF-1α. The functional relevance of our study was corroborated by significant reduction in the number of soft-agar colonies formed in hypoxic-siFAT1 treated U87MG cells. Hence, our study for the first time reveals FAT1 as a novel regulator of EMT/stemness in hypoxic GBM and suggests FAT1 as a potential therapeutic candidate.


Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Caderinas/genética , Glioblastoma/genética , Glioblastoma/patologia , Células-Tronco Neoplásicas/patologia , Neoplasias Encefálicas/metabolismo , Caderinas/biossíntese , Caderinas/metabolismo , Hipóxia Celular/genética , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Glioblastoma/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Células-Tronco Neoplásicas/metabolismo , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Células Tumorais Cultivadas
9.
Horm Metab Res ; 49(6): 452-456, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28472826

RESUMO

Insulinomas are rare pancreatic neuroendocrine tumors. The genetic causes underlying insulinoma are still being investigated. Recently, 3 independent studies reported a recurrent somatic mutation in YY1 gene (C>G; Thr372Arg) among insulinoma patients belonging to Chinese and Western Caucasian populations, which was found to increase insulin secretion by ß-cells. However, the status of this key gene variation remains unknown in patients of other ethnicities. We, therefore, screened Indian sporadic insulinoma patients for YY1 T372R mutation in the present study. Seventeen patients diagnosed with insulinoma were recruited retrospectively and their records of family history and clinical parameters were collected. Formalin-fixed paraffin-embedded tumor tissues were used to extract genomic DNA, which was subjected to PCR amplification of YY1 exon 5, followed by Sanger sequencing. Nucleotide sequences thus obtained were aligned against the documented sequence of YY1 exon 5. We found absence of C to G mutation at YY1 codon 372 in all 17 (100%) insulinoma tissues analyzed. On comparison with the mutation frequency observed in the Chinese patients, our results point to genetic heterogeneity in the pathogenesis of insulinoma. This is the first report on the status of YY1 T372R in insulinoma cases of Indian origin. This also warrants analysis of other documented as well as novel mutations in genes in insulinoma tumorigenesis.


Assuntos
Substituição de Aminoácidos/genética , Insulinoma/genética , Mutação/genética , Fator de Transcrição YY1/genética , Adolescente , Adulto , Idoso , Sequência de Bases , Feminino , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
Int J Cancer ; 139(11): 2570-82, 2016 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-27536856

RESUMO

The hypoxic microenvironment is an important contributor of glioblastoma (GBM) aggressiveness via HIF1α, while tumour inflammation is profoundly influenced by FAT Atypical Cadherin (FAT1). This study was designed to explore the functional interaction and significance of FAT1 and HIF1α under severe hypoxia-mimicking tumour microenvironment in primary human tumours. We first identified a positive correlation of FAT1 with HIF1α and its target genes in GBM tumour specimens, revealing the significance of the FAT1-HIF1α axis in glioma cells. We found that severe hypoxia leads to an increased expression of FAT1 and HIF1α in U87MG and U373MG cells. To reveal the relevance of FAT1 under hypoxic conditions, we depleted endogenous FAT1 under hypoxia and found a substantial reduction in the expression of HIF1α and its downstream target genes like CA9, GLUT1, VEGFA, MCT4, HK2, BNIP3 and REDD1, as well as a significant reduction in the invasiveness in GBM cells. At the molecular level, under hypoxia the FAT1 depletion-associated reduction in HIF1α was due to compromised EGFR-Akt signaling as well as increased VHL-dependent proteasomal degradation of HIF1α. In brief, for the first time, these results reveal an upstream master regulatory role of FAT1 in the expression and role of HIF1α under hypoxic conditions and that FAT1-HIF1α axis controls the invasiveness of GBM. Hence, FAT1 represents a novel potential therapeutic target for GBM.


Assuntos
Caderinas/metabolismo , Glioblastoma/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/biossíntese , Caderinas/biossíntese , Caderinas/genética , Hipóxia Celular/fisiologia , Linhagem Celular Tumoral , Receptores ErbB/metabolismo , Técnicas de Silenciamento de Genes , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Gradação de Tumores , Invasividade Neoplásica , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Transdução de Sinais , Proteína Supressora de Tumor Von Hippel-Lindau/biossíntese
11.
Tumour Biol ; 37(9): 12347-12358, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27306214

RESUMO

Resistance to drugs, which is aggravated by hypoxia, is a well-known feature of tumors. The combination of drug exposure and hypoxia can give rise to several survival strategies in the exposed cells. Glioblastoma multiforme (GBM) is among the most hypoxic of solid tumors, and we have used glial cells to identify a drug combination that would be synergistically effective in these cells under both normoxia and hypoxia. Cisplatin (CP) and 2-deoxy-D-glucose (2-DG), which have been used for second-line therapy and for preclinical research, are relatively ineffective as single agents. During in vitro experiments with A172 and LN229 cells, there was increased resistance to both drugs under hypoxia. However, the combination of CP and 2-DG showed a synergistic effect in reducing cell viability under both normoxia and hypoxia, with a combination index of less than 1. Increased autophagy is a distinct feature of the response to 2-DG. However, autophagic markers were reduced, and apoptotic markers were upregulated by the combination, indicating a switch over from autophagic to apoptotic pathways with reduction in endoplasmic reticulum (ER) stress. The combination also resulted in a decrease of pAKT levels. The effect of CP in the combination was replicated by the prototype AKT inhibitor LY294002, further supporting the role of AKT inhibition in the synergism. Combination of 2-DG with CP, or possibly an AKT inhibitor, can prove to be an effective rational combination for reducing chemoresistance under both normoxic and hypoxic conditions in gliomas.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Cisplatino/farmacologia , Desoxiglucose/farmacologia , Antineoplásicos/farmacologia , Apoptose/genética , Autofagia/genética , Western Blotting , Hipóxia Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Cromonas/farmacologia , Dacarbazina/análogos & derivados , Dacarbazina/farmacologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Citometria de Fluxo , Expressão Gênica/genética , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Morfolinas/farmacologia , Oxigênio/metabolismo , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Temozolomida , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
12.
Pancreas ; 53(1): e42-e48, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38019614

RESUMO

BACKGROUND AND AIM: Pancreatic ductal adenocarcinoma (PDAC) is one of the lethal malignancies worldwide characterized by poor prognosis. MicroRNAs (miRNAs) function as the key regulators in carcinogenesis and may act as noninvasive biomarkers in various malignancies including PDAC. The present study aimed to elucidate the role of miR-326, a known modulator of hedgehog (Hh) pathway in PDAC. MATERIALS AND METHODS: miR-326 circulating levels were assessed in 105 PDAC patients, 31 with chronic pancreatitis (CP) and 36 healthy controls by quantitative Polymerase chain reaction. The expression of miR-326 and smoothened (SMO) was checked in surgical PDAC tissue. SMO protein expression was analyzed by immunohistochemistry in different groups. Finally, the role of miR-326 as a modulator of Hh pathway was assessed in vitro. RESULTS: Our results demonstrate that miR-326 is downregulated in both blood and tissue of PDAC patients as compared with controls. In contrast, the target gene/protein expression of SMO is upregulated in PDAC. Moreover, the tumor stromal expression of SMO was found to be clinically associated with lymph-node metastasis and vascular encasement in PDAC. Overexpression of miR-326 in Panc1 cell line was found to induce downregulation of SMO suggesting the tumor suppressor role of miR-326 in PDAC. CONCLUSIONS: Taken together, miR-326 acts as a tumor suppressor in PDAC by modulating Hh pathway. It may be a promising target for the development of efficient drug therapies for the treatment of PDAC.


Assuntos
Carcinoma Ductal Pancreático , MicroRNAs , Neoplasias Pancreáticas , Humanos , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Neoplasias Pancreáticas/patologia , Carcinoma Ductal Pancreático/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , Transdução de Sinais , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral
13.
Cell Signal ; 119: 111178, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38640981

RESUMO

STAT1 (Signal Transducer and Activator of Transcription 1), belongs to the STAT protein family, essential for cytokine signaling. It has been reported to have either context dependent oncogenic or tumor suppressor roles in different tumors. Earlier, we demonstrated that Glioblastoma multiforme (GBMs) overexpressing FAT1, an atypical cadherin, had poorer outcomes. Overexpressed FAT1 promotes pro-tumorigenic inflammation, migration/invasion by downregulating tumor suppressor gene, PDCD4. Here, we demonstrate that STAT1 is a novel mediator downstream to FAT1, in downregulating PDCD4 in GBMs. In-silico analysis of GBM databases as well as q-PCR analysis in resected GBM tumors showed positive correlation between STAT1 and FAT1 mRNA levels. Kaplan-Meier analysis showed poorer survival of GBM patients having high FAT1 and STAT1 expression. SiRNA-mediated knockdown of FAT1 decreased STAT1 and increased PDCD4 expression in glioblastoma cells (LN229 and U87MG). Knockdown of STAT1 alone resulted in increased PDCD4 expression. In silico analysis of the PDCD4 promoter revealed four putative STAT1 binding sites (Site1-Site4). ChIP assay confirmed the binding of STAT1 to site1. ChIP-PCR revealed decrease in the binding of STAT1 on the PDCD4 promoter after FAT1 knockdown. Site directed mutagenesis of Site1 resulted in increased PDCD4 luciferase activity, substantiating STAT1 mediated PDCD4 inhibition. EMSA confirmed STAT1 binding to the Site 1 sequence. STAT1 knockdown led to decreased expression of pro-inflammatory cytokines and EMT markers, and reduced migration/invasion of GBM cells. This study therefore identifies STAT1 as a novel downstream mediator of FAT1, promoting pro-tumorigenic activity in GBM, by suppressing PDCD4 expression.


Assuntos
Proteínas Reguladoras de Apoptose , Caderinas , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Glioblastoma , Proteínas de Ligação a RNA , Fator de Transcrição STAT1 , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição STAT1/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Caderinas/metabolismo , Caderinas/genética , Linhagem Celular Tumoral , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Reguladoras de Apoptose/genética , Regiões Promotoras Genéticas/genética , Movimento Celular , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia
14.
Nanomedicine (Lond) ; 18(26): 1907-1919, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38078434

RESUMO

Aim: We investigated our previous finding of increased retention of poly(lactic-co-glycolic) acid nanoparticles (PLGA-NPs) with metabolic inhibitors (MI) and studied the effect of some small molecule inhibitors on PLGA-NP assimilation. Materials & methods: Intracellular PLGA-NP colocalization in the presence of MI was investigated by confocal microscopy. Intracellular retention of PLGA-NPs by some small molecules was estimated by fluorescence microscopy and flow cytometry after Pulse/Chase experiments. Results: MI caused PLGA-NP colocalization in intracellular membranous structures, mainly endosomes and lysosomes. Some small molecule inhibitors demonstrated increased intracellular PLGA-NP accumulation. Conclusion: This study elucidates the movement of PLGA-NP in cells and suggests that clinically used small molecules can reduce their extrusion by enhancing their stay within intracellular vesicles, with possible clinically beneficial consequences.


Nanoparticles are increasingly being used to carry drugs for treatment of cancer. We wish to decrease their movement out of the cells. This may give time for them to unload their drugs. Cells were treated with nanoparticles for 30 min and observed. Then the nanoparticles were washed off. Cells were again observed after 30 min. Various intracellular trafficking inhibitors were also added. Nanoparticle retention and subcellular localization were measured. We found that nanoparticles are trapped in some membranous compartments within the cells after energy depletion. We also discovered some commonly used clinical molecules that can decrease the excretion of nanoparticles from the cells. These inhibitors can be utilized for increasing the intracellular stay of the drug-loaded nanoparticles.


Assuntos
Nanopartículas , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ácido Poliglicólico/química , Ácido Láctico/química , Glicóis , Nanopartículas/química , Portadores de Fármacos/química
15.
Br J Ophthalmol ; 2023 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37734767

RESUMO

BACKGROUND: Pigmentation could be a relevant prognostic factor in uveal melanoma (UM) development. Microphthalmia-associated transcription factor (MITF) regulates melanin synthesis by activating tyrosinase-related protein 2 (TYRP2) and silver protein (SILV) that induce the melanogenesis pathway. Although their oncogenic potential has been observed in various malignancies but has not been investigated in UM Asian population. Our aim is to study the ultrastructure of melanosomes and the prognostic significance of pigmentation markers such as TYRP2, MITF and SILV in UM. METHODS: Transmission electron microscopy was performed to compare the ultrastructure of melanosomes in the normal choroid and UM cases. Immunoexpression of TYRP2, SILV and MITF was analysed in 82 UM samples. The mRNA expression level of all genes was measured in 70 UM cases. A statistical correlation was performed to determine the prognostic significance of all markers. RESULTS: Premelanosomes and mature melanosomes undergoing dedifferentiation were observed in high-pigmented UM cases as compared with low-pigmented UM cases. Seventy per cent of UM cases showed high SILV expression while TYRP2 and MITF expression was present in 58% and 56% of cases, respectively. At the mRNA level, upregulation of TYRP2, SILV and MITF markers was seen in around 50% of UM cases, which was statistically significant with high pigmentation. Reduced metastatic-free survival was statistically significant with the MITF protein expression. CONCLUSION: Our results demonstrated that ultrastructural changes in melanosomes and high expression of TYRP2, MITF and SILV could dysregulate the melanogenesis pathway and might be responsible for the aggressive behaviour of UM.

16.
EJIFCC ; 34(1): 42-56, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37124653

RESUMO

Background: Inflammatory and hematological markers are used extensively for early prognostication and monitoring in COVID-19.We aimed to determine whether routinely prescribed laboratory markers can predict adverse outcome at presentation in COVID-19. Methods: This retrospective observational study was performed on 401 samples collected between July to December 2020 from COVID-19 positive subjects, admitted at All India Institute of Medical Sciences, Delhi, India. Clinical details and laboratory investigations within 3 days of COVID-19 positivity were obtained. Clinical outcomes were noted from patient medical records, till discharge or death. Laboratory parameters, with individually defined cut-offs, were used, either singly or in combination to distinguish survival and death for those having severe and non-severe disease at initial presentation. Findings: Total Leukocyte count, Absolute neutrophil count, Neutrophil to Lymphocyte ratio, C-Reactive Protein (CRP), Interleukin-6 (IL-6), Lactate Dehydrogenase, Ferritin and Lymphocyte to CRP ratio (LCR) were significantly altered at presentation in severe COVID-19 as compared to non-severe cases; and, also in those who died due to COVID-19 compared to those who survived. A combination of four markers, CRP (≥3.9mg/dL); IL-6 (≥45.37pg/ml); Ferritin (≥373ng/mL); 1/LCR ≥0.405 was found to strongly predict mortality in cases with non-severe presentation as also in severe cases. Conclusion and Interpretation: The combination of routinely used markers, CRP, IL-6, Ferritin and 1/LCR can be used to predict adverse outcomes, even in those presenting with mild to moderate disease. This would identify subset of patients who would benefit from closer monitoring than usual for non-severe disease.

17.
Breathe (Sheff) ; 19(4): 230125, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38351949

RESUMO

Lung cancer is one of the common cancers globally with high mortality and poor prognosis. Most cases of lung cancer are diagnosed at an advanced stage due to limited diagnostic resources. Screening modalities, such as sputum cytology and annual chest radiographs, have not proved sensitive enough to impact mortality. In recent years, annual low-dose computed tomography has emerged as a potential screening tool for early lung cancer detection, but it may not be a feasible option for developing countries. In this context, exhaled breath condensate (EBC) analysis has been evaluated recently as a noninvasive tool for lung cancer diagnosis. The breath biomarkers also have the advantage of differentiating various types and stages of lung cancer. Recent studies have focused more on microRNAs (miRNAs) as they play a key role in tumourigenesis by regulating the cell cycle, metastasis and angiogenesis. In this review, we have consolidated the current published literature suggesting the utility of miRNAs in EBC for the detection of lung cancer.

18.
Appl Immunohistochem Mol Morphol ; 30(6): 410-417, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35708480

RESUMO

IDH wild-type (wt) grade 2/3 astrocytomas are a heterogenous group of tumors with disparate clinical and molecular profiles. cIMPACT-NOW recommendations incorporated in the new 2021 World Health Organization (WHO) Classification of Central Nervous System (CNS) Tumors urge minimal molecular criteria to identify a subset that has an aggressive clinical course similar to IDH -wt glioblastomas (GBMs). This paper describes the use of a panel of molecular markers to reclassify IDH -wt grade 2/3 diffuse astrocytic gliomas (DAGs) and study median overall survival concerning for to IDH -wt GBMs in the Indian cohort. IDH -wt astrocytic gliomas (grades 2, 3, and 4) confirmed by IDHR132H immunohistochemistry and IDH1/2 gene sequencing, 1p/19q non-codeleted with no H3F3A mutations were included. TERT promoter mutation by Sanger sequencing, epidermal growth factor receptor amplification, and whole chromosome 7 gain and chromosome 10 loss by fluorescence in situ hybridization was assessed and findings correlated with clinical and demographic profiles. The molecular profile of 53 IDH -wt DAGs (grade 2: 31, grade 3: 22) was analyzed. Eleven cases (grade 2: 8, grade 3: 3) (20.75%) were reclassified as IDH -wt GBMs, WHO grade 4 ( TERT promoter mutation in 17%, epidermal growth factor receptor amplification in 5.5%, and whole chromosome 7 gain and chromosome 10 loss in 2%). Molecular GBMs were predominantly frontal (54.5%) with a mean age of 36 years and median overall survival equivalent to IDH -wt GBMs (18 vs. 19 mo; P =0.235). Among grade 2/3 DAGs not harboring these alterations, significantly better survival was observed for grade 2 versus grade 3 DAGs (25 vs. 16 mo; P =0.002). Through the incorporation of a panel of molecular markers, a subset of IDH -wt grade 2 DAGs can be stratified into molecular grade 4 tumors with prognostic and therapeutic implications. However, IDH -wt grade 3 DAGs behave like GBMs irrespective of molecular profile.


Assuntos
Astrocitoma , Neoplasias Encefálicas , Glioblastoma , Telomerase , Adulto , Astrocitoma/genética , Neoplasias Encefálicas/patologia , Deleção Cromossômica , Receptores ErbB/genética , Glioblastoma/patologia , Humanos , Hibridização in Situ Fluorescente , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/metabolismo , Mutação , Telomerase/metabolismo
19.
Front Immunol ; 13: 813888, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35720420

RESUMO

FAT atypical cadherin 1 (FAT1) promotes glioblastoma (GBM) by promoting protumorigenic inflammatory cytokine expression in tumor cells. However, tumors also have an immunosuppressive microenvironment maintained by mediators such as transforming growth factor (TGF)-ß cytokines. Here, we have studied the role of FAT1 in tumor immune suppression. Our preliminary TIMER2.0 analysis of The Cancer Genome Atlas (TCGA) database revealed an inverse correlation of FAT1 expression with infiltration of tumor-inhibiting immune cells (such as monocytes and T cells) and a positive correlation with tumor-promoting immune cells [such as myeloid-derived suppressor cells (MDSCs)] in various cancers. We have analyzed the role of FAT1 in modulating the expression of TGF-ß1/2 in resected human gliomas, primary glioma cultures, and other cancer cell lines (U87MG, HepG2, Panc-1, and HeLa). Positive correlations of gene expression of FAT1 and TGF-ß1/2 were observed in various cancers in TCGA, Glioma Longitudinal Analysis Consortium (GLASS), and Chinese Glioma Genome Atlas (CGGA) databases. Positive expression correlations of FAT1 were also found with TGF-ß1/2 and Serpine1 (downstream target) in fresh-frozen GBM samples using q-PCR. siRNA-mediated FAT1 knockdown in cancer cell lines and in primary cultures led to decreased TGF-ß1/2 expression/secretion as assessed by q-PCR, Western blotting, and ELISA. There was increased chemotaxis (transmigration) of THP-1 monocytes toward siFAT1-transfected tumor cell supernatant as a consequence of decreased TGF-ß1/2 secretion. Reduced TGF-ß1 expression was also observed in THP-1 cultured in conditioned media from FAT1-depleted glioma cells, thus contributing to immune suppression. In U87MG cells, decreased TGF-ß1 upon FAT1 knockdown was mediated by miR-663a, a known modulator. FAT1 expression was also observed to correlate positively with the expression of surrogate markers of MDSCs [programmed death ligand-1 (PD-L1), PD-L2, and interleukin (IL)-10] in glioma tumors, suggesting a potential role of FAT1 in MDSC-mediated immunosuppression. Hence, our findings elaborate contributions of FAT1 to immune evasion, where FAT1 enables an immunosuppressive microenvironment in GBM and other cancers via TGF-ß1/2.


Assuntos
Caderinas , Glioblastoma , Glioma , Caderinas/genética , Caderinas/metabolismo , Linhagem Celular Tumoral , Glioblastoma/patologia , Glioma/genética , Glioma/metabolismo , Humanos , Fator de Crescimento Transformador beta1/metabolismo , Microambiente Tumoral , Regulação para Cima
20.
Exp Mol Pathol ; 90(2): 167-72, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21115003

RESUMO

Several single nucleotide polymorphisms of the TP53 gene have been reported, amongst which polymorphism in codon 72 (rs1042522) has received significant attention and shown to be associated with disease susceptibility in different cancer types. However, there are variable reports on this polymorphism in gliomas from worldwide with inconsistent results. In addition, the implications of other polymorphic loci are not much explored in gliomas. Hence, in the present study the TP53 sequence was analyzed for all polymorphism and mutations in a total of 84 gliomas of different types and grades from patients of Indian origin. The complete sequence of all coding exons (2 to 11) and introns 2, 3, 5 and 8 of TP53 gene were studied while for introns 1, 4, 6, 7, 9 and 10, only exon flanking regions could be studied. The polymorphic loci were compared with control population. In addition to the well known codon 72 polymorphism (rs1042522), three other polymorphisms rs1642785, rs1800370 and a 16 base pair insertion in intron-3 were found. At codon 72, our study showed higher Arg/Arg genotype in gliomas compared to normal population (38% versus 13%). The Arg allele frequency in glioma patients was comparatively higher than controls (0.55 versus 0.45; P=0.037). The Arg allele frequency was also high in adult glioblastomas compared to paediatric counterparts (0.55 versus 0.36). However, there was no significant association of TP53 mutations with any genotype of codon 72. At rs1642785, the G allele frequency was significantly higher in gliomas than in control population (0.55 versus 0.36, P=0.005). The genotype at a 16 base pair insertion in intron-3 was almost similar in case and control. However, the polymorphism at rs1800370 was exclusive to gliomas. This is the first report of TP53 gene polymorphism in glioma patients from India. Our study also delineates the frequency of four polymorphisms in gliomas for the first time. The codon 72 variant (rs1042522) and rs1642785 polymorphisms possibly poses risk to glioma development in Indian population. However, the functional significance of these polymorphism needs further elucidation.


Assuntos
Pareamento de Bases/genética , Códon/genética , Glioma/genética , Íntrons/genética , Mutagênese Insercional/genética , Polimorfismo de Nucleotídeo Único/genética , Proteína Supressora de Tumor p53/genética , Adolescente , Adulto , Idoso , Alelos , Astrócitos/metabolismo , Criança , Feminino , Frequência do Gene/genética , Genótipo , Glioma/classificação , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Mutação/genética , Oligodendroglia/metabolismo , Adulto Jovem
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