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1.
Mol Ther ; 23(2): 255-69, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25327178

RESUMEN

PTEN mutation is a frequent feature across a plethora of human cancers, the hot-spot being its C-terminus (PTEN-CT) regulatory domain resulting in a much diminished protein expression. In this study, the presence of C-terminus mutations was confirmed through sequencing of different human tumor samples. The kinase CKII-mediated phosphorylation of PTEN at these sites makes it a loopy structure competing with the E3 ligases for binding to its lipid anchoring C2 domain. Accordingly, it was found that PTEN-CT expressing stable cell lines could inhibit tumorigenesis in syngenic breast tumor models. Therefore, we designed a novel exosome-mediated delivery of the intrinsic PTEN domain, PTEN-CT into different cancer cells and observed reduced proliferation, migration, and colony forming ability. The delivery of exosome containing PTEN-CT to breast tumor mice model was found to result in significant regression in tumor size with the tumor sections showing increased apoptosis. Here, we also report for the first time an active PTEN when its C2 domain is bound by PTEN-CT, probably rendering its anti-tumorigenic activities through the protein phosphatase activity. Therefore, therapeutic interventions that focus on PTEN E3 ligase inhibition through exosome-mediated PTEN-CT delivery can be a probable route in treating cancers with low PTEN expression.


Asunto(s)
Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Exosomas/metabolismo , Fosfohidrolasa PTEN/genética , Fosfohidrolasa PTEN/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Dominios y Motivos de Interacción de Proteínas , Animales , Línea Celular , Proliferación Celular , Expresión Génica , Humanos , Ratones , Mutación , Neoplasias/genética , Neoplasias/metabolismo , Fosfohidrolasa PTEN/química , Dominios y Motivos de Interacción de Proteínas/genética , Proteolisis , Especificidad por Sustrato , Ubiquitina-Proteína Ligasas/metabolismo
2.
Indian J Med Res ; 143(6): 739-747, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27748298

RESUMEN

BACKGROUND & OBJECTIVES: Insulin resistance (IR) is a major confounding factor in polycystic ovarian syndrome (PCOS) irrespective of obesity. Its exact mechanism remains elusive till now. C/T polymorphism in the -34 promoter region of the CYP17 gene is inconsistently attributed to elucidate the mechanism of IR and its link to hyperandrogenemia in obese PCOS patients. In the present study we aimed to evaluate any association of this polymorphism with IR in non-obese women with PCOS. METHODS: Polymorphism study was performed by restriction fragment length polymorphism (RFLP) analysis of the Msp A1 digest of the PCR product of the target gene in 75 PCOS cases against 73 age and BMI matched control women. Serum testosterone, BMI and HOMA-IR (homeostatic model of assessment-insulin resistance) were analyzed by standard techniques. A realistic cut-off value for the HOMA-IR was obtained through receiver operating characteristic (ROC) curve for exploring any possible link between IR and T/C polymorphism in the case group. RESULTS: Significant increases in serum testosterone and HOMA-IR values were observed among the case group (P<0.001) without any significant elevation in BMI and FBG compared to controls. Cut-off value for IR in the PCOS patients was 1.40 against a maximum sensitivity of 0.83 and a minimum false positivity of 0.13. The analysis revealed an inconclusive link between the C/T polymorphic distribution and insulin resistant case subjects. INTERPRETATION & CONCLUSIONS: The results showed that CYP17A1 gene was not conclusively linked to either IR or its associated increased androgen secretion in non-obese women with PCOS. We propose that an increased sensitivity of insulin on the ovarian cells may be the predominant reason for the clinical effects and symptoms of androgen excess observed in non-obese PCOS patients in our region.


Asunto(s)
Resistencia a la Insulina/genética , Síndrome del Ovario Poliquístico/genética , Esteroide 17-alfa-Hidroxilasa/genética , Adulto , Glucemia , Índice de Masa Corporal , Estudios Transversales , Femenino , Estudios de Asociación Genética , Ligamiento Genético , Predisposición Genética a la Enfermedad , Humanos , Insulina/sangre , Insulina/genética , Síndrome del Ovario Poliquístico/sangre , Síndrome del Ovario Poliquístico/patología , Polimorfismo de Nucleótido Simple/genética , Embarazo
3.
Nanomedicine ; 12(7): 1973-1985, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27133192

RESUMEN

Triple negative breast cancer (TNBC) is one of the most common invasive malignancies among women, associated with poor prognosis. Standard chemotherapy targets all dividing cells, resulting in dose-limiting toxicities. In this study, we demonstrated a strategy of encapsulating a hydrophobic synthetic compound, nifetepimine, having anticancer properties, in poly (lactic-co-glycolic acid) nanoparticles to increase selectivity of drug to cancerous cells with minimum toxicity towards normal cells. Nanoencapsulated nifetepimine (30-100nm) having loading and encapsulation efficiency of 7.45% and 75% respectively, was successfully internalized inside TNBC cells upon sustained release resulting in apoptosis. An in vivo bio-distribution study indicated that nanonifetepimine selectively accumulated into breast tumor sites of mice, primarily due to prolonged blood circulation time and binding of nifetepimine to epidermal growth factor receptor that remains overexpressed in most of the TNBC tumors. Moreover, we observed significant reduction in breast tumor volume with improved survival implying high tumor targetability of nanonifetepimine.


Asunto(s)
Antineoplásicos/administración & dosificación , Pirimidinonas/administración & dosificación , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Animales , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Mama , Línea Celular Tumoral , Femenino , Humanos , Ratones , Nanopartículas , Pirimidinonas/farmacología , Distribución Tisular
4.
Breast Cancer Res ; 16(6): 496, 2014 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-25499975

RESUMEN

INTRODUCTION: Nuclear accumulation of ß-catenin is important for cancer development and it is found to overlap with p68 (DDX5) immunoreactivity in most breast cancers, as indicated by both clinical investigations and studies in cell lines. In this study, we aim to investigate the regulation of p68 gene expression through ß-catenin/transcription factor 4 (TCF4) signaling in breast cancer. METHODS: Formalin-fixed paraffin-embedded sections derived from normal human breast and breast cancer samples were used for immunohistochemical analysis. Protein and mRNA expressions were determined by immunoblotting and quantitative RT-PCR respectively. Promoter activity of p68 was checked using luciferase assay. Occupancy of several factors on the p68 promoter was evaluated using chromatin immunoprecipitation. Finally, a syngeneic mouse model of breast cancer was used to assess physiological significance. RESULTS: We demonstrated that ß-catenin can directly induce transcription of p68 promoter or indirectly through regulation of c-Myc in both human and mouse breast cancer cells. Moreover, by chromatin immunoprecipitation assay, we have found that both ß-catenin and TCF4 occupy the endogenous p68 promoter, which is further enhanced by Wnt signaling. Furthermore, we have also established a positive feedback regulation for the expression of TCF4 by p68. To the best of our knowledge, this is the first report on ß-catenin/TCF4-mediated p68 gene regulation, which plays an important role in epithelial to mesenchymal transition, as shown in vitro in breast cancer cell lines and in vivo in an animal breast tumour model. CONCLUSIONS: Our findings indicate that Wnt/ß-catenin signaling plays an important role in breast cancer progression through p68 upregulation.


Asunto(s)
Adenocarcinoma/genética , Neoplasias de la Mama/genética , ARN Helicasas DEAD-box/genética , ARN Mensajero/metabolismo , Factores de Transcripción/metabolismo , Vía de Señalización Wnt , beta Catenina/metabolismo , Adenocarcinoma/metabolismo , Animales , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , ARN Helicasas DEAD-box/metabolismo , Progresión de la Enfermedad , Transición Epitelial-Mesenquimal/genética , Femenino , Células HEK293 , Humanos , Células MCF-7 , Ratones , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas c-myc , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Transcripción 4 , Activación Transcripcional
5.
Trop Gastroenterol ; 35(2): 79-84, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25470869

RESUMEN

BACKGROUND AND AIM: The internal diameter of the portal vein varies with age and anthropometric parameters. The caliber of the normal portal vein in adults has been extensively studied but little is known about portal vein dimensions in the growing child. This study was conducted to establish standards of portal vein diameter by ultrasonography in healthy Indian children based on age, gender and anthropometric parameters. METHODS: Total 306 healthy children between the age of < 1 month and 12 years, visiting our outpatient departmentor accompanying their siblings were enrolled in the study. The children were distributed into ten age-groups. Each group was further divided in two sub-groups based on gender. Anthropometric parameters including weight, height and chest circumference were measured.Portal vein diameter was assessed by ultrasonography. RESULTS: The portal vein diameter increases with age, height, weight and chestcircumference. But the values are similar in boys and girls. Multiple logistic regression (adjusted R- square: 0.922) revealed age (p = 0.002), height/length (p < 0.0001), weight (p = 0.011), and chest circumference (p < 0.0001), as independent determinants of portal vein diameter. However, height/length emerged as the most consistent determinant (coefficient of regression: 1.536; p < 0.001; 95% confidence interval: 0.066-0.092). CONCLUSION: Our results provide a normal range of portal vein diameter according to age, gender and anthropometric parameters. We conclude that portal vein diameter strongly correlates with age and anthropometric variables like height, weight and chestcircumference,with height being the strongest determinant.


Asunto(s)
Vena Porta/anatomía & histología , Distribución por Edad , Antropometría , Niño , Preescolar , Estudios Transversales , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Vena Porta/diagnóstico por imagen , Valores de Referencia , Distribución por Sexo , Ultrasonografía
6.
J Pept Sci ; 18(12): 720-30, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23109400

RESUMEN

Radiolabeled somatostatin analogs have become powerful tools in the diagnosis and staging of neuroendocrine tumors, which express somatostatin receptors. The aim of this study was to evaluate a new somatostatin analog, 6-hydrazinopyridine-3-carboxylic acid-Ser3-octreotate (HYNIC-SATE) radiolabeled with 99mTc, using ethylenediamine-N,N'-diacetic acid and tricine as coligands, to be used as a radiopharmaceutical for the in vivo imaging of somatostatin receptor subtype 2 (SSTR2)-positive tumor. Synthesis of the peptide was carried out on a solid phase using a standard Fmoc strategy. Peptide conjugate affinities for SSTR2 were determined by receptor binding affinity on rat brain cortex and C6 cell membranes. Internalization rate of 99mTc-HYNIC-SATE was studied in SSTR2-expressing C6 cells that were used for intracranial tumor studies in rat brain. A reproducible in vivo C6 glioma model was developed in Sprague-Dawley rat and confirmed by histopathology and immunohistochemical analysis. Biodistribution and imaging properties of this new radiopeptide were also studied in C6 tumor-bearing rats. Radiolabeling was performed at high specific activities, with a radiochemical purity of >96%. Peptide conjugate showed high affinity binding for SSTR2 (HYNIC-SATE IC50=1.60±0.05 n m) and specific internalization into rat C6 cells. After administration of 99mTc-HYNIC-SATE in C6 glioma-bearing rats, a receptor specific uptake of radioactivity was observed in SSTR-positive organs and in the implanted intracranial tumor and rapid excretion from nontarget tissues via kidneys. 99mTc-HYNIC-SATE is a new receptor-specific radiopeptide for targeting SSTR2-positive brain tumor and might be of great promise in the scintigraphy of SSTR2-positive tumors.


Asunto(s)
Neoplasias Encefálicas/diagnóstico por imagen , Glioma/diagnóstico por imagen , Octreótido/análogos & derivados , Compuestos de Organotecnecio , Radiofármacos , Animales , Neoplasias Encefálicas/metabolismo , Línea Celular Tumoral , Femenino , Glioma/metabolismo , Trasplante de Neoplasias , Octreótido/síntesis química , Octreótido/metabolismo , Octreótido/farmacocinética , Compuestos de Organotecnecio/síntesis química , Compuestos de Organotecnecio/metabolismo , Compuestos de Organotecnecio/farmacocinética , Unión Proteica , Cintigrafía , Radiofármacos/síntesis química , Radiofármacos/metabolismo , Radiofármacos/farmacocinética , Ratas Sprague-Dawley , Receptores de Somatostatina/metabolismo , Distribución Tisular
7.
J Family Med Prim Care ; 10(1): 567-571, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34017792

RESUMEN

Wernicke's encephalopathy (WE) is an acute neurological condition characterized by the triad of ophthalmoparesis with nystagmus, ataxia, and global confusion. WE is a life-threatening illness caused by thiamine deficiency, primarily affecting the peripheral and central nervous systems. Thiamine deficiency is predominantly associated with chronic alcoholism, but various other causes have also been reported, including severe malnutrition, prolonged parenteral nutrition, malignancies, immunodeficiency syndromes, liver disease, hyperthyroidism and severe anorexia nervosa, and hyperemesis gravidarum. We, hereby, report a unique case of WE induced by hyperemesis gravidarum that presented in mid-trimester of pregnancy in a rather extremely unusual way with focal seizures and secondary generalization but fortunately ended up with a good feto-maternal outcome.

8.
J Cytol ; 37(2): 87-92, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32606496

RESUMEN

BACKGROUND: Being a minimally invasive diagnostic technique, Fine-Needle Aspiration Cytology (FNAC) has become the first-line test and corresponding aspirated material has become the target specimen for diagnosis and ancillary tests in lung carcinoma. Although the role of Cell Blocks (CBs) in diagnosis and in ancillary testing is well recognized in literature, limited attention has been paid to specimen procurement and triage in the preparation of CBs. In the present scenario, CBs are not consistently optimal because of its low cellularity. AIMS: This study is aimed to describe an improvised technique of specimen acquisition and cell block preparation in CT-guided FNACs of lung carcinoma cases in a resource-constrained center and to assess its efficacy for optimal representation of cellularity, morphology, and architecture. MATERIALS AND METHODS: Total 85 lung carcinoma cases undergoing CT-guided FNAC in our center from February 2017 to January 2018 were included in this study. 4 to 5 direct smears and subsequent CBs were made from material obtained by single pass. Cellularity of smears and corresponding cell blocks were assessed and categorized according to a scoring system (score 1 to 3 for number of cells <50, 50-100, >100, respectively). Preserved architecture and morphology were also assessed in smears and CBs. RESULTS: The evaluated samples showed a cellularity score 3 in 65.4%CBs and score 2 in 24.7% CBs. Overall, 90.1% cell blocks had acceptable cellularity. Cell morphology was preserved in all CBs of acceptable cellularity, except for two adenocarcinoma, one squamous cell carcinoma, and one small cell carcinoma blocks. Cellular architecture was also preserved in all CBs of acceptable cellularity. CONCLUSIONS: This simple improvised technique of CB preparation optimized its cellularity, morphology, and architectural preservation, even after adequate cellular FNA smears.

9.
Front Biosci (Landmark Ed) ; 24(3): 435-450, 2019 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-30468665

RESUMEN

In cerebral tissues, due to continuous and high metabolic demand, energy is produced exclusively by mitochondrial oxidative phosphorylation (OXPHOS). Obstruction of blood flow leads to cerebral ischemia, hypoxia and decreased cellular ATP production. The reactive oxygen species (ROS) generated as by-product of OXPHOS alter many intracellular signaling pathways and result in damaged cellular components. Under such hypoxic conditions, a key factor known as hypoxia inducible factor 1 (HIF1) is stabilized and activated and such activation induces expression of a defined set of target genes which are required for cell survival and angiogenesis. Reperfusion that follows such ischemia alters signaling pathways which are involved in cellular fate. Here, we will review the role of ROS, HIF-1 alpha and other signaling network in mitochondrial dysfunction and cell fate determination in ischemia-reperfusion models in the brain. We will also address both current and future therapeutic strategies for clinical significance that are being developed for treatment of cerebral ischemia.


Asunto(s)
Isquemia Encefálica/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Daño por Reperfusión/metabolismo , Accidente Cerebrovascular/metabolismo , Animales , Isquemia Encefálica/tratamiento farmacológico , Isquemia Encefálica/fisiopatología , Depuradores de Radicales Libres/uso terapéutico , Humanos , Mitocondrias/metabolismo , Inhibidores de Agregación Plaquetaria/uso terapéutico , Daño por Reperfusión/tratamiento farmacológico , Daño por Reperfusión/fisiopatología , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/fisiopatología
10.
Indian J Tuberc ; 64(2): 136-140, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28410697

RESUMEN

Tuberculosis is a major health problem in the developing world. One-third of children infected with Mycobacterium tuberculosis have extra pulmonary involvement. Skeletal tuberculosis occurs in 1-6% of them with vertebra being the commonest site. Pure tubercular osteomyelitis without joint involvement occurs in only 2-3% cases of osteoarticular tuberculosis. Common sites are femur, tibia, and fibula. Disseminated skeletal involvement is very rare in children (7%) and calvarial osteomyelitis is even rarer (1%). Here, we report a unique case of disseminated skeletal TB. A 7-year-old tribal girl with no evidence of immunodeficiency presented with multiple lytic lesions involving skull, sternum, and hip bone surprisingly sparing the joints and appendicular skeleton. There was no pulmonary involvement either. FNAC from all three swellings showed presence of acid-fast bacillus. Bone biopsy followed by culture in BACTEC further confirmed the diagnosis. There was complete resolution of the swellings after one year of anti-tubercular drug therapy.


Asunto(s)
Osteomielitis/diagnóstico por imagen , Osteomielitis/microbiología , Tuberculosis/complicaciones , Tuberculosis/diagnóstico por imagen , Niño , Femenino , Hueso Frontal , Humanos , Órbita , Esternón , Tomografía Computarizada por Rayos X
11.
Dalton Trans ; 46(17): 5670-5679, 2017 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-28181614

RESUMEN

4-Nitrobenzoic acid, 3-nitrobenzoic acid and 4'-nitro[1,1'-biphenyl]-4-carboxylic acid react with the multiply bonded paramagnetic dirhenium(iii,ii) complex Re2(µ-O2CCH3)Cl4(µ-Ph2PCH2PPh2)2 (1) in refluxing ethanol to afford the paramagnetic substitution products of the type Re2(µ-L)Cl4(µ-Ph2PCH2PPh2)2, where L represents the nitrobenzoate ligands [L = 4-nitrobenzoate, 2; 3-nitrobenzoate, 3; 4'-nitro[1,1'-biphenyl]-4-carboxylate, 4]. These are the first examples of paramagnetic dirhenium complexes containing nitrobenzoate ligands. The spectral (UV-vis, IR, and EPR) and electrochemical properties of the complexes are described. The identity of 4 has been established by single-crystal X-ray structure determination (Re-Re distance of 2.2967(4) Å). The electronic structures of the complexes were scrutinized by density functional theory (DFT) calculations. X-band EPR spectral measurements along with the DFT analysis show that the unpaired electron resides in the metal-metal δ* antibonding orbital. The complexes were also screened in vitro for their antiproliferative properties against the human breast cancer cell line MCF-7 by the MTT assay. Flow cytometry analysis showed that the complexes arrested the sub-G0/G1 phase.


Asunto(s)
Complejos de Coordinación/química , Magnetismo , Nitrobenzoatos/química , Renio/química , Supervivencia Celular/efectos de los fármacos , Complejos de Coordinación/síntesis química , Complejos de Coordinación/toxicidad , Cristalografía por Rayos X , Espectroscopía de Resonancia por Spin del Electrón , Puntos de Control de la Fase G1 del Ciclo Celular/efectos de los fármacos , Humanos , Ligandos , Células MCF-7 , Microscopía Confocal , Conformación Molecular , Teoría Cuántica , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta
12.
Front Biosci (Landmark Ed) ; 21(2): 225-50, 2016 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-26709771

RESUMEN

DEAD box protein family of RNA helicases are vital players of RNA metabolism, and constitute the largest family of RNA helicases. Members of this family share nine conserved motifs including an Asp-Glu-Ala-Asp motif, giving this family its characteristic name as DEAD box RNA helicases. These conserved motifs confer RNA binding and RNA unwinding properties. Besides functioning in RNA metabolism, emerging evidences suggests several DEAD box RNA helicases to possess potential roles in regulating gene expression by acting as a transcriptional co-activator. Many of them are deregulated in cancers, and are implicated in possessing oncogenic potential. On the contrary, each of them also possesses tumor suppressive property in a context dependent manner. In this review, we discuss the mechanistic insights of gene regulation by DEAD box RNA helicases, and their significance in cancers.


Asunto(s)
ARN Helicasas DEAD-box/metabolismo , Carcinogénesis , ARN Helicasas DEAD-box/química , Regulación de la Expresión Génica , Conformación Proteica
13.
Cell Signal ; 28(6): 675-87, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27012497

RESUMEN

Protein kinase CK2α is frequently upregulated in different cancers. Alteration of CK2α expression and its activity is sufficient to induce dramatic changes in cell fate. It has been established that CK2α induces oncogenesis through modulation of both AKT and PML. CK2α has been found to be overexpressed in breast cancer. In contrary, statistical reports have shown low level of PML. However, the regulation of CK2α gene expression is not fully understood. In the current study, we found that CK2α and activated AKT positively correlate with ERα, whereas PML follows an inverse correlation in human breast cancer tissues. Modulation of ERα signalling leads to recruitment of activated ERα on the ERE sites of CK2α promoter, resulting in CK2α transactivation. Furthermore, the DMBA induced tumours in rat showed elevated level of active CK2α. Consequently it mediates enhancement of AKT activity and PML degradation, resulting in increased cellular proliferation, migration and metastasis. Syngeneic ERα overexpressing stable mouse 4T1 cells produce larger primary tumours and metastatic lung nodules in mice, corroborating our in vitro findings. Hence, our study provides a novel route of ERα dependent CK2α mediated oncogenesis that causes upregulation and consequent AKT activation along with degradation of tumour suppressor PML.


Asunto(s)
Neoplasias de la Mama/genética , Carcinogénesis , Receptor alfa de Estrógeno/metabolismo , Regulación Neoplásica de la Expresión Génica , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Factores de Transcripción/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Animales , Neoplasias de la Mama/enzimología , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Carcinógenos , Quinasa de la Caseína II/genética , Línea Celular Tumoral , Femenino , Células HEK293 , Humanos , Neoplasias Pulmonares/secundario , Células MCF-7 , Neoplasias Mamarias Experimentales/inducido químicamente , Neoplasias Mamarias Experimentales/enzimología , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones Endogámicos BALB C , Regiones Promotoras Genéticas , Proteína de la Leucemia Promielocítica , Ratas , Ratas Sprague-Dawley , Transducción de Señal , Activación Transcripcional
14.
Biomed Res Int ; 2015: 320941, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25866775

RESUMEN

Brain tumors are one of the most formidable diseases of mankind. They have only a fair to poor prognosis and high relapse rate. One of the major causes of extreme difficulty in brain tumor treatment is the presence of blood brain barrier (BBB). BBB comprises different molecular components and transport systems, which in turn create efflux machinery or hindrance for the entry of several drugs in brain. Thus, along with the conventional techniques, successful modification of drug delivery and novel therapeutic strategies are needed to overcome this obstacle for treatment of brain tumors. In this review, we have elucidated some critical insights into the composition and function of BBB and along with it we have discussed the effective methods for delivery of drugs to the brain and therapeutic strategies overcoming the barrier.


Asunto(s)
Antineoplásicos , Barrera Hematoencefálica , Neoplasias Encefálicas , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapéutico , Transporte Biológico Activo/efectos de los fármacos , Barrera Hematoencefálica/efectos de los fármacos , Barrera Hematoencefálica/metabolismo , Barrera Hematoencefálica/patología , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Humanos
15.
J Biomol Struct Dyn ; 20(2): 265-73, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12354078

RESUMEN

Triplex forming oligonucleotides (TFOs) have the potential to modulate gene expression. While most of the experiments are directed towards triplex mediated inhibition of gene expression the strategy potentially could be used for gene specific activation. In an attempt to design a strategy for gene specific activation in vivo applicable to a large number of genes we have designed a TFO based activator-target system which may be utilized in Saccharomyces cerevisiae or any other system where Gal4 protein is ectopically expressed. The total genome sequence of Saccharomyces cerevisiae and expression profiles were used to select the target genes with upstream poly (pu/py) sequences. We have utilized the paradigm of Gal4 protein and its binding site. We describe here the selection of target genes and design of hairpin-TFO including the targeting sequences containing polypurine stretch found in the upstream promoter regions of weakly expressed genes. We demonstrate, the formation of hairpin-TFO, its binding to Gal4 protein, its ability to form triplex with the target duplex in vitro, the effect of polyethylenimine on complex formation and discuss the implication on in vivo transcription activation.


Asunto(s)
Regulación de la Expresión Génica , Oligonucleótidos/metabolismo , Saccharomyces cerevisiae/genética , Activación Transcripcional , Secuencia de Bases , Sitios de Unión , Cromosomas Fúngicos/genética , Dicroismo Circular , ADN de Hongos/metabolismo , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Genes Fúngicos , Modelos Biológicos , Ácidos Nucleicos Heterodúplex , Oligonucleótidos/síntesis química , Polietileneimina/farmacología , Regiones Promotoras Genéticas , Unión Proteica , Proteínas de Saccharomyces cerevisiae/metabolismo , Temperatura , Factores de Transcripción/metabolismo , Transcripción Genética
16.
Biomed Res Int ; 2014: 435197, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25121098

RESUMEN

The process of cell death has important physiological implications. At the organism level it is mostly involved in maintenance of tissue homeostasis. At the cellular level, the strategies of cell death may be categorized as either suicide or sabotage. The mere fact that many of these processes are programmed and that these are often deregulated in pathological conditions is seed to thought. The various players that are involved in these pathways are highly regulated. One of the modes of regulation is via post-translational modifications such as ubiquitination and deubiquitination. In this review, we have first dealt with the different modes and pathways involved in cell death and then we have focused on the regulation of several proteins in these signaling cascades by the different deubiquitinating enzymes, in the perspective of cancer. The study of deubiquitinases is currently in a rather nascent stage with limited knowledge both in vitro and in vivo, but the emerging roles of the deubiquitinases in various processes and their specificity have implicated them as potential targets from the therapeutic point of view. This review throws light on another aspect of cancer therapeutics by targeting the deubiquitinating enzymes.


Asunto(s)
Neoplasias/enzimología , Neoplasias/patología , Proteasas Ubiquitina-Específicas/metabolismo , Muerte Celular/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Humanos , Transducción de Señal/efectos de los fármacos
17.
Cell Signal ; 26(8): 1725-34, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24726840

RESUMEN

Signal transducer and activator of transcription 3 (Stat3) is a transcription factor that is involved in cell survival and proliferation and has been found to be persistently activated in most human cancers mainly through its phosphorylation at Tyr-705. However, the role and regulation of Stat3 Ser-727 phosphorylation in cancer cells have not been clearly evaluated. In our findings, correlation studies on the expression of CK2 and Stat3 Ser-727 phosphorylation levels in human glioma patient samples as well as rat orthotopic tumor model show a degree of negative correlation. Moreover, brain tumor cell lines were treated with various pharmacological inhibitors to inactivate the CK2 pathway. Here, increased Stat3 Ser-727 phosphorylation upon CK2 inhibition was observed. Overexpression of CK2 (α, α' or ß subunits) by transient transfection resulted in decreased Stat3 Ser-727 phosphorylation. Stat3 Tyr-705 residue was conversely phosphorylated in similar situations. Interestingly, we found PP2A, a protein phosphatase, to be a mediator in the negative regulation of Stat3 Ser-727 phosphorylation by CK2. In vitro assays prove that Ser-727 phosphorylation of Stat3 affects the transcriptional activity of its downstream targets like SOCS3, bcl-xl and Cyclin D1. Stable cell lines constitutively expressing Stat3 S727A mutant showed increased survival, proliferation and invasion which are characteristics of a cancer cell. Rat tumor models generated with the Stat3 S727A mutant cell line formed more aggressive tumors when compared to the Stat3 WT expressing stable cell line. Thus, in glioma, reduced Stat3 Ser-727 phosphorylation enhances tumorigenicity which may be regulated in part by CK2-PP2A pathway.


Asunto(s)
Quinasa de la Caseína II/metabolismo , Proteína Fosfatasa 2/metabolismo , Factor de Transcripción STAT3/metabolismo , Serina/metabolismo , Animales , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Quinasa de la Caseína II/antagonistas & inhibidores , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Transformación Celular Neoplásica , Ciclina D1/genética , Ciclina D1/metabolismo , Glioma/metabolismo , Glioma/patología , Células HEK293 , Humanos , Ácido Ocadaico/farmacología , Fosforilación/efectos de los fármacos , Proteína Fosfatasa 2/antagonistas & inhibidores , Ratas , Ratas Sprague-Dawley , Proteína 3 Supresora de la Señalización de Citocinas , Proteínas Supresoras de la Señalización de Citocinas/genética , Proteínas Supresoras de la Señalización de Citocinas/metabolismo , Trasplante Heterólogo , Proteína bcl-X/genética , Proteína bcl-X/metabolismo
18.
N Am J Med Sci ; 4(2): 77-80, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22408752

RESUMEN

BACKGROUND: In patients with chronic renal failure (CRF), carotid artery intima media thickness (CAIMT) is increased when the patients are on hemodialysis. Vascular events caused by atherosclerosis are the major cause of death in patients undergoing hemodialysis. AIMS: This study was done to find out the relationship between carotid artery intima media thickness and hemodialysis in chronic renal failure patients independent of classical risk factors and also the relationship between CAIMT of hemodialyzed patients and nonhemodialyzed CRF patients. MATERIALS AND METHODS: In this observational study, CAIMT of 78 CRF patients was examined by B-mode ultrasonography. Glomerular filtration rate (GFR) was calculated by using the "Modification of Diet in Renal Disease" formula. CRF patients, who had been on regular hemodialysis treatment (treated thrice weekly) for at least 6 months, were identified as hemodialyzed patients. Data were analyzed by software Statistical package for the social Sciences (SPSS) (17(th) version). RESULTS: There was significant positive correlation between CAIMT and hemodialysis (P=0.045) independent of traditional risk factors. Hemodialyzed patients had higher mean CAIMT (1136.30±21.21 µm, P<0.001) than mean CAIMT of age and sex matched nondialyzed patients (959.30±23.01 µm). CONCLUSION: Hemodialysis is an independent risk factor for atherosclerosis in CRF patents. Hemodialyzed patients have significantly higher CAIMT than nondialyzed CRF patients.

19.
J Cardiovasc Dis Res ; 3(2): 128-31, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22629031

RESUMEN

BACKGROUND: Carotid artery intima media is a surrogate marker of atherosclerosis and related with ethnicity, age, sex, traditional and non-traditional risk factors. Black ethnicity is related to greater mean and maximum carotid artery intima media thickness when compared to South Asians. Our study was done to find out the mean carotid artery intima media thickness (CAIMT) of normal healthy people of India and Bangladesh, and the relationship of non-modifiable risk factors such as age and sex with CAIMT. MATERIALS AND METHODS: In this observational study, CAIMT of 93 people were examined by B-mode ultrasonography. All subjects underwent a careful interview and clinical, radiological, biochemical examination. Data was analyzed by software statistical package for social sciences (SPSS) (17(th) version for window). RESULTS: In our study, the mean CAIMT of healthy subjects including all age group was (754.94 ± 11.96 micron.). Mean CAIMT was higher in age group of 61-80 years (908.75 ± 39.02 micron) than age group of 20-40 years (713.62 ± 16.59 micron) and 41-60 years (745.55 ± 13.05 micron). CAIMT was positively correlated with age (P value <0.001) and sex (P value=0.001). CONCLUSION: An aggregated analysis based on this study in different age groups of healthy people may be useful for assessing carotid artery abnormalities as an aid to defining abnormalities and predicting risk of atherosclerosis in individual healthy people living in India and Bangladesh.

20.
Heart Views ; 13(3): 91-6, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23181176

RESUMEN

OBJECTIVES: Cardiovascular disease is the leading cause of morbidity and mortality in patients with chronic renal failure (CRF). This study attempts to identify the factors responsible for atherosclerosis in CRF patients using carotid artery intima media thickness (CAIMT) as a surrogate marker of atherosclerosis. MATERIALS AND METHODS: CAIMT was measured by high-resolution B-mode ultrasonography in 100 CRF patients and 50 age- and sex-matched healthy controls. Data were analyzed by software SPSS (17(th) version) for Windows. RESULTS: CRF patients had a significantly higher CAIMT (1026.83 ± 17.19 micron, mean ± SE, P < 0.001) than age- and sex-matched healthy controls (722.46 ± 7.61 micron). There was inverse correlation between CAIMT and glomerular filtration rate (GFR) (P < 0.001) independent of traditional risk factors. There was also significant positive correlation between CAIMT and traditional risk factors of atherosclerosis. Ischemic heart disease (IHD) also showed positive correlation with CAIMT (P = 0.007) and inverse correlation with GFR (P = 0.005). CONCLUSIONS: There is high prevalence of atherosclerosis in CRF patients. CAIMT can be used to detect and predict future incidence of IHD in CRF patients.

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