Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 126
Filtrar
1.
Appl Radiat Isot ; 204: 111140, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38070360

RESUMO

Double differential neutron fluence distributions were measured in the 7Li(p,n)7Be reaction for proton beam energies 7, 9 and 12 MeV. Seven liquid scintillator based detectors were employed to measure neutron fluence distributions using the Time of Flight technique. Neutron ambient dose equivalents were determined from the measured fluence distribution using ICRP (International Commission on Radiological Protection) recommended fluence to dose equivalent conversion coefficients. Neutron dose equivalents were also measured using a conventional BF3 detector based REM counter. Ambient dose equivalent measured by the REM counter is found to be in agreement with that determined from the neutron fluence spectra within their uncertainties. Angular distributions of the ambient dose equivalents were also determined from the measured fluence distributions at different angles.

2.
J Appl Microbiol ; 130(3): 786-796, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32615006

RESUMO

AIMS: The emergence of multidrug resistant strains of Mycobacterium tuberculosis has made tuberculosis more difficult to manage clinically. With the aim of obtaining new and effective anti-mycobacterial agent(s), this study investigated the anti-mycobacterial activity of several imidazole and piperidine derivatives. METHODS AND RESULTS: Towards obtaining new anti-mycobacterial agents, Mycobacterium smegmatis cells were treated with different compounds for their growth inhibitory activity. Among these, benzyl 1H-imidazole-1-carbodithioate and allyl piperidine-1-carbodiothioate exhibited better inhibition than the others. Thereafter, anti-biofilm property of these two was examined by treating M. smegmatis with these agents before and after the formation of biofilm. The result showed that both the compounds at their sublethal dose inhibited the formation of biofilm as well as dispersed preformed biofilm. Consistently, they augmented the activity of isoniazid or rifampicin against biofilm-encapsulated cells. MTT assay was performed to examine the toxic effects of this combinatorial therapy on different cell lines. Results exhibited a low cytotoxicity for this combinatorial treatment. The activity of these two was also verified against dormant mycobacterial cells and was found to be effective. CONCLUSION: The present study identified two compounds that exhibited anti-mycobacterial activities against both planktonic and dormant cells. These two also exhibited anti-biofilm activity at their sublethal dose and augmented the activity of isoniazid and rifampicin against biofilm encapsulated cells. SIGNIFICANCE AND IMPACT OF THE STUDY: The current study provides two new agents that have the potential to be used in anti-mycobacterial therapy and may help in public health management.


Assuntos
Antibacterianos/farmacologia , Imidazóis/farmacologia , Mycobacterium smegmatis/efeitos dos fármacos , Piperidinas/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Humanos , Testes de Sensibilidade Microbiana , Rifampina/farmacologia
3.
Phys Rev Lett ; 125(13): 132501, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-33034500

RESUMO

We report the first observation of two wobbling bands in ^{183}Au, both of which were interpreted as the transverse wobbling (TW) band but with different behavior of their wobbling energies as a function of spin. It increases (decreases) with spin for the positive (negative) parity configuration. The crucial evidence for the wobbling nature of the bands, dominance of the E2 component in the ΔI=1 transitions between the partner bands, is provided by the simultaneous measurements of directional correlation from the oriented states ratio and the linear polarization of the γ rays. Particle rotor model calculations with triaxial deformation reproduce the experimental data well. A value of spin, I_{m}, has been determined for the observed TW bands below which the wobbling energy increases and above which it decreases with spin. The nucleus ^{183}Au is, so far, the only nucleus in which both the increasing and the decreasing parts are observed and thus gives the experimental evidence of the complete transverse wobbling phenomenon.

4.
Neth J Med ; 78(2): 92, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32332180
6.
Plant Biol (Stuttg) ; 18(6): 938-946, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27453497

RESUMO

Endophytic microbes isolated from plants growing in nutrient-deficient environments often possess properties that improve nutrition of agriculturally important plants. A consortium of non-rhizobial endophytic microbes isolated from a macrophyte Typha angustifolia growing in the marginal wetlands associated with a Uranium mine was characterized for their beneficial effect on rice and the mechanisms of growth promotion were investigated. The microbes were identified and characterized for their potential plant growth promoting (PGP) properties. Effect of these microbes on nitrogen (N)-metabolism of rice was tested as Typha endophytes were predominantly (N)-fixing. Relative N-use efficiency and expression of genes involved in N-uptake and assimilation were investigated in treated plants. Evidence of horizontal gene transfer (HGT) of dinitrogen reductase gene was observed within the consortium from a Pseudomonas stutzeri strain. The consortium behaved as plant probiotic and showed substantial growth benefits to Typha, their natural host as well as to rice. Typha endophytes colonized rice endosphere significantly increasing biomass, shoot length and chlorophyll content in rice plants both under N-sufficient and N-deficient conditions. N-uptake and assimilation genes were upregulated in plants treated with the endophytes even after three weeks post infection. Our results suggested, HGT of nitrogen-fixation trait to be highly prevalent among endophytes isolated from nutrient-poor habitats of the uranium mine. A long-term nitrogen deficiency response in the treated plants was elicited by the consortium improving N-uptake, assimilation and relative N-use efficiency of rice plants. This appeared to be at least one of the main strategies of plant growth promotion.


Assuntos
Endófitos/fisiologia , Nitrogênio/metabolismo , Oryza/microbiologia , Typhaceae/microbiologia , Biomassa , Endófitos/citologia , Fixação de Nitrogênio , Oryza/citologia , Oryza/metabolismo , Análise de Sequência de DNA
7.
Clin Exp Immunol ; 179(3): 398-413, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25302633

RESUMO

Several ß cell antigens recognized by T cells in the non-obese diabetic (NOD) mouse model of type 1 diabetes (T1D) are also T cell targets in the human disease. While numerous antigen-specific therapies prevent diabetes in NOD mice, successful translation of rodent findings to patients has been difficult. A human leucocyte antigen (HLA)-transgenic mouse model incorporating human ß cell-specific T cells might provide a better platform for evaluating antigen-specific therapies. The ability to study such T cells is limited by their low frequency in peripheral blood and the difficulty in obtaining islet-infiltrating T cells from patients. We have worked to overcome this limitation by using lentiviral transduction to 'reprogram' primary human CD8 T cells to express three T cell receptors (TCRs) specific for a peptide derived from the ß cell antigen islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP265-273 ) and recognized in the context of the human class I major histocompatibility complex (MHC) molecule HLA-A2. The TCRs bound peptide/MHC multimers with a range of avidities, but all bound with at least 10-fold lower avidity than the anti-viral TCR used for comparison. One exhibited antigenic recognition promiscuity. The ß cell-specific human CD8 T cells generated by lentiviral transduction with one of the TCRs released interferon (IFN)-γ in response to antigen and exhibited cytotoxic activity against peptide-pulsed target cells. The cells engrafted in HLA-A2-transgenic NOD-scid IL2rγ(null) mice and could be detected in the blood, spleen and pancreas up to 5 weeks post-transfer, suggesting the utility of this approach for the evaluation of T cell-modulatory therapies for T1D and other T cell-mediated autoimmune diseases.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Diabetes Mellitus Tipo 1/imunologia , Vetores Genéticos/genética , Imunoterapia Adotiva/métodos , Células Secretoras de Insulina/imunologia , Lentivirus/genética , Linfócitos T Citotóxicos/imunologia , Animais , Linfócitos T CD8-Positivos/transplante , Sobrevivência Celular , Glucose-6-Fosfatase/imunologia , Antígeno HLA-A2/genética , Antígeno HLA-A2/metabolismo , Humanos , Células Jurkat , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos Transgênicos , Fragmentos de Peptídeos/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Interleucina-2/genética , Linfócitos T Citotóxicos/transplante
8.
Oncogene ; 31(15): 1896-909, 2012 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-21874052

RESUMO

Emerging evidence suggests that cancers arise in stem/progenitor cells. Yet, the requirements for transformation of these primitive cells remains poorly understood. In this study, we have exploited the 'mammosphere' system that selects for primitive mammary stem/progenitor cells to explore their potential and requirements for transformation. Introduction of Simian Virus 40 Early Region and hTERT into mammosphere-derived cells led to the generation of NBLE, an immortalized mammary epithelial cell line. The NBLEs largely comprised of bi-potent progenitors with long-term self-renewal and multi-lineage differentiation potential. Clonal and karyotype analyses revealed the existence of heterogeneous population within NBLEs with varied proliferation, differentiation and sphere-forming potential. Significantly, injection of NBLEs into immunocompromised mice resulted in the generation of invasive ductal adenocarcinomas. Further, these cells harbored a sub-population of CD44(+)/CD24(-) fraction that alone had sphere- and tumor-initiating potential and resembled the breast cancer stem cell gene signature. Interestingly, prolonged in vitro culturing led to their further enrichment. The NBLE cells also showed increased expression of stemness and epithelial to mesenchymal transition markers, deregulated self-renewal pathways, activated DNA-damage response and cancer-associated chromosomal aberrations-all of which are likely to have contributed to their tumorigenic transformation. Thus, unlike previous in vitro transformation studies that used adherent, more differentiated human mammary epithelial cells our study demonstrates that the mammosphere-derived, less-differentiated cells undergo tumorigenic conversion with only two genetic elements, without requiring oncogenic Ras. Moreover, the striking phenotypic and molecular resemblance of the NBLE-generated tumors with naturally arising breast adenocarcinomas supports the notion of a primitive breast cell as the origin for this subtype of breast cancer. Finally, the NBLEs represent a heterogeneous population of cells with striking plasticity, capable of differentiation, self-renewal and tumorigenicity, thus offering a unique model system to study the molecular mechanisms involved with these processes.


Assuntos
Adenocarcinoma/patologia , Neoplasias da Mama/patologia , Transformação Celular Neoplásica , Glândulas Mamárias Humanas/citologia , Células-Tronco Neoplásicas/patologia , Telomerase/farmacologia , Proteínas Virais/farmacologia , Adenocarcinoma/genética , Animais , Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Técnicas de Cultura de Células , Diferenciação Celular/genética , Linhagem Celular Transformada , Linhagem Celular Tumoral , Proliferação de Células , Aberrações Cromossômicas , Transição Epitelial-Mesenquimal , Feminino , Perfilação da Expressão Gênica , Humanos , Camundongos , Vírus 40 dos Símios
9.
J Obstet Gynaecol ; 32(1): 78-80, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22185544

RESUMO

A retrospective review of 360 cases of carcinoma of the cervix with clinical stage IB and IIA who had undergone radical hysterectomy and pelvic node dissection between 2000 and 2005 was carried out. Lymph node metastasis was present in 79/360 patients (21.9%). LVSI positivity, full thickness stromal invasion, involvement of the uterine isthmus, positive parametrium, positive vaginal margins, involvement of uterine corpus was seen in: 25.3% and 9.2% (p < 0.001); 63% and 32% (p < 0.001); 32.9% and 13.8% (p < 0.001);15.2% and 5% (p < 0.004); 24% and 14.2% (p < 0.005); 17.7% and 13.8% (p = 0.11) of the patients, with and without lymph node metastasis, respectively. The tumour size was <4 cm in 50.6% and 58.3% and >4 cm in 49.3% and 41.6% of the patients, with and without lymph node metastasis, respectively (p = 0.22), which was statistically not significant. In the majority of patients, the histopathology type was squamous cell carcinoma in both the groups. In patients with lymph node metastases 79.7% had grade III tumour as compared with 69.5% in patients without lymph node metastases (p = 0.19). Multiple logistic regression indicated that only lymphovascular space involvement and full thickness stromal invasion were statistically significant (p < 0.001 and p < 0.002, respectively) for lymph node metastasis.


Assuntos
Carcinoma de Células Escamosas/patologia , Neoplasias do Colo do Útero/patologia , Adulto , Carcinoma de Células Escamosas/cirurgia , Feminino , Humanos , Linfonodos/patologia , Metástase Linfática , Pessoa de Meia-Idade , Análise Multivariada , Seleção de Pacientes , Estudos Retrospectivos , Neoplasias do Colo do Útero/cirurgia , Adulto Jovem
10.
Indian J Cancer ; 47(3): 314-6, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20587909

RESUMO

BACKGROUND: The cornerstones of successful treatment of hepatoblastoma (HB) include preoperative chemotherapy followed by complete anatomical resection of tumor, followed by chemotherapy. Advances in chemotherapy in the last 2 decades have been associated with a higher rate of tumor response and possibly a greater potential for resectability. AIMS: We analyzed our single center experience with neoadjuvant chemotherapy (NACT) and surgery in HBs. SETTINGS AND DESIGN: Our study included all children with HBs who received NACT and underwent surgical excision from January 1997 to July 2004. MATERIALS AND METHODS: Patient characteristics, clinical features, clinical course, treatment modalities, and long-term outcome were analyzed. RESULTS: There were 9 boys and 3 girls, aged 5-60 months (median age at tumor diagnosis was 24 months). All received NACT containing cisplatin and doxorubicin. Of the 12 children, 9 underwent hepatectomy and among them, 4 patients each had right and left hepatectomy and 1 patient underwent right extended hepatectomy. After surgery, all patients completed rest of the chemotherapy course (total 6 cycles). R0 resection was carried out in all the 9 cases with no life-threatening complications. CONCLUSIONS: Our experience of the 9 cases, although less in number, reaffirms the advantages of NACT followed by surgery. The prognosis for patients with resectable tumors is fairly good in combination with chemotherapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Hepatectomia , Hepatoblastoma/diagnóstico , Hepatoblastoma/terapia , Terapia Neoadjuvante , Centros Médicos Acadêmicos , Pré-Escolar , Cisplatino/administração & dosagem , Doxorrubicina/administração & dosagem , Feminino , Seguimentos , Hepatoblastoma/patologia , Hepatoblastoma/fisiopatologia , Humanos , Lactente , Masculino , Prognóstico , Resultado do Tratamento
11.
Clin Exp Immunol ; 161(2): 197-207, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20491789

RESUMO

Type 1 diabetes is an autoimmune disease characterized by destruction of the pancreatic islet beta cells that is mediated primarily by T cells specific for beta cell antigens. Insulin administration prolongs the life of affected individuals, but often fails to prevent the serious complications that decrease quality of life and result in significant morbidity and mortality. Thus, new strategies for the prevention and treatment of this disease are warranted. Given the important role of dendritic cells (DCs) in the establishment of peripheral T cell tolerance, DC-based strategies are a rational and exciting avenue of exploration. DCs employ a diverse arsenal to maintain tolerance, including the induction of T cell deletion or anergy and the generation and expansion of regulatory T cell populations. Here we review DC-based immunotherapeutic approaches to type 1 diabetes, most of which have been employed in non-obese diabetic (NOD) mice or other murine models of the disease. These strategies include administration of in vitro-generated DCs, deliberate exposure of DCs to antigens before transfer and the targeting of antigens to DCs in vivo. Although remarkable results have often been obtained in these model systems, the challenge now is to translate DC-based immunotherapeutic strategies to humans, while at the same time minimizing the potential for global immunosuppression or exacerbation of autoimmune responses. In this review, we have devoted considerable attention to antigen-specific DC-based approaches, as results from murine models suggest that they have the potential to result in regulatory T cell populations capable of both preventing and reversing type 1 diabetes.


Assuntos
Células Dendríticas/imunologia , Células Dendríticas/transplante , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/terapia , Imunoterapia/métodos , Animais , Diabetes Mellitus Tipo 1/prevenção & controle , Humanos , Camundongos
12.
Indian J Cancer ; 47(1): 8-15, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20071783

RESUMO

OBJECTIVES: Overexpression of the epidermal growth factor receptor family genes, which include ErbB-1, 2, 3 and 4, has been implicated in a number of cancers. We have studied the extent of ErbB-2 overexpression among Indian women with sporadic breast cancer. METHODS: Immunohistochemistry and genomic polymerase chain reaction (PCR) were used to study the ErbB2 overexpression. ErbB2 status was correlated with other clinico-pathological parameters, including patient survival. RESULTS: ErbB-2 overexpression was detected in 43.2% (159/368) of the cases by immunohistochemistry. For a sub-set of patients (n = 55) for whom total DNA was available, ErbB-2 gene amplification was detected in 25.5% (14/55) of the cases by genomic PCR. While the ErbB2 overexpression was significantly higher in patients with lymphnode (chi2 = 12.06, P < or = 0.001), larger tumor size (chi2 = 8.22, P = 0.042) and ductal carcinoma (chi2 = 15.42, P < or = 0.001), it was lower in patients with disease-free survival (chi2 = 22.13, P < or = 0.001). Survival analysis on a sub-set of patients for whom survival data were available (n = 179) revealed that ErbB-2 status (chi2 =25.94, P < or = 0.001), lymphnode status (chi2 = 12.68, P < or = 0.001), distant metastasis (chi2 = 19.49, P < or = 0.001) and stage of the disease (chi2 = 28.04, P < or = 0.001) were markers of poor prognosis. CONCLUSIONS: ErbB-2 overexpression was significantly greater compared with the Western literature, but comparable to other Indian studies. Significant correlation was found between ErbB-2 status and lymphnode status, tumor size and ductal carcinoma. ErbB-2 status, lymph node status, distant metastasis and stage of the disease were found to be prognostic indicators.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/patologia , Receptor ErbB-2/genética , Neoplasias da Mama/mortalidade , Carcinoma Ductal de Mama/mortalidade , Intervalo Livre de Doença , Feminino , Genes erbB-2 , Humanos , Imuno-Histoquímica , Índia , Estadiamento de Neoplasias , Reação em Cadeia da Polimerase , Prognóstico , Receptor ErbB-2/biossíntese
13.
Br J Cancer ; 102(1): 196-205, 2010 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-19953094

RESUMO

BACKGROUND: The role of Notch signalling in human epithelial cancers is of immense interest. In this study, we examine the interplay between Notch signalling and RhoC, a well-established molecular factor in metastasis. By linking the function of Notch and RhoC, we further strengthen the notion that there is a pro-oncogenic role of Notch signalling in human cervical cancers. METHODS: RhoC protein expression in cervical carcinoma cell lines was assessed by western blotting. Using CaSki and SiHa cells (cervical carcinoma cells lines), we show that RhoC contributes to wound healing, invasion and migration, anoikis resistance, colony formation, in vitro tube formation and tumour formation. Immunohistochemical studies were carried out to assess the co-expression of RhoC, pAkt and Notch1 in clinical sections. RESULTS: An assessment of the changes associated with epithelial-to-mesenchymal transition (EMT) shows that both Notch1 and RhoC have similar phenotypic contribution to EMT. Rho activity assessment on Notch1 inhibition with DAPT shows decreased RhoC activity. We further show that constitutively active RhoC rescues the phenotypic effect of Notch1 inactivation, and a comparison of Notch1 with RhoC expression shows an overlap between the two proteins in the same areas of the tissue. CONCLUSION: This study has provided evidence to suggest that RhoC is an effector of Notch1 in cervical carcinoma.


Assuntos
Carcinoma de Células Escamosas/patologia , Proteínas de Neoplasias/fisiologia , Receptor Notch1/fisiologia , Neoplasias do Colo do Útero/patologia , Proteínas rho de Ligação ao GTP/fisiologia , Animais , Anoikis/fisiologia , Carcinoma de Células Escamosas/irrigação sanguínea , Carcinoma de Células Escamosas/metabolismo , Divisão Celular , Linhagem Celular Tumoral , Movimento Celular , Transdiferenciação Celular , Progressão da Doença , Feminino , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Camundongos Nus , Invasividade Neoplásica , Neovascularização Patológica/fisiopatologia , RNA Interferente Pequeno/farmacologia , Receptor Notch1/antagonistas & inibidores , Receptor Notch1/genética , Transdução de Sinais/fisiologia , Ensaio Tumoral de Célula-Tronco , Neoplasias do Colo do Útero/metabolismo , Proteína de Ligação a GTP rhoC
14.
J Chem Phys ; 130(12): 124509, 2009 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-19334853

RESUMO

In this paper, we report angle-dispersive X-ray diffraction data of molybdenum melting, measured in a double-sided laser-heated diamond-anvil cell up to a pressure of 119 GPa and temperatures up to 3400 K. The new melting temperatures are in excellent agreement with earlier measurements up to 90 GPa that relied on optical observations of melting and in strong contrast to most theoretical estimates. The X-ray measurements show that the solid melts from the bcc structure throughout the reported pressure range and provide no evidence for a high temperature transition from bcc to a close-packed structure, or to any other crystalline structure. This observation contradicts earlier interpretations of shock data arguing for such a transition. Instead, the values for the Poisson ratios of shock compressed Mo, obtained from the sound speed measurements, and the present X-ray evidence of loss of long-range order suggest that the 210 GPa (approximately 4100 K) transition in the shock experiment is from the bcc structure to a new, highly viscous, structured melt.

16.
Phys Rev Lett ; 101(3): 032501, 2008 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-18764246

RESUMO

Results from the gamma-ray spectroscopy of {47,48}Ar exemplifying new limits of sensitivity for characterizing neutron-rich nuclei at energies around the Coulomb barrier are presented. The present results, along with interacting shell model calculations, highlight the role of cross-shell excitations and indicate the presence of a nonaxial deformation in 48Ar.

17.
Phys Rev Lett ; 99(8): 082502, 2007 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-17930944

RESUMO

Gamma rays deexciting states in the proton emitter 145Tm were observed using the recoil-decay tagging method. The 145Tm ground-state rotational band was found to exhibit the properties expected for an h{11/2} proton decoupled band. In addition, coincidences between protons feeding the 2{+} state in 144Er and the 2{+}-->0{+} gamma-ray transition were detected, the first measurement of this kind, leading to a more precise value for the 2{+} excitation energy of 329(1) keV. Calculations with the particle-rotor model and the core quasiparticle coupling model indicate that the properties of the pi{11/2} band and the proton-decay rates in 145Tm are consistent with the presence of triaxiality with an asymmetry parameter gamma approximately 20 degrees .


Assuntos
Raios gama , Prótons
18.
J Pathol ; 212(3): 325-34, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17516585

RESUMO

For many oncogenes, increased expression resulting from copy number gain confers a selective advantage to cells that consequently make up the tumour bulk. To identify oncogenes of potential biological significance in cervical squamous cell carcinoma (SCC), 36 primary samples and ten cell lines were screened by array comparative genomic hybridization (CGH). The most commonly occurring regions of copy number gain that also showed amplification were 5p15.2-14.3 (59%), 5p13.3 (65%), and 5p13.2-13.1 (63%). Gene copy numbers were significantly associated with expression levels for three candidate oncogenes at these loci: OSMR (oncostatin M receptor) (p=0.03), PDZK3 (PDZ domain containing protein 3) (p=0.04), and TRIO (triple functional domain) (p=0.03). Further examination by fluorescence in situ hybridization on a tissue microarray of 110 primary cervical SCC samples revealed copy number gain frequencies of 60.9%, 57.3%, and 54.5% for OSMR, PDZK3, and TRIO, respectively, with OSMR adversely influencing overall patient survival independently of tumour stage (p=0.046). By array CGH, copy number gain of OSMR was not seen in any of 40 microdissected precursor cervical squamous intraepithelial lesions (SILs). Moreover, global mRNA expression analysis, using Affymetrix U133A 2.0 Arrays, showed no overexpression of OSMR in SILs, suggesting that OSMR gain and overexpression are relatively late steps in cervical carcinogenesis. In the cervical SCC cell lines CaSki and SW756, exogenous OSM activated downstream-signalling elements of OSMR including STAT3, p44/42 MAPK, and S6 ribosomal protein, and induced transcription of the angiogenic factor VEGF, effects that were reduced by OSMR depletion using RNA interference. We conclude that copy number gain of OSMR is frequently found in cervical SCC and is associated with adverse clinical outcome. As well as being a potential prognostic marker, OSMR is a candidate cell surface therapeutic target.


Assuntos
Carcinoma de Células Escamosas/genética , Regulação Neoplásica da Expressão Gênica , Receptores de Oncostatina M/genética , Neoplasias do Colo do Útero/genética , Linhagem Celular Tumoral , Feminino , Amplificação de Genes , Perfilação da Expressão Gênica , Humanos , Hibridização in Situ Fluorescente , Análise de Sequência com Séries de Oligonucleotídeos , Prognóstico , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , RNA Mensageiro/análise , RNA Interferente Pequeno/genética , Receptores de Oncostatina M/análise , Receptores de Oncostatina M/metabolismo , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Análise de Sobrevida , Transfecção/métodos , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
19.
J Pathol ; 212(4): 368-77, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17471471

RESUMO

Gain of chromosome 5p is seen in over 50% of advanced cervical squamous cell carcinomas (SCCs), although the genes responsible for the selective advantage provided by this abnormality are poorly understood. In the W12 cervical carcinogenesis model, we observed that 5p gain was rapidly selected over approximately 15 population doublings and was associated with the acquisition of a growth advantage and invasiveness. The most significantly upregulated transcript following 5p gain was the microRNA (miRNA) processor Drosha. In clinically progressed cervical SCC, Drosha copy-number gain was seen in 21/36 clinical samples and 8/10 cell lines and there was a significant association between Drosha transcript levels and copy-number gain. Other genes in the miRNA processing pathway, DGCR8, XPO5 and Dicer, showed infrequent copy-number gain and over-expression. Drosha copy-number and expression were not elevated in pre-malignant cervical squamous intraepithelial lesions. Importantly, global miRNA profiling showed that Drosha over-expression in cervical SCC appears to be of functional significance. Unsupervised principal component analysis of a mixed panel of cervical SCC cell lines and clinical specimens showed clear separation according to Drosha over-expression. miRNAs most significantly associated with Drosha over-expression are implicated in carcinogenesis in other tissues, suggesting that they regulate fundamental processes in neoplastic progression. Our evidence suggests that copy-number driven over-expression of Drosha and consequent changes in miRNAs are likely to be important contributors to the selective advantage provided by 5p gain in cervical neoplastic progression.


Assuntos
Carcinoma de Células Escamosas/genética , MicroRNAs/genética , RNA Neoplásico/genética , Ribonuclease III/metabolismo , Neoplasias do Colo do Útero/genética , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Células Cultivadas , Cromossomos Humanos Par 5/genética , Feminino , Humanos , Invasividade Neoplásica , Proteínas de Neoplasias/metabolismo , Reação em Cadeia da Polimerase/métodos , Análise de Componente Principal , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia
20.
Br J Cancer ; 96(7): 1107-11, 2007 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-17342084

RESUMO

Cervical screening is not available for the majority of women in resource-poor countries. An important factor is a lack of skilled operators necessary for high-throughput assessment of the Papanicolaou (Pap) test currently in use. We compared the efficacy of immunocytochemistry for minichromosome maintenance (MCM) proteins vs standard Pap testing at detecting disease in 455 cervical smears processed in a typical Indian screening laboratory. Conventional (non-monolayer) smears were stained manually and then examined by a cytotechnologist and a cytopathologist. The MCM test was called positive when immunolabelled cells were identified as dyskaryotic by the Pap counterstain. The MCM test was read more quickly than the Pap test (approximately 2 vs 10 min) and there was 100% inter-observer agreement compared with 85% for Pap (P<0.0001). The MCM test detected 10 biopsy-proven cancers or pre-cancers that were not detected by Pap (P=0.002; P=0.016 excluding three cases where the Pap was deemed unsatisfactory on review). The cases in question included one recurrent squamous carcinoma and one adenocarcinoma in a screening patient who would have returned to 5 year recall. There were no false positive MCM test results. We propose that MCM immunocytochemistry has considerable advantages for cervical screening in developing countries like India.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Programas de Rastreamento , Proteínas Nucleares/metabolismo , Neoplasias do Colo do Útero/diagnóstico , Adenocarcinoma/diagnóstico , Adenocarcinoma/metabolismo , Adulto , Idoso , Proteínas de Ciclo Celular/imunologia , Estudos de Coortes , Países em Desenvolvimento , Reações Falso-Negativas , Feminino , Humanos , Técnicas Imunoenzimáticas , Índia , Pessoa de Meia-Idade , Componente 2 do Complexo de Manutenção de Minicromossomo , Proteínas Nucleares/imunologia , Teste de Papanicolaou , Estudos Prospectivos , Neoplasias do Colo do Útero/metabolismo , Esfregaço Vaginal , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA