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1.
J Virol ; 96(7): e0187821, 2022 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-35289647

RESUMO

Binding to the receptor, CD4, drives the pretriggered, "closed" (State-1) conformation of the human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer ([gp120/gp41]3) into more "open" conformations. HIV-1 Env on the viral membrane is maintained in a State-1 conformation that resists binding and neutralization by commonly elicited antibodies. Premature triggering of Env before the virus engages a target cell typically leads to increased susceptibility to spontaneous inactivation or ligand-induced neutralization. Here, we showed that single amino acid substitutions in the gp41 membrane-proximal external region (MPER) of a primary HIV-1 strain resulted in viral phenotypes indicative of premature triggering of Env to downstream conformations. Specifically, the MPER changes reduced viral infectivity and globally increased virus sensitivity to poorly neutralizing antibodies, soluble CD4, a CD4-mimetic compound, and exposure to cold. In contrast, the MPER mutants exhibited decreased sensitivity to the State 1-preferring inhibitor, BMS-806, and to the PGT151 broadly neutralizing antibody. Depletion of cholesterol from virus particles did not produce the same State 1-destabilizing phenotypes as MPER alterations. Notably, State 1-stabilizing changes in Env distant from the MPER could minimize the phenotypic effects of MPER alteration but did not affect virus sensitivity to cholesterol depletion. Thus, membrane-proximal gp41 elements contribute to the maintenance of the pretriggered Env conformation. The conformationally disruptive effects of MPER changes can be minimized by distant State 1-stabilizing Env modifications, a strategy that may be useful in preserving the native pretriggered state of Env. IMPORTANCE The pretriggered shape of the human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) is a major target for antibodies that can neutralize many strains of the virus. An effective HIV-1 vaccine may need to raise these types of antibodies, but this goal has proven difficult. One reason is that the pretriggered shape of Env is unstable and dependent on interactions near the viral membrane. Here, we showed that the membrane-proximal external region (MPER) of Env plays an important role in maintaining Env in a pretriggered shape. Alterations in the MPER resulted in global changes in Env conformation that disrupted its pretriggered shape. We also found that these disruptive effects of MPER changes could be minimized by distant Env modifications that stabilized the pretriggered shape. These modifications may be useful for preserving the native shape of Env for structural and vaccine studies.


Assuntos
Infecções por HIV , HIV-1 , Anticorpos Neutralizantes , Produtos do Gene env/química , Produtos do Gene env/imunologia , Glicoproteínas/química , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp41 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/química , HIV-1/imunologia , Humanos
2.
J Virol ; 96(8): e0166821, 2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35343783

RESUMO

Binding to the receptor, CD4, drives the pretriggered, "closed" (state-1) conformation of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) trimer into more "open" conformations (states 2 and 3). Broadly neutralizing antibodies, which are elicited inefficiently, mostly recognize the state-1 Env conformation, whereas the more commonly elicited poorly neutralizing antibodies recognize states 2/3. HIV-1 Env metastability has created challenges for defining the state-1 structure and developing immunogens mimicking this labile conformation. The availability of functional state-1 Envs that can be efficiently cross-linked at lysine and/or acidic amino acid residues might assist these endeavors. To that end, we modified HIV-1AD8 Env, which exhibits an intermediate level of triggerability by CD4. We introduced lysine/acidic residues at positions that exhibit such polymorphisms in natural HIV-1 strains. Env changes that were tolerated with respect to gp120-gp41 processing, subunit association, and virus entry were further combined. Two common polymorphisms, Q114E and Q567K, as well as a known variant, A582T, additively rendered pseudoviruses resistant to cold, soluble CD4, and a CD4-mimetic compound, phenotypes indicative of stabilization of the pretriggered state-1 Env conformation. Combining these changes resulted in two lysine-rich HIV-1AD8 Env variants (E.2 and AE.2) with neutralization- and cold-resistant phenotypes comparable to those of natural, less triggerable tier 2/3 HIV-1 isolates. Compared with these and the parental Envs, the E.2 and AE.2 Envs were cleaved more efficiently and exhibited stronger gp120-trimer association in detergent lysates. These highly cross-linkable Envs enriched in a pretriggered conformation should assist characterization of the structure and immunogenicity of this labile state. IMPORTANCE The development of an efficient vaccine is critical for combating HIV-1 infection worldwide. However, the instability of the pretriggered shape (state 1) of the viral envelope glycoprotein (Env) makes it difficult to raise neutralizing antibodies against HIV-1. Here, by introducing multiple changes in Env, we derived two HIV-1 Env variants that are enriched in state 1 and can be efficiently cross-linked to maintain this shape. These Env complexes are more stable in detergent, assisting their purification. Thus, our study provides a path to a better characterization of the native pretriggered Env, which should assist vaccine development.


Assuntos
Vacinas contra a AIDS , Infecções por HIV , HIV-1 , Produtos do Gene env do Vírus da Imunodeficiência Humana , Vacinas contra a AIDS/genética , Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/imunologia , Detergentes , Glicoproteínas/química , Glicoproteínas/imunologia , Anticorpos Anti-HIV/química , Anticorpos Anti-HIV/metabolismo , Proteína gp120 do Envelope de HIV/genética , Infecções por HIV/prevenção & controle , HIV-1/química , HIV-1/genética , HIV-1/imunologia , Humanos , Lisina , Conformação Proteica , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia
3.
J Virol ; 94(10)2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32161177

RESUMO

During human immunodeficiency virus type 1 (HIV-1) entry into cells, the viral envelope glycoprotein (Env) trimer [(gp120/gp41)3] binds the receptors CD4 and CCR5 and fuses the viral and cell membranes. CD4 binding changes Env from a pretriggered (state-1) conformation to more open downstream conformations. BMS-378806 (here called BMS-806) blocks CD4-induced conformational changes in Env important for entry and is hypothesized to stabilize a state-1-like Env conformation, a key vaccine target. Here, we evaluated the effects of BMS-806 on the conformation of Env on the surface of cells and virus-like particles. BMS-806 strengthened the labile, noncovalent interaction of gp120 with the Env trimer, enhanced or maintained the binding of most broadly neutralizing antibodies, and decreased the binding of poorly neutralizing antibodies. Thus, in the presence of BMS-806, the cleaved Env on the surface of cells and virus-like particles exhibits an antigenic profile consistent with a state-1 conformation. We designed novel BMS-806 analogues that stabilized the Env conformation for several weeks after a single application. These long-acting BMS-806 analogues may facilitate enrichment of the metastable state-1 Env conformation for structural characterization and presentation to the immune system.IMPORTANCE The envelope glycoprotein (Env) spike on the surface of human immunodeficiency virus type 1 (HIV-1) mediates the entry of the virus into host cells and is also the target for antibodies. During virus entry, Env needs to change shape. Env flexibility also contributes to the ability of HIV-1 to evade the host immune response; many shapes of Env raise antibodies that cannot recognize the functional Env and therefore do not block virus infection. We found that an HIV-1 entry inhibitor, BMS-806, stabilizes the functional shape of Env. We developed new variants of BMS-806 that stabilize Env in its natural state for long periods of time. The availability of such long-acting stabilizers of Env shape will allow the natural Env conformation to be characterized and tested for efficacy as a vaccine.


Assuntos
Glicoproteínas/química , Glicoproteínas/efeitos dos fármacos , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/efeitos dos fármacos , HIV-1/imunologia , Piperazinas/farmacologia , Internalização do Vírus/efeitos dos fármacos , Células A549 , Anticorpos Neutralizantes/imunologia , Antígenos CD4/efeitos dos fármacos , Antígenos CD4/metabolismo , Glicoproteínas/genética , Células HEK293 , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/efeitos dos fármacos , HIV-1/genética , Humanos , Ligantes , Modelos Moleculares , Conformação Proteica
4.
J Virol ; 93(21)2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31391272

RESUMO

Human immunodeficiency virus (HIV-1) entry into cells is mediated by the viral envelope glycoprotein (Env) trimer, which consists of three gp120 exterior glycoproteins and three gp41 transmembrane glycoproteins. When gp120 binds sequentially to the receptors CD4 and CCR5 on the target cell, the metastable Env trimer is triggered to undergo entry-related conformational changes. PF-68742 is a small molecule that inhibits the infection of a subset of HIV-1 strains by interfering with an Env function other than receptor binding. Determinants of HIV-1 resistance to PF-68742 map to the disulfide loop and fusion peptide of gp41. Of the four possible PF-68742 stereoisomers, only one, MF275, inhibited the infection of CD4-positive CCR5-positive cells by some HIV-1 strains. MF275 inhibition of these HIV-1 strains occurred after CD4 binding but before the formation of the gp41 six-helix bundle. Unexpectedly, MF275 activated the infection of CD4-negative CCR5-positive cells by several HIV-1 strains resistant to the inhibitory effects of the compound in CD4-positive target cells. In contrast to CD4 complementation by CD4-mimetic compounds, activation of CD4-independent infection by MF275 did not depend upon the availability of the gp120 Phe 43 cavity. Sensitivity to inhibitors indicates that MF275-activated virus entry requires formation/exposure of the gp41 heptad repeat (HR1) as well as CCR5 binding. MF275 apparently activates a virus entry pathway parallel to that triggered by CD4 and CD4-mimetic compounds. Strain-dependent divergence in Env conformational transitions allows different outcomes, inhibition or activation, in response to MF275. Understanding the mechanisms of MF275 activity should assist efforts to optimize its utility.IMPORTANCE Envelope glycoprotein (Env) spikes on the surface of human immunodeficiency virus (HIV-1) bind target cell receptors, triggering changes in the shape of Env. We studied a small molecule, MF275, that also induced shape changes in Env. The consequences of MF275 interaction with Env depended on the HIV-1 strain, with infection by some viruses inhibited and infection by other viruses enhanced. These studies reveal the strain-dependent diversity of HIV-1 Envs as they undergo shape changes in proceeding down the entry pathway. Appreciation of this diversity will assist attempts to develop broadly active inhibitors of HIV-1 entry.


Assuntos
Proteína gp120 do Envelope de HIV/metabolismo , Proteína gp41 do Envelope de HIV/metabolismo , Infecções por HIV/tratamento farmacológico , HIV-1/classificação , HIV-1/efeitos dos fármacos , Piridonas/farmacologia , Sulfonamidas/farmacologia , Internalização do Vírus/efeitos dos fármacos , Antivirais/farmacologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/genética , Proteína gp41 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/genética , Infecções por HIV/metabolismo , Infecções por HIV/virologia , Humanos , Ligação Proteica , Conformação Proteica , Multimerização Proteica , Piridonas/química , Receptores CCR5/genética , Receptores CCR5/metabolismo , Estereoisomerismo , Sulfonamidas/química , Replicação Viral
5.
Clin Exp Med ; 22(1): 1-7, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33990849

RESUMO

Circulating tumor DNA (ctDNA) can be used to evaluate the prognosis of lymphoma. However, there is no uniform consensus about the mechanistic role that ctDNA plays in the prognosis of lymphoma. This meta-analysis explores the prognostic value of ctDNA in lymphoma, especially in diffuse large B cell lymphoma (DLBCL). All relevant reports published as of May 14, 2020, were retrieved by searching electronic databases in Pubmed, Embase and Cochrane Library. The prognostic value of ctDNA was evaluated using meta-analysis. Revman 5.3 software was used for prognostic data extraction and analysis. Eight studies, including a total of 767 lymphoma patients, were enrolled in this meta-analysis. Five out of eight studies investigated the association between ctDNA levels and progression-free survival (PFS) in 501 lymphoma patients, indicating that high levels of ctDNA were significantly associated with poor PFS (HR 2.24, 95%CI: 1.63-3.08, P < 0.00001). We conducted a subgroup analysis of 379 patients with DLBCL across three of the studies and came to the same conclusion (HR 2.01, 95%CI: 1.42-2.85, P < 0.0001). Two studies with a total of 192 lymphoma patients described the association between ctDNA levels and event-free survival (EFS), showing that high levels of ctDNA were also associated with adverse EFS (HR 4.53, 95%CI: 1.79-11.47, P = 0.001). The remaining two studies analyzed the potential clinical value of ctDNA for predicting the overall survival time (OS) of DLBCL patients, demonstrating that high levels of ctDNA correlated with inferior OS (HR 3.09, 95%CI: 1.50-6.35, P = 0.002). Our meta-analysis showed that high levels of ctDNA were associated with poor prognosis in patients with lymphoma, especially DLBCL.


Assuntos
DNA Tumoral Circulante , Linfoma Difuso de Grandes Células B , DNA Tumoral Circulante/genética , Humanos , Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma Difuso de Grandes Células B/patologia , Prognóstico , Intervalo Livre de Progressão
6.
Clin Lymphoma Myeloma Leuk ; 22(2): e77-e88, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34593361

RESUMO

BACKGROUND: Consensus lacks regarding the association between diabetes mellitus (DM) and the prognosis of patients with non-Hodgkin lymphoma (NHL). We aimed to systematically evaluate the above association, as well as the potential influence of metformin use in a meta-analysis of cohort studies. MATERIALS AND METHODS: Cohort studies investigating the association between DM and survival outcomes of patients with NHL were included by search of electronic databases that included PubMed, Embase, and Web of Science. A random-effects model was adopted to combine the results. RESULTS: Eight cohort studies including 8652 patients with NHL were analyzed. Compared to non-DM patients with NHL, DM was associated with poor overall survival (OS, hazard ratio [HR] = 1.49, 95% confidence interval [CI]: 1.18-1.89, P < .001, I2 = 69%), progression-free survival (PFS, HR = 1.30, 95% CI: 1.09-1.56, P = .004, I2 = 0%), and lymphoma-specific survival (LSS, HR = 1.86, 95% CI: 1.41-2.45, P < .001, I2 = 0%). Subgroup analysis showed consistent results in patients with diffuse large B-cell lymphoma (DLBCL, HR = 1.42, 1.35, and 1.95 for outcomes of OS, PFS, and LSS, respectively; P values all <.05). However, the associations between DM and these survival outcomes became nonsignificant in subgroup analysis limited to DM patients with concurrent use of metformin (HR = 1.30, 1.12, and 1.43 for outcomes of OS, PFS, and LSS, respectively; P values all > .10). CONCLUSIONS: DM is associated with poor survival outcomes in patients with B-cell NHL, which is consistent in patients with DLBCL. Concurrent metformin use in DM patients with NHL may be associated with improved survival outcomes.


Assuntos
Diabetes Mellitus , Linfoma Difuso de Grandes Células B , Linfoma não Hodgkin , Estudos de Coortes , Diabetes Mellitus/epidemiologia , Humanos , Linfoma Difuso de Grandes Células B/complicações , Linfoma não Hodgkin/complicações , Linfoma não Hodgkin/tratamento farmacológico , Prognóstico
7.
Exp Ther Med ; 24(4): 627, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36160896

RESUMO

Long non-coding RNAs (lncRNAs) have been confirmed to be connected with tumor proliferation, apoptosis, metastasis and recurrence. Previous studies have indicated that lncRNA calcium voltage-gated channel subunit α1 G (CACNA1G)-antisense 1 (AS1) can function as a pro-oncogene in several types of cancer. However, the specific role and mechanism of CACNA1G-AS1 have not been fully elucidated in human diffuse large B cell lymphoma (DLBCL). In the present study, CACNA1G-AS1 expression was verified in DLBCL tissues and cells by reverse transcription-quantitative PCR, and the relationship between CACNA1G-AS1 and microRNA (miR)-3160-5p was confirmed using luciferase reporter assays. After CACNA1G-AS1-knockdown and miR-3160-5p-overexpression, MTT, colony formation and flow cytometry assays were conducted to assess the changes in the cytotoxicity and apoptosis of OCI-Ly10 and SUDHL-4 cells. In addition, in vivo experiments were performed to determine the impact of CACNA1G-AS1-knockdown on tumor growth and apoptosis. It was revealed that CACNA1G-AS1 was highly expressed in DLBCL tissues and cells and that expression of CACNA1G-AS1 was associated with the clinical stage of DLBCL. Functionally, CACNA1G-AS1-knockdown was demonstrated to increase cytotoxicity and expedite apoptosis in DLBCL cells in vitro and in vivo. In addition, CACNA1G-AS1 could downregulate miR-3160-5p by targeting binding in DLBCL cells. Overexpression of miR-3160-5p had the same effects on the cytotoxicity and apoptosis of DLBCL cells as CACNA1G-AS1-knockdown. Overall, the present study revealed that CACNA1G-AS1-knockdown and miR-3160-5p-overexpression could prevent DLBCL carcinogenesis, which might provide novel therapeutic targets for DLBCL.

8.
Cell Mol Immunol ; 19(11): 1302-1310, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36224497

RESUMO

Mutations in SARS-CoV-2 variants of concern (VOCs) have enhanced transmissibility and immune evasion with respect to current vaccines and neutralizing antibodies (NAbs). How naturally occurring spike mutations affect the infectivity and antigenicity of VOCs remains to be investigated. The entry efficiency of individual spike mutations was determined in vitro using pseudotyped viruses. BALB/c mice were immunized with 2-dose DNA vaccines encoding B.1.1.7, B.1.351, B.1.1.529  and their single mutations. Cellular and humoral immune responses were then compared to determine the impact of individual mutations on immunogenicity. In the B.1.1.7 lineage, Del69-70 and Del 144 in NTD, A570D and P681H in SD1 and S982A and D1118H in S2 significantly increased viral entry, whereas T716I resulted in a decrease. In the B.1.351 lineage, L18F and Del 242-244 in the NTD, K417N in the RBD and A701V in S2 also increased viral entry. S982A weakened the generation of binding antibodies. All sera showed reduced cross-neutralization activity against B.1.351, B.1.617.2 (Delta) and B.1.1.529 (Omicron BA.1). S982A, L18F, and Del 242-244 hindered the induction of cross-NAbs, whereas Del 69-70, Del144, R246I, and K417N showed the opposite effects. B.1.351 elicited adequate broad cross-NAbs against both B.1.351 and B.1.617.2. All immunogens tested, however, showed low neutralization against circulating B.1.1.529. In addition, T-cell responses were unlikely affected by mutations tested in the spike. We conclude that individual spike mutations influence viral infectivity and vaccine immunogenicity. Designing VOC-targeted vaccines is likely necessary to overcome immune evasion from current vaccines and neutralizing antibodies.


Assuntos
COVID-19 , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Animais , Humanos , Camundongos , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/imunologia , COVID-19/virologia , Camundongos Endogâmicos BALB C , Mutação , Testes de Neutralização , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia
9.
EBioMedicine ; 77: 103904, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35248996

RESUMO

BACKGROUND: Nearly 4 billion doses of the BNT162b2-mRNA and CoronaVac-inactivated vaccines have been administrated globally, yet different vaccine-induced immunity against SARS-CoV-2 variants of concern (VOCs) remain incompletely investigated. METHODS: We compare the immunogenicity and durability of these two vaccines among fully vaccinated Hong Kong people. FINDINGS: Standard BNT162b2 and CoronaVac vaccinations were tolerated and induced neutralizing antibody (NAb) (100% and 85.7%) and spike-specific CD4 T cell responses (96.7% and 82.1%), respectively. The geometric mean NAb IC50 and median frequencies of reactive CD4 subsets were consistently lower among CoronaVac-vaccinees than BNT162b2-vaccinees. CoronaVac did not induce measurable levels of nucleocapsid protein-specific IFN-γ+ CD4+ T or IFN-γ+ CD8+ T cells compared with unvaccinated. Against VOCs, NAb response rates and geometric mean IC50 titers against B.1.617.2 (Delta) and B.1.1.529 (Omicron) were significantly lower for CoronaVac (50%, 23.2 and 7.1%, <20) than BNT162b2 (94.1%, 131 and 58.8%, 35.0), respectively. Three months after vaccinations, NAbs to VOCs dropped near to detection limit, along with waning memory T cell responses, mainly among CoronaVac-vaccinees. INTERPRETATION: Our results indicate that vaccinees especially CoronaVac-vaccinees with significantly reduced NAbs may probably face higher risk to pandemic VOCs breakthrough infection. FUNDING: This study was supported by the Hong Kong Research Grants Council Collaborative Research Fund (C7156-20GF and C1134-20GF); the Wellcome Trust (P86433); the National Program on Key Research Project of China (Grant 2020YFC0860600, 2020YFA0707500 and 2020YFA0707504); Shenzhen Science and Technology Program (JSGG20200225151410198 and JCYJ20210324131610027); HKU Development Fund and LKS Faculty of Medicine Matching Fund to AIDS Institute; Hong Kong Innovation and Technology Fund, Innovation and Technology Commission and generous donation from the Friends of Hope Education Fund. Z.C.'s team was also partly supported by the Theme-Based Research Scheme (T11-706/18-N).


Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos Neutralizantes , Anticorpos Antivirais , Vacina BNT162 , Linfócitos T CD8-Positivos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Hong Kong/epidemiologia , Humanos , Imunidade , SARS-CoV-2/genética , Vacinação
10.
J Environ Sci (China) ; 23(9): 1497-502, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22432286

RESUMO

The adsorption behaviors of heavy metals onto novel low-cost adsorbent, red loess, were investigated. Red loess was characterized by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectra. The results indicated that red loess mainly consisted of silicate, ferric and aluminum oxides. Solution pH, adsorbent dosage, initial metal concentration, contact time and temperature significantly influenced the efficiency of heavy metals removal. The adsorption reached equilibrium at 4 hr, and the experimental equilibrium data were fitted to Langmuir monolayer adsorption model. The adsorption of Cu(II) and Zn(II) onto red loess was endothermic, while the adsorption of Pb(II) was exothermic. The maximum adsorption capacities of red loess for Pb(II), Cu(II) and Zn(II) were estimated to be 113.6, 34.2 and 17.5 mg/g, respectively at 25 degrees C and pH 6. The maximum removal efficiencies were 100% for Pb(II) at pH 7, 100% for Cu(II) at pH 8, and 80% for Zn(II) at pH 8. The used adsorbents were readily regenerated using dilute HCl solution, indicating that red loess has a high reusability. All the above results demonstrated that red loess could be used as a possible alternative low-cost adsorbent for the removal of heavy metals from aqueous solution.


Assuntos
Poluentes Ambientais/química , Poluentes Ambientais/isolamento & purificação , Sedimentos Geológicos/química , Metais Pesados/química , Metais Pesados/isolamento & purificação , Água/química , Cinética , Soluções , Fatores de Tempo
11.
Cancer Genet Cytogenet ; 165(1): 20-4, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16490593

RESUMO

Chromosomal aberrations (amplifications and deletions) underlie the genesis or development of cancer. Amplification of 8q24 is one of the most frequent events in esophageal cancer. To define whether C-MYC is the target gene for 8q24 amplification, we performed fluorescence in situ hybridization using a MYC (8q24.12 approximately q24.13) probe in esophageal cancer from southern China. Furthermore, we detected the expression status of several genes including C-MYC, TRIB1 (alias C8FW), and FAM84B (alias NSE2) in the regions of 8q24 via reverse transcriptase-polymerase chain reaction or immunohistochemical analysis (or both). Distinct amplification of 8q24 was found in esophageal carcinomas. Only 4 of 46 cases showed obvious protein expression in part of the esophageal cancerous nest. In particular, increased protein expression of C-MYC was shown only in a small part of a cancerous nest in the four cases. Positive C-MYC staining was detected mainly in the cytoplasm of esophageal cancer cells. No expression of TRIB1 was detected in esophageal squamous cell carcinomas. Of 59 cases, 39 (66%) cases showed increased expression of FAM84B in esophageal carcinomas. The results suggest that C-MYC and TRIB1 may not be the amplification target of 8q24 in esophageal cancer. FAM84B might be involved in the genesis or development of esophageal cancer in southern China. Whether FAM84B is the amplification target of esophageal cancer awaits further investigation.


Assuntos
Neoplasias Esofágicas/genética , Genes myc , Adulto , China , Mapeamento Cromossômico , Primers do DNA , Feminino , Amplificação de Genes , Regulação Neoplásica da Expressão Gênica , Humanos , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , RNA Neoplásico/genética , RNA Neoplásico/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
12.
Zhonghua Bing Li Xue Za Zhi ; 31(2): 132-4, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12419160

RESUMO

OBJECTIVE: To effectively screen p16 protein expression of different clinical stage nasopharyngeal carcinoma (NPC) by constructing and applying high-throughput tissue microarray/tissue chip. METHODS: A series of tissue chips were prepared by using tissue arrayer with samples from different clinical stage NPC tumors and noncancerous nasopharynx tissue. Specimens from 259 cases of nasopharyngeal lesions were detected immunohistochemically on a tissue chip for p16 protein expression and the correlation of p16 protein expression to clinical stage of NPC was analyzed statistically. RESULTS: p16 protein expression was detected in all 18 histologically normal nasopharyngeal epithelia. No p16 protein was detected in 3 of 3 (100%) stage I NPC, 38 of 44 (86.3%) stage II NPC, 59 of 68 (86.8%) stage III NPC, 23 of 28 (82.1%) stage IV NPC, 87 of 98 (88.8%) unclear stage NPC. The efficiency of p16 protein expression in NPC tissues was significantly lower than that in normal nasopharyngeal epithelia (chi(2) = 82.58, P < 0.001), and there was no apparent relationship between p16 protein expression and clinical stages (chi(2) = 0.09, P = 0.769). CONCLUSIONS: The frequent deletion of p16 protein in NPC suggests that p16 gene has an important role in the development and progression of NPC. The consistency of p16 protein deletion in different stages of NPC suggests that the deletion of p16 protein is an early event in the development of NPC, and it is feasible to utilize tissue microarray for a rapid, economic and accurate screening of clinical tissue specimens on a large scale.


Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/biossíntese , Neoplasias Nasofaríngeas/patologia , Humanos , Imuno-Histoquímica , Neoplasias Nasofaríngeas/metabolismo , Estadiamento de Neoplasias
13.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 15(3): 519-22, 2007 Jun.
Artigo em Zh | MEDLINE | ID: mdl-17605857

RESUMO

To study the serum levels of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in patients with myelodysplastic syndrome (MDS), serum from 43 MDS patients was examined by enzyme linked immunosorbent assay (ELISA). The results showed that serum levels of VEGF, bFGF in MDS patients were significantly elevated compared with normal control. Serum levels of VEGF and bFGF in RAEB patients and RAEBT patients were higher than that in RA patients and RAS patients (P < 0.05). No significant difference of serum levels of VEGF and bFGF was found between RAEBT patients and acute myeloid leukemia (AML) patients. The serum levels of VEGF and bFGF were correlated with the affected peripheral blood cells and the proportion of blast cells in bone marrow. There was positive correlation between serum VEGF and bFGF levels. It is concluded that the secretion of VEGF and bFGF in MDS patients is elevated and the serum levels of VEGF and bFGF are related to the classification and prognosis in MDS.


Assuntos
Fator 2 de Crescimento de Fibroblastos/sangue , Síndromes Mielodisplásicas/sangue , Fator A de Crescimento do Endotélio Vascular/sangue , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Adulto Jovem
14.
Ai Zheng ; 26(3): 312-7, 2007 Mar.
Artigo em Zh | MEDLINE | ID: mdl-17355798

RESUMO

BACKGROUND & OBJECTIVE: Recent researches showed that urokinase-type plasminogen activator (uPA) and its inhibitor, plasminogen activator inhibitor (PAI)-1, play an important role in the invasion and metastasis of solid tumors. However, their correlations to epithelial ovarian cancer have seldom been reported. This study was to investigate the roles of uPA and PAI-1 in the invasion and metastasis of epithelial ovarian cancer, to clarify their localization and relationship with prognosis. METHODS: Immunohistochemistry was applied to examine the protein expression of uPA and PAI-1 in 80 specimens of epithelial ovarian cancer and 20 specimens of benign ovarian tumor. The correlations of their expression to the clinicopathologic characteristics and prognosis of the patients were analyzed. RESULTS: The positive rates of uPA and PAI-1 were significantly higher in epithelial ovarian cancer than in benign ovarian tumor (77.5% vs. 30.0%, P<0.001; 55.0% vs. 20.0%, P=0.005). uPA expression was correlated positively to PAI-1 expression in epithelial ovarian cancer (P=0.001). Higher positive rate of uPA was associated with greater metastatic tumor in the peritoneal cavity (P=0.038), but not associated with age, FIGO stage, histological type, pathologic grade, serum CA125 level, ovarian tumor size, and the size of residual tumor (P>0.05). Higher positive rate of PAI-1 was associated with early FIGO stage (P=0.022), but not associated with other parameters (P>0.05). Multivariate analysis showed that uPA was an independent factor for progression-free survival and overall survival, and PAI-1 was an independent factor for overall survival. CONCLUSION: Both uPA and PAI-1 are up-regulated in epithelial ovarian cancer, and might be used as markers to predict the prognosis of epithelial ovarian cancer patients.


Assuntos
Cistadenocarcinoma Mucinoso/metabolismo , Cistadenocarcinoma Seroso/metabolismo , Neoplasias Ovarianas/metabolismo , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Adulto , Idoso , Antígeno Ca-125/sangue , Quimioterapia Adjuvante , Cistadenocarcinoma Mucinoso/tratamento farmacológico , Cistadenocarcinoma Mucinoso/patologia , Cistadenocarcinoma Mucinoso/cirurgia , Cistadenocarcinoma Seroso/tratamento farmacológico , Cistadenocarcinoma Seroso/patologia , Cistadenocarcinoma Seroso/cirurgia , Intervalo Livre de Doença , Feminino , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/cirurgia , Modelos de Riscos Proporcionais , Taxa de Sobrevida , Adulto Jovem
15.
Ai Zheng ; 22(6): 645-8, 2003 Jun.
Artigo em Zh | MEDLINE | ID: mdl-12948418

RESUMO

BACKGROUND & OBJECTIVE: Nasopharyngeal carcinoma (NPC) is closely related to Epstein-Barr virus (EBV) infection. Recently, it was reported that EBV DNA could be detected in the plasma or serum of NPC patients, but the clinical significance of EBV DNA concentration for monitoring of tumor recurrence and metastasis in NPC patients after radiotherapy has not been reported. This study was designed to quantitatively analyze the plasma EBV DNA concentration in NPC patients after radiotherapy, and to evaluate its application for monitoring of tumor recurrence and metastasis. METHODS: Ninety NPC outpatients after radiotherapy in Cancer Center, Sun Yat-sen University were followed up. The plasma EBV DNA were analyzed by using fluorescent quantitative PCR technique, and the quantity of plasma EBV DNA were compared between recurrent and clinical remission NPC patients. RESULTS: Ninety-six point seven percent (29/30) of recurrent and metastatic patients were detectable for plasma EBV DNA, with median concentration of 2650 copies/ml (range:0-5900000), whereas only 12%(7/60) of the clinical remission patients were detectable for plasma EBV DNA, with median concentration of 0 copy/ml (range:0-71000). The detectable proportion and concentration in recurrent and metastatic NPC patients were significantly higher than that in clinical remission NPC patients (P< 0.01). Three of the clinical remission NPC patients with elevated EBV DNA copy were confirmed for tumor local recurrence or metastasis after further 3-4 month follow-up. CONCLUSION: The results suggest that plasma EBV DNA detection may be a sensitive tumor marker for monitoring tumor recurrence and metastasis of NPC patients after radiotherapy.


Assuntos
DNA Viral/sangue , Herpesvirus Humano 4/genética , Neoplasias Nasofaríngeas/virologia , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Nasofaríngeas/patologia , Neoplasias Nasofaríngeas/radioterapia , Metástase Neoplásica , Recidiva Local de Neoplasia
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