Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Proc Natl Acad Sci U S A ; 121(25): e2401440121, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38875145

RESUMO

At fast-spreading centers, faults develop within the axial summit trough (AST; 0 to 250 m around the axis) primarily by diking-induced deformation originating from the axial magma lens (AML). The formation of the prominent abyssal-hill-bounding faults beyond the axial high (>2,000 m) is typically associated with the unbending of the lithosphere as it cools and spreads away from the AST. The presence of faults is rarely mapped between these two thermally distinct zones, where the lithosphere is still too hot for the faults to be linked with the process of thermal cooling and outside of the AST where the accretional diking process dominates the ridge axis. Here, we reveal a remarkable vertical alignment between the distinct morphological features of the magma body and the orientation of these faults, by comparison of 3-D seismic imagery and bathymetry data collected at the East Pacific Rise (EPR) 9°50'N. The spatial coincidence and asymmetric nucleation mode of the mapped faults represent the most direct evidence for magmatically induced faulting near the ridge axis, providing pathways for hydrothermalism and magma emplacement, helping to build the crust outside of the AST. The high-resolution seafloor and subsurface images also enable revised tectonic strain estimates, which shows that the near-axis tectonic component of seafloor spreading at the EPR is an order of magnitude smaller than previously thought with close to negligible contribution of lava buried faults to spreading.

2.
Fertil Steril ; 121(6): 971-981, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38272382

RESUMO

OBJECTIVE: To investigate whether PIEZO-intracytoplasmic sperm injection (PIEZO-ICSI) increases the fertilization rate, decreases the degeneration rate, and increases the utilization rate per oocyte injected compared with conventional intracytoplasmic sperm injection (ICSI). DESIGN: Sibling oocyte split multicenter trial. SETTING: Fertility clinics. PATIENTS: Women with a diagnosis of infertility who used ICSI as their method of insemination and had ≥6 mature oocytes for injection. INTERVENTIONS: Participants had their mature oocyte cohort divided, where half were injected using conventional ICSI and the other half were injected using PIEZO-ICSI. For patients with an uneven oocyte number, the extra oocyte was injected using conventional ICSI. The injection technique used first was also randomized to ensure that there was no bias due to order of injection. MAIN OUTCOME MEASURE: The primary outcome measure was the fertilization rate after injection. RESULTS: A total of 108 patients underwent a sibling split use of conventional ICSI and PIEZO-ICSI. The fertilization rate was 71.6% in PIEZO-ICSI, which significantly increased compared with that in conventional ICSI 65.6%. In addition, the oocyte degeneration rate decreased in PIEZO-ICSI compared with that in conventional ICSI (6.3% vs. 12.1% respectively), and the blastocyst quality increased, as measured by the number of grade A and B quality blastocysts present on day 5 of development (33.3% vs. 27.5%). No significant differences in the aneuploidy or utilization rate, clinical pregnancy, or live birth outcome after single embryo transfer were noted between the two injection techniques. CONCLUSIONS: This trial supports the possibility that PIEZO-ICSI increases the fertilization rates, decreases the oocyte degeneration rates, and increases the blastocyst quality compared with conventional ICSI; however, it does not appear to influence the clinical pregnancy or live birth rate per transfer. CLINICIAN TRIAL REGISTRATION NUMBER: Australian and New Zealand Clinical Trial Registry ACTRN12620000407998.


Assuntos
Oócitos , Injeções de Esperma Intracitoplásmicas , Humanos , Injeções de Esperma Intracitoplásmicas/métodos , Feminino , Gravidez , Adulto , Masculino , Resultado do Tratamento , Oócitos/fisiologia , Taxa de Gravidez , Infertilidade/terapia , Infertilidade/diagnóstico , Infertilidade/fisiopatologia , Irmãos
3.
Int J Mol Sci ; 24(16)2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37628721

RESUMO

The ectonucleotidases CD39 and CD73 are present on immune cells and play important roles in cancer progression by suppressing antitumour immunity. As such, CD39 and CD73 on peripheral blood mononuclear cells (PBMCs) are emerging as potential biomarkers to predict disease outcomes and treatment responses in cancer patients. This study aimed to examine T and B cells, including CD39 and CD73 expressing subsets, by flow cytometry in PBMCs from 28 patients with head and neck squamous cell carcinoma (HNSCC) and to assess the correlation with the treatment modality, human papillomavirus (HPV) status, and relapse-free survival (RFS). The PBMCs were examined pre-, mid-, and post-radiotherapy with concurrent cisplatin chemotherapy or anti-epidermal growth factor receptor antibody (cetuximab) therapy. Combination radiotherapy caused changes to T and B cell populations, including CD39 and CD73 expressing subsets, but no such differences were observed between concurrent chemotherapy and cetuximab. Pretreatment PBMCs from HPV+ patients contained increased proportions of CD39-CD73-CD4+ T cells and reduced proportions of CD39-/+CD73+CD4+ T cells compared to the equivalent cells from HPV- patients. Notably, the pretreatment CD4+:CD8+ T cell ratios and CD39+CD73+CD19+ B cell proportions below the respective cohort medians corresponded with an improved RFS. Collectively, this study supports the notion that CD39 and CD73 may contribute to disease outcomes in HNSCC patients and may assist as biomarkers, either alone or as part of immune signatures, in HNSCC. Further studies of CD39 and CD73 on PBMCs from larger cohorts of HNSCC patients are warranted.


Assuntos
Neoplasias de Cabeça e Pescoço , Infecções por Papillomavirus , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Cetuximab , Leucócitos Mononucleares , Recidiva Local de Neoplasia , Linfócitos T CD8-Positivos , Proteínas Adaptadoras de Transdução de Sinal , Antígenos CD19 , Doença Crônica , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Linfócitos T CD4-Positivos
4.
Biomolecules ; 12(9)2022 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-36139148

RESUMO

P2X7 is an extracellular adenosine 5'-triphopshate (ATP)-gated cation channel present on leukocytes, where its activation induces pro-inflammatory cytokine release and ectodomain shedding of cell surface molecules. Human P2X7 can be partially inhibited by amiloride and its derivatives at micromolar concentrations. This study aimed to screen a library of compounds derived from amiloride or its derivative 5-(N,N-hexamethylene) amiloride (HMA) to identify a potential P2X7 antagonist. 6-Furopyridine HMA (6-FPHMA) was identified as a novel P2X7 antagonist and was characterized further. 6-FPHMA impaired ATP-induced dye uptake into human RPMI8226 multiple myeloma cells and human P2X7-HEK293 cells, in a concentration-dependent, non-competitive manner. Likewise, 6-FPHMA blocked ATP-induced Ca2+ fluxes in human P2X7-HEK293 cells in a concentration-dependent, non-competitive manner. 6-FPHMA inhibited ATP-induced dye uptake into human T cells, and interleukin-1ß release within human blood and CD23 shedding from RPMI8226 cells. 6-FPHMA also impaired ATP-induced dye uptake into murine P2X7- and canine P2X7-HEK293 cells. However, 6-FPHMA impaired ATP-induced Ca2+ fluxes in human P2X4-HEK293 cells and non-transfected HEK293 cells, which express native P2Y1, P2Y2 and P2Y4. In conclusion, 6-FPHMA inhibits P2X7 from multiple species. Its poor selectivity excludes its use as a specific P2X7 antagonist, but further study of amiloride derivatives as P2 receptor antagonists is warranted.


Assuntos
Antagonistas do Receptor Purinérgico P2X , Receptores Purinérgicos P2X7 , Adenosina , Trifosfato de Adenosina/metabolismo , Amilorida/análogos & derivados , Amilorida/farmacologia , Animais , Cães , Células HEK293 , Humanos , Interleucina-1beta/metabolismo , Camundongos , Antagonistas do Receptor Purinérgico P2X/farmacologia
5.
Methods Mol Biol ; 2510: 77-98, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35776321

RESUMO

The murine anti-human P2X7 receptor monoclonal antibody (mAb) (clone L4) has been used to study the expression and function of the P2X7 receptor on primary leukocytes, keratinocytes, osteoblasts and neuronal cells, as well as various cell lines. This antibody has also been used to characterize polymorphic variants and isoforms of the P2RX7 gene and P2X7 site-directed mutations, and to identify molecules coassociated with P2X7 in the plasma membrane. This chapter describes the maintenance and cryopreservation of the L4 hybridoma cell line, as well as the generation of tissue culture supernatant containing the anti-human P2X7 mAb, and its subsequent purification by Protein A chromatography and conjugation to DyLight™ 488. Moreover, this chapter describes flow cytometric assays to assess the blocking activity and binding of the anti-human P2X7 mAb against P2X7 on human RPMI 8226 multiple myeloma cells.


Assuntos
Receptores Purinérgicos P2X7 , Proteína Estafilocócica A , Animais , Anticorpos Monoclonais , Células Cultivadas , Hibridomas , Camundongos , Receptores Purinérgicos P2X7/genética
6.
Proc Natl Acad Sci U S A ; 119(30): e2205602119, 2022 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-35862459

RESUMO

Comprehensive knowledge of the distribution of active hydrothermal vent fields along midocean ridges is essential to understanding global chemical and heat fluxes and endemic faunal distributions. However, current knowledge is biased by a historical preference for on-axis surveys. A scarcity of high-resolution bathymetric surveys in off-axis regions limits vent identification, which implies that the number of vents may be underestimated. Here, we present the discovery of an active, high-temperature, off-axis hydrothermal field on a fast-spreading ridge. The vent field is located 750 m east of the East Pacific Rise axis and ∼7 km north of on-axis vents at 9° 50'N, which are situated in a 50- to 100-m-wide trough. This site is currently the largest vent field known on the East Pacific Rise between 9 and 10° N. Its proximity to a normal fault suggests that hydrothermal fluid pathways are tectonically controlled. Geochemical evidence reveals deep fluid circulation to depths only 160 m above the axial magma lens. Relative to on-axis vents at 9° 50'N, these off-axis fluids attain higher temperatures and pressures. This tectonically controlled vent field may therefore exhibit greater stability in fluid composition, in contrast to more dynamic, dike-controlled, on-axis vents. The location of this site indicates that high-temperature convective circulation cells extend to greater distances off axis than previously realized. Thorough high-resolution mapping is necessary to understand the distribution, frequency, and physical controls on active off-axis vent fields so that their contribution to global heat and chemical fluxes and role in metacommunity dynamics can be determined.


Assuntos
Fontes Hidrotermais , Biodiversidade , Ecossistema , Oceano Pacífico
7.
Reprod Biomed Online ; 44(4): 609-616, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35279376

RESUMO

RESEARCH QUESTION: Does variation in day 5 assessment timing confound live birth prediction using snapshot blastocyst morphology and is it possible to develop a numerical prediction algorithm? DESIGN: Retrospective multicentre cohort study including 4851 autologous oocyte single day 5 fresh embryo transfers performed at 11 Monash IVF clinics between 2016 and 2020. Repeat cycles of the same patients were excluded to avoid clustering effects in regression analysis. RESULTS: Hours post insemination (HPI) at day 5 assessment (115.9 ± 2.6 h) significantly correlated with blastocyst developmental stage (r = 0.118, P < 0.001). Independent association (expressed as adjusted odds ratio [aOR] and 95% confidence interval [CI]) was identified between live birth and HPI (aOR 0.950, 95% CI 0.925-0.976, P < 0.001) after accounting for blastocyst morphology and a range of patient/cycle characteristics. Algorithms were constructed using four significant live birth predictors: HPI at day 5 assessment, blastocyst developmental stage (aOR 1.347, 95% CI 1.217-1.491, P < 0.001), morphological grade (aOR 1.314, 95% 1.197-1.443, P < 0.001) and maternal age (aOR 0.922, 95% CI 0.907-0.936, P < 0.001). Receiver operating characteristic (ROC) analysis showed consistent predicting performance of algorithms via five-fold cross-validation, with similar area under the ROC curve (AUC 0.718, 0.715, 0.720, 0.712, 0.726, P < 0.001, respectively, in development subsets; and AUC 0.718, 0.731, 0.709, 0.741, 0.684, P < 0.001, respectively, in validation subsets). A score (ranging from 0.1 to 4.7) calculator based on the final algorithm was subsequently created. CONCLUSIONS: Day 5 assessment timing is a confounding factor for live birth prediction using snapshot blastocyst morphology. A numerical algorithm incorporating day 5 assessment HPI, blastocyst morphology and maternal age can be developed for live birth prediction.


Assuntos
Transferência Embrionária , Nascido Vivo , Algoritmos , Blastocisto , Estudos de Coortes , Feminino , Fertilização in vitro , Humanos , Gravidez , Estudos Retrospectivos
8.
Pediatr Nephrol ; 37(10): 2369-2374, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35211794

RESUMO

BACKGROUND: Intronic WT1 mutations are usually causative of Frasier syndrome with focal segmental glomerulosclerosis as the characteristic nephropathy. Membranoproliferative glomerulonephritis is not commonly associated with disorders of sex development but has been recently identified as a WT1-associated nephropathy, but usually in cases of exonic mutations in either isolated Wilms tumor or Denys-Drash syndrome. METHODS: The clinical and genetic data from 3 individuals are reported. RESULTS: This report describes the kidney manifestations in 3 individuals from 2 unrelated families with Frasier syndrome intronic WT1 mutations, noting that 2 of the 3 individuals have histologically confirmed membranoproliferative glomerulonephritis. CONCLUSIONS: These case reports support expansion of the clinical spectrum of the kidney phenotypes associated with Frasier syndrome providing evidence of an association between WT1 mutation and an immune complex-related membranoproliferative glomerulonephritis. A higher resolution version of the Graphical abstract is available as Supplementary information.


Assuntos
Síndrome de Denys-Drash , Glomerulonefrite Membranoproliferativa , Disgenesia Gonadal , Neoplasias Renais , Tumor de Wilms , Síndrome de Denys-Drash/genética , Síndrome de Denys-Drash/patologia , Síndrome de Frasier/genética , Genes do Tumor de Wilms , Glomerulonefrite Membranoproliferativa/genética , Disgenesia Gonadal/genética , Humanos , Neoplasias Renais/genética , Mutação , Proteínas WT1/genética , Tumor de Wilms/genética
9.
J Assist Reprod Genet ; 39(1): 97-106, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34993708

RESUMO

PURPOSE: To study the morphometric and morphokinetic profiles of pronuclei (PN) between male and female human zygotes. METHOD(S): This retrospective cohort study included 94 consecutive autologous single day 5 transfer cycles leading to a singleton live birth. All oocytes were placed in the EmbryoScope + incubator post-sperm injection with all annotations performed retrospectively by one embryologist (L-SO). Timing parameters included 2nd polar body extrusion (tPB2), sperm-originated PN (tSPNa) or oocyte-originated PN (tOPNa) appearance, and PN fading (tPNF). Morphometrics were evaluated at 8 (stage 1), 4 (stage 2), and 0 h before PNF (stage 3), measuring PN area (um2), PN juxtaposition, and nucleolar precursor bodies (NPB) arrangement. RESULTS: Male zygotes had longer time intervals of tPB2_tSPNa than female zygotes (4.8 ± 0.2 vs 4.2 ± 0.1 h, OR = 1.442, 95% CI 1.009-2.061, p = 0.044). SPN increased in size from stage 1 through 2 to 3 (435.3 ± 7.2, 506.7 ± 8.0, and 556.3 ± 8.9 um2, p = 0.000) and OPN did similarly (399.0 ± 6.1, 464.3 ± 6.7, and 513.8 ± 6.5 um2, p = 0.000), with SPN being significantly larger than OPN at each stage (p < 0.05 respectively). More male than female zygotes reached central PN juxtaposition at stage 1 (76.7% vs 51.0%, p = 0.010), stage 2 (97.7% vs 86.3%, p = 0.048), and stage 3 (97.7% vs 86.3%, p = 0.048). More OPN showed aligned NPBs than in SPN at stage 1 only (44.7% vs 28.7%, p = 0.023). CONCLUSION(S): Embryos with different sexes display different morphokinetic and morphometric features at the zygotic stage. Embryo selection using such parameters may lead to unbalanced sex ratio in resulting offspring.


Assuntos
Oócitos/citologia , Espermatozoides/citologia , Zigoto/citologia , Adulto , Blastômeros/citologia , Blastômeros/microbiologia , Blastômeros/fisiologia , Núcleo Celular/microbiologia , Feminino , Humanos , Modelos Logísticos , Masculino , Oócitos/microbiologia , Estudos Retrospectivos , Espermatozoides/microbiologia , Imagem com Lapso de Tempo/métodos , Zigoto/microbiologia
10.
Purinergic Signal ; 16(3): 389-401, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32754836

RESUMO

CD39 and CD73 are ecto-nucleotidases present on human peripheral blood mononuclear cells (PBMCs) and are emerging biomarkers on these cells in various disorders including cancer. Many factors influence PBMC quality, so it is essential to validate sample processing methods prior to incorporation in clinical studies. This study examined the impact of both PBMC cryopreservation and PBMC isolation using SepMate density gradient centrifugation on CD39 and CD73 expressing subsets. First, PBMCs were isolated from the peripheral blood of 11 healthy donors by routine Ficoll-Paque density gradient centrifugation, cryopreserved and compared with freshly isolated PBMCs by flow cytometry. The proportions of T and B cells expressing combinations of CD39 and CD73 were relatively stable over 6-month cryopreservation, although some T cell combinations revealed small but significant changes. Second, peripheral blood was collected from six healthy donors to compare PBMCs isolated by SepMate or Ficoll-Paque density gradient centrifugation. Compared with Ficoll-Paque, the more rapid SepMate method yielded 9.1% less PBMCs but did not alter cell viability or proportions of T and B cells expressing combinations of CD39 and CD73. The present study reveals that cryopreservation is suitable for studying T and B cells expressing combinations of CD39 and CD73. However, caution should be exercised when observing small differences in these cryopreserved subsets between different cohorts. Further, SepMate and Ficoll-Paque methods of PBMC isolation show similar results for T and B cell subset analysis; however, SepMate is a faster and easier approach.


Assuntos
5'-Nucleotidase/metabolismo , Antígenos CD/metabolismo , Apirase/metabolismo , Separação Celular/métodos , Leucócitos Mononucleares/metabolismo , Linfócitos/metabolismo , Criopreservação , Citometria de Fluxo , Humanos
11.
Immunol Cell Biol ; 98(5): 397-410, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32181525

RESUMO

Regulatory T cells (Tregs) protect against graft-versus-host disease (GVHD), a life-threatening complication of allogeneic hematopoietic stem cell transplantation. The ectoenzyme CD39 is important for increasing the immunosuppressive function of Tregs. The rs10748643 (A â†’ G) single-nucleotide polymorphism (SNP) in intron 1 of the human ENTPD1 gene is associated with increased proportions of CD39+ Tregs. This study aimed to determine whether the rs10748643 SNP corresponded to increased proportions of CD39+ Tregs in an Australian donor population, and whether this SNP influences clinical GVHD in a humanized mouse model. Donors were genotyped for the rs10748643 SNP by Sanger sequencing, and the proportion of CD39+ T cells in donor peripheral blood was determined by flow cytometry. Donors encoding the G allele (donorsAG/GG ) demonstrated higher proportions of CD39+ CD3+ CD4+ CD25+ CD127lo Tregs, but not CD39+ CD3+ CD8+ T cells or CD39+ CD3+ CD4+ conventional T cells, compared with donors homozygous for the A allele (donorsAA ). NOD-SCID-IL2Rγnull mice were injected with human peripheral blood mononuclear cells from either donorsAA (hCD39AA mice) or donorsAG/GG (hCD39AG/GG mice). hCD39AG/GG mice demonstrated significantly greater weight loss and GVHD clinical scores, and significantly reduced survival, compared with hCD39AA mice. hCD39AG/GG mice showed significantly higher hCD4+ :hCD8+ T-cell ratios than hCD39AA mice, but displayed similar proportions of CD3+ hCD4+ hCD25+ hCD127lo Tregs and hCD39+ Tregs. However, the proportion of human Tregs corresponded to survival in hCD39AA mice, but not in hCD39AG/GG mice. This study demonstrates that donors encoding the G allele show higher percentages of CD39+ Tregs, but cause worsened GVHD in humanized mice compared with donors homozygous for the A allele.


Assuntos
Apirase/genética , Doença Enxerto-Hospedeiro , Linfócitos T Reguladores/imunologia , Animais , Austrália , Humanos , Leucócitos Mononucleares , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Polimorfismo de Nucleotídeo Único
12.
Proc Natl Acad Sci U S A ; 114(18): 4697-4702, 2017 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-28416700

RESUMO

Prolonged periods of extreme heat or drought in the first year after fire affect the resilience and diversity of fire-dependent ecosystems by inhibiting seed germination or increasing mortality of seedlings and resprouting individuals. This interaction between weather and fire is of growing concern as climate changes, particularly in systems subject to stand-replacing crown fires, such as most Mediterranean-type ecosystems. We examined the longest running set of permanent vegetation plots in the Fynbos of South Africa (44 y), finding a significant decline in the diversity of plots driven by increasingly severe postfire summer weather events (number of consecutive days with high temperatures and no rain) and legacy effects of historical woody alien plant densities 30 y after clearing. Species that resprout after fire and/or have graminoid or herb growth forms were particularly affected by postfire weather, whereas all species were sensitive to invasive plants. Observed differences in the response of functional types to extreme postfire weather could drive major shifts in ecosystem structure and function such as altered fire behavior, hydrology, and carbon storage. An estimated 0.5 °C increase in maximum temperature tolerance of the species sets unique to each survey further suggests selection for species adapted to hotter conditions. Taken together, our results show climate change impacts on biodiversity in the hyperdiverse Cape Floristic Region and demonstrate an important interaction between extreme weather and disturbance by fire that may make flammable ecosystems particularly sensitive to climate change.


Assuntos
Biodiversidade , Mudança Climática , Espécies Introduzidas , Tempo (Meteorologia) , Incêndios Florestais , Região do Mediterrâneo , África do Sul
13.
J Appl Meas ; 8(3): 237-48, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17804892

RESUMO

This paper provides an overview of the Programme for International Student Assessment (PISA), an on-going international comparative survey study of educational outcomes at age 15. PISA is sponsored by the Organization for Economic Co-operation and Development (OECD) and for the period 1998-2010 has been designed and implemented by a consortium led by the Australian Council for Educational Research (ACER).


Assuntos
Avaliação Educacional/normas , Cooperação Internacional , Desenvolvimento de Programas , Adolescente , Coleta de Dados , Humanos
14.
Oncology ; 64(4): 399-406, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12759538

RESUMO

OBJECTIVE: Regimens with prolonged infusions of taxanes have been developed for patients with cancer to overcome drug resistance. Our objective of the present study was to examine the impact of prolonged exposure on the cytotoxicity of taxanes against non-small-cell lung carcinoma (NSCLC) cell lines and the clinical response and outcome of the patients. METHODS: Five cell lines (NCI-H2882, -H2887, -H2973, -H3122, -H3255) were derived from previously untreated patients with NSCLC who participated in clinical trials of continuous 96-hour infusions of paclitaxel followed by bolus cisplatin. Two additional cell lines (NCI-H838, -H1299) with previously published data were used as controls. Drug sensitivities were assessed by the MTS (Promega) assay. Multidrug resistance (MDR) phenotypes were assessed by quantitative real-time PCR and HER-2/NEU by both immunohistochemistry and ELISA. RESULTS: The median of mean IC(50) values of docetaxel at the exposure durations of 3, 24, 72 and 120 h were 0.52, 0.06, 0.03 and 0.06 microM, respectively. The median of mean IC(50) values of paclitaxel at the exposure duration of 3, 24, 72 and 120 h were 0.48, 0.13, 0.03 and 0.02 microM, respectively. In all cell lines studied, there was a less than 4-fold difference in the IC(50) values between docetaxel and paclitaxel at 3-, 72-, and 120-hour exposure times. The single cell line with moderate MDR1 expression (NCI-H2887) was the only cell line established from a patient with progressive disease when treated with paclitaxel. CONCLUSIONS: This study demonstrates prolonged exposure to both docetaxel and paclitaxel inhibits the growth of NSCLC cell lines in similar fashion.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Paclitaxel/análogos & derivados , Paclitaxel/uso terapêutico , Taxoides , Adulto , Carcinoma Pulmonar de Células não Pequenas/química , Docetaxel , Ensaio de Imunoadsorção Enzimática , Feminino , Regulação Neoplásica da Expressão Gênica , Genes MDR , Humanos , Imuno-Histoquímica , Concentração Inibidora 50 , Neoplasias Pulmonares/química , Masculino , Pessoa de Meia-Idade , Proteínas Associadas à Resistência a Múltiplos Medicamentos/análise , Fenótipo , Reação em Cadeia da Polimerase , Receptor ErbB-2/análise , Células Tumorais Cultivadas
15.
Cancer Res ; 62(21): 6304-11, 2002 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-12414661

RESUMO

The regulation of biological functions including cell growth, viability, migration, and adhesion of small cell lung cancer (SCLC) cells depends largely on the autocrine or paracrine stimulation of growth factor receptors and chemokine receptors. Stem cell factor (SCF) and its receptor c-Kit have been identified as important regulators of SCLC viability and are coexpressed in approximately 40-70% of SCLC specimens. In vitro, the inhibition of c-Kit tyrosine kinase activity by the small molecule tyrosine kinase inhibitor STI571 (Gleevec) abrogates cell growth. We have investigated the role of c-Kit and chemokine receptors in the regulation of cell migration and adhesion of SCLC cells. CXCR4, the chemokine receptor for stromal cell-derived factor-1alpha (SDF-1alpha), was found to be the major chemokine receptor commonly expressed in all of the 10 SCLC cell lines tested. SCF and SDF-1alpha increased cellular proliferation over a course of 72 h in both the c-Kit- and the CXCR4-positive NCI-H69 SCLC cell line. Recently, SDF-1alpha and CXCR4 have been shown to be important regulators of migration and metastasis in breast and ovarian cancer. We found that SDF-1alpha dramatically increased cell motility and adhesion in CXCR4-expressing NCI-H446 SCLC cells. In addition, SDF-1alpha altered cell morphology with increased formation of filopodia and neurite-like projections. In NCI-H69 SCLC cells, SCF and SDF-1alpha cooperatively induced morphological changes and activated downstream signaling pathways. Treatment of NCI-H69 cells with STI571 specifically inhibited the c-Kit signaling events of Akt and p70 S6 kinase, whereas SDF-1alpha-mediated activation of Akt or p70 S6 kinase was normal. In contrast, the phosphatidylinositol 3-kinase inhibitor, LY294002, prevented these cells from adhering and completely blocked SCF- and/or SDF-1alpha-induced Akt or p70 S6 kinase phosphorylation. These results demonstrate that the CXCR4 receptor is functionally expressed in SCLC cells and may, therefore, be involved in the pathogenesis of SCLC in vivo. Inhibition of both the CXCR4 and the c-Kit downstream events could be a promising therapeutic approach in SCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Citoesqueleto/fisiologia , Neoplasias Pulmonares/patologia , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas c-kit/fisiologia , Receptores CXCR4/fisiologia , Benzamidas , Carcinoma Pulmonar de Células não Pequenas/enzimologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Adesão Celular/fisiologia , Divisão Celular/fisiologia , Movimento Celular/fisiologia , Tamanho Celular/fisiologia , Quimiocina CXCL12 , Quimiocinas CXC/fisiologia , Cromonas/farmacologia , Ativação Enzimática , Humanos , Mesilato de Imatinib , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/metabolismo , Morfolinas/farmacologia , Fosfatidilinositol 3-Quinases/fisiologia , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Proteínas Proto-Oncogênicas c-kit/biossíntese , Pirimidinas/farmacologia , Receptores CXCR4/antagonistas & inibidores , Receptores CXCR4/biossíntese , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Células Tumorais Cultivadas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...