Biomedical subjects

P P Massion

Publications and source records attributed to P P Massion.

13 recordsLinked to original sources

PubMed2005

Restoration of TGF-beta signalling reduces tumorigenicity in human lung cancer cells.

Members of the transforming growth factor-beta (TGF-beta) family regulate a wide range of biological processes including cell proliferation, migration, differentiation, apoptosis, and extracellular matrix deposition. Resistance to TGF-beta-mediated tumour suppressor function in human lung cancer may occur through the loss of type II receptor (TbetaRII) expression. In this study, we investigated the expression pattern of TbetaRII in human lung cancer tissues by RT-PCR and Western blot analyses. We observed downregulation of TbetaRII in 30 out of 46 NSCLC samples (65%) by semiquantitative RT-PCR. Western blot analyses with tumour lysates showed reduced expression of TbetaRII in 77% cases. We also determined the effect of TbetaRII expression in lung adenocarcinoma cell line (VMRC-LCD) that is not responsive to TGF-beta due to lack of TbetaRII expression. Stable expression of TbetaRII in these cells restored TGF-beta-mediated effects including Smad2/3 and Smad4 complex formation, TGF-beta-responsive reporter gene activation, inhibition of cell proliferation and increased apoptosis. Clones expressing TbetaRII showed reduced colony formation in soft-agarose assay and significantly reduced tumorigenicity in athymic nude mice. Therefore, these results suggest that reestablishment of TGF-beta signalling in TbetaRII null cells by stable expression of TbetaRII can reverse malignant behaviour of cells and loss of TbetaRII expression may be involved in lung tumour progression.

Animals↗

PubMed2005

Cloned fusion product from a rare t(15;19)(q13.2;p13.1) inhibit S phase in vitro.

BACKGROUND: Somatically acquired chromosomal translocation is a common mechanism of oncogene activation in many haematopoietic tumours and sarcomas. However, very few recurrent chromosomal translocations have been reported in more common epithelial tumours such as lung carcinomas. METHODS: We established a cell line HCC2429 from an aggressive, metastatic lung cancer arising in a young, non-smoking woman, demonstrating a t(15;19)(q13.2;p13.1). The breakpoints on chromosomes 15 and 19 were cloned using long distance inverse PCR and we determined by RT-PCR that the translocation results in a novel fusion transcript in which the 3' end Brd4 on chromosome 19p is fused to the 5' end of NUT on chromosome 15q. RESULTS: In total, 128 lung cancer tissues were screened using fluorescent in situ hybridisation, but none of the tumours screened demonstrated t(15;19), suggesting that this translocation is not commonly found in lung cancer. Consistent with previous literature, ectopic expression of wild type Brd4 was shown to inhibit G(1) to S progression. However, we also found that the Brd4-NUT fusion augments the inhibition of progression to S phase compared with wild type Brd4. CONCLUSION: Alteration in cell cycle kinetics is important in tumorigenesis, although the exact role of Brd4-NUT fusion protein in the pathogenesis of lung cancers remains unclear and need to be further elucidated.

Adult↗

PubMed2004

Nuclear survivin as a biomarker for non-small-cell lung cancer.

Survivin inhibits apoptosis and promotes mitosis. We determined whether nuclear or cytoplasmic localisation of survivin predicts survival of 48 patients with resected non-small-cell lung cancer (NSCLC). Patients with nuclear staining of survivin had significantly worse survival (relative risk: 3.9, P=0.02). Therefore, survivin may be a biomarker for NSCLC.

Aged↗

PubMed2002

Machine learning models for lung cancer classification using array comparative genomic hybridization.

Array CGH is a recently introduced technology that measures changes in the gene copy number of hundreds of genes in a single experiment. The primary goal of this study was to develop machine learning models that classify non-small Lung Cancers according to histopathology types and to compare several machine learning methods in this learning task. DNA from tumors of 37 patients (21 squamous carcinomas, and 16 adenocarcinomas) were extracted and hybridized onto a 452 BAC clone array. The following algorithms were used: KNN, Decision Tree Induction, Support Vector Machines and Feed-Forward Neural Networks. Performance was measured via leave-one-out classification accuracy. The best multi-gene model found had a leave-one-out accuracy of 89.2%. Decision Trees performed poorer than the other methods in this learning task and dataset. We conclude that gene copy numbers as measured by array CGH are, collectively, an excellent indicator of histological subtype. Several interesting research directions are discussed.

Algorithms↗

PubMed1998

Secretory component production by human bronchial epithelial cells is upregulated by interferon gamma.

Secretory immunoglobulin A (S-IgA) participates in the first noninflammatory line of defence of the respiratory tract. S-IgA consists of dimeric IgA (dIgA) produced by plasma cells and secretory component (SC) produced by epithelial cells. This study compared SC production by primary cultures of human bronchial epithelial cells (HBEC) and by respiratory epithelial cell lines. Among the cell lines, A549 did not produce detectable SC, 16HBE produced very low levels of SC, while CALU-3 produced significant levels of SC. HBEC produced SC in nonpolarized and polarized primary cultures, where it was secreted apically. Polarized HBEC transcytosed radiolabelled and cold dIgA, resulting in the presence of S-IgA in their apical media. SC production and IgA transcytosis by polarized HBEC were upregulated by interferon-gamma (IFN-gamma) after 48 h. By reverse transcription-polymerase chain reaction, no SC messenger ribonucleic acid (mRNA) was detected in A549 and 16HBE, while SC mRNA in CALU-3 was comparable to that of HBEC incubated for 48 h with IFN-gamma. By immunocytochemistry, HBEC expressed SC immunostaining and its intensity increased after 48 h with IFN-gamma. It is concluded that human bronchial epithelial cells produce secretory component and transcytose dimeric immunoglobulin A in vitro. These processes were apically polarized and upregulated by interferon-gamma. Among the cell lines studied, only CALU-3 expressed secretory component-messenger ribonucleic acid and produced detectable secretory component.

Aged↗

PubMed1996

Dimethyl sulfoxide decreases interleukin-8-mediated neutrophil recruitment in the airways.

In this study, we investigated the role of dimethyl sulfoxide (DMSO) in inhibiting interleukin-8 (IL-8)-mediated neutrophil recruitment induced by Pseudomonas aeruginosa (PA) bacterial supernatant. First, we tested whether DMSO could inhibit IL-8 production induced by PA in human bronchial epithelial (16-HBE) cells in vitro. In these cells, exposure to PA or H2O2 induced IL-8 production dose dependently, an effect that was inhibited by 1% DMSO at both the protein and RNA level. Second, we tested whether DMSO could block the recruitment of neutrophils induced by PA in a bypassed segment of dog trachea in vivo. PA supernatant was placed in the tracheal segment for 6 h in four dogs, and neutrophil recruitment and IL-8 concentrations were measured in the superfusate. DMSO prevented the recruitment of neutrophils and IL-8 production induced by PA time dependently. The results suggest that DMSO may play an anti-inflammatory role in the airway by inhibiting IL-8 production in epithelial cells.

Animals↗

PubMed1995

Staphylococcus aureus stimulates neutrophil recruitment by stimulating interleukin-8 production in dog trachea.

The present study examined whether neutrophil recruitment in dog airways by Staphylococcus aureus is mediated by interleukin-8 (IL-8). S. aureus culture supernatant was superfused into an isolated tracheal segment in six dogs, and neutrophil recruitment and IL-8 concentrations were measured in the superfusate. Dog IL-8 was cloned, expressed in Escherichia coli, purified by chromatography, and shown to be biologically active. With the use of an enzyme-linked immunoabsorbent assay (ELISA) for the measurement of dog IL-8, we showed that S. aureus supernatant induced neutrophil recruitment and increased IL-8 concentration in the superfusate in a time-dependent manner. The chemotactic activity present in the superfusate 6 h after superfusion with S. aureus was inhibited by an anti-IL-8 antibody. S. aureus supernatant also stimulated IL-8 production and gene expression by cultured canine tracheal epithelial cells. These results provide evidence that IL-8 plays a major role in S. aureus-induced neutrophil recruitment in the airways by stimulating IL-8 production in airway cells.

Amino Acid Sequence↗

PubMed1995

Plasma extravasation in the rat trachea induced by cold air is mediated by tachykinin release from sensory nerves.

Cold air was delivered to anesthetized, artificially ventilated, pathogen-free F344 rats via a tracheal cannula. Inhalation of cold air increased Evans blue dye extravasation in the trachea in a time-dependent (1 to 10 min) manner. Plasma extravasation increased after 3 min exposure to cold air and reached a maximum after 10 min exposure. The neutral endopeptidase inhibitor, phosphoramidon (2.5 mg/kg, intravenously), increased by 84% the plasma extravasation induced by inhalation of cold air for 1 min. The plasma extravasation evoked by 5 min exposure to cold air was abolished by the NK1 tachykinin receptor antagonist, CP-99,994 (4 mg/kg, intravenously); was reduced 30% by the B2 bradykinin receptor antagonist, HOE140 (0.1 mumol/kg, intravenously); and was not affected by H1 (pyrilamine, 10 mg/kg, intraperitoneally) or H2 (cimetidine, 10 mg/kg, intraperitoneally) histamine receptor antagonists or the cyclooxygenase inhibitor indomethacin (5 mg/kg, intravenously). In rats infected with Sendai virus, plasma extravasation evoked by inhalation of cold air was greater than in pathogen-free rats. Pretreatment with CP-99,994 (4 mg/kg, intravenously) inhibited completely the plasma extravasation induced by cold air in virus-infected rats. These findings indicate that cold air increases plasma extravasation in the rat trachea by a neurogenic mechanism that involves the release of tachykinins from sensory nerves. Kinin release may also play a role in this neurogenic inflammatory response.

Air↗

PubMed1995

Role of recruited neutrophils in interleukin-8 production in dog trachea after stimulation with Pseudomonas in vivo.

Cell-free supernatant of Pseudomonas aeruginosa (PA) recruits neutrophils into the airways indirectly by inducing the production of chemotactic factors, including interleukin-8 (IL-8). PA products stimulate IL-8 expression selectively in surface airway epithelium, gland ducts, serous cells, and recruited neutrophils. To examine the relative contribution of neutrophils in IL-8 release in the airway lumen, we studied the effect of inhibition of neutrophil recruitment on IL-8 concentration in tracheal fluid after introduction of PA supernatant into the dog trachea in vivo. Tracheal superfusion with PA supernatant caused neutrophil recruitment and increased the IL-8 concentration in the tracheal lumen; NPC 15669 inhibited both effects. To study whether migration of neutrophils into the airway lumen per se induces their expression of IL-8, we compared effects of local introduction of IL-8 and of PA supernatant into the trachea on IL-8 expression in neutrophils recruited into the trachea. PA supernatant, but not exogenous IL-8 alone, induced IL-8 mRNA expression in neutrophils recruited into the trachea. To determine what product(s) of PA stimulate IL-8 expression in neutrophils, we examined neutrophils isolated from peripheral blood. PA supernatant induced IL-8 production in neutrophils, an effect reproduced by PA lipopolysaccharide and inhibited by polymyxin B. These results suggest that neutrophils recruited into the airway lumen play a major role in local IL-8 production in airways in response to bacteria such as PA, depending on the presence of stimuli such as lipopolysaccharide.

Animals↗

PubMed1994

Pseudomonas stimulates interleukin-8 mRNA expression selectively in airway epithelium, in gland ducts, and in recruited neutrophils.

Neutrophils may play important roles in chronic airway diseases. Pseudomonas is a common pathogen in some chronic airway diseases, and expression of the neutrophil chemoattractant interleukin-8 (IL-8) is induced by Pseudomonas in various cells in vitro. Here we examine the localization of IL-8 mRNA expression after incubating human and dog bronchi with Pseudomonas supernatant in vitro. To examine IL-8 expression in recruited neutrophils, we also superfused the dog bypassed tracheal segment with Pseudomonas supernatant in vivo and measured neutrophil number and IL-8 concentration in luminal fluid; simultaneously, we introduced Pseudomonas supernatant by catheter in a peripheral airway. After 6 h, we analyzed IL-8 mRNA expression and localization in removed tissue. Unincubated bronchi showed no IL-8 mRNA expression, but incubation with Pseudomonas supernatant in vitro resulted in IL-8 mRNA expression in surface epithelial, gland duct, and a subpopulation of serous gland cells. In vivo, introduction of Pseudomonas supernatant into dog trachea and peripheral airways caused IL-8 mRNA expression in epithelial and gland duct cells but also in the recruited neutrophils. Pseudomonas lipopolysaccharide alone was without effect in vitro and in vivo. We conclude that Pseudomonas products, but not lipopolysaccharide, stimulate IL-8 expression in airways and that this expression occurs primarily in surface epithelial and gland duct cells, thus bringing the chemoattractant to the bacterial site. Furthermore, IL-8 expression in recruited neutrophils provides a potential mechanism for positive feedback of this protective antibacterial response.

Adult↗

PubMed1994

Novel Pseudomonas product stimulates interleukin-8 production in airway epithelial cells in vitro.

Because high concentrations of IL-8 are found in the sputum of cystic fibrosis patients, we hypothesized that Pseudomonas aeruginosa (PA) induces the production of IL-8 in airway epithelial cells and in monocytes. Therefore, we incubated the supernatant from PA culture with human transformed bronchial epithelial cells (16-HBE) or with monocytes. The culture medium of 16-HBE cells that had been incubated with PA supernatant for 6 h had chemotactic activity that was inhibited by an antibody to human IL-8. The PA supernatant induced IL-8 production by primary bronchial epithelial cells, by 16-HBE cells, and by monocytes. After incubation with PA supernatant, 16-HBE cells showed a marked increase in the levels of IL-8 gene expression. The PA product responsible for IL-8 production resisted freezing, boiling, and proteolysis. This product was not lipid extractable and was present in a 1-kD filtrate. We conclude that a small molecular mass product of PA stimulates IL-8 production by 16-HBE cells and by monocytes, and that the chemotactic activity produced by 16-HBE cells after exposure to PA is due principally to IL-8.

Blotting, Northern↗

PubMed1994

Pseudomonas-induced neutrophil recruitment in the dog airway in vivo is mediated in part by IL-8 and inhibited by a leumedin.

A bacteria-free supernatant of Pseudomonas aeruginosa induces the production of neutrophil chemotactic activity in human bronchial epithelial cells in vitro that is due to the potent chemotactic factor, interleukin-8 (IL-8). Because P. aeruginosa supernatant itself is not chemotactic, we hypothesized that intratracheal P. aeruginosa induces the production of neutrophil chemotactic factors, including IL-8, in vivo. Because neutrophils play a key role in cystic fibrosis, inhibition of neutrophil recruitment might be therapeutic. We studied the effect of P. aeruginosa supernatant in the isolated tracheal segment of dogs in vivo, and we measured neutrophil chemotactic activity in vitro in the tracheal fluid. We also determined the local effect of intratracheal administration of leumedin NPC 15669, an inhibitor of neutrophil recruitment, on IL-8- and Pseudomonas-induced neutrophil accumulation. P. aeruginosa supernatant and IL-8 both caused time-dependent accumulation of neutrophils in the tracheal fluid. Tracheal fluid obtained after P. aeruginosa administration had neutrophil chemotactic activity in vitro that was significantly inhibited by the IL-8 antibody. Intratracheal NPC 15669 prevented both IL-8- and Pseudomonas-induced accumulation of neutrophils. We conclude that P. aeruginosa supernatant recruits neutrophils into the airway indirectly by inducing the production of chemotactic factors, including IL-8. Our results suggest a potential therapeutic role for leumedins in chronic airway diseases.

Animals↗

PubMed1993

Parainfluenza (Sendai) virus infects ciliated cells and secretory cells but not basal cells of rat tracheal epithelium.

Sendai virus is a common respiratory pathogen in rodents. In the airways of rats infected with Sendai virus, viral antigen is present in epithelial cells, but whether all types of epithelial cells are infected is unknown. Because each type of epithelial cell has specific functions that could be affected by viral infection, we asked whether ciliated cells, secretory cells, and basal cells of the rat tracheal epithelium become infected by Sendai virus. We inoculated pathogen-free rats intranasally with Sendai virus, killed the rats 1 to 12 days after inoculation, and prepared the tracheas for double-labeling immunohistochemistry and for electron microscopy. In other studies, we maximized the infection by inoculating rats with a 100-fold higher titer of the virus, by inoculating weanling rats, or by inoculating tracheal explants with Sendai virus in vitro. We also determined whether Sendai virus can infect basal cells of tracheal explants after removal of the overlying columnar epithelial cells. Immunohistochemical studies showed that at the peak of the infection (5 days after inoculation), 30% of the surface epithelial cells stained for Sendai virus antigen, but no basal cells were stained. Electron microscopic examination confirmed the presence of viral particles in ciliated cells and secretory cells, but none were found in basal cells. No basal cells were infected under the conditions that maximized the infection. We conclude that ciliated cells and secretory cells of the rat tracheal epithelium become infected by Sendai virus, but basal cells do not become infected.

Analysis of Variance↗