scholarly journals Filamin-A is required to mediate SST2 effects in pancreatic neuroendocrine tumours

2016 ◽  
Vol 23 (3) ◽  
pp. 181-190 ◽  
Author(s):  
Eleonora Vitali ◽  
Valeria Cambiaghi ◽  
Alessandro Zerbi ◽  
Carlo Carnaghi ◽  
Piergiuseppe Colombo ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cell Adhesion ◽  
Cell Line ◽  
Neuroendocrine Tumours ◽  
Somatostatin Receptor ◽  
Inhibitory Effect ◽  
Filamin A ◽  
Pancreatic Neuroendocrine Tumours

Somatostatin receptor type 2 (SST2) is the main pharmacological target of somatostatin (SS) analogues widely used in patients with pancreatic neuroendocrine tumours (P-NETs), this treatment being ineffective in a subset of patients. Since it has been demonstrated that Filamin A (FLNA) is involved in mediating GPCR expression, membrane anchoring and signalling, we investigated the role of this cytoskeleton protein in SST2 expression and signalling, angiogenesis, cell adhesion and cell migration in human P-NETs and in QGP1 cell line. We demonstrated that FLNA silencing was not able to affect SST2 expression in P-NET cells in basal conditions. Conversely, a significant reduction in SST2 expression (−43±21%, P<0.05 vs untreated cells) was observed in FLNA silenced QGP1 cells after long term SST2 activation with BIM23120. Moreover, the inhibitory effect of BIM23120 on cyclin D1 expression (−46±18%, P<0.05 vs untreated cells), P-ERK1/2 levels (−42±14%; P<0.05 vs untreated cells), cAMP accumulation (−24±3%, P<0.05 vs untreated cells), VEGF expression (−31±5%, P<0.01 vs untreated cells) and in vitro release (−40±24%, P<0.05 vs untreated cells) was completely lost after FLNA silencing. Interestingly, BIM23120 promoted cell adhesion (+86±45%, P<0.05 vs untreated cells) and inhibited cell migration (−24±2%, P<0.00001 vs untreated cells) in P-NETs cells and these effects were abolished in FLNA silenced cells. In conclusion, we demonstrated that FLNA plays a crucial role in SST2 expression and signalling, angiogenesis, cell adhesion and cell migration in P-NETs and in QGP1 cell line, suggesting a possible role of FLNA in determining the different responsiveness to SS analogues observed in P-NET patients.

Role of acetylcholinesterase (AChE) secreted by parasitic nematodes on the growth of the cell line from epithelial origin HT29-D4

Parasitology ◽  
1999 ◽  
Vol 118 (5) ◽  
pp. 489-498 ◽  
Author(s):  
F. HUBY ◽  
S. MALLET ◽  
H. HOSTE
Keyword(s):  
Cell Growth ◽  
Cell Line ◽  
Polyclonal Antibodies ◽  
Polyacrylamide Gel Electrophoresis ◽  
Biological Significance ◽  
Inhibitory Effect ◽  
Parasitic Nematodes ◽  
Epithelial Origin

The excretory–secretory (E–S) products of the parasitic nematodes Trichostrongylus colubriformis and Nematodirus battus were found to modify the in vitro proliferation of the tumorous colic HT29-D4 cell line of epithelial origin. A characteristic feature of these E–S products is the presence of a high level of acetylcholinesterase (AChE) activity, the biological significance of which remains unclear. To determine a possible role of AChE on cell growth, the enzyme was purified from E–S products using edrophonium chloride. Purity was confirmed by polyacrylamide gel electrophoresis, using silver and Karnovsky stains, before assessing its effects on cell proliferation. The purified AChE was incorporated at different concentrations in a culture medium of HT29-D4 cells. A mitogenic effect was shown for low concentrations (0·1–14 units). By contrast, an inhibitory effect was noted at high concentrations (35–1400 units). Furthermore, polyclonal antibodies were prepared and depletion of AChE in E–S products by immunoprecipitation or affinity chromatography resulted in a partial or total disappearance of the stimulatory effect of cell growth. Thus, the results from this in vitro study suggest a modulatory role for AChE secreted by nematode parasites on the proliferation of epithelial cells of the host.

Inhibition of glutaminyl cyclase attenuates cell migration modulated by monocyte chemoattractant proteins

2012 ◽  
Vol 442 (2) ◽  
pp. 403-412 ◽  
Author(s):  
Yi-Ling Chen ◽  
Kai-Fa Huang ◽  
Wen-Chih Kuo ◽  
Yan-Chung Lo ◽  
Yu-May Lee ◽  
...  
Keyword(s):  
Cell Migration ◽  
Inhibitory Effect ◽  
Glutaminyl Cyclase ◽  
Monocyte Chemoattractant ◽  
Monocyte Migration ◽  
Similar Inhibitory Effect ◽  
And Migration ◽  
Interfering Rna

QC (glutaminyl cyclase) catalyses the formation of N-terminal pGlu (pyroglutamate) in peptides and proteins. pGlu formation in chemoattractants may participate in the regulation of macrophage activation and migration. However, a clear molecular mechanism for the regulation is lacking. The present study examines the role of QC-mediated pGlu formation on MCPs (monocyte chemoattractant proteins) in inflammation. We demonstrated in vitro the pGlu formation on MCPs by QC using MS. A potent QC inhibitor, PBD150, significantly reduced the N-terminal uncyclized-MCP-stimulated monocyte migration, whereas pGlu-containing MCP-induced cell migration was unaffected. QC small interfering RNA revealed a similar inhibitory effect. Lastly, we demonstrated that inhibiting QC can attenuate cell migration by lipopolysaccharide. These results strongly suggest that QC-catalysed N-terminal pGlu formation of MCPs is required for monocyte migration and provide new insights into the role of QC in the inflammation process. Our results also suggest that QC could be a drug target for some inflammatory disorders.

scholarly journals RET-Mediated Cell Adhesion and Migration Require Multiple Integrin Subunits

2010 ◽  
Vol 95 (11) ◽  
pp. E342-E346 ◽  
Author(s):  
Jessica G. Cockburn ◽  
Douglas S. Richardson ◽  
Taranjit S. Gujral ◽  
Lois M. Mulligan
Keyword(s):  
Cell Migration ◽  
Cell Adhesion ◽  
Cell Line ◽  
Adhesion Formation ◽  
Xenograft Model ◽  
Tumor Xenograft ◽  
Mouse Tumor ◽  
Cell Adhesion And Migration ◽  
And Migration

Context: The RET receptor tyrosine kinase is an important mediator of several human diseases, most notably of neuroendocrine cancers. These diseases are characterized by aberrant cell migration, a process tightly regulated by integrins. Objective: Our goals were to investigate the role of integrins in RET-mediated migration in two neoplastic cell models: the neural-derived cell line SH-SY5Y, and the papillary thyroid carcinoma cell line TPC-1. We also evaluated whether multiple integrin subunits have a role in RET-mediated cell migration. Design: We evaluated the expression and activation of integrins in response to RET activation using standard cell adhesion and migration (wound-healing) assays. We examined focal adhesion formation, using integrin-paxillin coimmunoprecipitations and immunofluorescence, as an indicator of integrin activity. Results: Our data indicate that β1 integrin (ITGB1) is expressed in both SH-SY5Y and TPC-1 cell lines and that these cells adhere strongly to matrices preferentially associated with ITGB1. We showed that RET can activate ITGB1, and that RET-induced cell adhesion and migration require ITGB1. Furthermore, we showed that β3 integrin (ITGB3) also plays a role in RET-mediated cell adhesion and migration in vitro and ITGB3 expression correlates with RET-mediated invasion in a mouse tumor xenograft model, suggesting that RET mediates the activity of multiple integrin subunits. Conclusions: Our data are the first to show that multiple integrin subunits contribute to cell adhesion and migration downstream of RET, suggesting that coordinated signaling through these pathways is important for cell interactions with the microenvironment during tumor invasion and progression.

Effect of Dipyridamole on Spontaneous Platelet Aggregation in Whole Blood Decreases with the Time After Venepuncture: Evidence for the Role of ADP

1987 ◽  
Vol 58 (02) ◽  
pp. 744-748 ◽  
Author(s):  
A R Saniabadi ◽  
G D O Lowe ◽  
J C Barbenel ◽  
C D Forbes
Keyword(s):  
Platelet Aggregation ◽  
Correlation Coefficient ◽  
Whole Blood ◽  
Blood Platelet ◽  
Inhibitory Effect ◽  
Time Interval ◽  
Adp Receptor ◽  
Spontaneous Platelet Aggregation

SummarySpontaneous platelet aggregation (SPA) was studied in human whole blood at 3, 5, 10, 20, 30, 40 and 60 minutes after venepuncture. Using a whole blood platelet counter, SPA was quantified by measuring the fall in single platelet count upon rollermixing aliquots of citrated blood at 37° C. The extent of SPA increased with the time after venepuncture, with a correlation coefficient of 0.819. The inhibitory effect of dipyridamole (Dipy) on SPA was studied: (a) 10 μM at each time interval; (b) 0.5-100 μM at 3 and 30 minutes and (c) 15 μM in combination with 100 μM adenosine, 8 μM 2-chloroadenosine (2ClAd, an ADP receptor blocker) and 50 μM aspirin. There was a rapid decrease in the inhibitory effect of Dipy with the time after venepuncture; the correlation coefficient was -0.533. At all the concentrations studied, Dipy was more effective at 3 minutes than at 30 minutes after venepuncture. A combination of Dipy with adenosine, 2ClAd or aspirin was a more effective inhibitor of SPA than either drug alone. However, when 15 μM Dipy and 10 μM Ad were added together, the inhibitory effect of Dipy was not increased significantly, suggesting that Dipy inhibits platelet aggregation independent of Ad. The increase in SPA with the time after venepuncture was abolished when blood was taken directly into the anticoagulant containing 5 μM 2ClAd. It is suggested that ADP released from the red blood cells is responsible for the increased platelet aggregability with the time after venepuncture and makes a serious contribution to the artifacts of in vitro platelet function studies.

Imaging of Pancreatic-Neuroendocrine Tumours: An Outline of Conventional Radiological Techniques

2019 ◽  
Vol 12 (2) ◽  
pp. 135-155 ◽  
Author(s):  
Muhammad Affan Zamir ◽  
Wasim Hakim ◽  
Siraj Yusuf ◽  
Robert Thomas
Keyword(s):  
Neuroendocrine Tumours ◽  
Treatment Options ◽  
Advantages And Disadvantages ◽  
Imaging Characteristics ◽  
Fundamental Understanding ◽  
Pancreatic Neuroendocrine Tumours ◽  
Direct Management ◽  
Important Disease ◽  
Similar Imaging

IIntroduction: Pancreatic Neuroendocrine Tumours (p-NETs) are an important disease entity and comprise of peptide-secreting tumours often with a functional syndrome. : Accounting for a small percentage of all pancreatic tumours, they have a good overall survival rate when diagnosed early, with surgery being curative. The role of nuclear medicine in the diagnosis and treatment of these tumours is evident. However, the vast majority of patients will require extensive imaging in the form of conventional radiological techniques. It is important for clinicians to have a fundamental understanding of the p-NET appearances to aid prompt identification and to help direct management through neoplastic staging. Methods: This article will review the advantages and disadvantages of conventional radiological techniques in the context of p-NETs and highlight features that these tumours exhibit. Conclusion: Pancreatic neuroendocrine tumours are a unique collection of neoplasms that have markedly disparate clinical features but similar imaging characteristics. Most p-NETs are small and welldefined with homogenous enhancement following contrast administration, although larger and less welldifferentiated tumours can demonstrate areas of necrosis and cystic architecture with heterogeneous enhancement characteristics. : Prognosis is generally favourable for these tumours with various treatment options available. However, conventional radiological techniques will remain the foundation for the initial diagnosis and staging of these tumours, and a grasp of these modalities is extremely important for physicians.

scholarly journals Amphetamine-Decreased Progesterone and Estradiol Release in Rat Granulosa Cells: The Regulatory Role of cAMP- and Ca2+-Mediated Signaling Pathways

Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 493
Author(s):  
 Chung-Yu Chen ◽  
Chien-Rung Chen ◽  
Chiao-Nan Chen ◽  
Paulus S. Wang ◽  
Toby Mündel ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Prostaglandin F2α ◽  
Inhibitory Effect ◽  
Inhibitory Effects ◽  
Steroidogenic Enzyme ◽  
Estradiol Secretion ◽  
Basal Release ◽  
Ca2 Channels

The purpose of this study is to evaluate the amphetamine effects on progesterone and estradiol production in rat granulosa cells and the underlying cellular regulatory mechanisms. Freshly dispersed rat granulosa cells were cultured with various test drugs in the presence of amphetamine, and the estradiol/progesterone production and the cytosolic cAMP level were measured. Additionally, the cytosolic-free Ca2+ concentrations ([Ca2+]i) were measured to examine the role of Ca2+ influx in the presence of amphetamine. Amphetamine in vitro inhibited both basal and porcine follicle-stimulating hormone-stimulated estradiol/progesterone release, and amphetamine significantly decreased steroidogenic enzyme activities. Adding 8-Bromo-cAMP did not recover the inhibitory effects of amphetamine on progesterone and estradiol release. H89 significantly decreased progesterone and estradiol basal release but failed to enhance a further amphetamine inhibitory effect. Amphetamine was capable of further suppressing the release of estradiol release under the presence of nifedipine. Pretreatment with the amphetamine for 2 h decreased the basal [Ca2+]i and prostaglandin F2α-stimulated increase of [Ca2+]i. Amphetamine inhibits progesterone and estradiol secretion in rat granulosa cells through a mechanism involving decreased PKA-downstream steroidogenic enzyme activity and L-type Ca2+ channels. Our current findings show that it is necessary to study the possibility of amphetamine perturbing reproduction in females.

scholarly journals Role of the V1G1 subunit of V-ATPase in breast cancer cell migration

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria De Luca ◽  
Roberta Romano ◽  
Cecilia Bucci
Keyword(s):  
Breast Cancer ◽  
Cell Migration ◽  
Cell Motility ◽  
Cancer Progression ◽  
Tumor Formation ◽  
Downstream Signaling ◽  
Late Endosomes ◽  
Intracellular Compartments

AbstractV-ATPase is a large multi-subunit complex that regulates acidity of intracellular compartments and of extracellular environment. V-ATPase consists of several subunits that drive specific regulatory mechanisms. The V1G1 subunit, a component of the peripheral stalk of the pump, controls localization and activation of the pump on late endosomes and lysosomes by interacting with RILP and RAB7. Deregulation of some subunits of the pump has been related to tumor invasion and metastasis formation in breast cancer. We observed a decrease of V1G1 and RAB7 in highly invasive breast cancer cells, suggesting a key role of these proteins in controlling cancer progression. Moreover, in MDA-MB-231 cells, modulation of V1G1 affected cell migration and matrix metalloproteinase activation in vitro, processes important for tumor formation and dissemination. In these cells, characterized by high expression of EGFR, we demonstrated that V1G1 modulates EGFR stability and the EGFR downstream signaling pathways that control several factors required for cell motility, among which RAC1 and cofilin. In addition, we showed a key role of V1G1 in the biogenesis of endosomes and lysosomes. Altogether, our data describe a new molecular mechanism, controlled by V1G1, required for cell motility and that promotes breast cancer tumorigenesis.

scholarly journals Analysis of a Preliminary microRNA Expression Signature in a Human Telangiectatic Osteogenic Sarcoma Cancer Cell Line

2021 ◽  
Vol 22 (3) ◽  
pp. 1163
Author(s):  
Gaia Palmini ◽  
Cecilia Romagnoli ◽  
Simone Donati ◽  
Roberto Zonefrati ◽  
Gianna Galli ◽  
...  
Keyword(s):  
Cell Line ◽  
Molecular Mechanisms ◽  
Osteogenic Sarcoma ◽  
Cancer Cell Line ◽  
Microscopic Features ◽  
In Vitro Establishment ◽  
Profile Characteristic ◽  
First Time

Telangiectatic osteosarcoma (TOS) is an aggressive variant of osteosarcoma (OS) with distinctive radiographic, gross, microscopic features, and prognostic implications. Despite several studies on OS, we are still far from understanding the molecular mechanisms of TOS. In recent years, many studies have demonstrated not only that microRNAs (miRNAs) are involved in OS tumorigenesis, development, and metastasis, but also that the presence in high-grade types of OS of cancer stem cells (CSCs) plays an important role in tumor progression. Despite these findings, nothing has been described previously about the expression of miRNAs and the presence of CSCs in human TOS. Therefore, we have isolated/characterized a putative CSC cell line from human TOS (TOS-CSCs) and evaluated the expression levels of several miRNAs in TOS-CSCs using real-time quantitative assays. We show, for the first time, the existence of CSCs in human TOS, highlighting the in vitro establishment of this unique stabilized cell line and an identification of a preliminary expression of the miRNA profile, characteristic of TOS-CSCs. These findings represent an important step in the study of the biology of one of the most aggressive variants of OS and the role of miRNAs in TOS-CSC behavior.

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