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1.
Breast Care (Basel) ; 16(5): 461-467, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34720805

ABSTRACT

BACKGROUND: Over the last decades, the number of acellular dermal matrix (ADM)-assisted implant-based breast reconstructions (IBBR) has substantially increased. However, there is still a lack of prospective data on complication rates. METHODS: We performed a non-interventional, multicenter, prospective cohort study to evaluate complication rates of a human ADM in patients undergoing an IBBR after skin- and nipple-sparing mastectomies. Patients with primary reconstruction (cohort A) and patients undergoing a secondary reconstruction after capsular fibrosis (cohort B) using the human ADM Epiflex® (DIZG gGmbH, Berlin, Germany) were enrolled in this study. Patients were followed-up for 12 months after surgery. RESULTS: Eighty-four eligible patients were included in this study of whom 28 women underwent a bilateral breast reconstruction, leading to 112 human ADM-assisted reconstructions in total (cohort A: 73, cohort B: 39). In 33.0% of the reconstructed breasts at least one of the complications of primary interest occurred, including implant loss 7.1%, seroma 15.2%; infection 5.4%, rash 8.0%, and Baker grade III/IV capsular fibrosis 2.7%, with no statistically significant differences between the cohorts. Previous radiation therapy was significantly associated with occurrence of any postoperative complication (OR 20.41; p value 0.027). CONCLUSION: The rates of most complications were comparable to the rates reported for other ADMs with relatively low rates of capsular fibrosis and infections. The rate of seroma was increased in our study. Prior radiation therapy increased the risk of any postoperative complications. Therefore, the use of ADM in these patients should be considered carefully.

2.
Eur J Surg Oncol ; 46(8): 1484-1490, 2020 08.
Article in English | MEDLINE | ID: mdl-32336622

ABSTRACT

INTRODUCTION: Implant-based or expander-supported breast reconstruction is an established surgical method after mastectomies due to cancer or to prophylactic reasons. Patient reported outcome (PRO) and cosmetic outcome after breast reconstruction with a synthetic surgical mesh was investigated in a prospective, single-arm, multi-center study. MATERIAL AND METHODS: Primary or secondary implant-based breast reconstruction with support of TiLOOP® Bra was performed in 269 patients during the PRO-BRA study. PRO 12 months after breast reconstruction was evaluated using Breast-Q questionnaire. Cosmetic outcome was evaluated by two independent experts by means of pictures taken preoperatively and at the follow-up visits. RESULTS: Breast-Q and 12 months FU were completed by 210 women. Patients without adverse event had a significantly higher Breast-Q score for "sexual well-being" (p = 0.001); "psychosocial well-being" was negatively influenced by prior therapies (p < 0.01), and older patients had significantly lower scores at 12 months FU compared to pre-OP for "satisfaction with breasts" (p < 0.01) while the opposite was true for younger patients. Unilateral surgery resulted in reduced "satisfaction with breast" at 12 months FU (p < 0.01). Radiotherapy negatively influenced "satisfaction with breast", "sexual well-being" and "physical well-being chest". The cosmetic evaluation showed a significant difference (p < 0.001) in the evaluation by the patients and experts with the patients' assessment being worse compared to experts' assessment. CONCLUSION: Our study showed that two years after implant-based breast reconstruction with support of TiLOOP® Bra PRO is influenced by different factors. This information can be used to improve the decision-making process for women who chose implant-based breast reconstruction.


Subject(s)
Breast Implants , Breast Neoplasms/surgery , Mammaplasty/methods , Patient Reported Outcome Measures , Surgical Mesh , Adult , Aged , Body Mass Index , Breast Neoplasms/pathology , Esthetics , Female , Humans , Lymph Nodes/pathology , Mammaplasty/adverse effects , Mammaplasty/psychology , Middle Aged , Neoplasm Staging , Polypropylenes , Prospective Studies , Quality of Life
3.
Heliyon ; 6(1): e03263, 2020 Jan.
Article in English | MEDLINE | ID: mdl-32021935

ABSTRACT

PURPOSE: Over 90% of all cancer related deaths are due to metastasis. However, current diagnostic tools can't reliably discriminate between invasive and localized cancers. PATIENTS AND METHODS: In this proof-of-concept study, we employed the embryonic stem cell marker TRA-1-60 (TRA+) to identify TRA + cells within the blood of prostate cancer patients and searched for TRA + cells in men with metastatic and localized cancers. We isolated whole peripheral blood mononuclear cells from 26 metastatic prostate cancer patients, from 13 patients with localized prostate cancer and from 17 healthy controls. Cells were stained for DAPI, CD45 and TRA + by immunofluorescence and imaged by epi-fluorescence microscopy. Imaged-based software was used both to identify TRA + cells, and to analyze CD45 levels in TRA+ and negative cells. RESULTS: We found high numbers of TRA + cells within the blood of metastatic cancer patients, whereas healthy individuals or men with localized prostate cancer showed none or very low numbers of TRA + cells. Further analysis of the CD45 levels of TRA + cells revealed a small population of TRA + cells with almost undetectable CD45 levels that were found frequently in metastatic prostate cancer patients. By excluding CD45 positive cells from the TRA + cell pool, we were able to refine the assay to be highly specific in identifying men with metastatic disease. In fact, the difference of CD45 levels between TRA+ and negative cells was a robust measure to distinguish between men with localized and metastatic prostate cancers in this small patient cohort. CONCLUSIONS: The data suggest that metastatic prostate cancer patient have significant numbers of TRA+/CD45low cells which might represent a potential tool for diagnostic assessment in the future.

4.
Dtsch Arztebl Int ; 115(38): 628-635, 2018 09 21.
Article in English | MEDLINE | ID: mdl-30373708

ABSTRACT

BACKGROUND: There has been increasing evidence in recent years that breast implants can, in rare cases, be associated with the development of an anaplastic large-cell lymphoma (ALCL). METHODS: This review is based on relevant publications retrieved by a selective search in PubMed for articles that appeared from the time of the initial description of breast-implant-associated ALCL onward (1997 to January 2018), and by a further search in German nationwide databases. RESULTS: 516 pathologically confirmed cases of breast-implant-associated (BIA) ALCL were documented around the world until February 2018; seven of these arose in Germany and were reported to the Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM). In approximately 80% of the affected women, the BIA-ALCL manifested itself as a late-developing seroma at the implant site; in the rest, as a solid tumor with or without an accompanying seroma. The mean implant exposure time ranged from 7 to 13 years on average. 16 fatalities have been reported worldwide. Among the 7 cases reported in Germany, four women had undergone breast reconstruction with implants after breast cancer surgery, and two had undergone breast augmentation surgery. In all patients, the entire capsule-and-implant unit was resected. One patient underwent chemotherapy and one further patient underwent chemotherapy and adjuvant radiotherapy. CONCLUSION: The risk that a woman with breast implants will develop a primary anaplastic large-cell lymphoma is estimated at 0.35 to 1 case per million persons per year. The incidence of implant-associated ALCL is thus very low, yet nevertheless markedly higher than that of other primary lymphomas of the breast. Because of the low case numbers, recommendations for the diagnostic evaluation and treatment of this entity have not been adequately evaluated. Treatment with primary curative intent for BIA-ALCL confers a much better prognosis than when performed for a systemic ALCL. Whenever a patient with a breast implant presents with a late-developing seroma, BIA-ALCL should be included in the differential diagnosis. This diagnosis is reportable.


Subject(s)
Breast Implants/adverse effects , Lymphoma, Large-Cell, Anaplastic/etiology , Adult , Breast Implants/statistics & numerical data , Female , Germany/epidemiology , Humans , Incidence , Lymphoma, Large-Cell, Anaplastic/diagnosis , Lymphoma, Large-Cell, Anaplastic/epidemiology , Prevalence , Prognosis
5.
Cell Signal ; 29: 218-225, 2017 01.
Article in English | MEDLINE | ID: mdl-27838375

ABSTRACT

The transcription factors NF-κB and p53 as well as their crosstalk determine the fate of tumor cells upon therapeutic interventions. Replicative stress and cytokines promote signaling cascades that lead to the co-regulation of p53 and NF-κB. Consequently, nuclear p53/NF-κB signaling complexes activate NF-κB-dependent survival genes. The 18 histone deacetylases (HDACs) are epigenetic modulators that fall into four classes (I-IV). Inhibitors of histone deacetylases (HDACi) become increasingly appreciated as anti-cancer agents. Based on their effects on p53 and NF-κB, we addressed whether clinically relevant HDACi affect the NF-κB/p53 crosstalk. The chemotherapeutics hydroxyurea, etoposide, and fludarabine halt cell cycle progression, induce DNA damage, and lead to DNA fragmentation. These agents co-induce p53 and NF-κB-dependent gene expression in cell lines from breast and colon cancer and in primary chronic lymphatic leukemia (CLL) cells. Using specific HDACi, we find that the class I subgroup of HDACs, but not the class IIb deacetylase HDAC6, are required for the hydroxyurea-induced crosstalk between p53 and NF-κB. HDACi decrease the basal and stress-induced expression of p53 and block NF-κB-regulated gene expression. We further show that class I HDACi induce senescence in pancreatic cancer cells with mutant p53.


Subject(s)
Histone Deacetylases/metabolism , NF-kappa B/metabolism , Neoplasms/metabolism , Neoplasms/pathology , Signal Transduction , Tumor Suppressor Protein p53/metabolism , Apoptosis/drug effects , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , Cellular Senescence/drug effects , DNA Damage , DNA, Neoplasm/metabolism , Etoposide/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Histone Deacetylase Inhibitors/pharmacology , Humans , Hydroxyurea/pharmacology , Models, Biological , Mutation/genetics , Neoplasms/genetics , Vidarabine/analogs & derivatives , Vidarabine/pharmacology
6.
Mol Cancer Ther ; 16(1): 143-155, 2017 01.
Article in English | MEDLINE | ID: mdl-27811011

ABSTRACT

Taxane therapy remains the standard of care for triple-negative breast cancer. However, high frequencies of recurrence and progression in treated patients indicate that metastatic breast cancer cells can acquire resistance to this drug. The actin regulatory protein MENA and particularly its invasive isoform, MENAINV, are established drivers of metastasis. MENAINV expression is significantly correlated with metastasis and poor outcome in human patients with breast cancer. We investigated whether MENA isoforms might play a role in driving resistance to chemotherapeutics. We find that both MENA and MENAINV confer resistance to the taxane paclitaxel, but not to the widely used DNA-damaging agents doxorubicin or cisplatin. Furthermore, paclitaxel treatment does not attenuate growth of MENAINV-driven metastatic lesions. Mechanistically, MENA isoform expression alters the ratio of dynamic and stable microtubule populations in paclitaxel-treated cells. MENA expression also increases MAPK signaling in response to paclitaxel treatment. Decreasing ERK phosphorylation by co-treatment with MEK inhibitor restored paclitaxel sensitivity by driving microtubule stabilization in MENA isoform-expressing cells. Our results reveal a novel mechanism of taxane resistance in highly metastatic breast cancer cells and identify a combination therapy to overcome such resistance. Mol Cancer Ther; 16(1); 143-55. ©2016 AACR.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Drug Resistance, Neoplasm/genetics , Gene Expression , Microfilament Proteins/genetics , Paclitaxel/pharmacology , Triple Negative Breast Neoplasms/genetics , Animals , Cell Cycle/drug effects , Cell Cycle/genetics , Cell Line, Tumor , Cell Movement/drug effects , Cell Survival/drug effects , Disease Models, Animal , Female , Humans , MAP Kinase Signaling System/drug effects , Mice , Microfilament Proteins/metabolism , Microtubules/metabolism , Neoplasm Metastasis , Protein Isoforms , Triple Negative Breast Neoplasms/diagnosis , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/metabolism , Tumor Burden/drug effects , Xenograft Model Antitumor Assays
7.
Dev Cell ; 36(4): 462-75, 2016 Feb 22.
Article in English | MEDLINE | ID: mdl-26906741

ABSTRACT

The microenvironment determines cell behavior, but the underlying molecular mechanisms are poorly understood because quantitative studies of cell signaling and behavior have been challenging due to insufficient spatial and/or temporal resolution and limitations on microenvironmental control. Here we introduce microenvironmental selective plane illumination microscopy (meSPIM) for imaging and quantification of intracellular signaling and submicrometer cellular structures as well as large-scale cell morphological and environmental features. We demonstrate the utility of this approach by showing that the mechanical properties of the microenvironment regulate the transition of melanoma cells from actin-driven protrusion to blebbing, and we present tools to quantify how cells manipulate individual collagen fibers. We leverage the nearly isotropic resolution of meSPIM to quantify the local concentration of actin and phosphatidylinositol 3-kinase signaling on the surfaces of cells deep within 3D collagen matrices and track the many small membrane protrusions that appear in these more physiologically relevant environments.


Subject(s)
Cell Culture Techniques , Cell Movement/physiology , Signal Transduction/physiology , Actins/metabolism , Cell Culture Techniques/methods , Cells, Cultured , Collagen/metabolism , Extracellular Matrix/metabolism , Humans , Microscopy/methods , Phosphatidylinositol 3-Kinases/metabolism
9.
J Neurosci ; 34(31): 10264-73, 2014 Jul 30.
Article in English | MEDLINE | ID: mdl-25080588

ABSTRACT

Deposition of aggregated amyloid-ß (Aß) peptide in brain is an early event and hallmark pathology of Alzheimer's disease and cerebral Aß angiopathy. Experimental evidence supports the concept that Aß multimers can act as seeds and structurally corrupt other Aß peptides by a self-propagating mechanism. Here we compare the induction of cerebral ß-amyloidosis by intraperitoneal applications of Aß-containing brain extracts in three Aß-precursor protein (APP) transgenic mouse lines that differ in levels of transgene expression in brain and periphery (APP23 mice, APP23 mice lacking murine APP, and R1.40 mice). Results revealed that beta-amyloidosis induction, which could be blocked with an anti-Aß antibody, was dependent on the amount of inoculated brain extract and on the level of APP/Aß expression in the brain but not in the periphery. The induced Aß deposits in brain occurred in a characteristic pattern consistent with the entry of Aß seeds at multiple brain locations. Intraperitoneally injected Aß could be detected in blood monocytes and some peripheral tissues (liver, spleen) up to 30 d after the injection but escaped histological and biochemical detection thereafter. These results suggest that intraperitoneally inoculated Aß seeds are transported from the periphery to the brain in which corruptive templating of host Aß occurs at multiple sites, most efficiently in regions with high availability of soluble Aß.


Subject(s)
Amyloid beta-Peptides/metabolism , Amyloid beta-Peptides/toxicity , Amyloidosis , Cerebral Cortex/pathology , Amyloid beta-Peptides/immunology , Amyloid beta-Protein Precursor/genetics , Amyloidosis/chemically induced , Amyloidosis/genetics , Amyloidosis/pathology , Animals , Antibodies/pharmacology , Blood Cells/metabolism , Blood Cells/pathology , Cerebral Cortex/drug effects , Cerebral Cortex/metabolism , Dose-Response Relationship, Drug , Drug Administration Routes , Female , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Mutation/genetics , Peritoneal Cavity/pathology , Plaque, Amyloid/pathology , Time Factors
10.
Oncotarget ; 5(10): 3184-96, 2014 May 30.
Article in English | MEDLINE | ID: mdl-24833526

ABSTRACT

The Janus tyrosine kinases JAK1-3 and tyrosine kinase-2 (TYK2) are frequently hyperactivated in tumors. In lung cancers JAK1 and JAK2 induce oncogenic signaling through STAT3. A putative role of TYK2 in these tumors has not been reported. Here, we show a previously not recognized TYK2-STAT3 signaling node in lung cancer cells. We reveal that the E3 ubiquitin ligase seven-in-absentia-2 (SIAH2) accelerates the proteasomal degradation of TYK2. This mechanism consequently suppresses the activation of STAT3. In agreement with these data the analysis of primary non-small-cell lung cancer (NSCLC) samples from three patient cohorts revealed that compared to lung adenocarcinoma (ADC), lung squamous cell carcinoma (SCC) show significantly higher levels of SIAH2 and reduced STAT3 phosphorylation levels. Thus, SIAH2 is a novel molecular marker for SCC. We further demonstrate that an activation of the oncologically relevant transcription factor p53 in lung cancer cells induces SIAH2, depletes TYK2, and abrogates the tyrosine phosphorylation of STAT1 and STAT3. This mechanism appears to be different from the inhibition of phosphorylated JAKs through the suppressor of cytokine signaling (SOCS) proteins. Our study may help to identify molecular mechanisms affecting lung carcinogenesis and potential therapeutic targets.


Subject(s)
Carcinoma, Non-Small-Cell Lung/metabolism , Lung Neoplasms/metabolism , Nuclear Proteins/metabolism , STAT3 Transcription Factor/metabolism , Signal Transduction , TYK2 Kinase/metabolism , Ubiquitin-Protein Ligases/metabolism , Cell Line, Tumor , Humans , Immunoblotting , Immunohistochemistry , Immunoprecipitation , Signal Transduction/physiology , Tissue Array Analysis , Transfection
11.
Biochim Biophys Acta ; 1845(2): 202-20, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24440709

ABSTRACT

Survivin belongs to the family of apoptosis inhibitors (IAPs), which antagonizes the induction of cell death. Dysregulated expression of IAPs is frequently observed in cancers, and the high levels of survivin in tumors compared to normal adult tissues make it an attractive target for pharmacological interventions. The small imidazolium-based compound YM155 has recently been reported to block the expression of survivin via inhibition of the survivin promoter. Recent data, however, question that this is the sole and main effect of this drug, which is already being tested in ongoing clinical studies. Here, we critically review the current data on YM155 and other new experimental agents supposed to antagonize survivin. We summarize how cells from various tumor entities and with differential expression of the tumor suppressor p53 respond to this agent in vitro and as murine xenografts. Additionally, we recapitulate clinical trials conducted with YM155. Our article further considers the potency of YM155 in combination with other anti-cancer agents and epigenetic modulators. We also assess state-of-the-art data on the sometimes very promiscuous molecular mechanisms affected by YM155 in cancer cells.


Subject(s)
Imidazoles/administration & dosage , Inhibitor of Apoptosis Proteins/biosynthesis , Naphthoquinones/administration & dosage , Neoplasms/genetics , Animals , Apoptosis/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Humans , Inhibitor of Apoptosis Proteins/antagonists & inhibitors , Inhibitor of Apoptosis Proteins/genetics , Mice , Neoplasms/pathology , Promoter Regions, Genetic/drug effects , Survivin , Xenograft Model Antitumor Assays
12.
J Neurosci ; 33(49): 19284-94, 2013 Dec 04.
Article in English | MEDLINE | ID: mdl-24305824

ABSTRACT

Pathological, genetic, and biochemical hallmarks of Alzheimer's disease (AD) are linked to amyloid-ß (Aß) peptide aggregation. Especially misfolded Aß42 peptide is sufficient to promote amyloid plaque formation. However, the cellular compartment facilitating the conversion of monomeric Aß to aggregated toxic Aß species remains unknown. In vitro models suggest lipid membranes to be the driving force of Aß conversion. To this end, we generated two novel mouse models, expressing either membrane-anchored or nonanchored versions of the human Aß42 peptide. Strikingly, membrane-anchored Aß42 robustly accelerated Aß deposition and exacerbated amyloid-associated toxicity upon crossing with Aß precursor protein transgenic mice. These in vivo findings support the hypothesis that Aß-membrane interactions play a pivotal role in early-onset AD as well as neuronal damage and provide evidence to study Aß-membrane interactions as therapeutic targets.


Subject(s)
Amyloid beta-Peptides/pharmacology , Amyloid beta-Peptides/toxicity , Plaque, Amyloid/pathology , Amyloid beta-Peptides/genetics , Animals , Benzothiazoles , Biotinylation , Blotting, Western , Cell Membrane/metabolism , Cell Membrane/pathology , Endopeptidase K/chemistry , Fluorescent Dyes , HEK293 Cells , Humans , Immunohistochemistry , Inflammation/pathology , Mice , Mice, Inbred C57BL , Phosphatidylinositols , Thiazoles , Type C Phospholipases/chemistry
13.
J Chromatogr A ; 1289: 139-44, 2013 May 10.
Article in English | MEDLINE | ID: mdl-23566920

ABSTRACT

During a routine determination of dimethyl sulfate in technical materials using gas chromatography-mass spectrometry (GC-MS), we found that residual monomethyl sulfate originating from a prior methylation reaction with dimethyl sulfate decomposed in the hot GC injection system to yield dimethyl sulfate and sulfuric acid. This thermal reaction leads to false positive or overestimated residue levels of dimethyl sulfate, accompanied by bad chromatographic peak shapes and poor precision and accuracy values. This short communication describes proper measures to counteract this problem and presents a fast, reliable and validated GC-MS method that is capable of determining dimethyl sulfate residues in the presence of monomethyl sulfate in technical materials using a simple dissolve-and-inject approach. Applying deuterated dimethyl sulfate as internal standard and with a sample weight of 25 mg, a limit of detection of 0.24 mg kg(-1) and a limit of quantification of 0.48 mg kg(-1) was achieved along with a linear range of 0.48-208.6 mg kg(-1). The method offers a precision of 9.1% and an accuracy of 96.5% at the limit of quantification and a precision of 3.6% and an accuracy of 93.8% at a dimethyl sulfate level of 1 mg kg(-1).


Subject(s)
Carcinogens/analysis , Gas Chromatography-Mass Spectrometry/methods , Sulfuric Acid Esters/analysis , Limit of Detection
14.
J Biol Chem ; 287(48): 40745-57, 2012 Nov 23.
Article in English | MEDLINE | ID: mdl-23043102

ABSTRACT

BACKGROUND: Store-operated Ca(2+) entry is important for cell migration. RESULTS: This study presents characterization of localization and roles of Orai1, STIM1, and PLA2g6 in adhesion dynamics during cell migration. CONCLUSION: Orai1 and PLA2g6 are involved in adhesion formation at the front, whereas STIM1 participates in both adhesion formation and disassembly. SIGNIFICANCE: Results uncovered new parameters of Orai1, STIM1, and PLA2g6 involvement in cell migration. Store-operated Ca(2+) entry and its major determinants are known to be important for cell migration, but the mechanism of their involvement in this complex process is unknown. This study presents a detailed characterization of distinct roles of Orai1, STIM1, and PLA2g6 in focal adhesion (FA) formation and migration. Using HEK293 cells, we discovered that although molecular knockdown of Orai1, STIM1, or PLA2g6 resulted in a similar reduction in migration velocity, there were profound differences in their effects on number, localization, and lifetime of FAs. Knockdown of STIM1 caused an increase in lifetime and number of FAs, their redistribution toward lamellae region, and an increase in cell tail length. In contrast, the number of FAs in Orai1- or PLA2g6-deficient cells was significantly reduced, and FAs accumulated closer to the leading edge. Assembly rate and Vinculin phosphorylation of FAs was similarly reduced in Orai1, PLA2g6, or STIM1-deficient cells. Although Orai1 and PLA2g6 accumulated and co-localized at the leading edge, STIM1 distribution was more complex. We found STIM1 protrusions in lamellipodia, which co-localized with FAs, whereas major accumulation could be seen in central and retracting parts of the cell. Interestingly, knockdown of Orai1 and PLA2g6 produced similar and non-additive effect on migration, whereas knockdown of STIM1 simultaneously with either Orai1 or PLA2g6 produced additional inhibition. Together these data suggest that although Orai1, PLA2g6, and STIM1 play major roles in formation of new FAs at the leading edge, STIM1 may also be involved in Orai1- and PLA2g6-independent disassembly of FAs in the back of cells.


Subject(s)
Calcium Channels/metabolism , Cell Movement , Focal Adhesions/metabolism , Membrane Proteins/metabolism , Neoplasm Proteins/metabolism , Phospholipases A2/metabolism , Calcium/metabolism , Calcium Channels/genetics , Focal Adhesions/genetics , HEK293 Cells , Humans , Membrane Proteins/genetics , Neoplasm Proteins/genetics , ORAI1 Protein , Phospholipases A2/genetics , Stromal Interaction Molecule 1
15.
J Biol Chem ; 287(27): 22865-72, 2012 Jun 29.
Article in English | MEDLINE | ID: mdl-22549787

ABSTRACT

Orai1 and STIM1 have been identified as the main determinants of the store-operated Ca(2+) entry (SOCE). Their specific roles in SOCE and their molecular interactions have been studied extensively following heterologous overexpression or molecular knockdown and extrapolated to the endogenous processes in naïve cells. Using molecular and imaging techniques, we found that variation of expression levels of Orai1 or STIM1 can significantly alter expression and role of some endogenous regulators of SOCE. Although functional inhibition of Ca(2+)-independent phospholipase A(2) ß (iPLA(2)ß or PLA2g6A), or depletion of plasma membrane cholesterol caused a dramatic loss of endogenous SOCE in HEK293 cells, these effects were attenuated significantly when either Orai1 or STIM1 were overexpressed. Molecular knockdown of iPLA(2)ß impaired SOCE in both control cells and cells overexpressing STIM1. We also discovered important cross-talk between expression of Orai1 and a specific plasma membrane variant of iPLA(2)ß but not STIM1. These data confirm the role of iPLA(2)ß as an essential mediator of endogenous SOCE and demonstrate that its physiological role can be obscured by Orai1 and STIM1 overexpression.


Subject(s)
Calcium Channels/genetics , Calcium Channels/metabolism , Calcium Signaling/physiology , Group VI Phospholipases A2/metabolism , Membrane Proteins/genetics , Membrane Proteins/metabolism , Neoplasm Proteins/genetics , Neoplasm Proteins/metabolism , Calcium/metabolism , Calcium Channels/physiology , Calcium Signaling/drug effects , Cell Membrane/metabolism , Cholesterol/metabolism , Down-Regulation/physiology , Gene Expression/physiology , Group VI Phospholipases A2/genetics , HEK293 Cells , Homeostasis/physiology , Humans , ORAI1 Protein , Stromal Interaction Molecule 1 , beta-Cyclodextrins/pharmacology
16.
J Cell Sci ; 125(Pt 1): 155-65, 2012 Jan 01.
Article in English | MEDLINE | ID: mdl-22250204

ABSTRACT

The spatially ordered formation and disassembly of focal adhesions is a basic requirement for effective cell locomotion. Because focal adhesions couple the contractile actin-myosin network to the substrate, their distribution determines the pattern of traction forces propelling the cell in a certain direction. In the present study, we quantitatively analyzed the spatial patterning of cell-substrate adhesion in migrating cells by mapping averaged focal adhesion growth dynamics to a standardized cell coordinate system. These maps revealed distinct zones of focal adhesion assembly, disassembly and stability and were strongly interrelated with corresponding actin flow and traction force patterns. Moreover, the mapping technique enables precise detection of even minute responses of adhesion dynamics upon targeted signaling perturbations. For example, the partial inhibition of vinculin phosphorylation was followed by the reduced number of newly formed adhesions, whereas growth dynamics of existing adhesions remained unaffected.


Subject(s)
Cell Movement , Cell Shape , Focal Adhesions/metabolism , Keratinocytes/cytology , Keratinocytes/metabolism , Actin Cytoskeleton/metabolism , Actins/metabolism , Cell Polarity , Humans , Phosphorylation , Vinculin/metabolism
17.
Clin Cancer Res ; 18(2): 417-31, 2012 Jan 15.
Article in English | MEDLINE | ID: mdl-22072733

ABSTRACT

PURPOSE: Environmental conditions in lymph node proliferation centers protect chronic lymphocytic leukemia (CLL) cells from apoptotic triggers. This situation can be mimicked by in vitro stimulation with CD40 ligand (CD40L) and interleukin 4 (IL-4). Our study investigates the impact of the drug leflunomide to overcome apoptosis resistance of CLL cells. EXPERIMENTAL DESIGN: CLL cells were stimulated with CD40L and IL-4 and treated with fludarabine and the leflunomide metabolite A771726. RESULTS: Resistance to fludarabine-mediated apoptosis was induced by CD40 activation alone stimulating high levels of BCL-XL and MCL1 protein expression. Apoptosis resistance was further enhanced by a complementary Janus-activated kinase (JAK)/STAT signal induced by IL-4. In contrast, CLL proliferation required both a CD40 and a JAK/STAT signal and could be completely blocked by pan-JAK inhibition. Leflunomide (A771726) antagonized CD40L/IL-4-induced proliferation at very low concentrations (3 µg/mL) reported to inhibit dihydroorotate dehydrogenase. At a concentration of 10 µg/mL, A771726 additionally attenuated STAT3/6 phosphorylation, whereas apoptosis of CD40L/IL-4-activated ("resistant") CLL cells was achieved with higher concentrations (IC(50): 80 µg/mL). Apoptosis was also effectively induced by A771726 in clinically refractory CLL cells with and without a defective p53 pathway. Induction of apoptosis involved inhibition of NF-κB activity and loss of BCL-XL and MCL1 expression. In combination with fludarabine, A771726 synergistically induced apoptosis (IC(50): 56 µg/mL). CONCLUSION: We thus show that A771726 overcomes CD40L/IL-4-mediated resistance to fludarabine in CLL cells of untreated as well as clinically refractory CLL cells. We present a possible novel therapeutic principle for attacking chemoresistant CLL cells.


Subject(s)
Aniline Compounds/pharmacology , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Drug Resistance, Neoplasm , Hydroxybutyrates/pharmacology , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Vidarabine/analogs & derivatives , Aged , Aged, 80 and over , CD40 Ligand/physiology , Cell Proliferation/drug effects , Crotonates , Humans , Interleukin-4/physiology , Isoxazoles/pharmacology , Janus Kinases/metabolism , Leflunomide , Leukemia, Lymphocytic, Chronic, B-Cell/metabolism , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Middle Aged , Nitriles , STAT Transcription Factors/metabolism , Signal Transduction , Toluidines , Tumor Cells, Cultured/drug effects , Vidarabine/pharmacology
18.
Cell Adh Migr ; 5(5): 431-8, 2011.
Article in English | MEDLINE | ID: mdl-21975552

ABSTRACT

The ability of mammalian cells to adhere and to migrate is an essential prerequisite to form higher organisms. Early migratory events include substrate sensing, adhesion formation, actin bundle assembly and force generation. Latest research revealed that filopodia are important not only for sensing the substrate but for all of the aforementioned highly regulated processes. However, the exact regulatory mechanisms are still barely understood. Here, we demonstrate that filopodia of human keratinocytes exhibit distinct cycles of repetitive elongation and persistence. A single filopodium thereby is able to initiate the formation of several stable adhesions. Every single filopodial cycle is characterized by an elongation phase, followed by a stabilization time and in many cases a persistence phase. The whole process is strongly connected to the velocity of the lamellipodial leading edge, characterized by a similar phase behavior with a slight time shift compared to filopodia and a different velocity. Most importantly, re-growth of existing filopodia is induced at a sharply defined distance between the filopodial tip and the lamellipodial leading edge. On the molecular level this re-growth is preceded by a strong filopodial reduction of the actin bundling protein fascin. This reduction is achieved by a switch to actin polymerization without fascin incorporation at the filopodial tip and therefore subsequent out-transport of the cross-linker by actin retrograde flow.


Subject(s)
Actins/metabolism , Carrier Proteins/metabolism , Keratinocytes/cytology , Microfilament Proteins/metabolism , Pseudopodia/chemistry , Pseudopodia/metabolism , Actins/chemistry , Cell Adhesion/physiology , Cell Adhesion Molecules/chemistry , Cell Adhesion Molecules/metabolism , Cell Line , Cell Movement , Focal Adhesions/metabolism , Humans , Keratinocytes/metabolism , Microfilament Proteins/chemistry , Polymerization
19.
Cell Signal ; 23(2): 436-48, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20965248

ABSTRACT

Protein kinase C ε (PKCε) is a transforming oncogene and plays a pivotal role in numerous cellular processes including proliferation, invasion and differentiation. Recently, we described a function of PKCε as a scaffold protein linking PLCγ1 to the EGFR module. Here, in the head and neck squamous carcinoma cell line (HNSCC) FaDu we demonstrate that over-expressed PKCε may be associated with the EGFR. This is linked with the consecutive inhibition of the recruitment of PLCγ1 to the EGFR, of the catalytical activation of PLCγ1 by EGF, and of the PLCγ1-mediated effect of EGF on cell proliferation. These effects are independent of the catalytical as well as the scaffold activity of PKCε but are a function of the cellular expression level of PKCε. In contrast to FaDu cells where the PLCγ1 pathway was selectively affected, in three other HNSCC cell lines investigated over-expression of PKCε resulted in association with EGFR and, subsequently, in either partial (ERK and Akt or PLCγ1 and Akt) or complete (ERK, PLCγ1 and Akt) inhibition of the main EGFR signalling pathways. Together, our data suggest that in particular carcinoma cells highly expressed PKCε may act as negative allosteric modulator of EGFR signalling. This novel function of PKCε provides also the first indication that the EGFR may be a target for allosteric modulation by accessory proteins.


Subject(s)
ErbB Receptors/physiology , Protein Kinase C-epsilon/physiology , Allosteric Regulation , Animals , COS Cells , Cell Movement , Cell Proliferation , Chlorocebus aethiops , Humans , Mice , Phospholipase C gamma/metabolism , Signal Transduction , Tumor Cells, Cultured
20.
BMC Anesthesiol ; 10: 5, 2010 May 07.
Article in English | MEDLINE | ID: mdl-20459661

ABSTRACT

BACKGROUND: Performance of patients immediately after anaesthesia is an area of special interest and so a clinical trial was conducted to compare Xenon with Isoflurane anaesthesia. In order to assess the early cognitive recovery the syndrome short test (SST) according to Erzigkeit (Geromed GmbH) was applied. METHODS: ASA I and II patients undergoing long and short surgical interventions were randomised to receive either general anaesthesia with Xenon or Isoflurane. The primary endpoint was the validated SST which covering memory disturbances and attentiveness. The test was used on the day prior to intervention, one and three hours post extubation. The secondary endpoint was the recovery index (RI) measured after the end of the inhalation of Xenon or Isoflurane. In addition the Aldrete score was evaluated up to 180 min. On the first post-operative day the patients rated the quality of the anaesthetic using a scoring system from 1-6. RESULTS: The demographics of the groups were similar. The sum score of the SST delivered a clear trend one hour post extubation and a statistically significant superiority for Xenon three hours post extubation (p < 0.01). The RI likewise revealed a statistically significant superiority of Xenon 5 minutes post extubation (p < 0.01). The Aldrete score was significantly higher for 45 min. The scoring system results were also better after Xenon anaesthesia (p < 0.001). CONCLUSIONS: The results show that recovery from anaesthesia and the early return of post-operative cognitive functions are significantly better after Xenon anaesthesia compared to Isoflurane. The results of the RI for Xenon are similar with the previously published results. TRIAL REGISTRATION: The trial was registered with the number ISRCTN01110844 http://www.controlled-trials.com/isrctn/pf/01110844.

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