114 research outputs found

    Whole-genome screen identifies diverse pathways that negatively regulate ciliogenesis.

    Get PDF
    We performed a high-throughput whole-genome RNAi screen to identify novel inhibitors of ciliogenesis in normal and basal breast cancer cells. Our screen uncovered a previously undisclosed, extensive network of genes linking integrin signaling and cellular adhesion to the extracellular matrix (ECM) with inhibition of ciliation in both normal and cancer cells. Surprisingly, a cohort of genes encoding ECM proteins was also identified. We characterized several ciliation inhibitory genes and showed that their silencing was accompanied by altered cytoskeletal organization and induction of ciliation, which restricts cell growth and migration in normal and breast cancer cells. Conversely, supplying an integrin ligand, vitronectin, to the ECM rescued the enhanced ciliation observed on silencing this gene. Aberrant ciliation could also be suppressed through hyperactivation of the YAP/TAZ pathway, indicating a potential mechanistic basis for our findings. Our findings suggest an unanticipated reciprocal relationship between ciliation and cellular adhesion to the ECM and provide a resource that could vastly expand our understanding of controls involving outside-in and inside-out signaling that restrain cilium assembly

    Effects of internal molecular degrees of freedom on the thermal conductivity of some glasses and disordered crystals

    Get PDF
    The thermal conductivity ÎÂș(T) of the fully ordered stable phase II, the metastable phase III, the orientationally disordered (plastic) phase I, as well as the nonergodic orientational glass (OG) phase, of the glass former cyclohexanol (C 6H 11OH) has been measured under equilibrium vapor pressure within the 2-200 K temperature range. The main emphasis is here focused on the influence of the conformational disorder upon the thermal properties of this material. Comparison of results with those regarding cyanoclyclohexane (C 6H 11CN), a chemically related compound, serves to quantify the role played by the terminal groups -OH and -CN on the phonon scattering processes. The picture that emerges shows that motions of such groups do play a minor role as scattering centers, both within the low-temperature orientationally ordered phases as well as in the OG states. The results are analyzed within the Debye-Peierls relaxation time model for isotropic solids comprising mechanisms for long-wave phonon scattering within the OG and orientational ordered low-temperature phases, as well as others arising from localized short-wavelength vibrational modes as pictured by the Cahill-Pohl model. By means of complementary neutron and Raman scattering we show that in the OG state the energy landscapes for both compounds are very similar. © 2012 American Physical Society.This work was ïŹnancially supported in part by the Spanish Ministry of Science and Innovation (Grant No. FIS2008-00837) and the Catalan Government (Grant No. 2009SGR-1251)Peer Reviewe

    Microscopic structures and dynamics of high- and low-density liquid trans-1,2-dichloroethylene

    Get PDF
    4 pågs.; 3 figs.; PACS number s : 64.70.Ja, 61.05.fm, 61.20. p, 61.25.EmWe present a study of the dynamics and structural changes for trans-1,2-dichloroethylene between high- and low-density liquids using neutron-scattering techniques diffraction, small-angle neutron scattering, and time of flight spectroscopy and molecular-dynamics simulations. We show that changes in the short-range ordering of molecules goes along with a change in the molecular dynamics: both structure and dynamics of the highdensity liquid are more cooperative than those of the low-density liquid. The microscopic mechanism underlying the cooperative motions in the high-density liquid has been found to be related to the backscattering of molecules due to a strong correlation of molecular ordering. ©2010 The American Physical SocietyThis work was supported by the Spanish Ministry of Science and Technology Grants No. FIS2008-00837 and No. BES-2007-17418, by the Government of Catalonia Grant No. 2009SGR-1251 and by the European Commission MI3/FP7.Peer Reviewe

    Prognostic role of elevated mir-24-3p in breast cancer and its association with the metastatic process

    Get PDF
    MicroRNAs have been shown to play important roles in breast cancer progression and can serve as biomarkers. To assess the prognostic role of a panel of miRNAs in breast cancer, we collected plasma prospectively at the time of initial diagnosis from 1,780 patients with stage I-III breast cancer prior to definitive treatment. We identified plasma from 115 patients who subsequently developed distant metastases and 115 patients without metastatic disease. Both groups were matched by: age at blood collection, year of blood collection, breast cancer subtype, and stage. The median follow up was 3.4 years (range, 1-9 years). We extracted RNA from plasma and analyzed the expression of 800 miRNAs using Nanostring technology. We then assessed the expression of miRNAs in primary and metastatic breast cancer samples from The Cancer Genome Atlas (TCGA). We found that, miR-24-3p was upregulated in patients with metastases, both in plasma and in breast cancer tissues. Patients whose primary tumors expressed high levels of miR-24-3p had a significantly lower survival rate compared to patients with low mir-24-3p levels in the TCGA cohort (n=1,024). RNA-Seq data of the samples with the highest miR-24-3p expression versus those with the lowest miR-24-3p in the TCGA cohort identified a specific gene expression signature for those tumors with high miR-24-3p. Possible target genes for miR-24-3p were predicted based on gene expression and binding site, and their effects on cancer pathways were evaluated. Cancer, breast cancer and proteoglycans were the top three pathways affected by miR-24-3p overexpression

    Clinical utility of serum HER2/neu in monitoring and prediction of progression-free survival in metastatic breast cancer patients treated with trastuzumab-based therapies

    Get PDF
    INTRODUCTION: The purpose of this retrospective study was to determine the clinical utility of serum HER2/neu in monitoring metastatic breast cancer patients undergoing trastuzumab-based therapy and to compare these results with those obtained using cancer antigen (CA) 15-3. We also sought to determine whether early changes in serum HER2/neu concentrations could be a predictor of progression-free survival. METHODS: Sera were obtained retrospectively from 103 women at four medical institutions. Patients eligible for participation were women with metastatic breast cancer who had HER2/neu tissue overexpression and were scheduled to be treated with trastuzumab with or without additional therapies as per the established practices of the treating physicians. A baseline serum sample for each patient was taken before trastuzumab-based therapy was started. Patients were subsequently monitored over 12 to 20 months and serum samples were taken at the time of clinical assessment and tested with Bayer's HER2/neu and CA15-3 assays. RESULTS: Concordance between clinical status in patients undergoing trastuzumab-based treatment and HER2/neu and CA15-3 used as single tests was 0.793 and 0.627, respectively, and increased to 0.829 when the tests were used in combination. Progression-free survival times did not differ significantly in patients with elevated baseline HER2/neu concentrations (≄ 15 ng/mL) and those with normal concentrations (<15 ng/mL). However, progression-free survival differed significantly (P = 0.043) according to whether the patient's HER2/neu concentration at 2 to 4 weeks after the start of therapy was >77% or ≀ 77% of her baseline concentration. The median progression-free survival times for these two groups were 217 and 587 days, respectively. A similar trend was observed for a subcohort of patients treated specifically with a combination of trastuzumab and taxane. CONCLUSION: These findings indicate that serum HER2/neu testing is clinically valuable in monitoring metastatic breast cancer patients undergoing trastuzumab-based treatment and provides additional value over the commonly used CA15-3 test. The percentage of baseline HER2/neu concentrations in the early weeks after the start of therapy may be an early predictor of progression-free-survival

    CD40 signaling predicts response to preoperative trastuzumab and concomitant paclitaxel followed by 5-fluorouracil, epirubicin, and cyclophosphamide in HER-2-overexpressing breast cancer

    Get PDF
    Introduction We performed gene expression analysis to identify molecular predictors of resistance to preoperative concomitant trastuzumab and paclitaxel followed by 5-fluorouracil, epirubicin, and cyclophosphamide (T/FEC). Methods Pretreatment fine-needle aspiration specimens from 45 patients with HER-2-overexpressing stage II to IIIA breast cancer were subjected to transcriptional profiling and examined for differential expression of various genes and gene sets. The primary endpoint for tumor response was pathologic complete response (pCR). Correlations between pCR and gene expression were sought. Results The overall pCR rate was 64%. Age, nuclear grade, tumor size, nodal status, quantitative expression of estrogen and HER-2 receptor mRNA, and HER-2 gene copy number showed no correlation with pCR. Results of gene set enrichment analysis suggested that the lower expression of genes involved with CD40 signaling is associated with a greater risk of residual cancer after the preoperative chemotherapy that includes trastuzumab. Conclusion CD40 signaling may play a role in determining response to trastuzumab-plus-T/FEC therapy in patients with HER-2-overexpressing breast cancer.PubMedWoSScopu

    HER2 therapy: Molecular mechanisms of trastuzumab resistance

    Get PDF
    Trastuzumab is a monoclonal antibody targeted against the HER2 tyrosine kinase receptor. The majority of patients with metastatic breast cancer who initially respond to trastuzumab develop resistance within one year of treatment initiation, and in the adjuvant setting 15% of patients still relapse despite trastuzumab-based therapy. In this review, we discuss potential mechanisms of antitumor activity by trastuzumab, and how these mechanisms become altered to promote therapeutic resistance. We also discuss novel therapies that may improve the efficacy of trastuzumab, and that offer hope that the survival of breast cancer patients with HER2-overexpressing tumors can be vastly improved

    Prognostic molecular markers in early breast cancer

    Get PDF
    A multitude of molecules involved in breast cancer biology have been studied as potential prognostic markers. In the present review we discuss the role of established molecular markers, as well as potential applications of emerging new technologies. Those molecules used routinely to make treatment decisions in patients with early-stage breast cancer include markers of proliferation (e.g. Ki-67), hormone receptors, and the human epidermal growth factor receptor 2. Tumor markers shown to have prognostic value but not used routinely include cyclin D(1 )and cyclin E, urokinase-like plasminogen activator/plasminogen activator inhibitor, and cathepsin D. The level of evidence for other molecular markers is lower, in part because most studies were retrospective and not adequately powered, making their findings unsuitable for choosing treatments for individual patients. Gene microarrays have been successfuly used to classify breast cancers into subtypes with specific gene expression profiles and to evaluate prognosis. RT-PCR has also been used to evaluate expression of multiple genes in archival tissue. Proteomics technologies are in development

    Recent advances in systemic therapy: Advances in systemic therapy for HER2-positive metastatic breast cancer

    Get PDF
    Human epidermal growth factor receptor (HER)2 over-expression is associated with a shortened disease-free interval and poor survival. Although the addition of trastuzumab to chemotherapy in the first-line setting has improved response rates, progression-free survival, and overall survival, response rates declined when trastuzumab was used beyond the first-line setting because of multiple mechanisms of resistance. Studies have demonstrated the clinical utility of continuing trastuzumab beyond progression, and further trials to explore this concept are ongoing. New tyrosine kinase inhibitors, monoclonal antibodies, PTEN (phosphatase and tensin homolog) pathway regulators, HER2 antibody-drug conjugates, and inhibitors of heat shock protein-90 are being evaluated to determine whether they may have a role to play in treating trastuzumab-resistant metastatic breast cancer
    • 

    corecore