40 research outputs found

    Loss of survivin in intestinal epithelial progenitor cells leads to mitotic catastrophe and breakdown of gut immune homeostasis

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    A tightly regulated balance of proliferation and cell death of intestinal epithelial cells (IECs) is essential for maintenance of gut homeostasis. Survivin is highly expressed during embryogenesis and in several cancer types, but little is known about its role in adult gut tissue. Here, we show that Survivin is specifically expressed in transit-amplifying cells and Lgr5(+) stem cells. Genetic loss of Survivin in IECs resulted in destruction of intestinal integrity, mucosal inflammation, and death of the animals. Survivin deletion was associated with decreased epithelial proliferation due to defective chromosomal segregation. Moreover, Survivin-deficient animals showed induced phosphorylation of p53 and H2AX and increased levels of cell-intrinsic apoptosis in IECs. Consequently, induced deletion of Survivin in Lgr5(+) stem cells led to cell death. In summary, Survivin is a key regulator of gut tissue integrity by regulating epithelial homeostasis in the stem cell niche

    ING3 promotes prostate cancer growth by activating the androgen receptor

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    Background The androgen receptor (AR) is a major driver of prostate cancer, and increased AR levels and co-activators of the receptor promote the development of prostate cancer. INhibitor of Growth (ING) proteins target lysine acetyltransferase or lysine deacetylase complexes to the histone H3K4Me3 mark of active transcription, to affect chromatin structure and gene expression. ING3 is a stoichiometric member of the TIP60 lysine acetyltransferase complex implicated in prostate cancer development. Methods Biopsies of 265 patients with prostate cancer were stained for ING3, pan-cytokeratin, and DNA. LNCaP and C4-2 androgen-responsive cells were used for in vitro assays including immunoprecipitation, western blotting, Luciferase reporter assay and quantitative polymerase chain reaction. Cell viability and migration assays were performed in prostate cancer cell lines using scrambled siRNA or siRNA targeting ING3. Results We find that ING3 levels and AR activity positively correlate in prostate cancer. ING3 potentiates androgen effects, increasing expression of androgen-regulated genes and androgen response element-driven reporters to promote growth and anchorage-independent growth. Conversely, ING3 knockdown inhibits prostate cancer cell growth and invasion. ING3 activates the AR by serving as a scaffold to increase interaction between TIP60 and the AR in the cytoplasm, enhancing receptor acetylation and translocation to the nucleus. Activation is independent of ING3's ability to target the TIP60 complex to H3K4Me3, identifying a previously unknown chromatin-independent cytoplasmic activity for ING3. In agreement with in vitro observations, analysis of The Cancer Genome Atlas (TCGA) data (n = 498) and a prostate cancer tissue microarray (n = 256) show that ING3 levels are higher in aggressive prostate cancers, with high levels of ING3 predicting shorter patient survival in a low AR subgroup. Including ING3 levels with currently used indicators such as the Gleason score provides more accurate prognosis in primary prostate cancer. Conclusions In contrast to the majority of previous reports suggesting tumor suppressive functions in other cancers, our observations identify a clear oncogenic role for ING3, which acts as a co-activator of AR in prostate cancer. Data from TCGA and our previous and current tissue microarrays suggest that ING3 levels correlate with AR levels and that in patients with low levels of the receptor, ING3 level could serve as a useful prognostic biomarker

    Trace of survivin in cancer

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    Survivin is one of the most cancer-specific proteins overexpressed in almost all malignancies, but is nearly undetectable in most normal tissues in adults. Functionally, as a member of the inhibitor of apoptosis family, survivin has been shown to inhibit apoptosis and increase proliferation. The antiapoptotic function of survivin seems to be related to its ability to inhibit caspases directly or indirectly. Furthermore, the role of survivin in cell cycle division control is related to its role in the chromosomal passenger complex. Consistent with its determining role in these processes, survivin plays a crucial role in cancer progression and cancer cell resistance to anticancer drugs and ionizing radiation. On the basis of these findings, recently survivin has been investigated intensively as an ideal tumor biomarker. Thus, multiple molecular approaches such as use of the RNA interfering technique, antisense oligonucleotides, ribozyme, and small molecule inhibitors have been used to downregulate survivin regulation and inhibit its biological function consequently. In this review, all these approaches are explained and other compounds that induced apoptosis in different cell lines through survivin inhibition are also reporte

    The twisted survivin connection to angiogenesis

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    The Impact of RFID Security Vulnerabilities on Supply Chain : Case Studies: RFID companies in Iran

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    Every technology has advantages and disadvantages. RFID is a new technology when compared with other technologies like networking and telecommunication technologies and much more modern in Iran, with lots of unrevealed and not recognized features and applications. In business fields like supply chain the concerns of RFID security vulnerabilities, seem to be the reason for low rate of adaption. The current research is trying to create or suggest a theory or model to executives of RFID in Iran, in order to help the speed up and spread. The researcher investigated through commercial and technical companies involved with RFID technology and implementations in Iran. The current research is focused on the companies' projects which support vast variety of supply chains and is a qualitative research based on case studies. This survey gives a comparison with foreign RFID executives' experiences and concerns in order to find the common and differential points. It would be helpful in specifying the heaviest concern or concerns in a statistical comparison.Here in the current research the area which the investigation is around it is the e-Commerce applications in the market place, which could be affected and become more efficient or accelerated by the use of wireless technology and devices generally, and RFID applications and accessories specifically. The attempt is towards finding and empirical test of a theoretical model aimed at explaining a comparison between security concerns to show the most important efficient one to be considered in the RFID context when implemented in supply chains.In the literature review, the foreign concerns and issues were categorized in three, E-Commerce security, RFID security concepts and issues and RFID in supply chains. Then a conceptual framework was proposed to build links between a secure model of RFID (AIMS4MSD) and supply chains members also with the backbone network where the databases and servers were located. In the current explanatory research relationships are the impacts of RFID on supply chain and security features are variables. With an inductive approach the theory is built from samples and cases towards rules and laws. The current thesis is based on grounded theory and case studies as strategies to complete the research. And the author followed within case and cross case procedures to analyze the primary and secondary data gathered from foreign works and in-depth interviews organized and performed with seven (7) RFID companies in Iran as the research statistical society with a snowball sampling method.At the end as the findings the research questions were answered and concluded that in order to benefit efficiently from RFID in supply chains it is needed to consider security concerns and standards and provide adequate trainings for users and staff concurrently. These would be helpful in recognizing the most effective vulnerabilities around RFID when being implemented in supply chains.Validerat; 20111101 (anonymous

    Regulation of Cell Death by The Drosophila ING Proteins

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    The inhibitor of growth (ING) family of type II tumor suppressors (ING1-ING5) are involved in various cellular processes including apoptosis, DNA repair and tumor growth. INGs are subunits of histone deacetylase (HDAC) and histone acetyltransferase (HAT) complexes. The Drosophila genome encodes 3 ING homologues, dING 2, 3 and 4. In this research, I showed that overexpression of dING2 leads to smaller tissue and clone size in Drosophila. dING2 was sufficient to induce caspase-dependent but p53-independent cell death, which promoted expression of the pro-apoptotic gene, reaper. Experiments conducted on polyploid tissues revealed that clonal overexpression of dING2 had little effect in cells in the larval fat body, but resulted in smaller salivary glands. My experiments established that overexpression of dING3 induces caspase-dependent cell death. However, neither dING2 nor dING3 is required for IR-induced apoptosis. This work should provide valuable insights into the role of INGs in apoptosis

    Additional file 1: Figure S1. of ING3 promotes prostate cancer growth by activating the androgen receptor

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    The four panels show representative images of a line of C4-2 cells stably infected with inducible lentiviral shCtrl or shING3, with or without Dox. The western blots show the efficiency of ING3 knockdown in the presence or absence of Dox. Figure S2. (A) Lysates from three AR-positive prostate cancer cell lines were subject to western blotting with antibodies against ING3, GAPDH, and actin. (B) mRNA levels of ING3 were normalized to actin in three prostate cancer cell lines. (C) LNCaP, C4-2, and VCaP cells were grown in media with charcoal stripped serum (CSS) for 48 h and treated with mibolerone (MB) or bicalutamide (Bic). Protein levels of ING3 and AR were visualized by western blotting with actin used as a loading control. (D) qRT-PCR study of ING3 in LNCaP cells after treatment with increasing concentrations of MB. The left graph shows mRNA levels of ING3 in response to MB. The right graph shows mRNA levels of seven androgen-regulated genes in response to MB. (E) A cycloheximide experiment using LNCaP cells grown in the presence or absence of MB to estimate ING3 half-life. Figure S3. (A) HEK293T cells were co-transfected with 1 μg of Myc-tagged AR and 1 μg of either empty vector or HA-tagged ING3 +/– 10 nM MB. ING3 was pulled down with HA-affinity beads, and precipitates were blotted with α-AR and α-HA. (B) To determine the effects of DNA on the interaction, co-immunoprecipitations were repeated with addition of ethidium bromide (EtBr). ING3 was precipitated using HA-affinity beads. Figure S4. LNCaP cells were infected with shCtrl or shING3 lentiviral particles for 72h under androgen deprived conditions and stained with anti-Ki67. Arrows indicate infected (RFP-positive) cells with associated Ki67 staining. RFP-positive and Ki67-positive cells were counted and percentages are shown in the table. Figure S5. ING3 affects PC migration. (A) LNCaP, PC3, and DU145 cells were transfected with either siCtrl or siING3 and, in case of LNCaP, treated with 1 nM MB for the times indicated. Transwell migration assays were performed at the indicated time points. Representative images are shown. (B) Images were taken from six random fields for each condition and counted manually on a computer using a blind experimental protocol (t test * < 0.05, ** < 0.01). (C) Wounds were made in monolayers of C4-2 cells stably expressing either shCtrl or shING3 in the presence of 10 nM MB and Dox to induce shRNA expression. Wounds were then allowed to heal during a course of 4 days. Images were taken from the same fields for each condition. Percentage of healed wound was then calculated based on pixels observed in each condition. (D) LNCaP cells were transfected with siCtrl or siING3 and treated with 1 nM MB for 72 h, then fixed and stained with Texas Red-conjugated phalloidin. Arrows highlight actin projections along cell axes consistent with filopodia formation. (E) The numbers of actin projections per cell were counted in a blind experimental protocol from a total of 50 cells, and the mean number of filopodia/cell was plotted (t test *** < 0.001). Figure S6. Representative images of prostate cancer samples showing low and high expression of AR as determined by immunohistochemistry. Samples are from the prostate cancer patient cohort used in this study. Figure S7. Kaplan-Meier survival curves using Gleason score as a known prognostic marker in the derivation and validation datasets. Figure S8. Kaplan-Meier survival curves in our prostate cancer patient cohort with low levels of AR, in the derivation and validation datasets. (PPT 4506 kb
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