165 research outputs found

    An immunohistochemical analysis of stathmin 1 expression in uterine smooth muscle tumors: differential expression in leiomyosarcomas and leiomyomas

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    The oncogenic phosphatidylinositol 3-kinase-AKT-mammlian target of rapamycin pathway (PI3K-AKT-mTOR) pathway is known to be activated in uterine smooth muscle tumors, and Stathmin 1 (STMN1) expression has been identified as a marker of PI3K-AKT-mTOR pathway activation. We hypothesized that STMN1 may have some diagnostic utility and explored how well STMN1 expression correlated with histologic classifications of uterine smooth muscle tumors into benign and malignant groupings. 84 smooth muscle tumors were assessed for STMN1 expression by immunohistochemistry. These included spindle cell leiomyosarcoma (n=32), conventional spindle cell leiomyomas (n=30), atypical (symplastic) leiomyoma (n=5), cellular leiomyoma (n=7), smooth muscle tumor of uncertain malignant potential (n=4), mitotically active leiomyomas (n=2), benign metastasizing leiomyoma (n=3), and cotyledonoid dissecting leiomyoma (n=1). All spindle cell leiomyosarcomas were positive (32/32 positive; 100%) as compared with conventional leiomyomata (11/30; 37%) (

    Impaired OXPHOS Complex III in Breast Cancer

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    We measured the mitochondrial oxidative phosphorylation (mtOXPHOS) activities of all five complexes and determined the activity and gene expression in detail of the Complex III subunits in human breast cancer cell lines and primary tumors. Our analysis revealed dramatic differences in activity of complex III between normal and aggressive metastatic breast cancer cell lines. Determination of Complex III subunit gene expression identified over expression and co-regulation of UQCRFS1 (encoding RISP protein) and UQCRH (encoding Hinge protein) in 6 out of 9 human breast tumors. Analyses of UQCRFS1/RISP expression in additional matched normal and breast tumors demonstrated an over expression in 14 out of 40 (35%) breast tumors. UQCRFS1/RISP knockdown in breast tumor cell line led to decreased mitochondrial membrane potential as well as a decrease in matrigel invasion. Furthermore, reduced matrigel invasion was mediated by reduced ROS levels coinciding with decreased expression of NADPH oxidase 2, 3, 4 and 5 involved in ROS production. These studies provide direct evidence for contribution of impaired mtOXPHOS Complex III to breast tumorigenesis

    Mitochondrial aconitase and citrate metabolism in malignant and nonmalignant human prostate tissues

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    BACKGROUND: In prostate cancer, normal citrate-producing glandular secretory epithelial cells undergo a metabolic transformation to malignant citrate-oxidizing cells. m-Aconitase is the critical step involved in this altered citrate metabolism that is essential to prostate malignancy. The limiting m-aconitase activity in prostate epithelial cells could be the result of a decreased level of m-aconitase enzyme and/or the inhibition of existing m-aconitase. Earlier studies identified zinc as an inhibitor of m-aconitase activity in prostate cells; and that the depletion of zinc in malignant cells is an important factor in this metabolic transformation. However, a possibility remains that an altered expression and level of m-aconitase enzyme might also be involved in this metabolic transformation. To address this issue, the in situ level of m-aconitase enzyme was determined by immunohistochemical analysis of prostate cancer tissue sections and malignant prostate cell lines. RESULTS: The immunocytochemical procedure successfully identified the presence of m-aconitase localized in the mitochondrial compartment in PC-3, LNCaP, and DU-145 malignant prostate cell lines. The examination of prostate tissue sections from prostate cancer subjects demonstrated that m-aconitase enzyme is present in the glandular epithelium of normal glands, hyperplastic glands, adenocrcinomatous glands, and prostatic intraepithelial neoplastic foci. Quantitative analysis of the relative level of m-aconitase in the glandular epithelium of citrate-producing adenomatous glands versus the citrate-oxidizing adenocarcinomatous glands revealed no significant difference in m-aconitase enzyme levels. This is in contrast to the down-regulation of ZIP1 zinc transporter in the malignant glands versus hyperplastic glands that exists in the same tissue samples. CONCLUSION: The results demonstrate the existence of m-aconitase enzyme in the citrate-producing glandular epithelial cells; so that deficient m-aconitase enzyme is not associated with the limiting m-aconitase activity that prevents citrate oxidation in these cells. The level of m-aconitase is maintained in the malignant cells; so that an altered enzyme level is not associated with the increased m-aconitase activity. Consequently, the elevated zinc level that inhibits m-aconitase enzyme is responsible for the impaired citrate oxidation in normal and hyperplastic prostate glandular epithelial cells. Moreover, the down-regulation of ZIP1 zinc transporter and corresponding depletion of zinc results in the increase in the activity of the existing m-aconitase activity in the malignant prostate cells. The studies now define the mechanism for the metabolic transformation that characterizes the essential transition of normal citrate-producing epithelial cells to malignant citrate-oxidizing cells

    hZip2 and hZip3 zinc transporters are down regulated in human prostate adenocarcinomatous glands

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    <p>Abstract</p> <p>Background</p> <p>The normal human prostate glandular epithelium has the unique function of accumulating high levels of zinc. In prostate cancer this capability is lost as an early event in the development of the malignant cells. The mechanism and factors responsible for the ability of the normal epithelial cells to accumulate zinc and the loss of this capability in the malignant cells need to be identified. We previously reported that Zip1 is an important zinc uptake transporter in prostate cells and is down regulated in the malignant cells in situ along with the depletion of zinc levels. In this report we investigated the expression of two other Zip family zinc transporters, Zip2 and Zip3 in malignant versus nonmalignant (normal and BPH) glands. Zip2 and Zip3 relative protein levels were determined by immunohistochemistry analysis of human prostate tissue sections.</p> <p>Results</p> <p>Normal and BPH glandular epithelium consistently exhibited the strong presence of both Zip 2 and Zip3; whereas both transporters consistently were essentially non-detectable in the malignant glands. This represents the first report of the expression of Zip3 in human prostate tissue; and more importantly, reveals that ZiP2 and Zip3 are down regulated in malignant cells in situ as we also had demonstrated for Zip1. Zip2 and Zip3 transporter proteins were localized predominantly at the apical cell membrane, which is in contrast to the Zip1 localization at the basolateral membrane. Zip2 and Zip3 seemingly are associated with the re-uptake of zinc from prostatic fluid.</p> <p>Conclusion</p> <p>These results coupled with previous reports implicate Zip2 and Zip3 along with Zip1 as important zinc uptake transporters involved in the unique ability of prostate cells to accumulate high cellular zinc levels. Zip1 is important for the extraction of zinc from circulation as the primary source of cellular zinc. Zip 2 and Zip3 appear to be important for retention of the zinc in the cellular compartment. The down regulation of all three transporters in the malignant cells is consistent with the loss of zinc accumulation in these cells. Since zinc imposes tumor suppressor effects, the silencing of the gene expression for these transporters is a required event for the manifestation of the malignant activities of the neoplastic cells. This now provides new insights into the genetic/molecular events associated with the development of prostate cancer; and supports our concept of Zip1, and now Zip2 and Zip3, as tumor suppressor genes and zinc as a tumor suppressor agent.</p

    hZIP1 zinc uptake transporter down regulation and zinc depletion in prostate cancer

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    BACKGROUND: The genetic and molecular mechanisms responsible for and associated with the development and progression of prostate malignancy are largely unidentified. The peripheral zone is the major region of the human prostate gland where malignancy develops. The normal peripheral zone glandular epithelium has the unique function of accumulating high levels of zinc. In contrast, the ability to accumulate zinc is lost in the malignant cells. The lost ability of the neoplastic epithelial cells to accumulate zinc is a consistent factor in their development of malignancy. Recent studies identified ZIP1 (SLC39A1) as an important zinc transporter involved in zinc accumulation in prostate cells. Therefore, we investigated the possibility that down-regulation of hZIP1 gene expression might be involved in the inability of malignant prostate cells to accumulate zinc. To address this issue, the expression of hZIP1 and the depletion of zinc in malignant versus non-malignant prostate glands of prostate cancer tissue sections were analyzed. hZIP1 expression was also determined in malignant prostate cell lines. RESULTS: hZIP1 gene expression, ZIP1 transporter protein, and cellular zinc were prominent in normal peripheral zone glandular epithelium and in benign hyperplastic glands (also zinc accumulating glands). In contrast, hZIP1 gene expression and transporter protein were markedly down-regulated and zinc was depleted in adenocarcinomatous glands and in prostate intra-epithelial neoplastic foci (PIN). These changes occur early in malignancy and are sustained during its progression in the peripheral zone. hZIP1 is also expressed in the malignant cell lines LNCaP, PC-3, DU-145; and in the nonmalignant cell lines HPr-1 and BPH-1. CONCLUSION: The studies clearly establish that hZIP1 gene expression is down regulated and zinc is depleted in adenocarcinomatous glands. The fact that all the malignant cell lines express hZIP1 indicates that the down-regulation in adenocarcinomatous glands is likely due to in situ gene silencing. These observations, coupled with the numerous and consistent reports of loss of zinc accumulation in malignant cells in prostate cancer, lead to the plausible proposal that down regulation of hZIP1 is a critical early event in the development prostate cancer

    CMOS Image Sensors for High Speed Applications

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    Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD) imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4∼5 μm) due to limitations in the optics, CMOS technology scaling can allow for an increased number of transistors to be integrated into the pixel to improve both detection and signal processing. Such smart pixels truly show the potential of CMOS technology for imaging applications allowing CMOS imagers to achieve the image quality and global shuttering performance necessary to meet the demands of ultrahigh-speed applications. In this paper, a review of CMOS-based high-speed imager design is presented and the various implementations that target ultrahigh-speed imaging are described. This work also discusses the design, layout and simulation results of an ultrahigh acquisition rate CMOS active-pixel sensor imager that can take 8 frames at a rate of more than a billion frames per second (fps)

    Epithelial Membrane Protein-2 Promotes Endometrial Tumor Formation through Activation of FAK and Src

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    Endometrial cancer is the most common gynecologic malignancy diagnosed among women in developed countries. One recent biomarker strongly associated with disease progression and survival is epithelial membrane protein-2 (EMP2), a tetraspan protein known to associate with and modify surface expression of certain integrin isoforms. In this study, we show using a xenograft model system that EMP2 expression is necessary for efficient endometrial tumor formation, and we have started to characterize the mechanism by which EMP2 contributes to this malignant phenotype. In endometrial cancer cells, the focal adhesion kinase (FAK)/Src pathway appears to regulate migration as measured through wound healing assays. Manipulation of EMP2 levels in endometrial cancer cells regulates the phosphorylation of FAK and Src, and promotes their distribution into lipid raft domains. Notably, cells with low levels of EMP2 fail to migrate and poorly form tumors in vivo. These findings reveal the pivotal role of EMP2 in endometrial cancer carcinogenesis, and suggest that the association of elevated EMP2 levels with endometrial cancer prognosis may be causally linked to its effect on integrin-mediated signaling

    Cellular Model of Warburg Effect Identifies Tumor Promoting Function of UCP2 in Breast Cancer and Its Suppression by Genipin

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    The Warburg Effect is characterized by an irreversible injury to mitochondrial oxidative phosphorylation (OXPHOS) and an increased rate of aerobic glycolysis. In this study, we utilized a breast epithelial cell line lacking mitochondrial DNA (rho0) that exhibits the Warburg Effect associated with breast cancer. We developed a MitoExpress array for rapid analysis of all known nuclear genes encoding the mitochondrial proteome. The gene-expression pattern was compared among a normal breast epithelial cell line, its rho0 derivative, breast cancer cell lines and primary breast tumors. Among several genes, our study revealed that over-expression of mitochondrial uncoupling protein UCP2 in rho0 breast epithelial cells reflects gene expression changes in breast cancer cell lines and in primary breast tumors. Furthermore, over-expression of UCP2 was also found in leukemia, ovarian, bladder, esophagus, testicular, colorectal, kidney, pancreatic, lung and prostate tumors. Ectopic expression of UCP2 in MCF7 breast cancer cells led to a decreased mitochondrial membrane potential and increased tumorigenic properties as measured by cell migration, in vitro invasion and anchorage independent growth. Consistent with in vitro studies, we demonstrate that UCP2 over-expression leads to development of tumors in vivo in an orthotopic model of breast cancer. Genipin, a plant derived small molecule, suppressed the UCP2 led tumorigenic properties, which were mediated by decreased reactive oxygen species and down-regulation of UCP2. However, UCP1, 3, 4 and 5 gene expression was unaffected. UCP2 transcription was controlled by SMAD4. Together, these studies suggest a tumor-promoting function of UCP2 in breast cancer. In summary, our studies demonstrate that i) the Warburg Effect is mediated by UCP2; ii) UCP2 is over-expressed in breast and many other cancers; iii) UCP2 promotes tumorigenic properties in vitro and in vivo and iv) genipin suppresses the tumor promoting function of UCP2

    Single-shot compressed ultrafast photography at one hundred billion frames per second

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    The capture of transient scenes at high imaging speed has been long sought by photographers, with early examples being the well known recording in 1878 of a horse in motion and the 1887 photograph of a supersonic bullet. However, not until the late twentieth century were breakthroughs achieved in demonstrating ultrahigh-speed imaging (more than 10^5 frames per second). In particular, the introduction of electronic imaging sensors based on the charge-coupled device (CCD) or complementary metal–oxide–semiconductor (CMOS) technology revolutionized high-speed photography, enabling acquisition rates of up to 10^7 frames per second. Despite these sensors’ widespread impact, further increasing frame rates using CCD or CMOS technology is fundamentally limited by their on-chip storage and electronic readout speed. Here we demonstrate a two-dimensional dynamic imaging technique, compressed ultrafast photography (CUP), which can capture non-repetitive time-evolving events at up to 10^(11) frames per second. Compared with existing ultrafast imaging techniques, CUP has the prominent advantage of measuring an x–y–t (x, y, spatial coordinates; t, time) scene with a single camera snapshot, thereby allowing observation of transient events with temporal resolution as tens of picoseconds. Furthermore, akin to traditional photography, CUP is receive-only, and so does not need the specialized active illumination required by other single-shot ultrafast imagers. As a result, CUP can image a variety of luminescentβ€”such as fluorescent or bioluminescentβ€”objects. Using CUP, we visualize four fundamental physical phenomena with single laser shots only: laser pulse reflection and refraction, photon racing in two media, and faster-than-light propagation of non-information (that is, motion that appears faster than the speed of light but cannot convey information). Given CUP’s capability, we expect it to find widespread applications in both fundamental and applied sciences, including biomedical research
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