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Increased Expression of 14-3-3 beta Promotes Tumor Progression and Predicts Extrahepatic Metastasis and Worse Survival in Hepatocellular Carcinoma (vol 179, pg 2698, 2011)
No full textStudies on the Roles of 14-3-3 Proteins and Focal Adhesion Kinases in Cancer Metastasis
No full text緒論：
肝癌是台灣地區的嚴重健康問題。雖然近年來在肝癌的早期診斷及積極治療方面有長足的進步，肝內復發以及肝外轉移依然還是許多病患治療失敗的原因。在我們先前的研究中發現，一種可以做為蛋白質co-factor的蛋白14-3-3，和大腸癌細胞的移動有密切的關係，而且其和細胞內一種和cytoskeleton關係密切的蛋白FAK (focal adhesion kinase)，的表現有相當高的一致性。由於在初步實驗中我們也發現14-3-3ε蛋白在部分肝癌細胞中有過度表現的情形，我們因此在本研究中假設14-3-3ε可以透過增加FAK蛋白的表現來增加肝癌的轉移，並嘗試加以證實；另外我們也將嘗試找尋可以抑制14-3-3ε-FAK途徑的標靶治療藥物，以期可以在臨床上應用本研究的成果。
病患及研究方法
在本研究中我們建立了兩個肝癌世代，收集了自西元1999年1月至西元2004年7月在台灣某醫學中心接受主要為手術切除治療的肝癌病患，兩個世代各有55人及114人，其中各有18人 (32.7%) 及34人 (29.8%) 後續發生肝外轉移。在本研究中，對病患檢體中14-3-3ε及FAK蛋白的表現量是以免疫組織染色 (immunohistochemical staining)檢驗，並以半定量的Quick score (Q-score) method方式判讀。其它的實驗方法則依照一般慣用的protocol及廠商提供的說明書加以進行。
結果
首先我們確認了在肝癌細胞株SK-Hep1中，14-3-3ε的過度表現會使其在two-chamber invasion assay中表現的細胞侵襲性明顯增加。而在病患世代研究中，14-3-3ε可以在61.3%病患的原發肝癌中發現其表現量增加，同時這些病患會有明顯較差的5年無疾病存活率 (54.9±7.7% vs. 28.6±5.4%，p=0.004)，明顯較差的5年整體存活率 (66.5±7.3% vs. 42.4±6.0%，p=0.007)，以及較高的5年累積肝外轉移發生率 (48.4±6.8% vs. 14.0±5.9%，p<0.001)。接著我們確認了在肝癌細胞株及病患檢體中14-3-3ε和FAK蛋白的表現有極高的一致性，同時在SK-Hep1細胞中14-3-3ε的過度表現會增加NF-κB 和FAK promoter的結合，因而增加FAK基因的轉錄及蛋白表現。另一方面，FAK蛋白也可以在61.8%的肝癌病患中過度表現，同時FAK的過度表現也和肝癌病患較差的5年無疾病存活率 (51.5±8.7% vs. 90.2±6.6%，p=0.041)，明顯較差的5年整體存活率 (51.5±8.7% vs. 90.2±6.6%，p=0.004) 以及較高的5年累積肝外轉移發生率 (36.1±9.2% vs. 20.9±8.4%，p=0.045) 明顯相關。在進一步的研究中，蛋白體抑制劑(proteasome inhibitors)如MG-132及PS-341 (bortezomib) 等，可以明顯在wound healing assay中抑制癌細胞的移動。而MG-132或PS-341均可以降低14-3-3ε和FAK promoter的活性，並進而抑制基因轉錄及蛋白表現。我們同時也證實MG-132或PS-341對FAK promoter的抑制是透過降低NF-κB和其promoter的結合而達成的。
結論及展望
在本研究中，我們確認14-3-3ε的過度表現可透過增加FAK的表現來促進肝癌的轉移，而且這個途徑具有重要的臨床意義；蛋白體抑制劑則具有抑制這個途徑的效果。根據這些結果，14-3-3ε及FAK蛋白的表現量可以做為肝癌病患的預後及發生肝癌轉移的重要預測因子，而蛋白體抑制劑也有可能可以做為肝癌病患接受根治性治療後預防再發或轉移的輔助治療 (adjuvant therapy) 之用；但這些概念的實際應用仍需待進一步的臨床試驗加以證實。Introduction:
Hepatocellular carcinoma (HCC) is a serious health problem in Taiwan. Despite the progress in early diagnosis and aggressive treatment for HCCs, intrahepatic recurrence and extrahepatic metastasis still result in a high proportion of treatment failure. In our previous study, we found that a co-factor protein, 14-3-3, is related to increased migration of colon cancer cells, and synchronized over-expression of a cytoskeleton protein, focal adhesion kinase (FAK), with 14-3-3 was identified also. Because our preliminary data revealed that 14-3-3ε is over-expressed in some HCCs, we hypothesized that 14-3-3ε can increase HCC metastasis through a FAK-mediated mechanism. Furthermore, we also want to explore if any targeted therapy could be used against this signaling pathway.
Patients and Methods:
Two patient cohorts were established in our study, enrolling 55 and 114 HCC patients, respectively, receiving mainly surgical resection from January of 1999 to July of 2004 in a medical center in Taiwan. Eighteen (32.7%) and 34 patients (29.8%) experienced extrahepatic metastasis in the two cohorts, respectively. The protein expression levels of 14-3-3ε and FAK in pathological specimens were evaluated by a semi-quantitative immunohistochemical staining method, i.e. the Quick score (Q-score) method. Other laboratory methods in this thesis were all complied with the usual protocols and the manufacturer’s instructions.
Results:
In the two-chamber invasion assay, SK-Hep1 cells with over-expressed 14-3-3ε showed increased invasiveness over control. In the 2nd cohort, 14-3-3ε over-expression was found in 61.3% of primary HCC, which predicted worse 5-year disease-free survival rate (54.9±7.7% vs. 28.6±5.4%, p=0.004), worse 5-year overall survival rate (66.5±7.3% vs. 42.4±6.0%, p=0.007) and higher 5-year cumulative incidence of extrahepatic metastasis (48.4±6.8% vs. 14.0±5.9%, p<0.001). Furthermore, we demonstrated the correlated protein expression of 14-3-3ε and FAK in cell lines and patient samples, and 14-3-3ε over-expression in SK-Hep1 cells resulted in increased NF-κB binding activities on FAK promoters and then increased FAK gene transcription. Next we found 61.8% of primary HCC over-expressed FAK, which was associated with worse 5-year disease-free survival rate (51.5±8.7% vs. 90.2±6.6%, p=0.041), worse 5-year overall survival rate (51.5±8.7% vs. 90.2±6.6%, p=0.004) and higher 5-year cumulative incidence of extrahepatic metastasis (36.1±9.2% vs. 20.9±8.4%, p=0.045). Proteasome inhibitors, MG-132 or PS-341 (bortezomib), significantly delayed the closure of wound by H1299 cells on a culture dish. In further experiments, the expression of 14-3-3ε was reduced by MG-132 or PS-341 treatment, and the effect is due to decreased 14-3-3ε promoter activities and transcription. FAK expression, similarly, can be suppressed by MG-132 or PS-341, and the effects were derived from suppression of FAK promoter activities in a NF-κB-dependent manner.
Conclusions and Perspectives:
We conclude that 14-3-3ε over-expression results in over-expressed FAK and increase in invasiveness of HCC. Proteasome inhibitors suppress the transcription of both 14-3-3ε and FAK. This study raises the potentials of 14-3-3ε and FAK as biomarkers for predicting prognosis and metastasis of HCC. Bortezomib may also serve as an adjuvant therapy to prevent metastasis after curative treatment for HCC. Further clinical and laboratory studies are required to confirm the concepts
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Cordycepin Regulates GSK-3 beta/beta-Catenin Signaling in Human Leukemia Cells
No full textBackground: Leukemia stem cells (LSCs) are a limitless cell source for the initiation and maintenance of leukemia. Activation of the Wnt/beta-catenin pathway is required for the survival and development of LSCs. Therefore, targeting beta-catenin is considered a therapeutic strategy for the treatment of leukemia. The goal of this study was to explore whether cordycepin, an active component of the traditional medicine Cordyceps sinensis, regulates beta-catenin expression in leukemia cells.
Methodology and Principal Findings: In this study, we found that cordycepin significantly suppressed cell proliferation in all malignant cancer cells, including U937, K562, A549, HepG2, SK-Hep1 and MCF7 in a dose-dependent manner. However, cordycepin reduced beta-catenin levels in U937, K562 and THP1 leukemia cells and had no effect on other solid cancer cells. In addition, treatment with cordycepin significantly suppressed leukemia colony formation in soft agar assay. Cordycepin enhanced proteasome-dependent degradation and inhibited nuclear translocation of beta-catenin in leukemia cells. Cordycepin-reduced beta-catenin stability was restored by the addition of a pharmacological inhibitor of GSK-3 beta, indicating that cordycepin-suppressed beta-catenin stability is mediated by the activation of GSK-3 beta. Furthermore, cordycepin abolished the effect of Wnt3a-induced beta-catenin in leukemia cells. In addition, cordycepin-impaired beta-catenin is regulated by Akt activation but is not significantly influenced by AMPK or mTOR signal pathways.
Significance: Our findings show for the first time that codycepin selectively reduces beta-catenin stability in leukemia but not in other solid tumor cells. This suppressive effect is mediated by regulating GSK-3 beta. A synergistic combination of cordycepin with other treatments should be used as a novel strategy to eradicate leukemia via elimination of LSCs
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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