215 research outputs found

    Tumour budding and poorly differentiated clusters in colon cancer – different manifestations of partial epithelial-mesenchymal transition

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    Morphological features including infiltrative growth, tumour budding (TB) and poorly differentiated clusters (PDCs), have a firmly established negative predictive value in colorectal cancer (CRC). Despite extensive research, the mechanisms underlying different tumour growth patterns remain poorly understood. The aim of this study was to investigate the involvement of epithelial-mesenchymal transition (EMT) in TB and PDCs in CRC. Using laser-capture microdissection, we obtained distinct parts of the primary CRC including TB, PDCs, expansive tumour front and the central part of the tumour and analysed the expression of EMT-related markers, i.e., miR-200 family, ZEB1/2, RND3 and CDH1. In TB, the miR-200 family and CDH1 were significantly downregulated, while ZEB2 was significantly upregulated. In PDCs, miR- 141, miR-200c and CDH1 were significantly downregulated. No significant differences were observed in the expression of any EMT-related markers between the expansive tumour front and the central part of the tumour. Our results suggest that both TB and PDCs are related to partial EMT. Discrete differences in morphology and EMT-related markers expression between TB and PDCs indicate that they represent different manifestations of partial EMT. TB seems to be closer to complete EMT than PDCs

    Comparative support for the expensive tissue hypothesis: Big brains are correlated with smaller gut and greater parental investment in Lake Tanganyika cichlids

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    This is the final version of the article. Available from the publisher via the DOI in this record.The brain is one of the most energetically expensive organs in the vertebrate body. Consequently, the energetic requirements of encephalization are suggested to impose considerable constraints on brain size evolution. Three main hypotheses concerning how energetic constraints might affect brain evolution predict covariation between brain investment and (1) investment into other costly tissues, (2) overall metabolic rate, and (3) reproductive investment. To date, these hypotheses have mainly been tested in homeothermic animals and the existing data are inconclusive. However, there are good reasons to believe that energetic limitations might play a role in large-scale patterns of brain size evolution also in ectothermic vertebrates. Here, we test these hypotheses in a group of ectothermic vertebrates, the Lake Tanganyika cichlid fishes. After controlling for the effect of shared ancestry and confounding ecological variables, we find a negative association between brain size and gut size. Furthermore, we find that the evolution of a larger brain is accompanied by increased reproductive investment into egg size and parental care. Our results indicate that the energetic costs of encephalization may be an important general factor involved in the evolution of brain size also in ectothermic vertebrates.The authors thank the staff of the Department of Fisheries of the Ministry of Agriculture and Cooperatives at Mpulungu, Zambia, for their cooperation during fieldwork, especially for collecting fishes from the deeper levels. They also thank H. Tanaka for collecting fish samples for us. This study was funded through the student exchange support program (scholarship for long-term study abroad) from the Japanese Student Services Organization (JASSO) to MT, the Zoologiska foundation to MT and AK, a Davis Expedition Fund grant, Helge Axelsson Johnson grant, and a Stiftelsen Hierta-Retzius stipendiefond grant to AH, the Austrian Science Fund (J 3304-B24) to AK, and a Swedish Research Council grant to NK. The authors have no conflict of interest to declare

    Improvement of conventional anti-cancer drugs as new tools against multidrug resistant tumors

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    Multidrug resistance (MDR) is the dominant cause of the failure of cancer chemotherapy. The design of antitumor drugs that are able to evade MDR is rapidly evolving, showing that this area of biomedical research attracts great interest in the scientific community. The current review explores promising recent approaches that have been developed with the aim of circumventing or overcoming MDR. Encouraging results have been obtained in the investigation of the MDR-modulating properties of various classes of natural compounds and their analogues. Inhibition of P-gp or downregulation of its expression have proven to be the main mechanisms by which MDR can be surmounted. The use of hybrid molecules that are able to simultaneously interact with two or more cancer cell targets is currently being explored as a means to circumvent drug resistance. This strategy is based on the design of hybrid compounds that are obtained either by merging the structural features of separate drugs, or by conjugating two drugs or pharmacophores via cleavable/non-cleavable linkers. The approach is highly promising due to the pharmacokinetic and pharmacodynamic advantages that can be achieved over the independent administration of the two individual components. However, it should be stressed that the task of obtaining successful multivalent drugs is a very challenging one. The conjugation of anticancer agents with nitric oxide (NO) donors has recently been developed, creating a particular class of hybrid that can combat tumor drug resistance. Appropriate NO donors have been shown to reverse drug resistance via nitration of ABC transporters and by interfering with a number of metabolic enzymes and signaling pathways. In fact, hybrid compounds that are produced by covalently attaching NO-donors and antitumor drugs have been shown to elicit a synergistic cytotoxic effect in a variety of drug resistant cancer cell lines. Another strategy to circumvent MDR is based on nanocarrier-mediated transport and the controlled release of chemotherapeutic drugs and P-gp inhibitors. Their pharmacokinetics are governed by the nanoparticle or polymer carrier and make use of the enhanced permeation and retention (EPR) effect, which can increase selective delivery to cancer cells. These systems are usually internalized by cancer cells via endocytosis and accumulate in endosomes and lysosomes, thus preventing rapid efflux. Other modalities to combat MDR are described in this review, including the pharmaco-modulation of acridine, which is a well-known scaffold in the development of bioactive compounds, the use of natural compounds as means to reverse MDR, and the conjugation of anticancer drugs with carriers that target specific tumor-cell components. Finally, the outstanding potential of in silico structure-based methods as a means to evaluate the ability of antitumor drugs to interact with drug transporters is also highlighted in this review. Structure-based design methods, which utilize 3D structural data of proteins and their complexes with ligands, are the most effective of the in silico methods available, as they provide a prediction regarding the interaction between transport proteins and their substrates and inhibitors. The recently resolved X-ray structure of human P-gp can help predict the interaction sites of designed compounds, providing insight into their binding mode and directing possible rational modifications to prevent them from becoming P-gp drug substrates. In summary, although major efforts were invested in the search for new tools to combat drug resistant tumors, they all require further implementation and methodological development. Further investigation and progress in the abovementioned strategies will provide significant advances in the rational combat against cancer MDR

    Half-lives of neutron-rich Cd 128-130

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    R. Dunlop et al. ; 6 págs.; 7 figs.; 1 tab. ; Rapid CommunicationsThe β-decay half-lives of Cd128-130 have been measured with the newly commissioned GRIFFIN γ-ray spectrometer at the TRIUMF-ISAC facility. The time structures of the most intense γ rays emitted following the β decay were used to determine the half-lives of Cd128 and Cd130 to be T1/2=246.2(21) ms and T1/2=126(4) ms, respectively. The half-lives of the 3/2+ and 11/2- states of Cd129 were measured to be T1/2(3/2+)=157(8) ms and T1/2(11/2-)=147(3) ms. The half-lives of the Cd isotopes around the N=82 shell closure are an important ingredient in astrophysical simulations to derive the magnitude of the second r-process abundance peak in the A∼130 region. Our new results are compared with recent literature values and theoretical calculations. ©2016 American Physical SocietyThis work has been partially supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canada Research Chairs Program. I.D. and R.C.-F. are supported by NSERC Discovery Grants SAPIN-2014-00028 and RGPAS 462257-2014. A.J. acknowledges financial support by the Spanish Ministerio de Ciencia e Innovación under contract FPA2011-29854-C04 and the Spanish Ministerio de Economía y Competitividad under contract FPA2014- 57196-C5-4-P. S.L.T acknowledges financial support from the U.S. National Science Foundation under contract NSF- 14-01574. E.P.-R. acknowledges financial support from the DGAPA-UNAM under the PASPA program. The GRIFFIN spectrometer was funded by the Canada Foundation for Innovation, TRIUMF, and the University of Guelph. TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada.Peer Reviewe

    The Potential Involvement of E-cadherin and β-catenins in Meningioma

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    To investigate the potential involvements of E-cadherin and β-catenin in meningioma.Immunohistochemistry staining was performed on samples from patients with meningioma. The results were graded according to the positive ratio and intensity of tissue immunoreactivity. The expression of E-cadherin and β-catenin in meningioma was analyzed by its relationship with WHO2007 grading, invasion, peritumoral edema and postoperative recurrence.The positive rates of E-cadherin in meningioma WHO I, II, III were 92.69%, 33.33% and 0, respectively, (P<0.05); while the positive rates of β-catenin in meningioma WHO I, II, III were 82.93%, 33.33% and 20.00%, respectively, (P<0.05). The positive rate of E-cadherin in meningioma without invasion (94.12%) was higher than that with invasion (46.67%) (P<0.05). The difference in the positive rate of β-catenin between meningioma without invasion (88.24%) and meningioma with invasion (33.33%, P<0.05) was also statically significant. The positive rates of E-cadherin in meningioma with peritumoral edema 0, 1, 2, 3 were 93.75%, 85.71%, 60.00% and 0 respectively, (P<0.05); the positive rates of β-catenin in meningioma with peritumoral edema 0, 1, 2, 3 were 87.50%, 85.71%, 30.00% and 0 respectively, (P<0.01). The positive rates of E- cadherin in meningioma with postoperative recurrence were 33.33%, and the positive rate with postoperative non-recurrence was 90.00% (P<0.01). The positive rates of β-catenin in meningioma with postoperative recurrence and non-recurrence were 11.11%, 85.00%, respectively (P<0.01).The expression levels of E- cadherin and β-catenin correlated closely to the WHO 2007 grading criteria for meningioma. In atypical or malignant meningioma, the expression levels of E-cadherin and β-catenin were significantly lower. The expression levels of E- cadherin and β-catenin were also closely correlated with the invasion status of meningioma, the size of the peritumoral edema and the recurrent probabilities of the meningioma, all in an inverse correlationship. Taken together, the present study provided novel molecular targets in clinical treatments to meningioma

    Oral acantholytic squamous cell carcinoma shares clinical and histological features with angiosarcoma

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    <p>Abstract</p> <p>Background</p> <p>acantholytic squamous cell carcinomas (ASCC) and intraoral angiosarcoma share similar histopathological features. Aim of this study was to find marker for a clear distinction.</p> <p>Methods</p> <p>Four oral acantholytic squamous cell carcinomas and one intraoral angiosarcoma are used to compare the eruptive intraoral growth-pattern, age-peak, unfavourable prognosis and slit-like intratumorous spaces in common histological staining as identical clinical and histopathological features. Immunohistochemical staining for pancytokeratin, cytokeratin, collagen type IV, γ2-chain of laminin-5, endothelial differentiation marker CD31 and CD34, F VIII-associated antigen, Ki 67-antigen, β-catenin, E-cadherin, α-smooth-muscle-actin and Fli-1 were done.</p> <p>Results</p> <p>Cytokeratin-immunoreactive cells can be identified in both lesions. The large vascularization of ASCC complicates the interpretation of vascular differential markers being characteristic for angiosarcoma. Loss of cell-cell-adhesion, monitored by loss of E-cadherin and β-catenin membrane-staining, are indetified as reasons for massive expression of invasion-factor ln-5 in ASCC and considered responsible for unfavourable prognosis of ASCC. Expression of Fli-1 in angiosarcoma and cellular immunoreaction for ln-5 in ASCC are worked out as distinguishing features of both entities.</p> <p>Conclusion</p> <p>Fli-1 in angiosarcoma and ln-5 in ASCC are distinguishing features.</p
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