1,721,349 research outputs found
Role of lymphangiogenesis and lymphangiogenic factors during pancreatic cancer progression and lymphatic spread
No full textTreatment options for ductal adenocarcinoma of the pancreas are limited by early lymphatic spread, but the lymphatic vessels in pancreatic carcinoma have not been studied to date. Here, we present a histomorphological analysis of lymphatic vessels in pancreatic cancer resection specimens. Both intratumoral and peritumoral tissue were devoid of active lymphangiogenesis. Intratumoral lymphatics were frequently collapsed and non-functional, whereas peritumoral lymphatic vessels were enlarged, and numerous lymphatic vessels were seen in metastases. In addition, we screened pancreatic cancer tissue and pancreatic carcinoma cell lines for mRNA expression of the lymphangiogenic growth factor, VEGF-C; its receptor, VEGFR-3/flt4; and Prox1, a transcription factor essential for embryonic development of both lymphatic vessels and the pancreatic bud. VEGF-C was abundantly expressed in pancreatic cancer tissue and -cell lines and VEGFR-3/flt4 was expressed in cancer stromal cells. Prox1 was strongly expressed in the normal exocrine pancreas but significantly reduced in pancreatic cancer specimens from patients with short survival rates. Well-differentiated cell lines displayed higher levels of Prox1 mRNA than poorly differentiated ones. These results suggest that active lymphangiogenesis is not required for lymphovascular spread of pancreatic cancer. VEGF-C may promote local tumor growth via paracrine signaling to stromal cells expressing VEGFR-3 and support the entry of cancer cells into peritumoral lymphatics. Furthermore, loss of Prox1 function may be a driving force behind pancreatic carcinoma progression
Discussion: Current Multimodality Treatment Options in Pancreatic Cancer in Clinical Practice − What Is the Future Impact of Molecular Biological Profiling?
No full textRole of lymphangiogenesis and lymphangiogenic factors during pancreatic cancer progression and lymphatic spread
No full textTreatment options for ductal adenocarcinoma of the pancreas are limited by early lymphatic spread, but the lymphatic vessels in pancreatic carcinoma have not been studied to date. Here, we present a histomorphological analysis of lymphatic vessels in pancreatic cancer resection specimens. Both intratumoral and peritumoral tissue were devoid of active lymphangiogenesis. Intratumoral lymphatics were frequently collapsed and non-functional, whereas peritumoral lymphatic vessels were enlarged, and numerous lymphatic vessels were seen in metastases. In addition, we screened pancreatic cancer tissue and pancreatic carcinoma cell lines for mRNA expression of the lymphangiogenic growth factor, VEGF-C; its receptor, VEGFR-3/flt4; and Prox1, a transcription factor essential for embryonic development of both lymphatic vessels and the pancreatic bud. VEGF-C was abundantly expressed in pancreatic cancer tissue and -cell lines and VEGFR-3/flt4 was expressed in cancer stromal cells. Prox1 was strongly expressed in the normal exocrine pancreas but significantly reduced in pancreatic cancer specimens from patients with short survival rates. Well-differentiated cell lines displayed higher levels of Prox1 mRNA than poorly differentiated ones. These results suggest that active lymphangiogenesis is not required for lymphovascular spread of pancreatic cancer. VEGF-C may promote local tumor growth via paracrine signaling to stromal cells expressing VEGFR-3 and support the entry of cancer cells into peritumoral lymphatics. Furthermore, loss of Prox1 function may be a driving force behind pancreatic carcinoma progression
Molecular alterations in pancreatic cancer
Full text linkGrundlagen: Das Pankreaskarzinom hat eine infauste Prognose. Die Ursachen für das aggressive Tumorwachstum und die frühe Metastasierung sind nur unzureichend bekannt. Mit Hilfe von modernen molekularbiologischen Untersuchungstechniken ist es in den vergangenen Jahren gelungen, einen Einblick in die Pathophysiologie dieser Erkrankung zu gewinnen.
Methodik: Im Rahmen dieser Übersicht wird die pathogenetische Bedeutung von Wachstumsfaktor-Rezeptoren (EGFR, c-erbB-2, c-erbB-3), Wachstumsfaktoren (EGF, TGF-α, Amphiregulin, Betacellulin, TGF-βs, FGFs) sowie von Genmutationen (p53, K-ras) und Adhäsionsmolekülen beim humanen Pankreaskarzinom dargestellt.
Ergebnisse: In einer signifikanten Anzahl der Pankreaskarzinome sind Wachstumsfaktorrezeptoren (EGFR, c-erbB-2, c-erbB-3), Wachstumsfaktoren (EGF, TGF-α, Amphiregulin, Betacellulin, TGF-βs, FGFs) und Adhäsionsmoleküle (ICAM-1, ELAM-1) überexprimiert sowie Genmutationen (p53, K-ras) vorhanden. Allerdings sind nicht alle diese molekularen Veränderungen mit einem schnelleren Tumorwachstum und einer schlechteren Prognose nach Tumorresektion vergesellschaftet.
Schlußfolgerungen: Molekulare Störungen in Pankreaskarzinomzellen tragen zum malignen Phänotyp bei. Diese Veränderungen erklären, warum die Pankreaskarzinomzellen schnell proliferieren und nur eine geringe Ansprechbarkeit auf adjuvante onkologische Behandlungen zeigen.Background: Pancreatic cancer is a devastating disease with poor prognosis. The reasons for its aggressive growth behavior and early metastases are unknown. In the past years molecular studies have contributed to a better understanding of the pathophysiology of this disease.
Methods: In the present review we describe the role of growth factor receptors (EGFR, c-erbB-2, c-erbB-3), growth factors (EGF, TGF-α, Amphiregulin, Betacellulin, TGF-βs, FGFs), gene mutations (p53, K-ras) and adhesion molecules in human pancreatic cancer.
Results: Overexpression of growth factor receptors (EGFR, c-erbB-2, c-erbB-3), growth factors (EGF, TGF-α, Amphiregulin, Betacellulin, TGF-βs, FGFs), gene mutations (p53, K-ras) and adhesion molecules (ICAM-1, ELAM-1) are present in a significant number of these tumors. However, not all of these molecular changes contribute to faster tumor growth and poorer prognosis following tumor resection.
Conclusions: Molecular alterations in pancreatic cancer cells contribute to the malignant phenotype. These changes explain why pancreatic cancer cells grow rapidly and exhibit low sensitivity to adjuvant oncological treatment
The techniques of duodenum preserving head resection of the pancreas in the treatment of chronic pancreatitis
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Connective Tissue Growth Factor Gene Expression Alters Tumor Progression in Esophageal Cancer
No full textThe ability of cancer cells to initiate specific fibroblast reactions may subsequently determine tumor evolution. In the present study, we examined the coordinated expression of transforming growth factor-beta-1 (TGF-beta1), its signaling receptors, and its downstream mediator-connective tissue growth factor (CTGF)-and their impact on tumor progression and fibrogenesis in esophageal carcinomas, Messenger ribonucleic acid (mRNA) expression of TGF-beta1, CTGF, TGF-beta receptor subtype I ALK5 (TbetaR-I-ALK5) and TGF-beta receptor type II (TbetaR-II) was studied by Northern blot analysis in esophageal cancer and the normal esophagus. By means of immunohistochemistry and Western blot analysis, the respective proteins were localized in the tissue samples and the protein content was quantitated. Northern blot analysis revealed 3-fold and 4-fold increases (p < 0.05) in TGF-beta1 and CTGF mRNA level's respectively, in esophageal cancer in comparison with normal controls: whereas TbetaR-1 mRNA levels were significantly decreased and TbetaR-II mRNA levels were unchanged in the cancer samples. Immunostaining revealed results similar to those seen on the RNA level. TGF-beta1 and CTGF immunoreactivity were increased, TbetaR-II was unchanged, and TbetaR-1(ALK5) immunoreactivity was decreased. CTGF immunoreactivity was mainly present in the stroma surrounding the cancer cells but was also present in the cancer cells. The degree of fibrosis was different in squamous and adenocarcinomas and was significantly related to CTGF mRNA expression levels. The presence of CTGF in squamous cell carcinomas was associated with longer survival, whereas in adenocarcinomas it influenced survival negatively. The findings indicate that TGF-beta signaling is disturbed in esophageal cancer. CTGF, a downstream effector of TGF-beta action, differentially influences the composition of tumor microenvironment and distinct cell-matrix interactions in the two histological types of esophageal carcinoma, resulting in differences in tumor progression and patient survival
Adjuvant therapy of pancreatic cancer using monoclonal antibodies and immune response modifiers
Full text linkVariations on the Author
Full text link“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
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