122 research outputs found
The H19 Non-Coding RNA Is Essential for Human Tumor Growth
Background. Mutations and epigenetic aberrant signaling of growth factors pathways contribute to carcinogenesis. Recent studies reveal that non-coding RNAs are controllers of gene expression. H19 is an imprinted gene that demonstrates maternal monoallelic expression without a protein product; although its expression is shut off in most tissues postnatally, it is reactivated during adult tissue regeneration and tumorigenesis. Moreover, H19 is highly expressed in liver metastasis derived from a range of carcinomas. The objective of this study is to explore the role of H19 in carcinogenesis, and to determine its identification as an anti-tumor target. Methodology / Principle Findings. By controlling oxygen pressure during tumor cell growth and H19 expression levels, we investigated the role of H19 expression in vitro and in vivo in hepatocellular (HCC) and bladder carcinoma. Hypoxia upregulates the level of H19 RNA. Ablations of tumorigenicity of HCC and bladder carcinomas in vivo are seen by H19 knockdown which also significantly abrogates anchorage-independent growth after hypoxia recovery, while ectopic H19 expression enhances tumorigenic potential of carcinoma cells in vivo. Knocking-down H19 message in hypoxic stress severely diminishes p57 kip2 induction. We identified a number of potential downstream targets of H19 RNA, including angiogenin and FGF18. Conclusions. H19 RNA harbors pro-tumorigenic properties, thus the H19 gene behaves as an oncogene and may serve as a potential new target for anti-tumor therapy
H19-Promoter-Targeted Therapy Combined with Gemcitabine in the Treatment of Pancreatic Cancer
Pancreatic cancer is the eighth cancer leading cause of cancer-related death in the world and has a 5-year survival rate of 1–4% only. Gemcitabine is a first line agent for advanced pancreatic therapy; however, its efficacy is limited by its poor intracellular metabolism and chemoresistance. Studies have been conducted in an effort to improve gemcitabine treatment results by adding other chemotherapeutic agents, but none of them showed any significant advantage over gemcitabine monotherapy. We found that 85% of human pancreatic tumors analyzed by in situ hybridization analyses showed moderated to strong expression of the H19 gene. We designed a preclinical study combining gemcitabine treatment and a DNA-based therapy for pancreatic cancer using a non viral vector BC-819 (also known as DTA-H19), expressing the diphtheria toxin A chain under the control of the H19 gene regulatory sequences. The experiments conducted either in an orthotopic and heterotopic pancreatic carcinoma animal model showed better antitumor activity following the sequential administration of the vector BC-819 and gemcitabine as compared to the effect of each of them alone. The results presented in the current study indicate that treatment with BC-819 in combination with gemcitabine might be a viable new therapeutic option for patients with advanced pancreatic cancer
From constrained stochastic processes to the nonlinear sigma model. Two old problems revisited
In this work a method is presented to derive the generating functional in
path integral form for a system with an arbitrary number of degrees of freedom
and constrained by general conditions. The method is applied to the case of the
dynamics of an inextensible chain subjected to external forces. Next, the
generating functional of the inextensible chain is computed assuming that the
interactions are switched off. Finally, the generating functional of a two
dimensional nonlinear sigma model with O(3) symmetry is derived exploiting its
similarities with the model describing the dynamics of the inextensible chain.Comment: 20 pages, LaTeX + RevTeX, 1 figur
Treatment of ovarian cancer ascites by intra-peritoneal injection of diphtheria toxin A chain-H19 vector: a case report
<p>Abstract</p> <p>Introduction</p> <p>Ovarian cancer ascitic fluid, which contains malignant cells, is usually present in women with an advanced stage disease. There are currently no effective therapies for the treatment of ovarian cancer ascitic fluid. We developed a new therapeutic strategy to target expression of the diphtheria toxin fragment A gene in ovarian tumor cells under the control of H19 regulatory sequences.</p> <p>Case presentation</p> <p>A 64-year-old Caucasian woman was diagnosed with a stage IIIc epithelial ovarian cancer. She suffered from progressive disease, accumulation of malignant ascites that needed to be drained weekly, abdominal pain, vomiting, anorexia and severe weakness. Infusion of the diphtheria toxin A chain-H19 plasmid into the peritoneum of our patient resulted in complete resolution of the ascites with minimum adverse events.</p> <p>Conclusion</p> <p>On the basis of this preliminary experience, we are currently conducting an extensive Phase I study on a larger number of patients in order to assess the safety and preliminary efficacy of this novel patient-oriented treatment approach.</p
NAF-1 and mitoNEET are central to human breast cancer proliferation by maintaining mitochondrial homeostasis and promoting tumor growth
Mitochondria are emerging as important players in the transformation
process of cells, maintaining the biosynthetic and energetic
capacities of cancer cells and serving as one of the primary sites of
apoptosis and autophagy regulation. Although several avenues of
cancer therapy have focused on mitochondria, progress in developing
mitochondria-targeting anticancer drugs nonetheless has
been slow, owing to the limited number of known mitochondrial
target proteins that link metabolism with autophagy or cell death.
Recent studies have demonstrated that two members of the newly
discovered family of NEET proteins, NAF-1 (CISD2) and mitoNEET
(mNT; CISD1), could play such a role in cancer cells. NAF-1 was
shown to be a key player in regulating autophagy, and mNT
was proposed to mediate iron and reactive oxygen homeostasis
in mitochondria. Here we show that the protein levels of NAF-1
and mNT are elevated in human epithelial breast cancer cells, and
that suppressing the level of these proteins using shRNA results in
significantly reduced cell proliferation and tumor growth, decreased
mitochondrial performance, uncontrolled accumulation
of iron and reactive oxygen in mitochondria, and activation of
autophagy. Our findings highlight NEET proteins as promising mitochondrial
targets for cancer therapy
From lists of behaviour change techniques (BCTs) to structured hierarchies: comparison of two methods of developing a hierarchy of BCTs
Objectives Behaviour change technique (BCT) Taxonomy v1 is a hierarchically grouped, consensus-based taxonomy of 93 BCTs for reporting intervention content. To enhance the use and understanding of BCTs, the aims of the present study were to (1) quantitatively examine the ‘bottom-up’ hierarchical structure of Taxonomy v1, (2) identify whether BCTs can be reliably mapped to theoretical domains using a ‘top-down’ theoretically driven approach, and (3) identify any overlap between the ‘bottom-up’ and ‘top-down’ groupings. Methods and design The ‘bottom-up’ structure was examined for higher-order groupings using a dendrogram derived from hierarchical cluster analysis. For the theory-based ‘top-down’ structure, 18 experts sorted BCTs into 14 theoretical domains. Discriminant Content Validity was used to identify groupings, and chi-square tests and Pearson's residuals were used to examine the overlap between groupings. Results Behaviour change techniques relating to ‘Reward and Punishment’ and ‘Cues and Cue Responses’ were perceived as markedly different to other BCTs. Fifty-nine of the BCTs were reliably allocated to 12 of the 14 theoretical domains; 47 were significant and 12 were of borderline significance. Thirty-four of 208 ‘bottom-up’ × ‘top-down’ pairings showed greater overlap than expected by chance. However, only six combinations achieved satisfactory evidence of similarity. Conclusions The moderate overlap between the groupings indicates some tendency to implicitly conceptualize BCTs in terms of the same theoretical domains. Understanding the nature of the overlap will aid the conceptualization of BCTs in terms of theory and application. Further research into different methods of developing a hierarchical taxonomic structure of BCTs for international, interdisciplinary work is now required. Statement of contribution What is already known on this subject? * Behaviour change interventions are effective in improving health care and health outcomes
Cytochalasin B-induced membrane vesicles convey angiogenic activity of parental cells
Naturally occurring extracellular vesicles (EVs) play essential roles in intracellular communication and delivery of bioactive molecules. Therefore it has been suggested that EVs could be used for delivery of therapeutics. However, to date the therapeutic application of EVs has been limited by number of factors, including limited yield and full understanding of their biological activities. To address these issues, we analyzed the morphology, molecular composition, fusion capacity and biological activity of Cytochalasin B-induced membrane vesicles (CIMVs). The size of these vesicles was comparable to that of naturally occurring EVs. In addition, we have shown that CIMVs from human SH-SY5Y cells contain elevated levels of VEGF as compared to the parental cells, and stimulate angiogenesis in vitro and in vivo
Development of targeted therapy for ovarian cancer mediated by a plasmid expressing diphtheria toxin under the control of H19 regulatory sequences
<p>Abstract</p> <p>Background</p> <p>Ovarian cancer ascites fluid (OCAF), contains malignant cells, is usually present in women with an advanced stage disease and currently has no effective therapy. Hence, we developed a new therapy strategy to target the expression of diphtheria toxin gene under the control of H19 regulatory sequences in ovarian tumor cells. H19 RNA is present at high levels in human cancer tissues (including ovarian cancer), while existing at a nearly undetectable level in the surrounding normal tissue.</p> <p>Methods</p> <p>H19 gene expression was tested in cells from OCAF by the in-situ hybridization technique (ISH) using an H19 RNA probe. The therapeutic potential of the toxin vector DTA-H19 was tested in ovarian carcinoma cell lines and in a heterotopic animal model for ovarian cancer.</p> <p>Results</p> <p>H19 RNA was detected in 90% of patients with OCAF as determined by ISH. Intratumoral injection of DTA-H19 into ectopically developed tumors caused 40% inhibition of tumor growth.</p> <p>Conclusion</p> <p>These observations may be the first step towards a major breakthrough in the treatment of human OCAF, while the effect in solid tumors required further investigation. It should enable us to identify likely non-responders in advance, and to treat patients who are resistant to all known therapies, thereby avoiding treatment failure.</p
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