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Xiong L, Ouyang KH, Chen H, Yang ZW, Hu WB, Wang N, Liu X, Wang WJ. Immunomodulatory effect of Cyclocarya paliurus polysaccharide in cyclophosphamide induced immunocompromised mice. BIOACTIVE CARBOHYDRATES AND DIETARY FIBRE 2020. [DOI: 10.1016/j.bcdf.2020.100224] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Figueras A, Arbos MA, Quiles MT, Viñals F, Germà JR, Capellà G. The impact of KRAS mutations on VEGF-A production and tumour vascular network. BMC Cancer 2013; 13:125. [PMID: 23506169 PMCID: PMC3610256 DOI: 10.1186/1471-2407-13-125] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 03/08/2013] [Indexed: 11/15/2022] Open
Abstract
Background The malignant potential of tumour cells may be influenced by the molecular nature of KRAS mutations being codon 13 mutations less aggressive than codon 12 ones. Their metabolic profile is also different, with an increased anaerobic glycolytic metabolism in cells harbouring codon 12 KRAS mutations compared with cells containing codon 13 mutations. We hypothesized that this distinct metabolic behaviour could be associated with different HIF-1α expression and a distinct angiogenic profile. Methods Codon13 KRAS mutation (ASP13) or codon12 KRAS mutation (CYS12) NIH3T3 transfectants were analyzed in vitro and in vivo. Expression of HIF-1α, and VEGF-A was studied at RNA and protein levels. Regulation of VEGF-A promoter activity was assessed by means of luciferase assays using different plasmid constructs. Vascular network was assessed in tumors growing after subcutaneous inoculation. Non parametric statistics were used for analysis of results. Results Our results show that in normoxic conditions ASP13 transfectants exhibited less HIF-1α protein levels and activity than CYS12. In contrast, codon 13 transfectants exhibited higher VEGF-A mRNA and protein levels and enhanced VEGF-A promoter activity. These differences were due to a differential activation of Sp1/AP2 transcription elements of the VEGF-A promoter associated with increased ERKs signalling in ASP13 transfectants. Subcutaneous CYS12 tumours expressed less VEGF-A and showed a higher microvessel density (MVD) than ASP13 tumours. In contrast, prominent vessels were only observed in the latter. Conclusion Subtle changes in the molecular nature of KRAS oncogene activating mutations occurring in tumour cells have a major impact on the vascular strategy devised providing with new insights on the role of KRAS mutations on angiogenesis.
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Affiliation(s)
- Agnès Figueras
- Translational Research Laboratory, Institut Català d'Oncologia-IDIBELL, Gran Via 199-203, 08908 L'Hospitalet del Llobregat, Barcelona, Spain
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Kalas W, Rybka J, Swiderek E, Ziolo E, Rybka W, Gamian A, Rak J, Strzadala L. H-Ras increases release of sphingosine resulting in down-regulation of TSP-1 in non-transformed cells. Int J Exp Pathol 2012; 93:202-9. [PMID: 22356213 DOI: 10.1111/j.1365-2613.2011.00805.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Tumour progression is continuously driven by a sequence of genetic events. The presence of mutant or activated Ras proteins represents an interesting paradigm for the investigation of oncogene-dependent induction of tumour angiogenesis. These genes are widely distributed in human cancers. Previously we have shown that cells harbouring mutant H-Ras release soluble unidentified factor(s) associated with lowered expression of an angiogenesis inhibitor - Thrombospondin-1 - (TSP-1) in adjacent normal tissue. In this study, we have addressed the question as to whether or not introduction of the H-ras oncogene leads to increased production of sphingosine. To assess the amount of sphingosine in conditioned media, we developed a technique based on sphingolipid isolation and GC-MSMS detection of specific silylated sphingosine derivatives. Cells harbouring mutant H-Ras, release significant amounts of sphingosine in contrast to normal isogenic cells or premalignant cells. Increased concentration of sphingosine in conditioned media was correlated with their ability to down-regulate the expression of TSP-1. Moreover, medium collected in the presence of U0126, an inhibitor of MAPK kinase (MEK), contained undetectable amounts of sphingosine and had no ability to down-regulate TSP-1 expression. Overall, our studies suggest a H-Ras-dependent mechanism of changing the equilibrium of angiogenic factors in favour of induction of angiogenesis, where a central role is played by sphingosine, a low molecular entity. This represents an example of how a mechanism of translating genetic changes within transformed cells could be amplified into a much larger effect involving the tumour parenchyma and stroma, and this could greatly in turn accelerate local tumour growth and metastasis.
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Affiliation(s)
- Wojciech Kalas
- Department of Experimental Oncology, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Wroclaw, Poland.
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Kang SY, Halvorsen OJ, Gravdal K, Bhattacharya N, Lee JM, Liu NW, Johnston BT, Johnston AB, Haukaas SA, Aamodt K, Yoo S, Akslen LA, Watnick RS. Prosaposin inhibits tumor metastasis via paracrine and endocrine stimulation of stromal p53 and Tsp-1. Proc Natl Acad Sci U S A 2009; 106:12115-20. [PMID: 19581582 PMCID: PMC2715504 DOI: 10.1073/pnas.0903120106] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Indexed: 02/06/2023] Open
Abstract
Metastatic tumors can prepare a distant site for colonization via the secretion of factors that act in a systemic manner. We hypothesized that non- or weakly metastatic human tumor cells may act in an opposite fashion by creating a microenvironment in distant tissues that is refractory to colonization. By comparing cell lines with different metastatic potential, we have identified a tumor-secreted inhibitor of metastasis, prosaposin (Psap), which functions in a paracrine and endocrine fashion by stimulating the expression of thrombospondin-1 (Tsp-1) in fibroblasts present in both primary tumors and distant organs, doing so in a p53-dependent manner. Introduction of Psap in highly metastatic cells significantly reduced the occurrence of metastases, whereas inhibition of Psap production by tumor cells was associated with increased metastatic frequency. In human prostate cancer, decreased Psap expression was significantly associated with metastatic tumors. Our findings suggest that prosaposin, or other agents that stimulate p53 activity in the tumor stroma, may be an effective therapy by inhibition of the metastatic process.
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Affiliation(s)
- Soo-Young Kang
- Vascular Biology Program, Department of Surgery, Children's Hospital Boston, Boston, MA 02115
- Department of Surgery, Harvard Medical School, Boston, MA 02115
| | - Ole J. Halvorsen
- The Gade Institute, Section for Pathology, University of Bergen, Haukeland University Hospital, N-5021 Bergen, Norway
| | - Karsten Gravdal
- The Gade Institute, Section for Pathology, University of Bergen, Haukeland University Hospital, N-5021 Bergen, Norway
| | - Nandita Bhattacharya
- Vascular Biology Program, Department of Surgery, Children's Hospital Boston, Boston, MA 02115
- Department of Surgery, Harvard Medical School, Boston, MA 02115
| | - Jung Min Lee
- Vascular Biology Program, Department of Surgery, Children's Hospital Boston, Boston, MA 02115
| | - Nathan W. Liu
- Vascular Biology Program, Department of Surgery, Children's Hospital Boston, Boston, MA 02115
| | - Brian T. Johnston
- Vascular Biology Program, Department of Surgery, Children's Hospital Boston, Boston, MA 02115
| | - Adam B. Johnston
- Vascular Biology Program, Department of Surgery, Children's Hospital Boston, Boston, MA 02115
- Department of Biochemical Sciences, Harvard College, Cambridge, MA 02138; and
| | - Svein A. Haukaas
- Department of Surgery, Section of Urology, University of Bergen, Haukeland University Hospital, N-5021 Bergen, Norway
| | - Kristie Aamodt
- Vascular Biology Program, Department of Surgery, Children's Hospital Boston, Boston, MA 02115
| | - Sun Yoo
- Vascular Biology Program, Department of Surgery, Children's Hospital Boston, Boston, MA 02115
| | - Lars A. Akslen
- The Gade Institute, Section for Pathology, University of Bergen, Haukeland University Hospital, N-5021 Bergen, Norway
| | - Randolph S. Watnick
- Vascular Biology Program, Department of Surgery, Children's Hospital Boston, Boston, MA 02115
- Department of Surgery, Harvard Medical School, Boston, MA 02115
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Kang SY, Watnick RS. Regulation of tumor dormancy as a function of tumor-mediated paracrine regulation of stromal Tsp-1 and VEGF expression. APMIS 2008; 116:638-47. [PMID: 18834408 DOI: 10.1111/j.1600-0463.2008.01138.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Tumor dormancy is a critical yet poorly understood phenomenon affecting both the diagnosis and treatment of human cancers. This is due in large part to the lack of model systems available to study dormant tumor cells and the length of time needed to adequately examine the models that do exist. It has been demonstrated in several types of human cancer that tumor dormancy is a function of an impairment in angiogenesis. The intracellular signaling pathways regulating the expression of several pro- and anti-angiogenic proteins have been well characterized in human cancer cells. The intercellular signaling that takes place between tumor cells and the surrounding tumor-associated stroma has not been as extensively studied with regard to the regulation of angiogenesis, and as a result dormancy. In this review we define the key players in the regulation of angiogenesis and examine how their expression is regulated in the tumor-associated stroma. The resulting analysis is often seemingly paradoxical, underscoring the complexity of intercellular signaling within tumors and the need to better understand the environmental context underlying these signaling mechanisms.
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Affiliation(s)
- Soo-Young Kang
- Vascular Biology Program, Department of Surgery, Children's Hospital Boston and Harvard Medical School, Boston, MA 02115, USA
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