| 1. |
- Burmakin, Mikhail, et al.
(författare)
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Imatinib increases oxygen delivery in extracellular matrix-rich but not in matrix-poor experimental carcinoma
- 2017
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Ingår i: Journal of Translational Medicine. - : BioMed Central. - 1479-5876. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Background: Imatinib causes increased turnover of stromal collagen, reduces collagen fibril diameter, enhances extracellular fluid turnover and lowers interstitial fluid pressure (IFP) in the human colonic carcinoma KAT-4/HT-29 (KAT-4) xenograft model. Methods: We compared the effects of imatinib on oxygen levels, vascular morphology and IFP in three experimental tumor models differing in their content of a collagenous extracellular matrix. Results: Neither the KAT4 and CT-26 colonic carcinoma models, nor B16BB melanoma expressed PDGF beta-receptors in the malignant cells. KAT-4 tumors exhibited a well-developed ECM in contrast to the other two model systems. The collagen content was substantially higher in KAT-4 than in CT-26, while collagen was not detectable in B16BB tumors. The pO(2) was on average 5.4, 13.9 and 19.3 mmHg in KAT-4, CT-26 and B16BB tumors, respectively. Treatment with imatinib resulted in similar pO(2)-levels in all three tumor models but only in KAT-4 tumors did the increase reach statistical significance. It is likely that after imatinib treatment the increase in pO(2) in KAT-4 tumors is caused by increased blood flow due to reduced vascular resistance. This notion is supported by the significant reduction observed in IFP in KAT-4 tumors after imatinib treatment. Vessel area varied between 4.5 and 7% in the three tumor models and was not affected by imatinib treatment. Imatinib had no effect on the fraction of proliferating cells, whereas the fraction of apoptotic cells increased to a similar degree in all three tumor models. Conclusion: Our data suggest that the effects of imatinib on pO(2)-levels depend on a well-developed ECM and provide further support to the suggestion that imatinib acts by causing interstitial stroma cells to produce a less dense ECM, which would in turn allow for an increased blood flow. The potential of imatinib treatment to render solid tumors more accessible to conventional treatments would therefore depend on the degree of tumor desmoplasia.
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| 2. |
- Friman, Tomas, et al.
(författare)
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Increased Fibrosis and Interstitial Fluid Pressure in Two Different Types of Syngeneic Murine Carcinoma Grown in Integrin β3-Subunit Deficient Mice
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:3, s. e34082-
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Tidskriftsartikel (refereegranskat)abstract
- Stroma properties affect carcinoma physiology and direct malignant cell development. Here we present data showing that alpha(V)beta(3) expressed by stromal cells is involved in the control of interstitial fluid pressure (IFP), extracellular volume (ECV) and collagen scaffold architecture in experimental murine carcinoma. IFP was elevated and ECV lowered in syngeneic CT26 colon and LM3 mammary carcinomas grown in integrin beta(3)-deficient compared to wild-type BALB/ c mice. Integrin beta(3)-deficiency had no effect on carcinoma growth rate or on vascular morphology and function. Analyses by electron microscopy of carcinomas from integrin beta(3)-deficient mice revealed a coarser and denser collagen network compared to carcinomas in wild-type littermates. Collagen fibers were built from heterogeneous and thicker collagen fibrils in carcinomas from integrin beta(3)-deficient mice. The fibrotic extracellular matrix (ECM) did not correlate with increased macrophage infiltration in integrin beta(3)-deficient mice bearing CT26 tumors, indicating that the fibrotic phenotype was not mediated by increased inflammation. In conclusion, we report that integrin beta(3)-deficiency in tumor stroma led to an elevated IFP and lowered ECV that correlated with a more fibrotic ECM, underlining the role of the collagen network for carcinoma physiology.
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| 3. |
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| 4. |
- Keunen, Olivier, et al.
(författare)
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Anti-VEGF treatment reduces blood supply and increases tumor cell invasion in glioblastoma
- 2011
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 108:9, s. 3749-3754
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Tidskriftsartikel (refereegranskat)abstract
- Bevacizumab, an antibody against vascular endothelial growth factor (VEGF), is a promising, yet controversial, drug in human glioblastoma treatment (GBM). Its effects on tumor burden, recurrence, and vascular physiology are unclear. We therefore determined the tumor response to bevacizumab at the phenotypic, physiological, and molecular level in a clinically relevant intracranial GBM xenograft model derived from patient tumor spheroids. Using anatomical and physiological magnetic resonance imaging (MRI), we show that bevacizumab causes a strong decrease in contrast enhancement while having only a marginal effect on tumor growth. Interestingly, dynamic contrast-enhanced MRI revealed a significant reduction of the vascular supply, as evidenced by a decrease in intratumoral blood flow and volume and, at the morphological level, by a strong reduction of large- and medium-sized blood vessels. Electron microscopy revealed fewer mitochondria in the treated tumor cells. Importantly, this was accompanied by a 68% increase in infiltrating tumor cells in the brain parenchyma. At the molecular level we observed an increase in lactate and alanine metabolites, together with an induction of hypoxia-inducible factor 1α and an activation of the phosphatidyl-inositol-3-kinase pathway. These data strongly suggest that vascular remodeling induced by anti-VEGF treatment leads to a more hypoxic tumor microenvironment. This favors a metabolic change in the tumor cells toward glycolysis, which leads to enhanced tumor cell invasion into the normal brain. The present work underlines the need to combine anti-angiogenic treatment in GBMs with drugs targeting specific signaling or metabolic pathways linked to the glycolytic phenotype.
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| 5. |
- Kłosowska-Wardega, Agnieszka, et al.
(författare)
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Combined anti-angiogenic therapy targeting PDGF and VEGF receptors lowers the interstitial fluid pressure in a murine experimental carcinoma
- 2009
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 4:12, s. e8149-
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Tidskriftsartikel (refereegranskat)abstract
- Elevation of the interstitial fluid pressure (IFP) of carcinoma is an obstacle in treatment of tumors by chemotherapy and correlates with poor drug uptake. Previous studies have shown that treatment with inhibitors of platelet-derived growth factor (PDGF) or vascular endothelial growth factor (VEGF) signaling lowers the IFP of tumors and improve chemotherapy. In this study, we investigated whether the combination of PDGFR and VEGFR inhibitors could further reduce the IFP of KAT-4 human carcinoma tumors. The tumor IFP was measured using the wick-in-needle technique. The combination of STI571 and PTK/ZK gave an additive effect on the lowering of the IFP of KAT-4 tumors, but the timing of the treatment was crucial. The lowering of IFP following combination therapy was accompanied by vascular remodeling and decreased vascular leakiness. The effects of the inhibitors on the therapeutic efficiency of Taxol were investigated. Whereas the anti-PDGF and anti-VEGF treatment did not significantly inhibit tumor growth, the inhibitors enhanced the effect of chemotherapy. Despite having an additive effect in decreasing tumor IFP, the combination therapy did not further enhance the effect of chemotherapy. Simultaneous targeting of VEGFR and PDGFR kinase activity may be a useful strategy to decrease tumor IFP, but the timing of the inhibitors should be carefully determined.
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| 6. |
- Oldberg, Åke, et al.
(författare)
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Collagen-binding proteoglycan fibromodulin can determine stroma matrix structure and fluid balance in experimental carcinoma.
- 2007
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Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 104:35, s. 13966-13971
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Tidskriftsartikel (refereegranskat)abstract
- Research on the biology of the tumor stroma has the potential to lead to development of more effective treatment regimes enhancing the efficacy of drug-based treatment of solid malignancies. Tumor stroma is characterized by distorted blood vessels and activated connective tissue cells producing a collagen-rich matrix, which is accompanied by elevated interstitial fluid pressure (IFP), indicating a transport barrier between tumor tissue and blood. Here, we show that the collagen-binding proteoglycan fibromodulin controls stroma structure and fluid balance in experimental carcinoma. Gene ablation or inhibition of expression by anti-inflammatory agents showed that fibromodulin promoted the formation of a dense stroma and an elevated IFP. Fibromodulin-deficiency did not affect vasculature but increased the extracellular fluid volume and lowered IFP. Our data suggest that fibromodulin controls stroma matrix structure that in turn modulates fluid convection inside and out of the stroma. This finding is particularly important in relation to the demonstration that targeted modulations of the fluid balance in carcinoma can increase the response to cancer therapeutic agents.
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| 7. |
- Salnikov, Alexei, et al.
(författare)
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Inhibition of carcinoma cell-derived VEGF reduces inflammatory characteristics in xenograft carcinoma
- 2006
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 119:12, s. 2795-2802
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Tidskriftsartikel (refereegranskat)abstract
- The stroma of carcinomas shares several characteristics with inflamed tissues including a distorted vasculature, active angiogenesis and macrophage infiltration. In addition, the tumor interstitial fluid pressure (P-IF) of the stroma is pathologically elevated. We show here that bevacizumab [rhuMab vascular endothelial growth factor (VEGF), Avastin], a monoclonal antibody to VEGF, at a dose of 5 mg/kg modulated inflammation in KAT-4 xenograft human anaplastic thyroid carcinoma tissue. At this dose, bevacizumab reduced the density of macrophages, MHC class II antigen expression by macrophages and II-1 beta mRNA expression. Furthermore, bevacizumab lowered tumor extracellular fluid volume, plasma protein leakage from tumor vessels, the number of CD31positive structures and tumor P-IF. The tumor plasma volume and the number of alpha-smooth muscle actin-positive vessels, however, remained unchanged. Our data suggest that carcinoma cellderived VEGF either directly or indirectly participates in maintaining an inflammatory microenvironment in experimental KAT4 carcinoma. Furthermore, our data indicate that the reduction of inflammation resulting in reduced vascular permeability and decrease in the tumor extracellular fluid volume by bevacizurnab contributes to reduced tumor P-IF.
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| 8. |
- Salnikov, Alexei V, et al.
(författare)
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Lowering of tumor interstitial fluid pressure specifically augments efficacy of chemotherapy
- 2003
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Ingår i: The FASEB Journal. - : Wiley. - 0892-6638 .- 1530-6860. ; 17:12, s. 1756-1758
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Tidskriftsartikel (refereegranskat)abstract
- Chemotherapy of solid tumors is presently largely ineffective at dosage levels that are compatible with survival of the patient. Here, it is argued that a condition of raised interstitial fluid pressure (IFP) that can be observed in many tumors is a major factor in preventing optimal access of systemically administered chemotherapeutic agents. Using prostaglandin E1-methyl ester (PGE1), which is known transiently to reduce IFP, it was shown that 5-fluorouracil (5-FU) caused significant growth inhibition on two experimental tumors in rats but only after administration of PGE1. Furthermore, timing experiments showed that only in the period in which IFP is reduced did 5-FU have an antitumor effect. These experiments uniquely demonstrate a clear and, according to the starting hypothesis, logical, synergistic effect of PGE1 and 5-FU that offers hope for better treatment of many tumors in which raised IFP is likely to be inhibiting optimal results with water-soluble cancer chemotherapeutic agents.
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| 9. |
- Stuhr, Linda E. B., et al.
(författare)
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Peritumoral TNF alpha administration influences tumour stroma structure and physiology independently of growth in DMBA-induced mammary tumours
- 2008
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Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 68:7, s. 602-611
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Tidskriftsartikel (refereegranskat)abstract
- Background. Systemic treatment of malignancies with high doses of tumour necrosis factor-alpha (TNF alpha) has an anticancer effect, but also serious side effects. The aim of the present study was to elucidate the effects of local TNF alpha administration alone or in combination with chemotherapy on tumour stroma structure and physiology in di-methyl-benz-anthracene (DMBA)-induced mammary carcinomas in rats. Methods. TNF alpha (500 ng/mL in a volume of 5 mu L) was given s.c. around the carcinoma and 5-fluorouracil (5-FU) (1.5 mg/kg, volume of 0.2 mL) was given i.p on days 1, 4, 7 and 10. Results. Treatment with TNF alpha resulted in a significant reduction of tumour interstitial fluid pressure (TIFP: 75-87 %, p<0.02-0.001), as well as in the number of tumour-infiltrating macrophages, extracellular volume (ECV) and collagen fibril density in carcinoma. In addition, pH was lowered in tumours treated with TNF alpha, suggesting decreased aerobic metabolism. Treatment with TNF alpha, however, had no effect on tumour growth, arterial blood pressure, tumour vessel density, plasma volume or body weight. Concentrations of locally produced VEGF and IL-1 beta in carcinoma interstitial fluid or in serum were not affected by TNF alpha. The study demonstrated that these cytokines are produced locally in the tumour. Furthermore, TNF alpha had no effect on efficacy of treatment with 5-FU. Conclusions: Locally administered TNF alpha did not affect DMBA-induced mammary tumour growth or vasculature, but reduced inflammation and ECM structure, suggesting the latter to be of importance in the observed reduction in TIFP.
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