| 1. |
- Stuhr, L. E. B., et al.
(författare)
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High-dose, short-term, anti-inflammatory treatment with dexamethasone reduces growth and augments the effects of 5-fluorouracil on dimethyl-alpha- benzanthracene-induced mammary tumors in rats
- 2006
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Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 66:6, s. 477-486
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To evaluate the effects of dexamethasone (DXM) alone or in combination with 5-fluorouracil (5-FU) on dimethyl-alpha-benzanthracene (DMBA)-induced mammary tumors in rats. Material and methods. Female Sprague-Dawley rats were divided into 4 groups receiving: 1) saline (controls), 2) DXM (3 mg/kg), 3) 5-FU (1.5 mg/kg) and 4) DXM and 5-FU combined. The drugs were given i.p. every day for 4 days. Interstitial fluid pressure (Pif) and tumor growth were determined in all tumors on days 1, 5 and 7 using the "wick-in-the needle'' technique and by external size measurements, respectively. Vessel density and inflammatory cell infiltration of tumor tissue were analyzed by immunohistochemistry. Results. DXM treatment significantly retarded tumor growth and reduced Pif. Treatment with a combination of DXM and 5-FU reduced tumor size significantly more than any of the agents alone (p < 0.01 - 0.001). Enhanced uptake of 5-FU by DXM treatment was demonstrated by microdialysis. There were no differences in the density of CD31-positive vessels after DXM or 5-FU treatment, but inflammatory cell infiltration of tumor tissue was significantly reduced after DXM treatment. Conclusions. Our data suggest that DXM may be beneficial as an adjuvant to chemotherapy in the treatment of mammary cancer by increasing the uptake of 5-FU in the tumor.
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| 2. |
- 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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| 3. |
- Fortin, Marc-André, et al.
(författare)
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Immuno-PET of undifferentiated thyroid carcinoma with radioiodine-labelled antibody cMAb U36 : application to antibody tumour uptake studies
- 2007
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 34:9, s. 1376-1387
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: We tested the suitability of the chimeric monoclonal anti-human CD44 splice version 6 antibody (cMAb U36) for targeting and visualising human anaplastic thyroid carcinoma with PET. We also performed experiments aimed at elucidating the relation between tumour interstitial fluid pressure (TIFP) and the tumour uptake of antibodies. METHODS: The affinity and specificity of the cMAb U36 for KAT-4 cells were evaluated in vitro, as was the Na+/I- symporter (NIS) expression. Biodistribution studies were performed on KAT-4 carcinoma-bearing mice injected with 124I-cMAb U36 or free iodine. Biodistribution studies were also performed in animals treated with the specific TGF-beta1 and -beta3 inhibitor Fc:TbetaRII, which lowers TIFP. Treated and non-treated animals were scanned by microPET. RESULTS: Cultured human undifferentiated/anaplastic thyroid carcinoma KAT-4 cells expressed low levels of NIS and uptake of free iodine was insignificant. The cMAb U36 expressed an affinity (KD) of 11+/-2 nM. Tumour radioactivity uptake reached maximum values 48 h after injection of 124I-cMAb U36 (approximately 22%IA/g). KAT-4 carcinomas were readily identified in all 124I-immuno-PET images. Radioactivity tumour uptake in Fc:TbetaRII-treated animals was significantly lower at 24 and 48 h after injection, and five times higher thyroid uptake was also noted. CONCLUSION: We successfully used 124I-cMAb U36 to visualise CD44v6-expressing human anaplastic thyroid carcinoma. Given the lack of NIS expression in KAT-4, tumour visualisation is not due to free iodine uptake. Lowering the TIFP in KAT-4 carcinomas did not increase the uptake of mAbs into tumour tissue.
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| 4. |
- Olof Olsson, P., et al.
(författare)
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Inhibition of integrin αvβ6 changes fibril thickness of stromal collagen in experimental carcinomas
- 2018
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Ingår i: Cell Communication and Signaling. - : Springer Science and Business Media LLC. - 1478-811X. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chemotherapeutic efficacy can be improved by targeting the structure and function of the extracellular matrix (ECM) in the carcinomal stroma. This can be accomplished by e.g. inhibiting TGF-β1 and -β3 or treating with Imatinib, which results in scarcer collagen fibril structure in xenografted human KAT-4/HT29 (KAT-4) colon adenocarcinoma. Methods: The potential role of αVβ6 integrin-mediated activation of latent TGF-β was studied in cultured KAT-4 and Capan-2 human ductal pancreatic carcinoma cells as well as in xenograft carcinoma generated by these cells. The monoclonal αVβ6 integrin-specific monoclonal antibody 3G9 was used to inhibit the αVβ6 integrin activity. Results: Both KAT-4 and Capan-2 cells expressed the αVβ6 integrin but only KAT-4 cells could utilize this integrin to activate latent TGF-β in vitro. Only when Capan-2 cells were co-cultured with human F99 fibroblasts was the integrin activation mechanism triggered, suggesting a more complex, fibroblast-dependent, activation pathway. In nude mice, a 10-day treatment with 3G9 reduced collagen fibril thickness and interstitial fluid pressure in KAT-4 but not in the more desmoplastic Capan-2 tumors that, to achieve a similar effect, required a prolonged 3G9 treatment. In contrast, a 10-day direct inhibition of TGF-β1 and -β3 reduced collagen fibril thickness in both tumor models. Conclusion: Our data demonstrate that the αVβ6-directed activation of latent TGF-β plays a pivotal role in modulating the stromal collagen network in carcinoma, but that the sensitivity to αVβ6 inhibition depends on the simultaneous presence of alternative paths for latent TGF-β activation and the extent of desmoplasia.
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| 5. |
- Olsson, P. Olof, et al.
(författare)
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Inhibition of integrin alpha(V)beta(6) changes fibril thickness of stromal collagen in experimental carcinomas
- 2018
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Ingår i: Cell Communication and Signaling. - : BMC. - 1478-811X. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chemotherapeutic efficacy can be improved by targeting the structure and function of the extracellular matrix (ECM) in the carcinomal stroma. This can be accomplished by e.g. inhibiting TGF beta 1 and -beta 3 or treating with Imatinib, which results in scarcer collagen fibril structure in xenografted human KAT-4/HT29 (KAT-4) colon adenocarcinoma.Methods: The potential role of a(v)beta(6) integrin-mediated activation of latent TGF-beta was studied in cultured KAT-4 and Capan-2 human ductal pancreatic carcinoma cells as well as in xenograft carcinoma generated by these cells. The monoclonal a(v)beta(6) integrin-speafic monoclonal antibody 3G9 was used to inhibit the a(v)beta(6) integrin activity.Results: Both KAT-4 and Capan-2 cells expressed the a(v)beta(6) integrin but only KAT-4 cells could utilize this integrin to activate latent TGF-beta in vitro. Only when Capan-2 cells were co-cultured with human F99 fibroblasts was the integrin activation mechanism triggered, suggesting a more complex, fibroblast-dependent, activation pathway. In nude mice, a 10-day treatment with 3G9 reduced collagen fibril thickness and interstitial fluid pressure in KAT-4 but not in the more desmoplastic Capan-2 tumors that, to achieve a similar effect, required a prolonged 3G9 treatment. In contrast, a 10-day direct inhibition of TGF-beta 1 and -beta 3 reduced collagen fibril thickness in both tumor models.Conclusion: Our data demonstrate that the a(v)beta(6)-directed activation of latent TGF-beta plays a pivotal role in modulating the stromal collagen network in carcinoma, but that the sensitivity to a(v)beta(6) inhibition depends on the simultaneous presence of alternative paths for latent TGF-beta activation and the extent of desmoplasia.
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| 6. |
- Salnikov, Alexei V., et al.
(författare)
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Inhibition of TGF-beta modulates macrophages and vessel maturation in parallel to a lowering of interstitial fluid pressure in experimental carcinoma
- 2005
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Ingår i: Laboratory Investigation. - : Elsevier BV. - 0023-6837 .- 1530-0307. ; 85:4, s. 512-521
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Tidskriftsartikel (refereegranskat)abstract
- A pathologically elevated interstitial fluid pressure (IFP) is a characteristic of both clinical and experimental carcinoma. The soluble TGF-beta receptor type II-murine Fc:IgG2A chimeric protein (Fc:TbetaRII) lowers IFP in the KAT-4 experimental model for anaplastic thyroid carcinoma. Analyses of messenger RNA (mRNA) expressions by Affymetrix microarrays and RNase protection assays, as well as of protein expressions identified tumor macrophages as targets for Fc:TbetaRII. Treatment with Fc:TbetaRII reduced albumin extravasation, increased coverage of alpha-smooth muscle actin-positive cells and reduced expression of NG2, a marker of activated pericytes, in KAT-4 carcinoma blood vessels. Specific inhibition of interleukin-1 (IL-1), a major cytokine produced by activated macrophages, lowered carcinoma IFP to a similar degree as Fc:TbetaRII but had no significant effect on the parameters of blood vessel maturation. Neither Fc:TbetaRII nor inhibition of IL-1 changed blood vessel density. Finally, pretreatment of KAT-4 carcinomas with Fc:TbetaRII increased the antitumor efficacy of doxorubicin. Our data emphasize a potential role of tumor macrophages in carcinoma physiology and identify these cells as potential stromal targets for treatment aimed to improve efficacy of chemotherapy.
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| 7. |
- 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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