| 1. |
- Franck-Lissbrant, I, et al.
(författare)
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Testosterone stimulates angiogenesis and vascular regrowth in the ventral prostate in castrated adult rats.
- 1998
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 139:2, s. 451-6
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Tidskriftsartikel (refereegranskat)abstract
- The castration-induced regression and testosterone stimulated regrowth of the vasculature in the rat ventral prostate lobe were studied using stereological techniques. Seven days after castration, the endothelial cell proliferation rate (bromodeoxyuridine labeling index); the total weights of blood vessel walls, blood vessel lumina, endothelial cells, glandular epithelial cells; and total organ weight were all decreased. Within 2 days after sc treatment with testosterone, the total weights of blood vessel walls, endothelial cells, and vascular lumina, as well as the endothelial cell proliferation rate, were all normalized. In contrast to the rapid response of the vasculature, the total weight of glandular epithelium and total organ weight were not normalized during the 4 days of testosterone treatment. Growth of the vasculature apparently precedes growth of the glandular epithelium. The testosterone- dependent factors stimulating the vasculature are unknown, but factors derived from epithelial cells, mast cells (which accumulate in the prostate during the first day of testosterone treatment), and tissue macrophages could all be involved. Castration-induced regression and testosterone-stimulated regrowth of the prostatic vasculature can be used as an experimental model to study factors regulating angiogenesis and organ growth in the prostate.
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| 2. |
- Häggström, S, et al.
(författare)
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Expression of vascular endothelial growth factor and its receptors in the rat ventral prostate and Dunning R3327 PAP adenocarcinoma before and after castration.
- 1998
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Ingår i: The Prostate. - 0270-4137 .- 1097-0045. ; 36:2, s. 71-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Angiogenesis is important for prostate organogenesis and prostate cancer progression. It is not yet known whether androgens promote part of their control of prostate structure and function by influencing angiogenesis. The aim of this study was to explore the possible androgenic regulation of the angiogenic factor vascular endothelial growth factor (VEGF) and its receptors flt-1 and flk-1/KDR in the rat ventral prostate (VP) and Dunning R3327 PAP adenocarcinoma.METHODS: RNA was prepared from VP and tumors of intact and castrated rats. VEGF, flt-1, and flk-1/KDR mRNA levels were determined using competitive RT-PCR.RESULTS: VEGF121, VEGF165, and VEGF189 together with flt-1 and flk-1/KDR mRNA were detected. The VEGF, but not flt-1 mRNA levels were significantly decreased in the VP after castration. The Dunning tumor expressed high levels of mRNA for VEGF and its receptors compared to the VP. The flt-1 mRNA level in the tumor increased after castration, while the VEGF mRNA levels were unchanged.CONCLUSIONS: Decreased mRNA expression of VEGF, but not flt-1, was found in the rat VP after castration. However, in the Dunning tumor, castration did not alter the expression of VEGF mRNA. Moreover, elevated levels of both mRNA for VEGF and its receptors relative to the VP were observed, indicating that the VEGF system may be important for Dunning tumor development.
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| 3. |
- Häggström, S, et al.
(författare)
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Testosterone induces vascular endothelial growth factor synthesis in the ventral prostate in castrated rats.
- 1999
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Ingår i: Journal of Urology. - 0022-5347 .- 1527-3792. ; 161:5, s. 1620-5
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Recent studies suggest that the vasculature is important for the control of prostate growth. Castration induces an involution of the prostate gland and its vasculature. Replacement of testosterone stimulates endothelial cell proliferation and normalizes vascular volumes and blood flow several days before organ regrowth. Antiangiogenesis treatment inhibits the growth of prostate tumors. Understanding the regulation of the prostate vasculature may therefore provide important knowledge of the mechanisms responsible for the growth of non-malignant and malignant prostate tissue. Castration induced regression and testosterone stimulated regrowth of the prostatic vasculature have here been used to study the involvement of the angiogenic factor vascular endothelial growth factor (VEGF) and its receptors flt-1 and flk-1/KDR in the regulation of the prostatic vasculature.MATERIALS AND METHODS: VEGF, flt-1, and flk-1/KDR levels were quantified in the rat ventral prostate following castration and testosterone replacement. Methods used were competitive RT-PCR, Western blot and immunohistochemistry.RESULTS: VEGF mRNA and protein levels were significantly decreased by castration and testosterone treatment induced VEGF synthesis in the rat ventral prostate epithelium. Flt-1 and flk-1/KDR receptor levels were unaffected by castration and testosterone treatment.CONCLUSIONS: Castration down regulates VEGF and testosterone induces VEGF synthesis in epithelial cells in the rat ventral prostate.
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| 4. |
- Wikström, P, et al.
(författare)
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Alterations of transforming growth factor beta1 (TGF-beta1) and TGFbeta receptor expressions with progression in Dunning rat prostatic adenocarcinoma sublines.
- 1999
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Ingår i: Urological research. - 0300-5623 .- 1434-0879. ; 27:3, s. 185-93
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Tidskriftsartikel (refereegranskat)abstract
- Transforming growth factor-beta1 (TGF-beta1) inhibits epithelial cell proliferation in the normal prostate. Prostate tumours express high levels of TGF-beta1, and seem to acquire resistance to its anti-proliferative effects with tumour progression. In this study, TGFbeta variations with tumour progression were examined in the Dunning prostatic adenocarcinoma model. Expression of TGF-beta1 and TGFbeta receptor type I and type II (TGFbeta-RI and TGFbeta-RII) in rat dorsolateral prostate (DLP) and Dunning tumour sublines (PAP, AT-1, AT-2, AT-3 and MatLyLu) was examined in vitro and in vivo, using competitive reverse transcription-polymerase chain reaction (RT-PCR), Northern and Western blot, and immunohistochemistry. All tumours expressed elevated levels of TGF-beta1 and TGFbeta-RI mRNA, when compared with the DLP (P < or = 0.05). All tumours except MatLyLu also expressed elevated levels of TGFbeta-RII mRNA (P < or = 0.05). Interestingly, TGFbeta-RII protein levels were very low in the highly metastatic AT-3 and MatLyLu tumours in vivo, when compared with levels in the PAP, AT-1, and AT-2 tumours. This difference was not detected for the AT-1, AT-2, and AT-3 cells in vitro. Immunostaining of TGF-beta1, TGFbeta-RI, and TGFbeta-RII was localised principally in normal and tumour epithelial cells, and occasionally in smooth muscle cells. In conclusion, high expression of TGF-beta1 and TGFbeta-RI and low expression of TGFbeta-RII may contribute to tumour progression and metastasis in the Dunning prostatic adenocarcinoma model.
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