| 1. |
- Yang, Xiaojuan, et al.
(författare)
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Vascular endothelial growth factor-dependent spatiotemporal dual roles of placental growth factor in modulation of angiogenesis and tumor growth
- 2013
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 110:34, s. 13932-13937
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Tidskriftsartikel (refereegranskat)abstract
- Placental growth factor (PIGF) remodels tumor vasculatures toward a normalized phenotype, which affects tumor growth, invasion and drug responses. However, the coordinative and spatiotemporal relation between PIGF and VEGF in modulation of tumor angiogenesis and vascular remodeling is less understood. Here we report that PlGF positively and negatively modulate tumor growth, angiogenesis, and vascular remodeling through a VEGF-dependent mechanism. In two independent tumor models, we show that PlGF inhibited tumor growth and angiogenesis and displayed a marked vascular remodeling effect, leading to normalized microvessels with infrequent vascular branches and increased perivascular cell coverage. Surprisingly, elimination of VEGF gene (i.e., VEGF-null) in PIGF-expressing tumors resulted in (i) accelerated tumor growth rates and angiogenesis and (ii) complete attenuation of PIGF-induced vascular normalization. Thus, PIGF positively and negatively modulates tumor growth, angiogenesis, and vascular remodeling through VEGF-dependent spatiotemporal mechanisms. Our data uncover molecular mechanisms underlying the complex interplay between PIGF and VEGF in modulation of tumor growth and angiogenesis, and have conceptual implication for antiangiogenic cancer therapy.
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| 2. |
- Yang, Xiaojuan, et al.
(författare)
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VEGF-B promotes cancer metastasis through a VEGF-A-independent mechanism and serves as a marker of poor prognosis for cancer patients
- 2015
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 112:22, s. E2900-E2909
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Tidskriftsartikel (refereegranskat)abstract
- The biological functions of VEGF-B in cancer progression remain poorly understood. Here, we report that VEGF-B promotes cancer metastasis through the remodeling of tumor microvasculature. Knockdown of VEGF-B in tumors resulted in increased perivascular cell coverage and impaired pulmonary metastasis of human melanomas. In contrast, the gain of VEGF-B function in tumors led to pseudonormalized tumor vasculatures that were highly leaky and poorly perfused. Tumors expressing high levels of VEGF-B were more metastatic, although primary tumor growth was largely impaired. Similarly, VEGF-B in a VEGF-A-null tumor resulted in attenuated primary tumor growth but substantial pulmonary metastases. VEGF-B also led to highly metastatic phenotypes in Vegfr1 tk(-/-) mice and mice treated with anti-VEGF-A. These data indicate that VEGF-B promotes cancer metastasis through a VEGF-A-independent mechanism. High expression levels of VEGF-B in two large-cohort studies of human patients with lung squamous cell carcinoma and melanoma correlated with poor survival. Taken together, our findings demonstrate that VEGF-B is a vascular remodeling factor promoting cancer metastasis and that targeting VEGF-B may be an important therapeutic approach for cancer metastasis.
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| 3. |
- Yang, Yunlong, et al.
(författare)
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Anti-VEGF- and anti-VEGF receptor-induced vascular alteration in mouse healthy tissues
- 2013
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 110:29, s. 12018-12023
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Tidskriftsartikel (refereegranskat)abstract
- Systemic therapy with anti-VEGF drugs such as bevacizumab is widely used for treatment of human patients with various solid tumors. However, systemic impacts of such drugs in host healthy vasculatures remain poorly understood. Here, we show that, in mice, systemic delivery of an anti-VEGF or an anti-VEGF receptor (VEGFR)-2 neutralizing antibody caused global vascular regression. Among all examined tissues, vasculatures in endocrine glands, intestinal villi, and uterus are the most affected in response to VEGF or VEGFR-2 blockades. Thyroid vascular fenestrations were virtually completely blocked by VEGF blockade, leading to marked accumulation of intraendothelial caveolae vesicles. VEGF blockade markedly increased thyroid endothelial cell apoptosis, and withdrawal of anti-VEGF resulted in full recovery of vascular density and architecture after 14 d. Prolonged anti-VEGF treatment resulted in a significant decrease of the circulating level of the predominant thyroid hormone free thyroxine, but not the minimal isoform of triiodothyronine, suggesting that chronic anti-VEGF treatment impairs thyroid functions. Conversely, VEGFR-1-specific blockade produced virtually no obvious phenotypes. These findings provide structural and functional bases of anti-VEGF-specific drug-induced side effects in relation to vascular changes in healthy tissues. Understanding anti-VEGF drug-induced vascular alterations in healthy tissues is crucial to minimize and even to avoid adverse effects produced by currently used anti-VEGF-specific drugs.
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| 4. |
- Lim, Sharon, et al.
(författare)
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Cold-induced activation of brown adipose tissue and adipose angiogenesis in mice
- 2012
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Ingår i: Nature Protocols. - : Nature Publishing Group. - 1754-2189 .- 1750-2799. ; 7:3, s. 606-615
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Tidskriftsartikel (refereegranskat)abstract
- Exposure of humans and rodents to cold activates thermogenic activity in brown adipose tissue (BAT). This protocol describes a mouse model to study the activation of BAT and angiogenesis in adipose tissues by cold acclimation. After a 1-week exposure to 4 degrees C, adult C57BL/6 mice show an obvious transition from subcutaneous white adipose tissue (WAT) into brown-like adipose tissue (BRITE). The BRITE phenotype persists after continuous cold exposure, and by the end of week 5 BRITE contains a high number of uncoupling protein-1-positive mitochondria, a characteristic feature of BAT. During the transition from WAT into BRITE, the vascular density is markedly increased owing to the activation of angiogenesis. In BAT, cold exposure stimulates thermogenesis by increasing the mitochondrial content and metabolic rate. BAT and the increased metabolic rate result in a lean phenotype. This protocol provides an outstanding opportunity to study the molecular mechanisms that control adipose mass.
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