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Related Concept Videos

Regulation of Angiogenesis and Blood Supply01:24

Regulation of Angiogenesis and Blood Supply

Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits.  Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl hydroxylase and factor...
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The platelet phase, the second stage of hemostasis, commences around 15-20 seconds after an injury. It follows and overlaps with the vascular phase, during which blood vessels constrict to minimize blood loss.
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Mechanism of Angiogenesis01:10

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An In Vitro Assay to Study Platelet Migration Using RGD-Functionalized Avidin-Biotin Tethers
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Platelets actively sequester angiogenesis regulators.

Giannoula Lakka Klement1, Tai-Tung Yip, Flavia Cassiola

  • 1Children's Hospital, Boston, MA 02115, USA. giannoula_klement@dfci.harvard.edu

Blood
|November 28, 2008
PubMed
Summary
This summary is machine-generated.

Platelets selectively accumulate angiogenesis regulators in tumor-bearing animals, offering potential new biomarkers for early cancer detection and treatment monitoring. This contrasts with unreliable plasma markers.

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Last Updated: Jun 27, 2026

An In Vitro Assay to Study Platelet Migration Using RGD-Functionalized Avidin-Biotin Tethers
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Monitoring Functionality and Morphology of Vasculature Recruited by Factors Secreted by Fast-growing Tumor-generating Cells
09:03

Monitoring Functionality and Morphology of Vasculature Recruited by Factors Secreted by Fast-growing Tumor-generating Cells

Published on: November 23, 2014

Area of Science:

  • Oncology
  • Hematology
  • Biochemistry

Background:

  • Clinical trials of antiangiogenic agents have faced challenges due to unreliable plasma/serum markers for cancer detection and response.
  • Platelets have been identified as reservoirs for numerous angiogenesis-regulating proteins.

Purpose of the Study:

  • To investigate the selective accumulation of angiogenesis regulators in platelets of tumor-bearing animals.
  • To assess the potential of platelet-associated angiogenesis regulators as diagnostic or therapeutic markers.

Main Methods:

  • Comparison of angiogenesis regulator levels in platelets and plasma/serum of tumor-bearing versus non-tumor-bearing animals.
  • Analysis of platelet uptake of vascular endothelial growth factor (VEGF) in response to implanted VEGF-enriched Matrigel or microscopic tumors.
  • Evaluation of platelet sequestration of other angiogenesis proteins like platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF).

Main Results:

  • Angiogenesis regulators significantly accumulate in platelets of tumor-bearing animals compared to plasma/serum and non-tumor-bearing controls.
  • Platelets selectively sequester these proteins, not taking up other plasma proteins like albumin proportionally.
  • Elevated platelet VEGF levels were observed with VEGF-enriched Matrigel or microscopic tumors, without changes in plasma VEGF.
  • Platelet sequestration profiles of PDGF and bFGF also indicated tumor presence before macroscopic evidence.

Conclusions:

  • Platelets selectively concentrate angiogenesis regulators in cancer-bearing hosts.
  • This platelet-based biomarker approach may aid in the early diagnosis and management of angiogenesis-related diseases.
  • Findings suggest a potential guide for optimizing antiangiogenic therapies.