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Updated: Jul 29, 2026

Assessing Tumor Microenvironment of Metastasis Doorway-Mediated Vascular Permeability Associated with Cancer Cell Dissemination using Intravital Imaging and Fixed Tissue Analysis
09:42

Assessing Tumor Microenvironment of Metastasis Doorway-Mediated Vascular Permeability Associated with Cancer Cell Dissemination using Intravital Imaging and Fixed Tissue Analysis

Published on: June 26, 2019

Arginine metabolic pathways involved in the modulation of tumor-induced angiogenesis by macrophages

Lilia Elena Davel1, María Adela Jasnis, Eulalia de la Torre

  • 1Instituto de Oncología Angel H. Roffo, Av. San Martín 5481, CP 1417, Buenos Aires, Argentina.

FEBS Letters
|December 3, 2002
PubMed

Insights

Tumor-associated macrophages (TAMs) enhance tumor growth and blood vessel formation (angiogenesis) by modulating LMM3 tumor cells. This process involves specific enzyme activities and polyamine synthesis, highlighting TAMs as a therapeutic target.

Area of Science:

  • Immunology
  • Oncology
  • Cancer Biology

Background:

  • Neovascularization is crucial for tumor progression and metastasis.
  • Macrophages (Mps) in the tumor microenvironment can modulate angiogenesis.
  • The LMM3 tumor cell line's angiogenicity is influenced by Mps.

Purpose of the Study:

  • To investigate how Mps regulate the angiogenicity of the LMM3 tumor cell line.
  • To determine the mechanisms by which tumor-associated Mps (TMps) influence LMM3 tumor growth.

Main Methods:

  • In vivo studies using LMM3 tumor-bearing mice.
  • Peritoneal Mps from tumor-bearing mice (TMps) were isolated.
  • CD31 immunoblotting assays were performed.
  • Analysis of nitric oxide synthase (NOS) and arginase (A) activity and expression.

Main Results:

  • TMps from LMM3 tumor-bearing mice potentiated in vivo LMM3 angiogenicity.
  • TMp activity was dependent on nitric oxide synthase (NOS) and arginase (A) activity.
  • AI and AII arginase isoforms were upregulated in TMps, while inducible and neuronal NOS isoforms were highly expressed in normal Mps.

Conclusions:

  • TMps positively modulate tumor growth by stimulating the angiogenic cascade.
  • Polyamine synthesis is a key pathway through which TMps promote angiogenesis.
  • Targeting TAMs and their enzymatic activities may offer therapeutic strategies for cancer treatment.

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