Tumor microenvironment: Difference between revisions

Latest revision as of 11:28, 23 March 2025

Overview of the tumor microenvironment

Tumor Microenvironment[edit]

The tumor microenvironment (TME) is the environment surrounding a tumor within the body, consisting of various cell types, signaling molecules, and the extracellular matrix (ECM). The TME plays a crucial role in tumorigenesis, influencing tumor growth, progression, and response to therapy.

Components of the tumor microenvironment

Components[edit]

The TME is composed of a variety of cellular and non-cellular components:

Cancer cells: The primary component of the tumor, these cells proliferate uncontrollably and can invade surrounding tissues.
Stromal cells: These include fibroblasts, endothelial cells, and pericytes, which contribute to the structural framework of the tumor.
Immune cells: The TME contains various immune cells such as macrophages, T cells, and natural killer cells, which can either attack the tumor or be co-opted to support tumor growth.
Extracellular matrix (ECM): A complex network of proteins and polysaccharides that provides structural support and influences cell behavior.

Tumor Stroma[edit]

The tumor stroma is the supportive tissue around the tumor, consisting of the ECM and stromal cells. It plays a significant role in tumor progression by providing structural support and modulating the behavior of cancer cells.

Hypoxia[edit]

Hypoxia, or low oxygen levels, is a common feature of the TME. It results from the rapid growth of tumors outpacing their blood supply. Hypoxia can lead to the activation of hypoxia-inducible factors (HIFs), which regulate the expression of genes involved in angiogenesis, metabolism, and cell survival.

Immune Evasion[edit]

Tumors can evade the immune system through various mechanisms, including the expression of immune checkpoint molecules that inhibit T cell activation. The TME can also recruit regulatory T cells and myeloid-derived suppressor cells to suppress immune responses.

Angiogenesis[edit]

Angiogenesis, the formation of new blood vessels, is critical for tumor growth and metastasis. The TME promotes angiogenesis through the secretion of growth factors such as vascular endothelial growth factor (VEGF).

Metastasis[edit]

The TME facilitates metastasis by providing pathways for cancer cells to invade surrounding tissues and enter the bloodstream or lymphatic system. The ECM and stromal cells can be remodeled to support this process.

Related Pages[edit]

@@ Line 1: / Line 1: @@
-'''Tumor microenvironment''' is the immediate cellular environment in which a [[tumor]] exists, including surrounding [[blood vessels]], [[immune cells]], [[fibroblasts]], [[signaling molecules]] and the [[extracellular matrix]] (ECM). The tumor microenvironment is dynamic and changes as the tumor grows and develops.
+{{Short description|Overview of the tumor microenvironment}}
-== Overview ==
+== Tumor Microenvironment ==
+The '''tumor microenvironment''' (TME) is the environment surrounding a [[tumor]] within the body, consisting of various cell types, signaling molecules, and the [[extracellular matrix]] (ECM). The TME plays a crucial role in [[tumorigenesis]], influencing tumor growth, progression, and response to therapy.
-The tumor microenvironment is a complex and dynamic system that plays a crucial role in [[cancer]] progression and response to therapy. It is composed of various cell types including [[cancer cells]], [[stromal cells]], and [[immune cells]], as well as non-cellular components such as the [[extracellular matrix]] and signaling molecules.
+[[File:Components-of-the-tumor-microenvironment.png|Components of the tumor microenvironment|thumb|right]]
-== Components ==
+=== Components ===
+The TME is composed of a variety of cellular and non-cellular components:
-=== Cancer cells ===
+* '''Cancer cells''': The primary component of the tumor, these cells proliferate uncontrollably and can invade surrounding tissues.
+* '''Stromal cells''': These include [[fibroblasts]], [[endothelial cells]], and [[pericytes]], which contribute to the structural framework of the tumor.
+* '''Immune cells''': The TME contains various immune cells such as [[macrophages]], [[T cells]], and [[natural killer cells]], which can either attack the tumor or be co-opted to support tumor growth.
+* '''Extracellular matrix (ECM)''': A complex network of proteins and polysaccharides that provides structural support and influences cell behavior.
-[[Cancer cells]] are the main component of the tumor microenvironment. They are characterized by uncontrolled growth and division, and the ability to invade other tissues.
+[[File:Stromal_cell_in_tumor_microenvironment.jpg|Stromal cell in tumor microenvironment|thumb|left]]
-=== Stromal cells ===
+=== Tumor Stroma ===
+The tumor stroma is the supportive tissue around the tumor, consisting of the ECM and stromal cells. It plays a significant role in tumor progression by providing structural support and modulating the behavior of cancer cells.
-[[Stromal cells]] are non-cancerous cells that are part of the tumor microenvironment. They include [[fibroblasts]], [[endothelial cells]], and [[pericytes]]. These cells can support tumor growth and progression.
+[[File:Tumour_stroma_and_extracellular_matrix_in_hypoxia.svg|Tumor stroma and extracellular matrix in hypoxia|thumb|right]]
-=== Immune cells ===
+=== Hypoxia ===
+Hypoxia, or low oxygen levels, is a common feature of the TME. It results from the rapid growth of tumors outpacing their blood supply. Hypoxia can lead to the activation of [[hypoxia-inducible factors]] (HIFs), which regulate the expression of genes involved in angiogenesis, metabolism, and cell survival.
-[[Immune cells]] in the tumor microenvironment can either promote or inhibit tumor growth. They include [[T cells]], [[B cells]], [[macrophages]], and [[neutrophils]].
+[[File:HIF_regulates_interactions_of_cancer_cells_with_ECM_and_ECM_biosynthesis.svg|HIF regulates interactions of cancer cells with ECM|thumb|left]]
-=== Extracellular matrix ===
+=== Immune Evasion ===
+Tumors can evade the immune system through various mechanisms, including the expression of immune checkpoint molecules that inhibit T cell activation. The TME can also recruit regulatory T cells and myeloid-derived suppressor cells to suppress immune responses.
-The [[extracellular matrix]] (ECM) is a network of proteins and carbohydrates that provides structural and biochemical support to cells. In the tumor microenvironment, the ECM can influence tumor growth and progression.
+[[File:Immune_checkpoints_of_immunosuppressive_actions_associated_with_breast_cancer.svg|Immune checkpoints in breast cancer|thumb|right]]
-== Role in cancer progression ==
+=== Angiogenesis ===
+Angiogenesis, the formation of new blood vessels, is critical for tumor growth and metastasis. The TME promotes angiogenesis through the secretion of growth factors such as [[vascular endothelial growth factor]] (VEGF).
-The tumor microenvironment plays a crucial role in cancer progression. It can promote tumor growth, invasion, and metastasis, and can also influence the response to therapy.
+=== Metastasis ===
+The TME facilitates [[metastasis]] by providing pathways for cancer cells to invade surrounding tissues and enter the bloodstream or lymphatic system. The ECM and stromal cells can be remodeled to support this process.
-== See also ==
+[[File:Tumor-associated_immune_cells_in_the_tumor_microenvironment_(TME)_of_breast_cancer_models.svg|Tumor-associated immune cells in the tumor microenvironment (TME) of breast cancer models|thumb|left]]
+== Related Pages ==
 * [[Cancer]]
-* [[Tumor]]
+* [[Metastasis]]
-* [[Extracellular matrix]]
+* [[Angiogenesis]]
-* [[Immune cells]]
+* [[Hypoxia-inducible factor]]
-* [[Stromal cells]]
+* [[Immune checkpoint]]
+[[Category:Oncology]]
 [[Category:Cancer]]
 [[Category:Cell biology]]
-[[Category:Immunology]]
-{{stub}}