Stroma

Definition

Stroma refers to the supportive tissue surrounding the functional components of an organ, particularly in the context of tumors, where it consists of connective tissues, blood vessels, immune cells, and fibroblasts. In cancer genomics and precision oncology, stroma plays a crucial role in influencing tumor behavior, growth, and response to therapies by creating a microenvironment that can either support or inhibit cancer progression.

5 Must Know Facts For Your Next Test

1. Stroma contains various cell types including fibroblasts, immune cells, and endothelial cells, which all interact with cancer cells and influence tumor behavior.
2. The composition of the stroma can differ significantly between tumor types, affecting how tumors grow and spread.
3. Fibroblasts in the stroma can become activated during cancer progression, leading to a more aggressive tumor phenotype through the production of growth factors and extracellular matrix components.
4. Therapeutic strategies that target the stroma are being investigated to enhance the effectiveness of existing treatments and to overcome drug resistance.
5. The interaction between cancer cells and stromal components can lead to changes in gene expression in both cell types, which is critical for understanding cancer biology.

Review Questions

• How does the composition of the stroma influence tumor behavior in different types of cancer?
  • The stroma's composition plays a pivotal role in determining tumor behavior by providing a supportive microenvironment that can promote or hinder cancer cell proliferation. Different types of cancers have unique stromal characteristics, with variations in cell types, signaling molecules, and extracellular matrix components. For example, an abundant presence of activated fibroblasts may enhance tumor growth and invasiveness by secreting growth factors, while certain immune cells may help suppress tumor development or vice versa depending on their type and activation state.
• Evaluate the significance of targeting stromal components in precision oncology approaches for cancer treatment.
  • Targeting stromal components has emerged as a significant strategy in precision oncology because it addresses the tumor microenvironment's role in cancer progression and therapy resistance. By disrupting the supportive interactions between cancer cells and stromal elements, therapies can potentially enhance their efficacy. For instance, inhibiting fibroblast activation or reprogramming immune cell infiltration may improve responses to standard treatments like chemotherapy or immunotherapy. This approach could lead to more effective personalized treatment regimens based on individual tumor-stromal interactions.
• Synthesize information on how stroma can affect genomic profiling results in cancer diagnostics.
  • Stroma can significantly impact genomic profiling results by influencing the genetic expression patterns observed in tumors. Since stromal cells contribute to the overall transcriptomic landscape of a tumor sample, the presence of reactive stroma might skew results towards a more aggressive tumor phenotype. This can lead to misinterpretation of genomic data when developing targeted therapies or prognostic assessments. Consequently, isolating pure tumor cells from stroma during biopsies or analyses becomes crucial for accurate genomic profiling, ensuring that treatment decisions are based on precise molecular characterizations rather than confounding stromal influences.

Related terms

Tumor Microenvironment: The complex mixture of cells, signaling molecules, and extracellular matrix surrounding a tumor that affects its development and response to treatment.

Fibroblasts: Connective tissue cells in the stroma that produce extracellular matrix components and contribute to tissue structure and repair.

Immune Cell Infiltration: The process by which immune cells enter the tumor microenvironment, impacting tumor progression and response to therapies.