Cancer epigenetics

Definition

Cancer epigenetics is the study of how changes in gene expression, caused by mechanisms other than changes in the DNA sequence itself, contribute to the development and progression of cancer. These epigenetic modifications, such as DNA methylation and histone modification, can lead to the activation of oncogenes or the silencing of tumor suppressor genes, significantly impacting cancer biology and treatment approaches.

5 Must Know Facts For Your Next Test

1. Epigenetic alterations can be reversible, making them a potential target for cancer therapies aimed at reversing aberrant gene expression patterns.
2. Specific patterns of DNA methylation and histone modifications are often associated with different types of cancers, providing insights into diagnosis and prognosis.
3. Environmental factors, such as diet and exposure to toxins, can induce epigenetic changes that may increase cancer risk by altering gene expression.
4. Epigenetic changes can be inherited across cell divisions, leading to stable changes in gene expression that can contribute to tumor formation.
5. Research into cancer epigenetics has led to the development of drugs that specifically target epigenetic modifiers, offering new avenues for treatment.

Review Questions

• How do epigenetic modifications influence gene expression in cancer cells?
  • Epigenetic modifications, such as DNA methylation and histone modifications, influence gene expression in cancer cells by altering the accessibility of genes. Methylation typically silences tumor suppressor genes or activates oncogenes, leading to uncontrolled cell growth. This means that even without mutations in the DNA sequence itself, the way genes are expressed can dramatically change the behavior of cells and contribute to cancer progression.
• Discuss the role of environmental factors in shaping the epigenetic landscape associated with cancer.
  • Environmental factors play a significant role in shaping the epigenetic landscape related to cancer by inducing changes in DNA methylation and histone modifications. Factors such as diet, pollutants, and lifestyle choices can lead to these modifications, potentially increasing an individual’s risk of developing cancer. Understanding this relationship highlights how external influences can alter gene expression patterns linked to cancer without changing the underlying DNA sequence.
• Evaluate the implications of reversibility in epigenetic alterations for cancer therapy and patient outcomes.
  • The reversibility of epigenetic alterations has significant implications for cancer therapy because it opens new avenues for intervention. By targeting specific epigenetic changes with drugs that reverse these modifications, it may be possible to restore normal gene function and inhibit tumor growth. This approach not only allows for personalized treatment plans tailored to an individual’s unique epigenetic profile but also raises hope for improved patient outcomes as these therapies could lead to more effective management of various cancers.

Related terms

DNA Methylation: A key epigenetic mechanism involving the addition of a methyl group to DNA, which can affect gene expression by repressing transcription.

Histone Modification: Chemical changes to the proteins called histones that help package DNA, influencing how tightly or loosely DNA is wound and thus affecting gene accessibility and expression.

Oncogenes: Genes that have the potential to cause cancer when mutated or expressed at high levels; they are often activated by epigenetic changes in cancer cells.