Final answer:
DNA methylation is an epigenetic mechanism that affects gene expression by adding methyl groups to the DNA, often silencing genes when occurring in promoter regions. In cancer cells, such modifications can lead to uncontrolled growth. Drugs targeting these alterations aim to restore normal gene function and could potentially treat cancer by altering gene expression patterns.
Step-by-step explanation:
DNA Methylation and Its Role in Gene Expression
DNA methylation is an epigenetic modification where a methyl group is added to the DNA molecule, particularly to the cytosine bases within CpG islands found in gene promoter regions. This process, primarily carried out by the enzyme DNA methyltransferase, often results in the silencing of gene transcription. In the context of cancer, such epigenetic silencing can contribute to the uninhibited cellular growth that characterizes malignant cells. New therapies aim to reverse these epigenetic alterations to reinstate normal gene expression and inhibit cancer cell proliferation.
Drugs that reduce DNA methylation or prevent the removal of acetyl groups from histone proteins can alter the tightly coiled state of chromatin, making the underlying DNA accessible for transcription. This reverse-silencing effect can activate the expression of tumor suppressor genes and other genes that help control cell growth and division, which might help kill tumor cells and inhibit the growth of cancer.
Understanding gene expression in cancer cells provides insight into the specific genetic and epigenetic alterations at play. Tailored treatments can be devised depending on the epigenetic landscape of the tumor, potentially leading to more effective cancer therapies. In essence, DNA methylation patterns and histone modifications dictate whether genes are turned 'on' or 'off' and can have significant implications for cancer development and treatment.