Epigenetic effects including DNA methylation and histone modifications contribute to the genetic alterations leading to cancer.

How do epigenetic changes in cancer cells contribute to the development of cancers?

Answer and Explanation:

An epigenetic change is defined as a change in genome that occur without modification of the primary DNA sequence. The most common epigenetic changes are DNA methylation and histone modifications.

DNA methylation involves the addition of methyl groups (-CH₃) to regions in DNA with a high frequency of Cytosine and Guanine bases (often called CpG island). In general, genes related to regulation of cell cycle and mantainance of chromosone stability and transcription regulation are not methylated. Methylation in these regions can lead to gene knowout which are related to apopthosis, regulation of cell cycle and in consequence, it can lead to tumor formation and progression.

Other epigenetic modification is histone modification though methylation or acetilation. As DNA packing in chromosomes is assisted by histone proteins, the modification of histones can lead to changes in chromatin structure. The packing or unpacking of DNA regulates the gene expresion. The alteration in the normal packing DNA could produce silencing of gene related to transcriptional regulation processes which in last instance can cause cancer.