New Technique for Identifying Epigenetic Markers in Cancer Cells Could Improve Patient Treatment

Scientists have known for decades that cancer can be caused by genetic mutations, but more recently they have discovered that chemical modifications of a gene can also contribute to cancer. These alterations, known as epigenetic modifications, control whether a gene is turned on or off. Analyzing these modifications can provide important clues to the type of tumor a patient has, and how it will respond to different drugs. For example, patients with glioblastoma, a type of brain tumor, respond well to a certain class of drugs known as alkylating agents if the DNA-repair gene MGMT is silenced by epigenetic modification. A team of MIT chemical engineers has now developed a fast, reliable method to detect this type of modification, known as methylation, which could offer a new way to choose the best treatment for individual patients. “It’s pretty difficult to analyze these modifications, which is a need that we’re working on addressing. We’re trying to make this analysis easier and cheaper, particularly in patient samples,” says Dr. Hadley Sikes, the Joseph R. Mares Assistant Professor of Chemical Engineering and the senior author of a paper describing the technique first published online on April 28, 2014 in the journal Analyst. The paper’s lead author is Brandon Heimer, an MIT graduate student in chemical engineering. After sequencing the human genome, scientists turned to the epigenome — the chemical modifications, including methylation, that alter a gene’s function without changing its DNA sequence. In some cancers, the MGMT gene is turned off when methyl groups attach to specific locations in the DNA sequence — namely, cytosine bases that are adjacent to guanine bases. When this happens, proteins bind the methylated bases and effectively silence the gene by blocking it from being copied into RNA.
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