MAR 08, 2017 7:39 PM PST

DNA Enhancer Elements Promote Colorectal Cancer

WRITTEN BY: Carmen Leitch

Colon and rectal cancer rate are on the rise, especially in the young. Scientists don't know what lies behind the increase, but knowing more about colorectal cancer will help improve therapeutics for the disease. New work from researchers at Case Western Reserve University has implicated a genetic feature called enhancers in the promotion of colon cancer formation. Alterations in very specific parts of the genome can actually promote the expression of genes that encourage tumor growth. These alterations, which happen outside of genes related to colorectal cancer, are very consistently observed in tumor samples; that consistency opens a window for drug development.

The genome is replete with small bits of DNA that can regulate gene expression. One such piece, called an enhancer element, can interact with various regions of the genome, some of which are physically very far away, when genetic material is compacted and folded in three dimensions. This new work indicates that on the chromosomes that contain colorectal cancer genes, there are high levels of enhancer elements that can turn on the expression of certain genes. The video above is a lecture from the NIH regarding enhancers.

"Our data suggest that the survival of colon cancer cells often depends on the expression of genes associated with common enhancer changes," explained the senior author of the work, Peter Scacheri, PhD, an Associate Professor of Genetics and GenomeSciences at Case Western Reserve University School of Medicine. Scacheri said that these common alterations in enhancers are in alignment with specific DNA sequences that are known to elevate colorectal cancer risk.

The scientists found that thousands of enhancer elements were unexpectedly changed in colorectal cancer samples. After tinkering with the enhancer elements, that investigators observed that the previously active colorectal cancer genes became inactive. The researchers thus suggest that the manipulating enhancer elements might be a way to silence the colorectal cancer genes and hopefully slow the growth of tumors.

The research team aimed to analyze a diverse set of colorectal cancer samples in order to elucidate the role of these enhancer alterations. While the work recognizes the influence of previously identified, causative genetic mutations, it also shows that there are other areas of the genome involved in colorectal cancer development. It is postulated that the enhancer elements work in conjunction with genetic mutations in the growth of colorectal tumors.

"Enhancer elements are distinguishable by specific chemical tags on DNA, like bulbs on a string of lights," Scacheri explained. "Identifying common enhancer changes helps us pinpoint a specific set of genes that are consistently switched on during transformation of normal cells to cancer cells. These genes define the tumor state, and therefore could be just as important to tumor growth as those that are commonly mutated."

The Centers for Disease Control and Prevention identifies colorectal cancer causes as the second leading cause of cancer-related death in the United States. These findings indicate that these enhancer elements might be prime therapeutic targets to combat the cancer. "Our next step is to determine exactly how the common enhancers form in colon cancer, and whether we can target their destruction as a strategy to kill tumor cells without harming normal cells," concluded Scacheri.

The above video from Mayo Clinic discusses how colonoscopies can help prevent colorectal cancer.

Sources: AAAS/Eurekalert! via Case Western Reserve University, Nature Communications

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
SEP 21, 2020
Cancer
Black women have delayed and longer breast cancer treatment
SEP 21, 2020
Black women have delayed and longer breast cancer treatment
A study led by UNC Lineberger Comprehensive Cancer Center researchers has quantified the healthcare inequities in cancer ...
SEP 29, 2020
Cancer
Gut microbiome influences oral therapy for prostate cancer treatment
SEP 29, 2020
Gut microbiome influences oral therapy for prostate cancer treatment
Research from a team of scientists at Lawson Health Research Institute and Western University suggests that bacteria in ...
OCT 14, 2020
Immunology
Self-Healing Microcapsules Make Promising Leukemia Vaccines
OCT 14, 2020
Self-Healing Microcapsules Make Promising Leukemia Vaccines
Leukemia is a cancer affecting tissues in the body that produce blood cells, including the bone marrow and the lymphatic ...
NOV 03, 2020
Genetics & Genomics
One Eight Cancer Patients Also Carry Inherited Genetic Mutations
NOV 03, 2020
One Eight Cancer Patients Also Carry Inherited Genetic Mutations
Genetic sequencing technologies have rapidly advanced, reducing the time required to sequence the entire human genome fr ...
NOV 11, 2020
Cancer
A New CDK Inhibitor Could Help with Unresponsive Liver Cancer
NOV 11, 2020
A New CDK Inhibitor Could Help with Unresponsive Liver Cancer
Amongst the most common targets of anti-cancer drugs are small regulatory molecules called cyclin-dependent kinases (CDK ...
NOV 23, 2020
Cancer
Platelets May Protect Cancer Against PD-1 Therapies
NOV 23, 2020
Platelets May Protect Cancer Against PD-1 Therapies
One of cancer’s greatest tools is its ability to manipulate the immune system. Many cancer therapies have arisen t ...
Loading Comments...