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Discovery Of New Genetic Mutations Occurring In Malignant Melanoma Could Lead To Changes In Cancer Treatment

Scientists have aggressively been trying to map the cancer genome in hopes of understanding what spurs the development of cancer. Genome sequencing data provides important clues on how cancer behaves and why. Recent research has uncovered new genetic mutations that occur commonly in the majority of malignant melanoma tumors. In analyzing the whole of the genome data, researchers found two mutations in 89 percent of the tumors. When they specifically examined melanoma tumors, the same two mutations were present in 71 percent of them. The DNA sequences of 70 malignant melanomas led to the new discovery.

A team, led by Rajiv Kumar of the German Cancer Research Center in Heidelberg and Dirk Schadendorf of the University of Essen, looked for the mutations in a family whose members tended to get melanoma, according to the New York Times.

The cancer-associated mutations are the first to be discovered in the vast regions of DNA in cancer cells that do not contain genetic instructions for making proteins. The mutations are located in non-protein-coding DNA that regulates the activity of genes.

The presence of these mutations in the vast majority of tumors studied suggests that researchers may have stumbled upon a fundamental mechanism of cancer cells. The mutations spur cells to make an enzyme called telomerase, which keeps cells immortal by preventing them from gradually losing the ends of their chromosome, the telomeres. When telomeres erode, a cell dies, which is what happens regular cells (apoptosis). The discovery of these genetic mutations could reveal a more keen understanding of how tumors germinate, consequently leading to more effective treatments against one of the most pernicious cancers.

Dr. Levi A. Garraway and other researchers found the mutations in a region that regulates genes. Dr. Levi Garraway, of the Dana-Farber Cancer Institute and the Broad Institute of Harvard and Massachusetts Institute of Technology (MIT) participating in the research, said:

“This represents the discovery of two of the most prevalent melanoma gene mutations.”

Cancer is the uncontrolled growth of abnormal cells in the body. Tumors, lesions formed by an unusual germination of neoplastic cells, can be malignant or benign. Malignant is cancerous, composed of cells that invade and destroy nearby tissue and spread to other parts of the body (metastasize). Benign is non-cancerous. Benign tumors may grow akin to cancerous ones, but do not spread to other parts of the body.

Malignant melanoma is one of the two types of skin cancer; the other non-melanoma. Melanoma is a malignant tumor of melanocytes. Melanin is a photochemical present in skin, hair, and eyes. It determines color and is produced by melanocytes (cells) found in the basal layer of the epidermis (outermost layer of the skin). Melanoma can originate in any part of the body that contains melanocytes. Melanoma is responsible for 75 percent of deaths related to skin cancer, particularly among Caucasians of northwestern European descent. However, that does not mean those with darker pigment are completely immune from developing skin cancer.

UV radiation absorbed from sun exposure is a contributing factor in 90 percent of all cases of skin cancer. Excessive exposure to UV rays damages the skin on a cellular level, potentially mutating the DNA over time. When the integrity of DNA is compromised, a cancer-related mutation can result.

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