'Immortal' Gene Mutation May Allow Some Cancerous Cells to Live Forever
For years, it has remained a mystery how cancer cells are able to live forever, while typical cells die. Recent research performed by scientists at the Duke Cancer Institute have found that a single gene may be responsible for three of the most common types of brain tumors, in addition to liver cancer, tongue cancer and cancer of the urinary tract. In addition, the study involved research into the inner workings of 1,200 tumors and 60 different types of cancer. Researchers hope that, with this finding, doctors will soon be able to beat cancer at its own game.
The secret is in the telomere, which sticks to the end of the chromosome and prevents the ends from fraying or sticking together. When cells divide normally, the telomeres become shorter and shorter. When the telomere reaches a certain length, the cell can no longer divide and it dies. This process requires the use of an enzyme called telomerase.
Scientists have found that some cancerous cells have a gene mutation that affects the enzyme. Because the telomere does not become shorter and shorter, the cells become immortal and are able to divide forever. The researchers at Duke Cancer Institute found nine cancer types that are highly associated with this gene mutation. All of the cancerous cells arise in areas of the body where there is a low rate of cell renewal, so it seems that the cells needed such a mechanism to stay alive.
The cancer types include the following: melanomas; liposarcomas; hepatocellular carcinomas; transitional cell carcinomas of the urinary tract; squamous cell carcinomas of the tongue; medulloblastomas; as well as subtypes of gliomas, which includes 83 percent of primary glioblastomas, the most common brain tumor in adults, a devastating illness with a median survival of only 15 months.
"Now we see this," Zachary J. Reitman, Ph.D., the co-lead author of the study, said in a statement. "This is a major discovery in brain tumors, because this single mutation can now distinguish one tumor from another - and these are tumors that are difficult to classify with a typical pathology test. For primary glioblastoma, the TERT mutation is remarkably common, while for astrocytomas, it is rare. Using both IDH1 and TERT, we can greatly improve diagnosis and prognosis."
Spotting the mutation means that the biomarker could provide an early way of spotting liver and urinary tract cancer, improving prognoses of the disease. It could also serve as a new target for drugs against cancer.
However, many cancer types, like breast and prostate cancers, did not have this mutation, which indicates that the cancerous cells in those region have developed another way to live forever.
The study was published in the Proceedings of the National Academy of Science.