A Single Letter Change in DNA Made Humans Prone to Cancer

Scientists are still in the process of collecting more data about cancer — records that can make people easily understand its origin. One possible reason humans are prone to the disease is the evolving process of primates to humans. Evolving alters certain DNA qualities, and this one change is related to humankind’s vulnerability to cancer.

Photo: Pixabay/mtanenbaum

Primates rarely get diagnosed with cancer. Proof of that is the autopsies of the primates who died at the Philadelphia Zoo between 1901 and 1932. Out of 971 non-human primates, only 8 of them had tumors.

Aside from that, researchers from the Memorial Sloan Kettering Cancer Center in New York studied the difference between primates and human genes. Christine Iacobuzio-Donahue and her team led the observation, and their paper was published in the journal Cell Reports.

Results found that human evolution altered a gene called BRCA2. The function of the BRCA2 gene is to build a protein that will serve as a tumor suppressor. It contains the tumor cells and stops them from growing fast, restraining the cell from rapidly dividing.

Consequently, that 20% change made repairing DNA worse compared to a primate’s genes. Humans became more susceptible to cancer due to a lack of tumor suppressors. The results were even more solidified with a previous study, concluding that humans with a particular BRCA2 variant develop tumors, primarily on the ovaries and breast.

Photo: Pixabay/geralt

According to Christine Iacobuzio-Donahue, the study is not yet complete, and the question of why BRCA2 evolved in humans still has no definite answer. “One possibility is that reduced BRCA2 activity has been selected for in humans to enhance fertility, since research shows that women with BRCA2 variants linked to cancer seem to become pregnant more easily,” she says.

As the team researches for more reliable data, they are hopeful that new and improved treatments can be discovered with the recent findings. Iacobuzio-Donahue also disclosed an example of a new treatment where they can apply their findings regarding BRCA2. In theory, scientists can rewrite a human’s BRCA2 gene to replicate those existing in non-human primates. Formulating a more advanced cancer treatment will hopefully be in process soon.