One woman had 12 tumors – seven benign and five cancerous – before her 40th birthday. Medical researchers recently discovered the reason she is so vulnerable to abnormal development: She carries a set of genetic mutations never before seen in humans.
The woman, now 36, carries two mutated copies of a gene called MAD1L1 from each parent, according to a new report published Wednesday (Nov. 2) in the journal. Advances in science (Opens in a new tab). The gene codes for a protein called MAD1, which plays an important role in cell division.
When a cell divides into two, it first reproduces itself DNA It then packages the genetic material into compact structures called chromosomes. The chromosomes then line up nicely along the middle line of the cell and are cut in half; In this way, when the mother cell divides into two, half of the DNA is in each daughter cell. The MAD1 protein helps the chromosomes line up correctly in this process, so that all cells reach the normal 23 pairs of chromosomes. UniProt (Opens in a new tab)A database of protein sequence and functional information.
When laboratory mice carry two mutant copies of MAD1L1, the mice die in utero. However, in the woman’s case, she survived into adulthood, but was highly susceptible to tumors throughout her life. She developed her first cancerous tumor at age 2 and her latest at age 28.
Related: The drug deceives cancer cells by mimicking a virus
“It was very difficult to understand how this woman could survive with this mutation,” said co-senior author Marcos Malumbres (Opens in a new tab)The head of the Cell Unit and Cancer Group at Spain’s National Cancer Research Center (CNIO) in Madrid told a Spanish newspaper. The country (Opens in a new tab). “There must have been something else that helped her escape [death]” says Malumbres, according to Live Science Translation.
An analysis of the patient’s blood showed that 30% to 40% of the circulating blood cells had an abnormal number of chromosomes – either too many or too few.
Other genetic mutations that affect MAD1L1 cause people to carry cells with different chromosomes. In some patients, but not all, this seems to increase the risk of cancer, the researchers in their report. 90% of cancer tumors contain cells with extra or missing chromosomes National Cancer Institute (Opens in a new tab); However, scientists are still investigating exactly how this genetic quirk contributes to the development and spread of cancer.
Although he has cancer five times, the patient is treated relatively easily every time he is diagnosed with the disease. And since her last tumor was removed in 2014, the patient has not developed another. The medical researchers think that this can be a special thanks to her Immune system.
In their analysis, the team found that the presence of cells with an abnormal number of chromosomes triggered an immune response in cells with the normal 23 pairs. These immune cells are activated Swelling Inside the woman’s body and by spitting out certain molecules and triggers, the cells help the immune system recognize and destroy cancerous tumors when they arise. This could explain why the patient responded well to cancer treatments including chemotherapy, radiotherapy and surgery, the team theorized.
“The constant production of transformed cells has created a chronic immune response against these cells in the patient, and this helps the tumors to disappear,” said Malumbres. press release (Opens in a new tab). The team to further study the woman’s immune system, to see if they can be reproduced in other cancer patients.
“We think that boosting the immune response of other patients will help them stop the growth of the tumor,” Malembers said. At least in concept, such treatment is similar to immunotherapies designed to boost the immune system’s ability to attack and kill cancer cells.