Autism and brain cancer are two extremely different conditions that are often not discussed together. Autism is a developmental disorder, with mostly psychological and behavioral symptoms, whereas brain cancers are extremely dangerous and oftentimes fatal. Therefore, when I saw an article on ScienceToday.com titled “What Autism Can Teach Us About Brain Cancer”, I was immediately interested. The article references a study done at John Hopkins in which the researchers discovered that both disorders involve the same protein: NHE9. In all human cells, endosomes transport proteins to different parts of the cell. The acidity of the endosomes greatly affects the speed of this transport. Monitoring the pH of the endosomes requires a delicate balance of pumps that push protons into the endosome, and proteins such as NHE9, which remove protons from the endosome. In autism, NHE9 is defective, causing the endosome to become too acidic and proteins to become destroyed before they reach their destinations.
Interestingly, while examining the tumors of patients with glioblastoma, one of the most deadly forms of brain cancer, researchers found that tumors with high levels of NHE9 grew more quickly. They then found that NHE9 is overactive in brain cancer, causing endosomes to become too alkaline. When endosomes are too alkaline, the removal of the protein EGFR is hindered. EGFR sends cancer promoting signals, causing tumors to grow more quickly. Thus, therapies targeting both NHE9 and EGFR could be potential treatments for glioblastoma. Further research could also investigate whether or not there is a correlational relationship between autism and brain cancer.
Johns Hopkins Medicine. (2015, February 9). What autism can teach us about brain cancer:Both disorders involve faults in same protein. ScienceDaily. Retrieved February 9, 2015 from http://www.sciencedaily.com/releases/2015/02/150209095008.htm
Kalyan C. Kondapalli, Jose P. Llongueras, Vivian Capilla-González, Hari Prasad, Anniesha Hack, Christopher Smith, Hugo Guerrero-Cázares, Alfredo Quiñones-Hinojosa, Rajini Rao. A leak pathway for luminal protons in endosomes drives oncogenic signalling in glioblastoma. Nature Communications, 2015; 6: 6289 DOI: 10.1038/ncomms7289