First recognized in 1926, ataxia-telangiectasia, otherwise referred to as AT, is an extremely rare and ineluctably progressive disease which slowly denigrates the nervous system. Ataxia–telangiectasia is an autosomal recessive, caused by mutations in the ataxia–telangiectasia mutated gene (ATM), which is best described as a serine/threonine kinase that activates over two dozen proteins involved in controlling cell growth and division. Individuals who are found with the variant AT phenotypes usually have abnormal features, such as dystonia and myoclonus, and are susceptible to cancer . A-T patients who survive into their teens have a highly elevated susceptibility for cancer, in particular about a 30- to 50-fold increase in specific leukemias and lymphomas. Scientific research over the last two decaedes, have cloned the AT gene has now revealed that ATM functions as the master regulator of the cells’ response to double stranded breaks in DNA.
However, besides its definite neurological effects, the variation and inactivation of the ATM gene also increases susceptibility to cancer, more specifically on pancreatic cancer and radiation. Within a study, it was found that a pancreatic cancer’s molecular profile influences its response to radiotherapy. Biallelic germline inactivation of ATM causes, Ataxia Telangiectasia, which carries a twenty five percent risk of cancer with it. Patients who suffer with Ataxia Telangiectasia are usually unable to respond effectively to DNA double-stranded breaks (DSBs) and are hypersensitive to radiation. ATM has been identified as a pancreatic cancer susceptibility gene and biallelic inactivation of the ATM gene has been identified in the pancreatic cancers of patients with heterozygous germline ATM mutations. Furthermore, ATM status is important when predicting radiation and chemotherapy response in certain settings. Thus, when the ATM gene becomes inactivated, this process becomes more difficult.
Scientists Ayars, Eshleman, Goggins, examined the effect of ATM-depletion in multiple pancreatic cancer cell lines and examined the effect of radiation on DNA integrity and repair kinetics in ATM-deficient pancreatic cancer cells, in their study. In the study, the ATM expression was knocked down using shRNA in two cell lines with ATM and with a mutant TP53 and one wild-type ATM cell line with wild-type TP53. It was concluded that the chemosensitivity of ATM-deficient cancer cells are extremely dependent on the specific cell type and mutational background.
In addition to this, Richard Gatti touches on Ataxia Telangiectasia in relation to lymphoid cancer. ATM-dependent cancer link involves the decrease of ATM by microRNA-421, which is increased by the different transcription factors. However, sensitivity to ionizing radiation appears to be directly associated with double strand break repair defects and lymphoid cancer susceptibility.
Thus, about 500 unique mutations of the ATM gene have been identified. These are found and distributed widely across the gene, ignoring the kinase region or for other known entities. Ignoring the kinase regions is a massive issue, for over twenty-five proteins are now believed to be targets of the ATM kinase. A fraction of these mutations (approximately one-third of these mutations) are founder mutations, recurring within certain countries, ethnic groups, or religious affiliates. Although ataxia-telangiectasia is an extremely disheartening disease, due to the mutations in the ATM gene, there is constantly improvements being made in relation to the knowledge of it, and its susceptibility to cancer, to improve life.