Gentronix develops technology for the accurate identification of genotoxic compounds. These are compounds which in various ways damage the information stored in chromosomes. Since cancer can arise as a consequence of exposure to genotoxins all new chemicals such as pharmaceuticals and consumer products that come into contact with humans have to be tested for genotoxicity. The challenge for genetic toxicology is to provide tests which are accurate. For safety assessment there has to be a high degree of certainty that carcinogens will be detected, and exposure limited. For hazard assessment there has to be a high degree of certainty that non-carcinogens are not misclassified, as this can lead to scare stories, needless concern about chemicals that are safe and rejection of potentially valuable compounds.
Genetic toxicology is a complex science because there are many different types of chromosome damage, caused by a variety of different chemicals. There are also many different types of cancers and DNA damage is not the only starting point. Extra or missing chromosomes which change gene dosage, as well as the interchange of sections of chromosomes which change gene regulation and even damage to a single base pair in one gene, can all increase the chance of developing cancer. However there are highly evolved and effective cellular defenses against genome damage, which ensure efficient repair, or elimination of damaged cells. It is the activity of these defense systems that Gentronix exploits to detect genotoxin exposure.
To ensure that the whole diversity of genetic damage is detected, current regulatory guideline require a battery of genotoxicity tests including both in vitro and in vivo testing. This regulatory battery is effective in the identification of DNA damaging agents (positive results). However, recent re-evaluation of a great deal of in vitro regulatory data has shown the battery to be less effective in the identification of non genotoxins (negative results). Well over half of non-genotoxins tested have a positive result in one or other of the in vitro regulatory tests. The obvious need for more accurate tests has been recognized by the pharmaceutical industry and by several authorities, including ECVAM
(European Center for the Validation of Alternative Methods), ILSIandFDA / C-Path.
Inevitably the result of this poor accuracy is that a positive in vitro result is often not seen as serious, and animal testing is then used to distinguish the real genotoxins from the mistakes. Hence, more animals are used, at great cost, only to discover that about one third of the positive results are real.