One manipulation. For cancer, environmental factors and the

One of the major research challenges in both the biological
and biomedical sciences is reproducibility in the pathology of cancers and
neurological disorders. Invasive molecular analyses often can reveal important
factors that lead to a disease state if that certain disorder has a genetic
basis. However, these tests can very rarely be done on humans, so it is common
to use an analogous model organism, usually rat or mouse. Yet, this relies on
the idea that these model organisms can reliably reflect the true disease state
of humans. In recent years, this has shown to be a problem in research on
certain cancers and neurological disorders such as Alzheimer’s.  In each case, but for different reasons, the
rat and mouse models have been unreliable in reproducing the same disease state
with the same genetic manipulation. For cancer, environmental factors and the exploitation
of specific oncogenes can have a drastic effect on the pathology of a certain
cancer. With the advent of new studies that may not be reproducible,
pharmaceutical companies may invest in methods that will have little to no
effect in patients with a certain form of cancer. This has been one of the main
reasons for the push for genomic screening and personalized medicine. For
Alzheimer’s, the reigning hypothesis has involved the presence of Tau tangles
and beta-amyloid plaques that interrupt axonal communication leading to
apoptosis. Although this seems to be a relatively consistent pathological state
in humans, the results are extremely variable when testing in rats and mice. Oftentimes,
the animal models do not reflect the neuronal and synaptic loss that is
characteristic of the pathological state in Alzheimer’s disease. Until
researchers in these respective fields are able to successfully reproduce the
physiological characteristics of these highly variable disorders in basic
research, it will be impossible to translate experimental drugs to humans.