Understanding disease susceptibility in humans and non-human primates

Humans and chimpanzees have very similar genome sequences, but display a number of very distinct characteristics. Their genetics and gene expression patterns are very similar; therefore, if the differences in these patterns are studied, there may be answers about human phenotypes, including the causes, and eventually cures, for certain diseases that are prevalent in humans but rare in chimpanzees.

We had previously collected data on the differences in gene expression between humans and chimpanzees in a number of different tissues. There was an enrichment for genes involved in epithelial cancer progression in humans. These cancers are common in humans, but very rare in non-human primates. Our data was analyzed with particular attention to differentially expressed genes related to the development of certain cancers. After careful research, the KRAS gene was discovered as a pivotal gene in the propagation of lung, mucinous, pancreas, and colorectal carcinomas.

We are currently analyzing the link between the expression of this gene in chimpanzees and humans, as well as its effect on the development of cancer, by cloning the regulatory region of this gene into a reporter vector. We hypothesize that the regulatory sequence from the chimpanzee KRAS gene plays a major role in the expression of the gene, especially in its role in the development of such previously stated cancers.