Whole genome sequence differences between somatic and cancerous cells
A recent paper in Nature has reported a study that I've been waiting to see for so long. They took two cell lines from a single individual - one cultured from normal somatic tissue and the other cultured from a tumour - and aligned the whole genome sequences.
They found some mutations in genes that have been previously identified as candidates for cancer phenotypes, but what's interesting is how the advancement of technology just multiplies the complexity of the problem!
Many issues are likely to confound these types of studies:
- Sequencing a whole genome requires plenty of DNA. Whole genome PCR is selective, so tissue cultures were used to generate the required material. However this is also a selective process, with genotypes adapted to the culture environment likely to be overrepresented.
- If mutator strains arise in the tumour then very high numbers of de novo mutations will occur. Cell cultures will represent a small sample of these mutations, the vast majority of which will be aetiologically unrelated.
- If mutations can be identified as causally related with the disease, this will not reveal any new information about common polymorphisms that contribute towards the disease's heritability.
Nonetheless, overcoming these problems and implementing on a larger scale will probably be very illuminating.
Typing and design by Gib Hemani