Tumor evolution, one cell at a time

When applying NGS to study genome modifications occurring in specialized cellular populations extracted from a tissue, one can incur in confusing results due to the contamination from common cells present in the sample. Thus the "evolution" process resulting in the specialized function can be hard to evaluate. One interesting application to circumvent this limitation is single-cell sequencing, that allows to obtain detailed genomic information from a single cell extracted from any biological sample.

This has been applied recently in tumors to elucidate the exact mutational process that transform a normal tissue cell in a cancerous one. Knowing exactly the time schedule of mutations finally resulting in the malignant phenotype can be crucial to understand cancer biology and identify early genetic marker of transformation. Moreover this kind of study can identify mechanism of cancer evolution, that make the cancer cells able to respond to treatment developing various kind of resistance.

After a first paper applying this approach appeared in Nature in April 2011, now two other studies have been published in Cell, both supported by the BGI institute and both based on single-cell exome sequencing: the first one by Xu et al. present results from a clear cell renal cell carcinoma, the second one by Hou et al. studied the evolution of a JAK2-negative myeloproliferative neoplasm.

Graphical abstract from Hou et al.

Graphical abstract from Xu et al.