For the first time the entire DNA, RNA of a patient with lung cancer has been sequenced by researchers.
The 61-year-old woman patient, whose lung cancer had entered her bloodstream and spread to other parts of her body, had been treated with several types of chemotherapy.
The study used Whole Genome Sequencing (WGS), also called Next-Generation Sequencing (NGS), to look at all 3 billion chemical bases of the patient's normal, as well as the patient's tumour, DNA.
It went further by examining the normal and tumour RNA for whole transcriptome sequencing, which can reveal the possible defects in how proteins are synthesized. This provided an even more intricate view of the tumours biological make up and what might have led to her cancer.
"Evidently, this is very exciting. Next-Generation Sequencing now offers us the ability to survey the global landscape of cancer," said Dr. John Carpten, Director of TGen's Integrated Cancer Genomics Division and senior author of the presentation.
A review of well-characterized cancer-related genes found that a mutation resided in the TP53 gene, a mutation in the tumour (one base change in the genetic code), and that the mutation was always present in both the DNA and RNA. Such a mutation can halt the creation of tumour suppressor genes and result in the generation of a tumour. Interestingly, the cancer specimen showed no loss of heterozygosity (LOH), in which one side of the DNA's chromosome becomes inactive because of a mutation.
"This observation highlights the complexity of cancer and how different genetic mechanisms can alter a gene. This novel finding would not have been readily determined without the combined DNA and RNA integration approach," said Dr. David Craig, Associate Director of TGen's Neurogenomics Division, and also a senior author of the presentation.
The study will be published in a special supplement of the Journal of Thoracic Oncology.