Next generation sequencing (NGS) has been a recent and important breakthrough in the field of genetics with major implications in the realm of oncology and cancer treatment.
An international spotlight was first put on DNA sequencing in 1990 when the Human Genome Project endeavored to document all 3 billion base pairs of the human genome (1, 2). One of the primary goals of the study for the scientists involved was to better understand the human body and “build […] genetic and physical maps of the human […] genome.” (1) This project was completed in 2003 using the “bacterial artificial chromosome” (BAC) approach, which utilized clones to duplicate the DNA in smaller and more manageable fragments (2). Approximately 20,000 BAC clones were used to sequence the entire human genome, and information collected via BAC was then assembled to re-create the sequence (2).
Results of the study were published and gained considerable traction. One of the primary findings of the study was the direct association between specific genetic mutations and certain diseases, which inspired a paradigm shift in medical research and produced an increased interest in improving DNA sequencing technology (1).
Compared to sequencing methods used in the Human Genome Project, the newer NGS technology is able to produce copious amounts of genomic data and has evolved to become the technology scientists rely on now for sequencing. NGS has proven to be much more powerful than older DNA sequencing technology such as Sanger sequencing, which was developed in the 1970s and its main constraint was in the amount of data that it could produce (5). NGS enables scientists to sequence millions of base pairs simultaneously, allowing analyses to be performed at a much lower cost and more efficient rate (7). Sequencing the entire human genome can now be replicated in a short amount of time with NGS and at a much lower cost (7).
NGS technology has since been adapted in various ways in cancer treatment, most notably in combination with liquid biopsy for cancer diagnosis. Through NGS liquid biopsy, oncologists are able to diagnose cancer through blood tests and NGS genetic analysis instead of having to extract tissue from the patient’s tumor for examination (13). Certain types of liquid biopsy rely on NGS technology to examine blood samples for certain genetic mutations that may be associated and have a correlation with different types of cancer (6). Adapting NGS for liquid biopsy has helped make the diagnosis more comprehensive as physicians now have access to more data generated from NGS analyses (6).
If the Human Genome Project is the past of genetic sequencing, NGS is its future. As physicians and researchers begin to tackle health issues such as cancer through genetics, NGS will continue to make its mark and prove to be an important tool to developing new cancer treatment and diagnosis methods.
References:
- Chial H. (2008). DNA Sequencing technologies key to the Human Genome Project. Nature Education 1(1):219 https://www.nature.com/scitable/topicpage/dna-sequencing-technologies-key-to-the-human-828
- National Human Genome Research Institute. (2018, November 12) Human Genome Project FAQ. Retrieved from https://www.genome.gov/human-genome-project/Completion-FAQ
- Meldrum C., Doyle M. & Tothill R. (2011). Next-Generation Sequencing for Cancer Diagnostics: a Practical Perspective. Clin Biochem Rev. 32(4): 177-195 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3219767/
- Kulski J. (2016). Next-Generation Sequencing — An Overview of the History, Tools, and “Omic” Applications. InTechOpen http://dx.doi.org/10.5772/61964
- Shendure J., Balasubramanian S., Church G.M., Gilbert W., Rogers J., Schloss J.A. & Waterston R.H. (2017). DNA sequencing at 40: past, present and future. Nature doi:10.1038/nature24286
- TechnologyNetworks.com. (2019, January 15) Recent Advances in Liquid Biopsy for Cancer. Retrieved from https://www.technologynetworks.com/diagnostics/articles/recent-advances-in-liquid-biopsy-for-cancer-314440
- Kamps, R., Brandão, R. D., Bosch, B. J., Paulussen, A. D., Xanthoulea, S., Blok, M. J., & Romano, A. (2017). Next-Generation Sequencing in Oncology: Genetic Diagnosis, Risk Prediction and Cancer Classification. International journal of molecular sciences, 18(2), 308. doi:10.3390/ijms18020308
- Malapelle, U., Pisapia, P., Rocco, D., Smeraglio, R., di Spirito, M., Bellevicine, C., & Troncone, G. (2016). Next generation sequencing techniques in liquid biopsy: focus on non-small cell lung cancer patients. Translational lung cancer research, 5(5), 505–510. doi:10.21037/tlcr.2016.10.08
- Thermo Fisher Scientific. (2015, June 17). How Does Sanger Sequencing Work? Retrieved from https://www.thermofisher.com/blog/behindthebench/how-does-sanger-sequencing-work/
- Illumina.com. (2019). Introduction to NGS. Retrieved from https://www.illumina.com/science/technology/next-generation-sequencing.html
- Illumina.com. (2019). Key differences between next-generation sequencing and Sanger sequencing. Retrieved from https://www.illumina.com/science/technology/next-generation-sequencing/ngs-vs-sanger-sequencing.html
- Illumina.com. (2019). An introduction to Next-Generation Sequencing Technology. Retrieved from https://www.illumina.com/documents/products/illumina_sequencing_introduction.pdf
- Roche. (2019). What is liquid biopsy? Retrieved from https://www.roche.com/research_and_development/what_we_are_working_on/oncology/liquid-biopsy.htm