Genomics will lead to tailor-made treatments

Research and development in genomics has been rapidly gathering pace over the past few years. Genomics, particularly in the area of precision medicine, will undoubtedly exert a positive effect on the way health professionals care for their patients. For instance, two people having breast cancer may be suffering from the same cancer type but at the molecular level under the microscope, the cancerous cells may look very different. Put differently, tailor-made treatments for individuals should gain greater importance in the future as gene-based diagnoses and therapies become more personalised for the patient.

Here we look at three of the promising areas in the field of genomics.

Liquid biopsies

In recent years, liquid biopsies – the analysis of biomarkers shed by tumours circulating in the bloodstream – have garnered considerable interest among medical professionals. This is primarily due to the promise that the technology can spark further medical advances, especially when it comes to cancer diagnosis, prognosis and monitoring. Based simply on a blood specimen extracted from an individual, traces of the cancer cells or pieces of the tumour’s DNA can provide physicians with information about the types of treatment that are most likely to work for the individual.

The ability to detect and characterise tumours through such a simple, minimally invasive way could have significant clinical ramifications for cancer care, especially in personalised medicine.

The minimally invasive nature of a liquid biopsy, which typically requires between 5ml and 10ml of blood, means that it is more comfortable for the patients in terms of pain tolerance. Furthermore, the procedure is shorter in duration than the more invasive procedure of a surgical biopsy, which usually involves a surgeon making an incision in the skin to remove a tissue sample from a lump or mass for examination under a microscope.

Infectious disease diagnostics

Microbes that attack the body can cause diseases in humans. Also known as infectious agents or pathogens, these microscopic living things can range from bacteria and viruses to parasites and fungi. Since infectious diseases can be transmitted directly or indirectly from one person to another through contact with blood, body fluids, or aerosols (coughing and sneezing), healthcare professionals are increasingly turning to genetic testing techniques to detect the presence of the offending agents in our bodies.

As a molecular technique, for instance, nucleic acid testing is extensively used to diagnose infectious diseases by detecting the genetic material of the causative agents.

As the concentration of their genetic material is often extremely low, many nucleic acid testing includes an additional step that amplifies the genetic material by making unlimited copies of it. This type of test is called the nucleic acid amplification test (NAAT). In particular, the polymerase chain reaction (PCR) variant of the NAAT has become an indispensable tool in modern molecular biology. Not only does this method allow scientists to take a very tiny genetic sample and have it magnified to a large enough amount to study it in greater detail, but the PCR technique is also more rapid and sensitive compared to the traditional methods of diagnosis, like culture or serology.

Gene editing

CRISPR/Cas9 (hereafter CRISPR), which stands for clustered regularly interspaced short palindromic repeats, is an innovative genetic engineering technology that allows scientists to alter DNA sequences and modify gene function. Held widely as a revolutionary technique in the field of genome editing, CRISPR could enable scientists to repair genetic defects and treat debilitating illnesses ranging from Huntington disease to sickle cell disease and genetic blindness. This compares with some of the more traditional variants of gene therapies, which use viruses to insert new genes into cells to treat diseases. As CRISPR employs targeted molecular tools to make changes directly in the DNA, its treatments largely circumvent the need to turn to the use of viruses, which have previously caused some safety problems.

The technique, which has been compared to the cut and paste function in a computer processing programme, allows scientists to remove or modify the offending genes that are causing a problem.

Although recently developed programmable editing tools, such as zinc-finger nucleases and transcription activator-like effector nucleases, have significantly improved the capacity for precise genome modification, these techniques have limitations.

CRISPR represents a significant improvement over these next generation genome-editing tools due to its precision, efficiency, and ease of use. This means that the CRISPR system allows for site-specific genomic targeting in virtually any organism.