Acinetobacter baylyi a bacteria is now capable of detecting tumor DNA in living organisms. An international study between the University of California San Diego and colleagues in Australia has genetically engineered Acinetobacter baylyi to perform this task.
According to studies A. baylyi are non-pathogenic in normal conditions and naturally competent and capable of introducing new genetic material into their genomes via horizontal gene transfer.
Studies report tumors constantly undergo a process called “tumor DNA release or shedding” wherein tumors spread their DNA material into the environment.
Acinetobacter baylyi Detects the KRAS gene
A. baylyi was designed to take up these shed DNA and incorporate them in its own genome causing the expression of an induced antibiotic resistance gene. The bacteria was designed to detect a gene present in tumor cells called KRAS (regulates cell differentiation), which is mostly mutated in cancers of the colon.
The novel method designed is known as CATCH: CRISPR-discriminated horizontal gene transfer. The bacteria was integrated with a functional CRISPR-Cas9 system, which includes a guide RNA (gRNA) to detect the KRAS gene in cancerous cells.
Detecting the KRAS gene was followed by activation of the CRISPR-Cas 9 system and the horizontal gene transfer system. After the uptake and incorporation of the mutated KRAS gene bacteria were now able to transcribe genes such as antibiotic resistance genes that made them detectable.
The bacteria were capable of performing this function both in cell culture and mice animal models. The researchers observed that bacteria that had incorporated the tumor DNA grew green-colored bacterial colonies under the microscope.
FUTURE BENEFITS
CATCH-based biosensors could enable non-invasive liquid biopsies, allowing cancer-specific DNA detection in blood or other bodily fluids. This would reduce the need for invasive tissue biopsies and provide valuable information about disease status.
CATCH might contribute to personalized medicine approaches by allowing for the targeted detection of genetic mutations or markers that are relevant to an individual’s specific disease. This could guide treatment decisions and optimize therapeutic strategies.
Biosensors based on CATCH could monitor the effectiveness of cancer treatments in real-time. Changes in the detected DNA sequences could provide insights into whether a treatment is working or if resistance is developing.
The ability of horizontal transfer has the potential to facilitate the discovery of new therapeutic targets or the development of potential drug candidates.
The gene transfer aspect of CATCH might be harnessed for delivering gene-editing tools, such as CRISPR-Cas, to specific target cells within the body.
Further research is needed to see if this CATCH system can be incorporated into other bacteria and used for the detection of other types of cancers.
According to the synthetic biology team at the University of California, San Diego more studies, development, and refinements need to be conducted to utilize this technology.
Researchers everywhere have praised this novel method for detection, hoping for a future without colorectal cancer.
