John Hopkins researchers have developed a highly insightful test to look for DNA attachments that often are early warning signs of cancer. It is done with the help of tiny crystals called quantum dots. The research claims that this test spots both the existence and the quantity of certain DNA changes. It can alert people who are at a threat of developing the disease and could supposedly also tell a doctor how a particular treatment is functioning.
“If it leads to early detection of cancer, this test could have huge clinical implications. Doctors usually have the greatest success in fighting cancer if they can treat it in its early stage,” comments Jeff Tza-Huei Wang, an associate professor of mechanical engineering whose lab team played a leading role in developing the technique.
For the past 3 years, Wang and his students along with his colleagues at the Johns Hopkins Kimmel Cancer Center worked on developing the test. The test seems to signify ‘a very promising platform’ to assist doctors detect cancer at an early stage shares Stephen B. Baylin, deputy director of the center and a co-author of the Genome Research analysis. Through this test doctors can also apparently calculate which patients are most expected to gain an advantage from a particular therapy.
To demonstrate that the technology was sound, the latest research included the detection of DNA markers in the sputum from lung cancer patients. As opposed to the present techniques, the test apparently appears to be more sensitive and presented results very swiftly.
Baylin remarks “The technique looks terrific, but it still needs to be tested in many real-world scenarios. Some of these studies are already under way here. If we continue to see exciting progress, this testing method could easily be in wide use within the next five years.”
DNA methylation is a biochemical change which is the aim of the test and it arises when a chemical group called methyl joins itself to cytosine, one of the four nucleotides or base building blocks of DNA. Methylation, when it happens in decisive gene locations seems to arrest the release of proteins that curb tumors. Hence it appears to be quite easy for the cancer cells to form and multiply. A person may have a higher threat of acquiring cancer whose DNA has this abnormal gene DNA methylation. Adding to it these methylation changes appear to be a premature occasion that lead to the appearance of genetic mutations, another forerunner to cancer.
The John Hopkins team discovered a mode to single out the worrying DNA stands that have a methyl group joined to them, so that they can spot this DNA methylation. All segments that do not have a methyl group are changed into another nucleotide through a chemical process called bisulfite conversion.
During a lab process, they had to make extra copies of the remaining target DNA strands that are connected to cancer, two molecules are joined to opposite ends of each DNA strand. One of them is a protein named Biotin. The fluorescent dye is the other one. These partner molecules are joined to assist researchers spot and count those related to cancer.
The personalized DNA strands were mixed with quantum dots, which are crystals of semiconductor objects, whose volume is in the range of only few nanometers across. They proved to be supportive even in biological applications and these dots are generally engaged in electronic circuitry reveal experts. Energy appears to be effortlessly transferred by them and claims to the significant quality possessed by them. Apparently when light shines on a dot the dot passes the energy to a nearby molecule that uses the energy to produce a fluorescent glow. Due to this the cancer related DNA strands light up and are thus identified.
In the John Hopkins cancer test, an experiment was conducted to observe the DNA strands that light up and the cancer–linked DNA could be analyzed. The researchers could then find out how much of the DNA methylation was present. Larger the amount, supposedly the higher the threat for cancer.
Vasudev J. Bailey, a biomedical engineering doctoral student from Bangalore, India, who was one of the two lead authors on the Genome Research paper mentions “This kind of information could allow a patient with positive methylation to undergo more frequent cancer screening tests. This method could replace the traditionally more invasive ways for obtaining patient samples with a simple blood test. It’s also important because these test results could possibly help a doctor determine whether a particular cancer treatment is working. It could pave the way for personalized chemotherapy.”
Different types of cancer display characteristic genetic markers. Researchers also mention that the test would be able to identify what type of cancer the patient is at the threat of developing. For instance the markers for Leukemia are unlike the markers for lung cancer.
These findings were reported in a paper called ‘MS-qFRET: a quantum dot-based method for analysis of DNA methylation,’ which was published in the journal Genome Research. The work also was presented at a conference of the American Association of Cancer Research.