On March 14, KAIST announced that Professor Tae-Young Yoon from the Department of Physics and Professor Won Do Heo from the Department of Biological Sciences developed a technique to observe the characteristics of carcinogenic proteins in cancer tissues, real-time at a molecular level. With a small sample from the patient, this technology allows the analysis of how carcinogenic proteins turn into cancer, allowing targeted cancer detection and treatment for individual patients.
Modern medical techniques can only statistically speculate the cause and mechanism of cancer. Recently, the United States, along with several other nations, applied a large-scale sequencing technology to analyze the DNA of cancer patients, but actually proving that the determining the mechanism of how carcinogenic proteins cause cancer at an individual cancer tissue level has long been a difficult challenge.
The research team first developed a fluorescent microscope capable of observing single molecules. Also, the team applied immunoprecipitation - a technology used to detect specific proteins using the affinity between antigens and antibodies - to develop a new immunoprecipitation method, real-time single-molecule co-immunoprecipitation. Using this new method, the research team successfully observed the interaction between carcinogenic proteins and other proteins in real-time.
To verify the technology, the research team investigated the ras carcinogenic protein, statistically known to mutate into cancer 30% of the time. The experiment result showed that of the total ras protein in cancer cells of mice and humans, 30% to 50% existed in an activated state while in normal cells, less than 5% of ras protein were in an activated state, thus proving that if the ras protein is abnormally excited, it causes cancer. Conventional research results only predicted the increase in ras protein ratio and failed to measure the exact ratio value.
The research team proposed a new monomolecular level detection technique to figure out how the cancer is progressing in the patient by measuring the activated carcinogenic protein ratio in cancer cells.
Professor Yoon commented that the newly developed technology does not require additional protein expressions or purification steps, which were necessary in conventional methods. This allows direct observation of carcinogenic proteins in actual cancer cells, opening new steps towards personalized chemotherapy. He also commented that since the technology allows the observation of samples in single molecular states, this can be used with small amounts of protein samples from cancer patients to run various tests (current techniques cannot amplify small amounts of protein samples from cancer cells). Professor Yoon added that the clinical trials of the technology started last December and he expects the technology to be used for personalized cancer detection and treatment in several years.
The research result was published in the February 19 issue of Nature Communications. The research team members, other than Professor Yoon and Professor Heo, include Professor Dae-Sik Lim from the Department of Biological Sciences, Professor Changbong Hyoen of Korea Institute for Advanced Study, and other researchers in various fields.