Researchers have found that cisplatin binds 20-times more pervasively to RNA than to DNA. This makes RNA a possible new drug target for cisplatin, a compound used to fight nearly 70% of all human cancer tumors.
Although patients treated with cisplatin often experience a reduction in tumor size, use of the drug is frequently discontinued due to toxicities including anemia, gastrointestinal problems, nerve damage, renal insufficiency, and tinnitus.
“We're looking at RNA as a new drug target,” affirmed Victoria J. DeRose, a chemist at University of Oregon in Eugene and coauthor of the ACS Chemical Biology paper detailing the cisplatin/RNA discovery. “We think this is an important discovery because we know that RNA is very different in tumors than it is in regular healthy cells.”
Researchers applied cisplatin to quickly dividing and RNA-rich cells, Saccharomyces cerevisiae. The RNA retained the platinum compound, and the platinum attached to the RNA quickly, appearing on the RNA as soon as 1 hour after treatment. Although the cisplatin was 2 to 3 times denser on DNA, the whole-cell concentration on RNA was much higher.
Eventually, scientists may find ways to target specific section of RNA with cisplatin and, as a result, reduce the drug's toxicity.