University Times

Cisplatin, a commonly employed chemotherapy drug, greatly increases the expression of liposome-delivered genes in tumor cells of laboratory animals, according to a report by University of Pittsburgh Medical Center (UPMC) researchers in the Dec. 15 issue of the "Proceedings of the National Academy of Sciences." Liposomes are small spheres of fat molecules that may be used to carry other substances.

"This research points to the development of a clinical protocol in which physicians use cisplatin to prime cancer cells so that they respond much better to gene therapy," said Leaf Huang, principal investigator of the study and professor of pharmacology at the UPMC.

"Many times, tumor cells in patients treated with cisplatin become resistant to this drug or they learn how to get rid of it," Huang continued. "Our research suggests that this resistance, which thwarts the ability of cisplatin to kill tumor cells, could actually facilitate an effective gene therapy." The study was conducted in laboratory mice transplanted with human ovarian tumors. Researchers injected one group of mice with cisplatin. A week later these mice were injected with DNA-liposome complexes. Another group of mice was injected only with DNA-liposome complexes. The researchers detected expression of transferred DNA much more in tumor cells of mice first treated with cisplatin than in the mice that did not receive cisplatin.

In addition to ovarian cancer cells, the UPMC researchers found increased expression of liposome-delievered reporter genes in cisplatin-sensitized human lung, head and neck tumor cells.