Two tumor-suppressing genes given intravenously reduced cancer separately but had their most powerful effect when administered together, cutting the number of tumors per mouse by 75 percent and the weight of tumors by 80 percent.
"In cancer treatment we have combination chemotherapy, and we also combine different modes of therapy - surgery, radiation and chemotherapy. Now you've got the possibility of combined targeted gene therapy," said Jack Roth, M.D., professor and chair of the M. D. Anderson Department of Thoracic and Cardiovascular Surgery and a senior researcher on the project.
The genes wrapped in the nanoparticles were p53, a well-known tumor suppressor that works by causing defective cells to commit suicide and is often shut down or defective in cancer cells, and FUS1, a tumor-suppressor discovered by the research group that is deficient in most human lung cancers. Each nanoparticle carried one of the two genes.
The Cancer Research paper reports that FUS1 works with p53 to force the lung cancer cells to kill themselves - a process known as apoptosis.
Further analysis showed that the combination achieved greater cell suicide because FUS1 suppresses a gene that expresses a protein known to rapidly degrade p53, says senior author Lin Ji, Ph.D., M. D. Anderson associate professor of thoracic and cardiovascular surgery.
The FUS1/p53 combination also activates a cell suicide pathway based in the cells' mitochondria, their energy powerhouse.
Lab experiments first showed that the gene combination cut the number of viable cells in four lines of human non-small cell lung ca
Source:University of Texas M. D. Anderson Cancer Center