Tiny particles carrying a killer gene can effectively suppress ovarian tumor growth in mice, said U.S. researchers.

The findings, reported Thursday in the journal Cancer Research, could lead to a new treatment for ovarian cancer, according to researchers from Massachusetts Institute of Technology.

They deliver a gene that encodes the diphtheria toxin, which kills cells by disrupting their ability to manufacture proteins. The "killer gene" is engineered to be over-expressed in ovarian cells but is inactive in other cell types. So it can selectively target the varian tumors and slow its growth in mice.

Human clinical trials could start, after some additional preclinical studies, in about a year or two, says Daniel Anderson, a senior author of the study paper.

Currently ovarian cancer patients undergo surgery followed by chemotherapy. In many cases, the cancer returns after treatment, and there are no good therapies for recurring and advanced-stage tumors. The gene therapy was equally as effective, and in some cases more effective, than the traditional chemotherapy.

In future studies, the team plans to examine the effectiveness of nanoparticle-delivered diphtheria toxin genes in other types of cancer, including brain, lung and liver cancers.

(Xinhua News Agency July 31, 2009)