Nanoparticles combined with 'suicide' genes slowed ovarian tumor growth

It is very good to hear that nanoparticles have slowed ovarian tumor growth in mouse experiments since it might help one day many women suffering from late stage ovarian cancer. Ovarian tumor growth was a big issue for the past years though the ovarian tumor at initial stages was treated surgically followed by chemotherapy the treatment for ovarian cancer in advanced stages had no effective results. It is disproportionately deadly because it lacks any clear early detection or screening, meaning they are diagnosed only after they have reached advanced stages. Over 75% of ovarian cancers are diagnosed at an advanced stage. Currently the treatment for ovarian cancer is give by chemotherapy but in many cases the cancer returns back and there are no good therapies for recurring and advanced stage ovarian tumors. This new treatment reported by July 31 issue science daily, delivers a gene that produces the diphtheria toxin, which kills cells by disrupting their ability to manufacture proteins. This toxin is normally produced by cornynebacterium diphtheriae. The other good thing about this treatment on advanced ovarian tumor growth unlike chemotherapy which acts on both good and bad cells is that it acts only on the infected tumor cells leaving back the good ones said the lead researcher Janet Sawicki, Ph.D., a professor at the Lankenau institute for medical research. It is also said that Sawicki along with her team experimented the efficiency of cationic biodegradable beta-amino ester polymer as a vector for the nanoparticle delivery of a DNA encoding diphtheria toxin suicide gene. They are called poly beta amino esters because they are the new nanoparticles and are made with positively charged, biodegradable polymers known as poly beta amino esters. When mixed together, these polymers can spontaneously assemble with DNA to form nanoparticles. The polymer-DNA nanoparticle can deliver functional DNA when injected into or near the targeted tissue. These were injected into mice with ovarian tumors. The result was not happy so the team again did the management of nanoparticles in three different mouse models. This showed a very good suppression of tumor size with minimal non-specific cytotoxcity. It did not have toxic effects of chemotherapy because the gene is engineered to be over expressed in ovarian cells but is inactive in other cell types.

mucinous ovarian tumour (source: wikipedia)

The main thing about treating this advanced stage ovarian cancer is that finding the target where these cancerous cell prevail was very difficult said Edward Sausville, M.D., Ph.D., an associate editor of cancer research and associate director for clinical research at the Greenebaum Cancer Center at the University of Maryland who is working in the Oncology department studying ways to kill tumors for a long time. But now Sausville is happy that this new method of treating ovarian cancer can find the target in many different ways.

In count to ovarian cancer, these nanoparticles have demonstrated potential for treatment of a variety of diseases, including prostrate cancer and viral infection. In future studies the team has plans to examine the effectiveness of nanoparticle-delivered diphtheria genes in other types of cancer, including brain, lung and liver cancers.