David Douglas
Reuters Health
Posting Date: January 23, 2004

Last Updated: 2004-01-23 13:53:36 -0400 (Reuters Health)

　　NEW YORK (Reuters Health) - Inhibition of mRNA by means of small interfering RNA (siRNA) shows promise in arresting cancer growth, researchers report. As lead investigator Dr. A. Raja Choudhury told Reuters Health, "our results demonstrate that it is possible to harness this exciting new technology, RNA interference, to silence the Her-2/neu gene which is associated with a variety of cancers."

　　Dr. Choudhury of the Karolinska Institute in Stockholm, Sweden and colleagues note in the January 1st issue of the International Journal of Cancer that SiRNA are short double-stranded RNA fragments that are identical in sequence to those of the target mRNA. The presence of the double-stranded RNA signals cellular machinery to degrade the target mRNA.

　　The researchers designed three such siRNA to act against the HER2 gene that plays an important role in the oncogenesis of breast, ovarian, colon and other cancers.

　　In vitro studies showed that introduction of siRNA greatly reduced cell surface expression of HER2 protein. Other effects included growth inhibition and apoptosis. The magnitudes of these responses, the investigators point out, "appear to be greater than [those] of other approaches."

　　Thus, they conclude that "siRNA may be an effective method of abrogating the effect of HER2 in tumorigenesis."

　　In fact, Dr. Choudhury added, "the utility of RNA interference to answer research questions is becoming increasingly apparent. In the future, it may be possible to use siRNA clinically for the treatment of cancer, viral infections like HIV and many other diseases."

Int J Cancer 2004;108:71-77.