M. D. Anderson Cancer Center Newsroom
News Release: Weakened RNA Interference Reduces Survival in Ovarian Cancer
Date: December 17, 2008
Duration: 0 / 02:54
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This week in the New England Journal of Medicine Dr. Anil Sood of The University of Texas M. D. Anderson Cancer Center and colleagues report that the presence of two proteins in women ovarian cancer tumor are strongly associated with her likelihood of survival.
When the two proteins Dicer and Drosha are abundant the median survival rate is four times as long as when they are present at low levels or absent.
The team also found that the pair’s presence in tumors also affects survival in breast and lung cancer patients.
Anil Sood, M.D.:
So in this project we looked at the role of two enzymes Dicer and Drosha in ovarian cancer human samples as well as in cell lines. These two enzymes play a critical role in how genes are regulated inside the cells both normal as well as in tumor cells. Remarkably we found that about half of ovarian cancer samples tended to have low levels of Dicer as well as Drosha. When both of these enzymes were present at a low level those patients tended to have significantly shorter survival on average about 2.6 years when these enzymes were present at normal or high levels then the survival is greater then 11 years so there was quite a bit of difference.
Our clinical findings were validated in separate cohorts of cancer patients as well as even in other malignancies such as lung cancer and breast cancer.
There are many potential applications for the clinic from our findings, one is that given that we found those individuals whether it is ovarian cancer patients or those who have lung or breast cancer who have low levels of Dicer especially tend to have shorter survival. So in the long run this kind of a factor may be useful as a prognostic factor as well for determining outcome. Then the other potential applications are that as the therapies based upon RNA interference get developed, there may be implications on what specific strategies can be applied based upon whether or not there are alterations in this kind of enzymatic machinery.
There are many next steps. We are trying to understand further why is it that this kind of machinery is altered in cancer cells and then secondly downstream of this kind of machinery what are the pathways that are altered in cancer cells and what the implications of such alterations are both for human patients in terms of clinical outcome as well as for actual behavior of cancers in terms of growth, spread and so on. So there are many steps that we are still working on.
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Videographer/video editor: Deborah E. Thomas
Producer: Scott Merville
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