Message #15 From:
TheMachine Date: October 27, 2008 11:10:55 AM
Glioblastoma multiforme : Mechanism in cells forming brain tumours may offer target for gene therapy
Washington, Oct 25 (ANI): In a new study, researchers at
Cedars-Sinai Medical Center’’s Maxine Dunitz Neurosurgical Institute
have discovered a molecular mechanism involved in the development of
cells that give rise to malignant brain tumours.
The scientists say that their findings may provide a target for
killing malignant brain tumours at their source, and will also prevent
them from recurring.
Cancer stem cells, like normal stem cells, have multi-potent and
self-renewing properties, but instead of producing healthy cells, they
propagate cancer cells. Thus, destroying such “mother cells” would mean
that the tumour would not survive.
Alternatively, if such cells are not removed or destroyed, the
tumour would continue to return despite the use of existing
cancer-killing therapies.
Glioblastoma multiforme is the most malignant form of tumour that
develops in the brain, but all glioblastomas are not identical.
Subgroups are comprised of cells originating from different brain
tumour stem cells with unique genetic characteristics that use
different signalling pathways in their development and growth.
Now, the researchers are building genetic “profiles” of these cancer stem cells and the tumours they appear to produce.
In the current study, they identified a subset of brain tumour stem
cells that is dependent on a protein called Sonic Hedgehog, and another
subset that is not Hedgehog dependent.
Brain tumours resulting from each subset did have the “signalling
dependency” characteristics of the mother cells. Pathway-specific
blocking interventions prevented the brain tumour stem cells from being
able to renew themselves in laboratory experiments and studies in
laboratory mice.
According to scientists, Sonic Hedgehog signalling mechanism looks
like one of the molecular mechanisms regulating both normal stem cell
growth and cancer stem cell growth.
“According to our analysis, patients who have malignant brain tumors
produced from cancer stem cells that rely on this mechanism have a
shorter survival than those who don”t,” said John S. Yu, M.D., director
of Surgical Neuro-oncology at Cedars-Sinai and senior author of the
Stem Cells article.
The findings could pave the way for therapies to block the
underlying cancer-causing mechanisms with genes or small molecules,
according to the research team.
The study is published in the journal Stem Cells. (ANI)
