A secret of tumor stem cell survival: Scientists make progress against a devastating cancer
Malignant glioma is generally a death sentence for patients. These tumors, which arise from non-neuronal cells within the brain, grow quickly and aggressively, and contain a core population of glioma stem cells (GSCs) that are largely invulnerable to the weapons typically brought to bear against other cancers. “GSCs display resistance to radiation due to increased activation of DNA damage repair pathways, and also possess intrinsic resistance mechanisms against chemotherapy-induced cell death,” explains Prabha Sampath of the A*STAR Institute of Medical Biology. New work from Sampath and her co-workers has revealed a potential vulnerability in GSCs that might give glioma patients a fighting chance. Her team studies microRNAs, tiny RNA molecules that do not encode protein; instead, they govern the production of proteins encoded by other genes. This research has a direct bearing on glioma progression. “MicroRNA-mediated translational control is known to be a major factor in brain tumor pathology,” explains Sampath. She and her colleagues obtained GSCs from five patients with malignant glioma, and examined how their expression levels of known microRNAs differed relative to normal neural stem cells (NSCs). This revealed that GSCs produce markedly higher levels of the microRNA miR-138; importantly, miR-138 levels dropped when the researchers chemically forced the GSCs to ‘mature’ into differentiated brain cells, supporting a role for this RNA in uncontrolled tumor growth. Treatment with ‘antimiR-138’, a molecule that selectively blocks the function of miR-138, killed cultured GSCs but had no effect on normal NSCs. Closer examination revealed that the inactivation of this microRNA prevented GSCs from undergoing cell division, and instead caused these cells to undergo a cellular ‘self-destruct’ program.
Read more at: http://phys.org/news/2012-11-secret-tumor-stem-cell-survival.html#jCp
Apogenix’s Apocept(TM) for Glioblastoma Multiforme Named One of “Top 10 Projects to Watch”
“We are honored that our lead candidate, Apocept, has been selected as one of Windhover’s Top 10 Projects to Watch,” said Dr. Höger. “Apocept is the first drug in more than a decade that has shown clear benefits in a randomized, controlled clinical trial regarding quality of life, progression free survival as well as overall survival in patients with recurrent GBM, a disease that represents a tremendous unmet medical need. Best responses were seen in patients expressing a newly identified biomarker. Apocept’s unique mechanism of action has potential in many other cancers beyond GBM.”
Scorpion venom with nanoparticles slows spread of brain cancer