Id1 knockdown in primary human glioma stem cells. Homo sapiens

Abnormal activation of stemness factors is a crucial signature of cancer stem cells (CSCs), a highly tumorigenic subpopulation in malignant tumors. However, it is unclear whether multi-signaling pathways are activated in CSCs, as like normal stem cells. I would like to report that an inhibitor of differentiation 1 (ID1) activates intracellular multi-signaling involved in proliferation, genesis, and maintenance of glioma stem cells (GSCs) by suppression of Cullin3, an E3 ubiquitin ligase that degrades Cyclin E and components of SHH and WNT signaling. ID1 inhibits BMP-dependent differentiation of GSCs by activation of BMPR2-targeting miR17/20a. ID1HIGH-Cullin3LOW signature correlates with a poor prognosis of GBM patients with a significant association to gene signatures enriched in EGF, WNT, SHH, and BMP signaling. Combinational inhibition of GSC intracellular multi-signaling network increases tumor-bearing mice survival. These results provide insights on molecular and cellular basis of GSC biology, and also suggest necessity of multi-signaling inhibition for GSCs therapy. Overall design: Two human primary glioma stem cells (GSCs) such as GSC2 and GSC8 were isolated from two individual primary human glioma specimens. The GSCs were directly transfected with pSuper-GFP-ID1-shRNA and pSuper-GFP-Scrambled-shRNA using FuGENE 6 reagent (Roche). The RNA extraction in these cells was used to analyze gene expression.