TWIST1 over-expression does not generate an E- to N-cadherin switch in GBM cell lines. Absolute quantification of E-cadherin (A) and N-cadherin (B) mRNA expression levels in GBM cells by qRT-PCR demonstrates variable levels of gene expression. Of note, E-cadherin is low or barely detectable in two of five lines tested. (C) Relative quantification of E- and N-cadherin gene expression in GBM cell lines with TWIST1 over-expression relative to control cells transduced with empty vector (accepted as 1 and shown as horizontal line). E-cadherin expression change is not shown for T98G because of expression levels close to background (see panel A). Contrary to carcinoma cells where TWIST1 expression activates a "cadherin switch" TWIST1 over-expression in GBM cell lines did not reduce E-cadherin expression concurrent with increased N-cadherin in any line tested.