Effects of HIF-1α-siRNA and CTM in U251MG and U343MG Cells: qRT-PCR of HIF-1α mRNA Levels. A (U251MG) and B (U343MG), Silencing of normoxic and hypoxic HIF-1α mRNA levels using 75 nM HIF-1α-specific siRNA in comparison with 75 nM control siRNA treated and untreated cells. C (U251MG), CTM slightly enhanced the HIF-1α mRNA expression under normoxic and hypoxic conditions. 75 nM CTM in comparison with DMSO-treated and untreated cells. D (U343MG), CTM decreased the normoxic and hypoxic HIF-1α mRNA expression. 75 nM CTM in comparison with DMSO-treated and untreated cells.