Real-time PCR analysis shows that both HMGCR splice variants are preferentially up-regulated by insensitive MM cells exposed to lovastatin. (A) A schematic illustrating the real-time PCR strategy used to detect HMGCR-FL (i), HMGCR-D13 (ii), and total endogenous HMGCR (iii). MM cells were exposed to the indicated concentrations of lovastatin for various lengths of time and assayed for HMGCR-FL (B) or HMGCR-D13 (C) expression by real-time PCR using primers i and ii (A), respectively, measured relative to GAPDH. Both the dose range for 16 hours (left) and time course at 20μM lovastatin (middle) indicated that LP1 cells up-regulated HMGCR expression more significantly than KMS11 cells. This differential was extended to include other sensitive and insensitive MM cell lines exposed to 20μM lovastatin for 16 hours (right). *P < .05 (Student t test with Welch adjustment for multiple testing). All experiments were performed a minimum of 3 times. Data are mean ± SD.