Like HMGCR, the expression of HMGCS1, but not LDLR, is also differentially regulated in response to lovastatin exposure in insensitive MM cells. MM cells were exposed to the indicated concentrations of lovastatin for various lengths of time and assayed for HMGCS1 (A) or LDLR (B) expression by real-time PCR, 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 HMGCS1 expression, but not LDLR, 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.