MYC knock-down inhibits cell growth: MYC, a bona fide client of HSP90 chaperon, is overexpressed in MCL patient samples. (A) Immunoblot showing reduction in MYC expression 4 days after transfection with siMYC or control (CTRL, pmaxGFP Vector provided by Amaxa) in MCL cell lines. GAPDH, loading control. (B) MYC protein levels determined by immunoblotting in panel A were quantified and normalized to GAPDH. (C) Growth of siMYC or GFP-transfected MCL cells over the course of 8 days postnucleofection. (D) Immunoblot of MYC in MCL whole-cell lysates (lane1s), chemical precipitates with PU-H71-conjugated beads (lane 2s), immunoprecipitates with anti-HSP90-conjugated beads (lane 3s) or control beads (lane 4s). GAPDH, loading control. (E) Immunoblot of HSP90 in primary MCL cells (Pt 1-11, n = 11), in normal B cells from 5 healthy donors (N1-N5), or from MCL cell lines. b-actin, loading control. (F) Levels of HSP90 protein in each groups shown in panel B were quantified and normalized to b-actin. One-way analysis of variance was used for statistical analysis. Bars represent means ± standard error of the mean. P values are indicated.