(+)-JQ1

(+)-JQ1 enantiomer binds directly into the Kac binding site of BET bromodomains. (+)-JQ1 (500 nM) binds BRD4 competitively with chromatin resulting in differentiation and growth arrest of NMC cells. (+)-JQ1 (500 nM) attenuates rapid proliferation of NMC 797 and Per403 cell lines as demonstrated by reduced Ki67 staining. (+)-JQ1 (500 nM) potently decreases expression of both BRD4 target genes in NMC 797 cells. (+)-JQ1 inhibits cellular viability with IC50 of 4 nM in NMC 11060 cells. ^[1] (+)-JQ1 results in robust inhibition of MYC expression in MM cell lines. (+)-JQ1 inhibits proliferating of KMS-34 and LR5 with IC50 of 68 nM and 98 nM, respectively. (+)-JQ1 (500 nM)-treated MM.1S cells results in a pronounced decrease in the proportion of cells in S-phase, with a concomitant increase in cells arrested in G0/G1. (+)-JQ1 (500 nM) results in pronounced cellular senescence by beta-galactosidase staining. (+)-JQ1 (800 nM) exposure leads to a significant reduction in cell viability among the majority of CD138+ patient-derived MM samples tested. ^[2] (+)-JQ1 inhibits growth of LP-1 cells with GI50 of 98 nM. (+)-JQ1 (625 nM) results in an increase in the percentage of LP-1 cells in G0/G1. (+)-JQ1 (500 nM) suppresses the expression of MYC, BRD4 and CDK9 in LP-1 cells. ^[3] (+)-JQ1 (1 μM) activates HIV transcription in latently infected Jurkat T cells. (+)-JQ1 (50 μM) stimulates predominantly Tat-dependent HIV transcription in both Jurkat and HeLa cells. (+)-JQ1 (5 μM) induces Brd4 dissociation enables Tat to recruit SEC to HIV promoter and induce Pol II CTD phosphorylation and viral transcription in J-Lat A2 cells. JQ1 enables Tat to increase CDK9 T-loop phosphorylation and partially dissociates P-TEFb from 7SK snRNP in Jurkat T cells. ^[4]