BIBR 1532 is an effective, specific and non-competitive telomerase inhibitor (IC50: 100 nM, in a cell-free assay).

Telomerase:100 nM

在MCF-7/WT和抗美法仑的MCF-7/MlnR 细胞系中,BIBR 1532（2.5 μM）通过抑制端粒酶活性降低形成集落的能力,并缩短端粒长度,且诱导对化疗增敏。在体外,BIBR 1532剂量依赖性地非竞争性抑制端粒酶活性（IC50：100 nM）。BIBR 1532对T细胞幼淋巴细胞白血病具有选择性细胞毒性,该毒性具有剂量依赖性,BIBR 1532处理过的细胞也出现核浓缩及凋亡小体形成现象。在JVM13白血病细胞系中,BIBR 1532具有剂量依赖性的抗增殖效果（IC50：52 μM）,且对其他白血病细胞系,包括 Nalm-1,HL-60和Jurkat的结果相似。此外, 在急性髓细胞性白血病中,BIBR 1532具有抗增殖效果（IC50：56 μM）,而且不影响正常造血干细胞的增殖能力。

Conventional Telomerase Assay : For the direct telomerase assay with the endogenous telomerase, 10 μL of telomerase-enriched extract is mixed with different concentrations of BIBR1532 in a final volume of 20 μL. After 15-minute preincubation on ice, 20 μL of the reaction mixture is added, and the reaction is initiated by transferring the tubes to 37 °C. The final concentrations in the reaction mixture are 25 mM Tris-Cl (pH 8.3), 1 mM MgCl2, 1 mM EGTA, 1 mM dATP, 1 mM dTTP, 6.3 μM cold dGTP, 15 μCi [α-32P]dGTP (3000 Ci/mmol; NEN), 1.25 mM spermidine, 10 units of RNasin, 5 mM 2-mercaptoethanol, and 2.5 μM TS-primer (5

Cells are plated as triplicates in complete RPMI 1640 medium with various concentrations of BIBR1532. After 24 to 72 hours, water-soluble tetrazolium (WST-1) is added, which is transformed into formazan by mitochondrial reductase systems. The increase in the number of viable cells results in an increase of activity of mitochondrial dehydrogenases, leading to an increase of formazan dye formed, which is quantified by ELISA reader after 2, 3, and 4 hours of incubation. (Only for Reference)