BMS-345541

BMS-345541 dose-dependently inhibits the TNF-α-stimulated phosphorylation of IκBα in THP-1 monocytic cells with an IC50 of ~4 μM. This compound inhibits lipopolysaccharide-stimulated tumor necrosis factorα, interleukin-1β, interleukin-8, and interleukin-6 in THP-1 cells with IC50 values in the 1- to 5 μM range. It binds in a mutually exclusive manner with respect to a peptide inhibitor corresponding to amino acids 26 - 42 of IκBα with Ser-32 and Ser-36 changed to aspartates and in a non-mutually exclusive manner with respect to ADP. This chemical binds to similar allosteric sites on IKK-1 and IKK-2, which then affects the active sites of the subunits differently. ^[1] It affects several mitotic cell cycle transitions, including mitotic entry, prometaphase to anaphase progression and cytokinesis. Adding this compound to the cells released form arrest in G-phase blocks the activation of Aurora A, B, and C, Cdk1 activation and histone H3 phosphorylation. Treatment of the mitotic cells with this chemical results in precocious cyclin B1 and securin degradation, defective chromosome separation and improper cytokinesis. It is also found to override the spindle checkpoint in nocodazole-arrested cells. These effects are not primarily due to a direct inhibitory effect of this compound on mitotic kinases such as Cdk1, Aurora A or B, Plk1 or NEK2. ^[2] This compound (10 μM) inhibits growth of Normal human epidermal melanocytes, and metastatic melanoma cells (SK-MEL-5, A375, and Hs 294T) by 96% and 99% at 72h, respectively. Application of 100 μM of it to SK-MEL-5 cell culture results in 87% apoptotic cells at 24 h through caspase-independent and AIF-dependent mitochondria-mediated manner. Treatment with this chemical (10 μM) results in 76% and 95% reduction in IKK activities and NF-kB activity, as well as CXCL1 production. ^[3] It inhibits the growth of T-cell acute lymphoblastic leukemia (T-ALL) cells line BE-13, RPMI-8402 and DND-41, all three harboring a Notch1 mutation, and T-ALL primary cells from pediatric patients, with IC50 of 2-6 μM. 5 μM of this compound induces an arrest in the G2/M phase of the cell cycle in BE-13 and DND-41 cells, and sub-G1 peak increase in RPMI-8402 cells. 5 μM of it treated for 16 h leads to an increase in apoptotic cells in all these cell, accompanied by a time-dependent cleavage of procaspase-8, procaspase-3 and poly (ADP-ribose) polymerase (PARP). This chemical (5 μM) induces a time dependent dephosphorylation of IκBα and p65. T-ALL cells treated with it displays nuclear translocation of FOXO3a and restoration of its functions, including control of p21^Cip1 expression levels. ^[4] It inhibits the TNFα-induced expression of both ICAM-1 and VCAM-1 in human umbilical vein endothelial cells with IC50 of 5 μM. ^[5]

1×10⁵ cells per well are plated in six-well plates with 10% fetal bovine serum medium overnight to allow cell adhesion. Cells ae cultured in medium containing BMS-345541 for 72 hours of treatment. Cells are counted with a hemocytometer.

BMS-345541 effectively inhibits melanoma tumor growth in a dose-dependent manner. Tumor-bearing mice treated with 75 mg/kg of this compound shows effective inhibition of growth of SK-MEL-5, A375, and Hs 294T tumors by 86 %, 69% and 67%, respectively, when compared with control animals treated with vehicle alone. [3] This compound administered orally at doses of 100 mg/kg, reduces the severity of dextran sulfate sodium-induced colitis in mice with weight ratio, clinical scoring of colons, mean injury score and mean inflammation score of 0.86 (vs 0.77 of vehicle group), 1.0 (vs 2.5 of vehicle group), 5.66 (vs 8.52 of vehicle group), 6.82 (vs 12.33 of vehicle group), respectively. ^[6] This chemical (100 mg/kg), when administered by oral gavage in water once daily beginning at the time of the first collagen immunization, inhibits clinical signs of disease in the murine CIA model (0 vs ~8 of vehicle group), accompanied by reduced paw swelling. It reduces cumulative arthritis injury score from 4.4 to 0, accompanied by lower degrade of tibiotarsal joints and severity of inflammation, synovial hyperplasia, bone resorption, and cartilage erosion. No discernible injury is observed in the joints of animals, which is histologically indistinguishable from those from age-matched, disease-free control animals. This compound dose-dependently inhibits IL-1β message, with animals in the 100 mg/kg dose group showing levels comparable with those of disease-free control animals. ^[7]