Anti-CDK1 polyclonal antibody

A novel series of pyrazoles and pyrazolo [1,5-alpha] pyrimidines bearing benzothiazole moiety were designed and synthesized. Chemical structures were confirmed by spectral data and elemental analyses. Nine compounds were selected and screened for their cytotoxic activity at the National Cancer Institute (NCI), USA against 60 cancer cell lines in a single dose assay. Compounds 4 and 5 exerted the most potent growth inhibitory activity against most cancer cell lines with growth inhibition (GI%) ranges from 44.86% to 84.59% and 31.20% to 52.36%, respectively. Consequently, they were further investigated through IC50 determination using five dose MIT colorimetric assay against three sensitive cell lines, leukemia CCRF-CEM, non-small cell lung cancer HOP-92 and liver cancer Hep-G2. Compound 4 exhibited potent cytotoxic activity against the three tested cell lines with IC50 16.34, 3.45 and 7.79 mu M, respectively representing half potency, 3.5 folds potency and nearly equipotent to roscovitine. To investigate its mechanism of action, cell cycle analysis of compound 4 was conducted and showed that it induced cell cycle arrest at G2/M phase and apoptosis in HOP-92 cells. In correlation with the previous results, caspase-3 activation was tested and illustrated elevation in its concentration by nearly 14 folds than control. Besides, enzyme inhibition assay of compound 4 was evaluated towards two common antitumor targets namely KDM1 and CDK1 showing significant inhibitory activity with IC50 0.096 and 0.078 mu M, respectively.

Isoorientin (ISO) is a naturally occurring C-glycosyl flavone that has various pharmacological properties, such as anti-bacterial and anti-inflammatory effects. However, its underlying molecular mechanisms in human lung cancer cells remain unknown. In the present study, the effects of ISO on the induction of apoptosis and relative molecular mechanisms in A549 human lung cancer cells were investigated. The results of Cell Counting Kit-8 assay (CCK-8) indicated that ISO exerted significant cytotoxic effects on 3 lung cancer cell lines, but had no obvious side-effects on normal cells. Moreover, flow cytometry and western blot analysis revealed that ISO induced mitochondrial-dependent apoptosis by reducing mitochondrial membrane potential. ISO also increased the expression levels of Bax, cleaved-caspase-3 (cle-cas-3) and poly(ADP-ribose) polymerase (PARP; cle-PARP), and decreased the expression levels of Bcl-2 in A549 cells. Furthermore, ISO induced G2/M cell cycle arrest by decreasing the expression levels of cyclin B1 and CDK1/2, and increasing the expression levels of p21 and p27 in A549 cells. As the duration of ISO treatment increased, intracellular reactive oxygen species (ROS) levels in A549 cells also increased. However, pre-treatment of the cells with the ROS scavenger, N-acetylcysteine (NAC), inhibited ISO-induced apoptosis. In addition, ISO increased the expression levels of p-p38, p-JNK and I kappa B-alpha; and decreased the expression levels of p-extracellular signal-regulated kinase (ERK), p-signal transducer and activator of transcription (STAT)3, p-nuclear factor (NF)-kappa B, NF-kappa B and p-I kappa B; these effects were induced by mitogen-activated protein kinase (MAPK) inhibitors and blocked by NAC. Taken together, the results of the present study indicate that ISO induces the apoptosis of A549 lung cancer cells via the ROS-mediated MAPK/STAT3/NF-kappa B signaling pathway, and thus may be a potential drug for use in the treatment of lung cancer.