Anti-PDK1 polyclonal antibody

Warburg effect, a preference of aerobic glycolysis for energy production even in the presence of adequate oxygen, is one of the most prominent distinctions of cancer cells from their normal equivalents. Upregulated pyruvate dehydrogenase kinase 1 (PDK1) was found to dominate the pivotal switch from mitochondrial respiration to aerobic glycolysis by inactivating pyruvate dehydrogenase (PDH) in cancer cells. PDK1 inhibition may lead to an unfavorable environment for cancer cells, which presents an opportunity for anticancer therapy. However, up to now, only limited number of PDK1 inhibitors were reported. In this work, we reported our attempt to discover novel small molecules from a diverse chemical library containing 15 000 small molecules selected from the Chembridge screening library. We developed a kinase activity-based high throughput screening (HTS) assay for initial screening of PDK1 inhibitors. Seven PDK1 inhibitory compounds were identified with IC50 values range from 0.68 and 45.69 mu M. Follow up evaluations on these compounds revealed good PDK1 binding affinity and antiproliferative activities in cancer cell lines, with two novel hits (9 and 10) clearly outperformed others compounds in terms of PDK1 inhibition and the suppression of cancer cell proliferation. 9 and 10 may serve as new chemistry starting points for further structural modifications to improve the potency on PDK1 inhibition for anticancer treatment.

The migration of mesenchymal stem cells (MSCs) is critical for their use in cell-based therapies. Accumulating evidence suggests that microRNAs are important regulators of MSC migration. Here, we report that the expression of miR-375 was downregulated in MSCs treated with hepatocyte growth factor (HGF), which strongly stimulates the migration of these cells. Overexpression of miR-375 decreased the transfilter migration and the migration velocity of MSCs triggered by HGF. In our efforts to determine the mechanism by which miR-375 affects MSC migration, we found that miR-375 significantly inhibited the activation of Akt by downregulating its phosphorylation at T308 and S473, but had no effect on the activity of mitogen-activated protein kinases. Further, we showed that 3'phosphoinositide-dependent protein kinase-1 (PDK1), an upstream kinase necessary for full activation of Akt, was negatively regulated by miR-375 at the protein level. Moreover, miR-375 suppressed the phosphorylation of focal adhesion kinase (FAK) and paxillin, two important regulators of focal adhesion (FA) assembly and turnover, and decreased the number of FAs at cell periphery. Taken together, our results demonstrate that miR-375 inhibits HGF-elicited migration of MSCs through downregulating the expression of PDK1 and suppressing the activation of Akt, as well as influencing the tyrosine phosphorylation of FAK and paxillin and FA periphery distribution.