YES1 Is a Targetable Oncogene in Cancers Harboring YES1 Gene Amplification.

Targeting genetic alterations of oncogenes by molecular-targeted agents (MTA) is an effective approach for treating cancer. However, there are still no clinical MTA options for many cancers, including esophageal cancer. We used a short hairpin RNA library to screen for a new oncogene in the esophageal cancer cell line KYSE70 and identified YES proto-oncogene 1 (YES1) as having a significant impact on tumor growth. An analysis of clinical samples showed that YES1 gene amplification existed not only in esophageal cancer but also in lung, head and neck, bladder, and other cancers, indicating that YES1 would be an attractive target for a cancer drug. Because there is no effective YES1 inhibitor so far, we generated a YES1 kinase inhibitor, CH6953755. YES1 kinase inhibition by CH6953755 led to antitumor activity against YES1-amplified cancers in vitro and in vivo. Yes-associated protein 1 (YAP1) played a role downstream of YES1 and contributed to the growth of YES1-amplified cancers. YES1 regulated YAP1 transcription activity by controlling its nuclear translocation and serine phosphorylation. These findings indicate that the regulation of YAP1 by YES1 plays an important role in YES1-amplified cancers and that CH6953755 has therapeutic potential in such cancers. SIGNIFICANCE: These findings identify the SRC family kinase YES1 as a targetable oncogene in esophageal cancer and describe a new inhibitor for YES1 that has potential for clinical utility.See related commentary by Rai, p. 5702.

Design and evaluation of azaindole-substituted N-hydroxypyridones as glyoxalase I inhibitors.

We conducted a high throughput screening for glyoxalase I (GLO1) inhibitors and identified 4,6-diphenyl-N-hydroxypyridone as a lead compound. Using a binding model of the lead and public X-ray coordinates of GLO1 enzymes complexed with glutathione analogues, we designed 4-(7-azaindole)-substituted 6-phenyl-N-hydroxypyridones. 7-Azaindole's 7-nitrogen was expected to interact with a water network, resulting in an interaction with the protein. We validated this inhibitor design by comparing its structure-activity relationship (SAR) with that of corresponding indole derivatives, by analyzing the binding mode with X-ray crystallography and by evaluating its thermodynamic binding parameters.

Angiogenesis inhibitors identified by cell-based high-throughput screening: synthesis, structure-activity relationships and biological evaluation of 3-[(E)-styryl]benzamides that specifically inhibit endothelial cell proliferation.

Proliferation of endothelial cells is critical for angiogenesis. We report orally available, in vivo active antiangiogenic agents which specifically inhibit endothelial cell proliferation. After identifying human umbilical vein endothelial cell (HUVEC) proliferation inhibitors from a cell-based high-throughput screening (HTS), we eliminated those compounds which showed cytotoxicity against HCT116 and vascular endothelial growth factor receptor 2 (VEGFR-2) inhibitory activity. Evaluations in human Calu-6 xenograft model delivered lead compound 1. Following extensive lead optimization and alteration of the scaffold we discovered 32f and 32g, which both inhibited the proliferation and tube formation of HUVEC without showing inhibitory activity against any of 25 kinases or cytotoxicity against either normal fibroblasts or 40 cancer cell lines. Upon oral administration, 32f and 32g had good pharmacokinetic profiles and potent antitumor activity and decreased microvessel density (MVD) in Calu-6 xenograft model. Combination therapy with a VEGFR inhibitor enhanced the in vivo efficacy. These results suggest that 32f and 32g may have potential for use in cancer treatment.

Design and synthesis of novel macrocyclic 2-amino-6-arylpyrimidine Hsp90 inhibitors.

Macrocyclic compounds bearing a 2-amino-6-arylpyrimidine moiety were identified as potent heat shock protein 90 (Hsp90) inhibitors by modification of 2-amino-6-aryltriazine derivative (CH5015765). We employed a macrocyclic structure as a skeleton of new inhibitors to mimic the geldanamycin-Hsp90 interactions. Among the identified inhibitors, CH5164840 showed high binding affinity for N-terminal Hsp90α (K(d)=0.52nM) and strong anti-proliferative activity against human cancer cell lines (HCT116 IC(50)=0.15µM, NCI-N87 IC(50)=0.066µM). CH5164840 displayed high oral bioavailability in mice (F=70.8%) and potent antitumor efficacy in a HCT116 human colorectal cancer xenograft model (tumor growth inhibition=83%).

Discovery of 6-benzyloxyquinolines as c-Met selective kinase inhibitors.

A novel quinoline derivative that selectively inhibits c-Met kinase was identified. The molecular design is based on a result of the analysis of a PF-2341066 (1)/c-Met cocrystal structure (PDB code: 2wgj). The kinase selectivity of the derivatives is discussed from the view point of the sequence homology of the kinases, the key interactions found in X-ray cocrystal structures, and the structure-activity relationship (SAR) obtained in this work.

Quantitative analysis of influenza virus RNP interaction with RNA cap structures and comparison to human cap binding protein eIF4E.

Influenza virus polymerase uses capped RNA primers for transcription initiation in infected cells. This unique mechanism involves the specific binding of the polymerase to capped mRNA precursors in the nucleus of infected cells. These host RNAs are then cleaved by a polymerase associated endonuclease at a position 10-15 nucleotides downstream of the cap structure. The resulting capped RNA oligonucleotides function as primers for transcription initiation. The viral cap binding site has previously been mapped to the PB2 subunit of the trimeric influenza polymerase complex. We have established a quantitative assay system for the analysis of cap interaction with PB2 as part of the native, viral ribonucleoprotein complex (RNP) using a specific UV cross-linking approach. Cap binding was not affected by the RNase pretreatment of the capped RNA substrate and cap binding was not inhibited by excess uncapped RNA, indicating that under the assay conditions, the majority of the binding energy was contributed by the interaction with the cap structure. Binding to 7-methyl-GTP was found to involve synergistic interaction with 7-methyl guanosine and triphosphate binding subsites. A similar mode of interaction with 7-methyl-GTP was found for human cap binding protein eIF4E. However, the potency of 7-methyl-GTP for cap binding inhibition was 200-fold stronger with eIF4E and had a higher contribution from the triphosphate moiety as compared to influenza RNP. Due to this difference in cap subsite interaction, it was possible to identify novel cap analogues, which selectively interact with influenza virus, but not human cap binding protein.