The tetrahydropyran 4-(((3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)-4-phenylbutyl)amino)methyl)-N,N-dimethylaniline was reported to disrupt the SCFSKP2 E3 ligase complex. Efficient syntheses of this tetrahydropyran derivative and analogues, including the des-dimethyl derivative 4-(((3-(tetrahydro-2H-pyran-4-yl)-4-phenylbutyl)amino)methyl)-N,N-dimethylaniline, are described. The enantiomers of the des-dimethyl compound were obtained using Evans’ chiral auxiliaries. Structure–activity relationships for these tetrahydropyrans and analogues have been determined by measurement of growth-inhibitory activities in HeLa cells, which indicated a non-specific mechanism of action that correlates with inhibitor lipophilicity. However, preliminary data with (R)- and (S)-4-(((3-(tetrahydro-2H-pyran-4-yl)-4-phenylbutyl)amino)methyl)-N,N-dimethylaniline showed enantioselective inhibition of the degradation of p27 in a cell-based assay that acts as a reporter of SKP2 activity.

Cell lines established from the TH-MYCN transgenic murine model of neuroblastoma are a valuable preclinical, immunocompetent, syngeneic model of neuroblastoma, for which knowledge of their p53 pathway status is important. In this study, the Trp53 status and functional response to Nutlin-3 and ionising radiation (IR) were determined in 6 adherent TH-MYCN transgenic cell lines using Sanger sequencing, western blot analysis and flow cytometry. Sensitivity to structurally diverse MDM2 inhibitors (Nutlin-3, MI-63, RG7388 and NDD0005) was determined using XTT proliferation assays. In total, 2/6 cell lines were Trp53 homozygous mutant (NHO2A and 844MYCN+/+) and 1/6 (282MYCN+/-) was Trp53 heterozygous mutant. For 1/6 cell lines (NHO2A), DNA from the corresponding primary tumour was found to be Trp53 wt. In all cases, the presence of a mutation was consistent with aberrant p53 signalling in response to Nutlin-3 and IR. In comparison to TP53 wt human neuroblastoma cells, Trp53 wt murine control and TH-MYCN cell lines were significantly less sensitive to growth inhibition mediated by MI-63 and RG7388. These murine Trp53 wt and mutant TH-MYCN cell lines are useful syngeneic, immunocompetent neuroblastoma models, the former to test p53-dependent therapies in combination with immunotherapies, such as anti-GD2, and the latter as models of chemoresistant relapsed neuroblastoma when aberrations in the p53 pathway are more common. The spontaneous development of Trp53 mutations in 3 cell lines from TH-MYCN mice may have arisen from MYCN oncogenic driven and/or ex vivo selection. The identified species-dependent selectivity of MI-63 and RG7388 should be considered when interpreting in vivo toxicity studies of MDM2 inhibitors.

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The clinical, serological and electron microscopic findings in a 47 year old woman with bioprosthetic valve coxiella endocarditis occurring 15 years after streptococcal endocarditis are described. The patient underwent valvular surgery a total of four times to control symptoms and remains weli on medical therapy more than two years after her last operation. (3 Clin Pathol 1996;49:679-687)