Successful Identification of a Novel Therapeutic Compound for Hepatocellular Carcinoma Through Screening of ADAM9 Inhibitors.

BACKGROUND/AIM: MHC-class I-related chain A (MICA) functions as a ligand for natural killer group D, an activating receptor on natural killer (NK) cells, and its expression correlates with the carcinogenesis and progression of hepatocellular carcinoma (HCC). Although membranous MICA (mMICA) activates NK cells, soluble forms of MICA (sMICA), shed by cleaving enzymes, such as A disintegrin and metalloprotease (ADAM) 9, suppress NK cells. Therefore, the prevention of MICA shedding through the inhibition of ADAM9 has the potential to activate cancer immunity. Although we have discovered several ADAM inhibitors, many did not sufficiently activate NK cells without being cytotoxic, and, thus, new ADAM9 inhibitor candidates are needed. MATERIALS AND METHODS: To identify possible compounds for drug development, chemical library screening (a total of 741 compounds) was conducted using a fluorescence assay. Compounds with reduced fluorescence intensity were used as hit compounds in a subsequent analysis. Their impact on sMICA and mMICA in HCC cell lines was assessed using ELISA and flow cytometry, respectively. The cytotoxicity of NK cells was also evaluated by co-culturing NK cells with HCC cells. RESULTS: CCL347, a symmetrical compound with five benzene rings, was identified as a hit compound. CCL347 significantly reduced sMICA levels in the culture medium supernatant with negligible cytotoxicity. Although mMICA was also reduced, CCL347 successfully enhanced NK cell cytotoxicity in co-cultures of NK cells and HCC cells. CONCLUSION: CCL347 has potential as a novel therapeutic drug for HCC.

Analysis of the haplotype and linkage disequilibrium of PPARγ gene polymorphisms rs3856806, rs12490265, rs1797912, and rs1175543 among patients with metabolic syndrome in Kazakh of Xinjiang Province.

We investigated the relationship between haplotype and linkage disequilibrium of the PPARγ gene polymorphisms rs3856806, rs12490265, rs1797912, and rs1175543 and metabolic syndrome (MS) in the Kazakh people of Xinjiang Province. For PPARγ, rs3856806, rs12490265, rs1797912, and rs1175543 genotypes were detected in 489 subjects (including 245 MS patients and 244 controls) using matrix-assisted laser desorption-ionization time-of-flight mass spectrometry. Frequencies of rs3856806T, rs12490265A, rs1797912C, and rs1175543G alleles in MS patients were significantly lower than those of controls [rs3856806T allele: 12.53 vs 17.01% (P = 0.044), rs12490265A allele: 31.84 vs 38.52% (P = 0.029), rs1797912C allele: 35.31 vs 43.24% (P = 0.011), rs1175543G allele: 40.61 vs 47.54% (P = 0.029)]. Significant linkage disequilibrium was observed between the PPARγ rs1797912 and rs1175543 polymorphisms as well as between the rs12490265 and rs1175543 polymorphisms. A total of 14 haplotypes were found. Patients with rs3856806T, rs12490265A, rs1797912C, and rs1175543G were observed 0.267 times more frequently [95% confidence interval = 0.126-0.566] than those with rs3856806C, rs12490265G, rs1797912A, and rs1175543A, respectively. The PPARγ gene polymorphisms rs3856806, rs12490265, rs1797912, and rs1175543 were associated with MS in Kazakh subjects. Very strong linkage disequilibrium was found between the PPARγ rs1797912 and rs1175543 polymorphisms as well as between the rs12490265 and rs1175543 polymorphisms. AGCC and GAAT haplotypes may serve as protective factors against MS. The rs3856806T, rs12490265A, rs1797912C, and rs1175543G alleles may enhance the protective effect of MS.