Abstract. An anticancer compound, triterpene glycoside, was isolated from Holothuria nobilis Selenka. Its chemical structure and configuration were determined by two-dimensional nuclear magnetic resonance spectroscopy and electrospray ionization mass spectrometry. The novel active compound was identified as nobiliside D, with the molecular formula C 40 H 61 O 17 SNa and chemical name 3alcohol. An antitumor test was performed using xCELLigence Real-Time Cell Analysis. Nobiliside D exhibited inhibitory effects on human leukemic cell line K562, human leukemia cell line U937, human lung cancer cell line A-549, human cervix carcinoma cell line HeLa, human breast cancer cell line MCF-7 and human liver carcinoma cell line HepG2. Nobiliside exhibited the greatest inhibitory effect on K562 and MCF-7 cells with an IC 50 of 0.83±0.14 and 0.82±0.11 µg/ml, respectively. When human tumor cell lines K562 and MCF-7 were treated by nobiliside D (0.5 µg/ml) for 24 h, 45.8% of K562 cells and 58.7% of MCF-7 cells were apoptotic, whereas only 0.5% of un-treated control cells were apoptotic. These data indicate the compound should offer potential as a novel drug for the treatment of a range of cancers.

Background Aspirin resistance (AR) results in major adverse cardiovascular events, and DNA methylation might participate in the regulation of this pathological process. Methods In present study, a sum of 35 patients with AR and 35 non‐AR (NAR) controls were enrolled. Samples from 5 AR and 5 NAR were evaluated in an 850 BeadChip DNA methylation assay, and another 30 AR versus 30 NAR were evaluated to validate the differentially methylated CpG loci (DML). Then, qRT‐PCR was used to investigate the target mRNA expression of genes at CpG loci. Finally, Gene Ontology (GO) as well as Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to reveal the enriched pathways. Results The AR and NAR groups displayed significant differences in DNA methylation at 7707 positions, with 270 hypermethylated sites (e.g., cg09555818 located in APOC2) and 7437 sites hypomethylated sites (e.g., cg26828689 located in SLC12A5). Six DML were validated by pyrosequencing, and it was confirmed that DNA methylation (cg16391727, cg21008208, cg21293749, and cg13945576) was related to the increasing risk of AR. The relative mRNA expression of the ROR1 gene was also associated with AR (p = 0.007), suggesting that the change of cg21293749 in DNA methylation might lead to differential ROR1 mRNA expression, ultimately resulting in AR. Furthermore, the identified differentially methylated sites were associated with the molecular pathways such as circadian rhythms and insulin secretion. Conclusion Hence, the distinct DNA methylation might play a vital role in the biological regulation of AR through the pathways such as circadian rhythms.

Purpose Clopidogrel resistance (CR) is mostly caused by interindividual variability of the platelet inhibition of clopidogrel, which may induce cardiovascular events. The aim of this research was to evaluate whether DNAm levels of CREB5 (cg01534253) are involved in CR among acute coronary syndrome (ACS) patients treated with clopidogrel. Methods 72 patients(36 CR and 36 non‐CR) who underwent ACS were included in this study. The VerifyNow P2Y12 assay was selected to evaluate residual platelet reactivity, and bisulfite pyrosequencing methods was used to examine DNA methylation levels on cg01534253. Secondly, CREB5 mRNA expression was analyzed via quantitative real‐time PCR. Last, we employed logistic regression to test the interaction between genetic factors of CREB5 methylation and multiple clinical variables in CR patients. Results Subunit analysis indicated that for patients whose HbA1c levels were ≥6.5% or whose GLU levels were ≥7 mmol/L, lower methylation of cg01534253 indicated a poorer clopidogrel response. In addition, CREB5 mRNA expression was increased in CR patients with GLU levels ≥7 mmol/L. Moreover, regression analysis indicated that the values of albumin and uric acid were correlated with the incidence of CR. Conclusions Our findings were likely to provide fresh understanding for the new mechanism of platelet inhibition failure and promote individualized antiplatelet therapy.