Dihydromyricetin promotes apoptosis, suppresses proliferation and tumor necrosis factor-α-mediated nuclear factor kappa-B activation in nasopharyngeal carcinoma CNE-2 cell.

OBJECTIVE: To investigate the efficacy of dihydromyricetin (DMY) on nasopharyngeal carcinoma (NPC) cell proliferation, apoptosis and to reveal the underlying mechanism in vitro experiments. METHODS: The CNE-2 cell line was treated with different concentrations of DMY and the effects of DMY on cell viability and proliferation were evaluated using cell counting kit-8 (CCK-8) assay and plate colony formation assay. Cellular apoptosis was detected by flow cytometry following Annexin V fluorescein isothiocyanate/propidine iodide staining. Nuclei morphology was observed under a fluorescence microscope following Hoechst 333258 staining. The expression of phosphorylated inhibitor of nuclear factor kappa-B kinase subunit beta (p-IKKß), phosphorylated inhibitor of nuclear factor kappa-B kinase subunit alpha (p-IKKα), inhibitor of nuclear factor kappa-B alpha (IκB-α), nuclear factor kappa-B (NF-κB)/p65 was examined by Western blot analysis and the nuclear translocation of NF-κB/p65 was observed using a confocal laser scanning microscopy. RESULTS: DMY inhibited the proliferative capability and colony formation of NPC CNE-2 cells. Meanwhile, DMY induced apoptosis of CNE-2 cells in a dose and time-dependent manner via upregulating B-cell lymphoma-2 associated X, but downregulating B-cell lymphoma-2 and pro-caspase-3. Importantly, we found that DMY suppressed tumor necrosis factor alpha (TNF-α)-mediated NF-κB activation via inhibiting p-IKKß, p-IKKα and blocking NF-κB subunit p65. CONCLUSION: Our experiments demonstrated that DMY had significant antiproliferative and apoptosisinducing effects on CNE-2 cells. Additionally, DMY promoted inactivation of p-IKKß, p-IKKα, and blocked the nuclear translocation of NF-κB subunit p65. These results suggest that DMY may be an important therapeutic approach for NPC.

[Molecular Genetic Analysis of One Sudden Unexplained Death in the Young by Whole Exome Sequencing].

OBJECTIVE: To find the mutation of disease-causing genes of sudden unexplained death syndrome (SUDS) in the young by whole exome sequencing in one case. METHODS: One SUDS case was found no obvious fatal pathological changes after conventional autopsy and pathological examination. The whole exome sequencing was performed with the Ion Torrent PGM™ System with hg19 as reference sequence for sequencing data. The functions of mutations were analyzed by PhyloP, PolyPhen2 and SIFT. A three-step bioinformatics filtering procedure was carried out to identify possible significative single nucleotide variation (SNV), which was missense mutation with allele frequency < 1% of myocardial cell. RESULTS: Four rare suspicious pathogenic SNV were identified. Combined with the analysis of conventional autopsy and pathological examination, the mutation MYOM2 (8_2054058_G/A) was assessed as high-risk deleterious mutation by PolyPhen2 and SIFT, respectively. CONCLUSION: Based on the second generation sequencing technology, analysis of whole exome sequencing can be a new method for the death cause investigation of SUDS. The gene MYOM2 is a new candidate SUDS pathogenic gene for mechanism research.