Objective: To investigate the effects of dihydromyricetin on proliferation and apoptosis of human lung adenocarcinoma cell line NCI-H1975 in vitro, and to explore its molecular mechanism. Methods: After treatment with different concentrations of dihydromyricetin (10, 25, 50, 75 and 100 μmol/L) for different time (12, 24 and 48 h), the proliferation of human lung adenocarcinoma NCI-H1975 cells was detected by CCK-8 assay. The cell cycle and apoptosis rate of NCI-H1975 cells treated with different concentrations of dihydromyricetin (25, 50 and 100 μmol/L) for 24 h were determined by flow cytometry, and the change of cell morphology was observed by inverted phase contrast microscopy. Real-time fluorescent quantitative-PCR and Western blotting were used to analyze the expression levels of Bcl-2, Bax and Bad genes in NCI-H1975 cells treated with 25, 50 or 100 μmol/L dihydromyricetin for 24 h. Results: Dihydromyricetin significantly inhibited the proliferation of human lung adenocarcinoma NCI-H1975 cells in a dose- and time-dependent manner (P < 0.05). Dihydromyricetin significantly induced apoptosis of NCI-H1975 cells (P < 0.01), but it did not induce cell cycle arrest (P > 0.05). Furthermore, dihydromyricetin significantly decreased the expression levels of Bcl-2 mRNA and protein in NCI-H1975 cells (both P < 0.05), and up-regulated the expression levels of Bax mRNA and protein as well as the expression level of phospho-Bad protein (all P < 0.05), but did not change the expression levels of Bad mRNA and protein (both P > 0.05). Conclusion: Dihydromyricetin can suppress the growth of human lung adenocarcinoma cells through regulating the expression of Bcl-2 protein family in mitochondrial apoptotic pathway. Dihydromyricetin may be a potential drug for the treatment of lung carcinoma.

The rice Rim2/Hipa is a stress-induced transposon superfamily recently identified in Oryza genomes. Genomic variation was found in the Rim2 core region among rice genetic resources/genomes, indicative of high genomic divergence accumulated during the Rim2 evolution. Based on the divergence and quiescent state of the Rim2 elements, a Rim2 paralog display-based fingerprinting approach was developed to effectively identify rice genetic resources and explore their genetic relationships within a set of rice germplasm including 45 accessions ofO. sativa and 8 accessions of its wild relatives O. rufipogon. A dendrogram showed not only clear genetic diversity of rice germplasm, but also considerable genetic differentiation among wild rice resources. The wild rice relatives were either clustered as an independent group, or among the japonica varieties. This Rim2-based fingerprinting approach could also serve as a sensitive tool to identify rice hybrids from their parents, and variety stability, demonstrating its great potential in evolution study ofrice genomes and in rice breeding and seed production.