Regulation of demethylation and re-expression of RASSF1A gene in gastric cancer cell lines by combined treatment of 5-Aza-CdR and NaB

AIM: To investigate the changes of methylation state and expression of RASSF1A gene in human gastric cancer cell lines SGC7901 and BGC823 which were treated in vitro with demethlylating agent 5-Aza-CdR in combination with histone deacetylase inhibitor NaB. METHODS: After SGC7901 and BGC823 cells were treated with 5-Aza-CdR and/or NaB,the methylation state of RASSF1A gene was detected by methylation-specific PCR,and the changes in expression of mRNA and protein level of RASSF1A gene were observed by RT-PCR and Western-blotting before and after drug treatment. RESULTS: Hypermethylation was detected in the promoter region of RASSF1A gene in both SGC7901 and BGC823 cells,and there was no expression of this gene at both mRNA and protein level. After treatment with 5-Aza-CdR,demethylation occurred in the promoter region of RASSF1A gene,which subsequently induced re-expression of this gene. The treatment with NaB alone showed no effect on the methylation state and expression of RASSF1A gene. The combined treatment of 5-Aza-CdR and NaB induced complete demethylation of RASSF1A gene,leading to a significantly higher re-expression of the mRNA and protein of RASSF1A than those treated with 5-Aza-CdR alone (P < 0.05). CONCLUSION: Hypermethylation in the promoter region is related to inactivation of RASSF1A gene in human gastric cancer cell lines SGC7901 and BGC823,while demethlylating agent 5-Aza-CdR can reverse the methylation state of RASSF1A gene and induce its re-expression. Histone deacetylase inhibitor NaB had a synergistic effect with 5-Aza-CdR in both demethylation and gene transcriptional regulation.

Allele-specific expression and alternative splicing in horse×donkey and cattle×yak hybrids

Divergence of gene expression and alter native splicing is a crucial driving force in the evolution of species;to date, however the molecular mechanism remains unclear. Hybrids of closely related species provide a suitable model to analyze allele-specific expressi on (ASE) and allele-specific alter native splicing (ASS). Analysis of ASE and ASS can uncover the differences in cis-regulatory elements between closely related species, while eliminating interferenee of trans-regulatory elements. Here, we provide a detailed characterization of ASE and ASS from 19 and 10 transcriptome datasets across five tissues from reciprocal-cross hybrids of horsex don key (mule/hi nny) and cattlexyak (dzo), respectively. Results showed that 4.8%-8.7% and 10.8%-16.7% of genes exhibited ASE and ASS, respectively. Notably, IncRNAs and pseudogenes were more likely to show ASE than protein-coding genes. In addition, genes showing ASE and ASS in mule/hinny were found to be involved in the regulation of muscle strength, whereas those of dzo were involved in high-altitude adaptati on. In con clusi on, our study dem on strated that explorati on of genes showing ASE and ASS in hybrids of closely related species is feasible for species evolution research.

Molecular phylogeny and morphological comparisons of the genus Hebius Thompson, 1913(Reptilia:Squamata: Colubridae) uncover a new taxon from Yunnan Province, China, and support revalidation of Hebius septemlineatus(Schmidt, 1925)

We describe a new species of the genus Hebius and provide evidence for the validity of H.septemlineatus comb.nov..Morphological and molecular analyses of Hebius specimens collected in Yunnan Province,China,revealed three distinct lineages,namely the newly described Hebius weixiensis sp.nov.,as well as H.octolineatus(Boulenger,1904),and H.septemlineatus comb.nov.(Schmidt 1925),which is removed from synonymy with H.octolineatus.Based on mitochondrial genealogy,Hebius weixiensis sp.nov.is sister to H.septemlineatus comb.nov.,while H.octolineatus is sister to H.bitaeniatus.The new species and H.septemlineatus comb.

Pathological pattern of endometrial abnormalities in postmenopausal women with bleeding or thickened endometrium

BACKGROUND Postmenopausal bleeding and an endometrial thickness≥5 mm on sonograms of menopausal women can indicate the presence of endometrial lesions.Diagnostic hysteroscopy is a powerful method for endometrial diseases.AIM To investigate the pathological pattern of endometrial abnormalities in postmenopausal women with bleeding or asymptomatic thickened endometrium diagnosed by hysteroscopy.METHODS A total of 187 postmenopausal women with bleeding or asymptomatic thickened endometrium underwent diagnostic hysteroscopy.The women were subsequently divided into three groups:Postmenopausal bleeding(PMB)group(n=84),asymptomatic group(n=94),and additional group(n=9).Women in the additional group manifested abdominal pain and leukorrhagia.RESULTS Among the 187 patients examined,84(44.9%)were diagnosed with PMB and 94(50.3%)with asymptomatic thickened endometrium.Endometrial polyp was the most common endometrial abnormality,which was detected in 51.2%,76.6%and 77.8%of the PMB,asymptomatic,and additional groups,respectively.In the PMB group,7(8.3%)women had hyperplasia with atypia and 14(16.7%)had endometrial adenocarcinoma.Fewer malignant lesions were detected in the asymptomatic group.Endometrial hyperplasia without atypia was found in 8.3%of the PMB group and 7.4%of the asymptomatic group.CONCLUSION Endometrial polyp was the most common pathology in the PMB group.Diagnostic hysteroscopy is recommended for women with PMB and asymptomatic thickened endometrium.