【摘要】 DHRS4/NRDR基因编码一种属于SDR家族的酶,在维甲酸合成、类固醇代谢和苯甲基代谢中发挥生物合成催化作用.DHRS4基因定位于14q11.2,有两个相似的拷贝基因,分别为DHRS4L2和DHRS4L1.我们前期发现了DHRS4L2基因一个上游转录起始位点,命名为DHRS4L2-Ea.在本研究中,我们用RT-PCR和双脱氧测序法发现一个新的从DHRS4L2-Ea转录的选择性剪接亚型DHRS4L2-900a(KC237374).同时RT-PCR结果显示在SK-N-SH细胞DHRS4L2-Ea选择性剪接亚型中DHRS4L2-iso(AY616183)表达最多,为主要亚型.在SK-N-SH细胞过表达DHRS4L2-800a(AY920361)使DHRS4L2-Ea基因下游CPNE6 mRNA表达下调.在HeLa细胞过表达DHRS4L2-800a(AY920361)或DHRS4L2-900a(KC237374)进一步表明DHRS4L2-Ea抑制CPNE6表达的作用.定量PCR结果显示si-RNA抑制DHRS4L2-Ea表达使CPNE6 mRNA表达上调.亚硫酸盐测序结果显示在SK-N-SH转染DHRS4L2-800a(AY920361)的样本中CPNE6基因DNA CpG甲基化增加.综上所述,本研究揭示DHRS4L2表达的非编码RNA抑制其下游基因CPNE6的表达.更多还原

【Abstract】 The DHRS4 /NRDR gene encodes an enzyme of the SDR family for retinoic acid biosynthesis,steroids metabolism and benzyl metabolism. In humans,DHRS4 maps to 14q11. 2,together with other two tandem repeated genes,DHRS4L2 and DHRS4L1. The transcription start site of the DHRS4L2 gene was previously identified as DHRS4L2-Ea. Here we discovered an alternatively spliced form,DHRS4L2-900a( KC237374),by RT-PCR and Sanger sequencing. We found another spliced form,DHRS4L2-iso( AY616183), was most abundant in SK-N-SH cells. The overexpression of DHRS4L2-800a( AY920361) in SK-N-SH inhibited the mRNA expression of CPNE6,a gene adjacently downstream of DHRS4L2. Overexpression of DHRS4L2-800 a and DHRS4L2-900 a also repressed CPNE6 expression in HeLa cells. Knockdown of DHRS4L2-Ea by si-RNA increased CPNE6 expression. Transfection of DHRS4L2-800 a mildly increased the methylation of CPNE6 promoter DNA in SK-N-SH cells as shown by bisulfite sequencing. We concluded that spliced DHRS4L2 transcripts inhibited the expression CPNE6.更多还原