Cloning and characterization of a cDNA encoding human differentiation antigen 5D4

A 1 846 bp cDNA is isolated from a human tonsil cell λgt 11 cDNA library (ATCC No. 37546) with mAb 5D4 reactive strongly with human B cell line 3D5, but weakly with human B cell line Daudi and human T cell line Jurkat as a probe. RT-PCR also shows a strong reaction in 3D5 cell and a weak reaction in Daudi and Jurkat cell for 5D4 mRNA. There is an open reading frame from 88 to 1 209 bp in 5D4 cDNA encoding a 374 AA protein. Both the Northern blot analysis and the two consecutive stop codens before start coden demonstrate that the cDNA is a full-length cDNA. Secondary structure prediction suggests that there are a region from 295 to 334 AA in the protein with strong hydrophobicity and a transmembrane helix region with high score from 313 to 334 AA with an orientation from the inside to the outside of the cell.     

编码人分化抗原5D4的全长cDNA克隆及其编码蛋白质的二级结构分析

用 3D5细胞染色强阳性 ,而Daudi与Jurkat细胞染色弱阳性的单克隆抗体5D4,从一个人扁桃体细胞λgt1 1cDNA文库 (ATCCNo .375 46 )筛选到一个长 1 846bp的cDNA克隆 .RT_PCR显示 3D5细胞、Daudi细胞和Jurkat细胞 5D4mRNA均阳性 ,但 3D5细胞明显强于后两者 . 5D4cDNA中 88～ 1 2 0 9bp为一个开放阅读框架 ,编码374个氨基酸的蛋白质 .Northernblot分析结果和起始密码子前 5′端非编码区有 2个连续的终止密码子表明 ,这是一个全长cDNA .从其开放阅读框架推断的蛋白质的氨基酸序列中 2 95～ 334aa为一强疏水区 ,预测 31 3～ 334aa为一分值极高的跨膜螺旋区 ,其方向最可能是由膜内到膜外 .     

Inhibition of metastasis to lung of a human nasopharyngeal carcinoma cell line CNE-2L2 transfected with pRc/CMV-antisense 6A8 cDNA in nude mice

The growth of CNE-2L2 cell, a cloned line of human nasopharyngeal carcinoma with a high potentiality of metastasis to lung was inhibited to a certain extent after transfection with a recombinant antisense expression vector of a cDNA encoding a human α-mannosidase (pRc/CMV-antisense 6A8 cDNA)( the Genbank accession number of 6A8 cDNA is U37248) in comparison with that of the cell transfected with the Mock and of the wild cell. Two months after a subcutaneous inoculation of CNE-2L2 cell into the axilla of nude mice metastatic lesions in the lung were observed in 9/10 mice (90%) with grade Ⅲ in 8 mice and grade Ⅱ in one mouse in the wild cell group, in 6/8 mice (75%) with grade Ⅲ in one mouse, grade Ⅱ in 2 mice and grade Ⅰ in 3 mice in the Mock-transfection group, in only 3/10 mice (30%) with all grade Ⅰ in pRc/CMV-antisense 6A8 cDNA-transfection group.     

转染反义6A8cDNA对人鼻咽癌细胞肺转移的抑制

人鼻咽癌高肺转移克隆株CNE 2L2转染编码人α 甘露糖苷酶的cDNA( 6A8cDNA ,GenBank接受号为U3 72 48)的重组反义表达载体 ( pRc/CMV 反义6A8cDNA)后 ,与转染空载质粒pRc/CMV及未作任何转染的细胞相比 ,其生长受一定程度抑制 .接种于无胸腺鼠皮下 2个月 ,野型CNE 2L2细胞组有肺转移的小鼠数为 9/10 ( 90 % ) ,其中Ⅲ级 8只 ,Ⅱ级 1只 ;转染空载质粒pRc/CMV ,有肺转移者为6/8( 75 % ) ,其中Ⅲ级 1只 ,Ⅱ级 2只 ,Ⅰ级 3只 ;转染pRc/CMV 反义 6A8cDNA ,有肺转移者为 3 /10 ( 3 0 % ) ,全部为Ⅰ级 .