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【medical-news】鼠神经母细胞瘤内源性逆转录病毒
纽约（路透社健康新闻）8月1日报道，在鼠神经母细胞瘤细胞系中的研究表明肿瘤细胞表达的内源性逆转录病毒通过明显减低自然抗肿瘤免疫反应而在肿瘤发生中起着重要作用。
“癌免疫编辑”理论认为肿瘤细胞为了免于肌体免疫系统的清除而表现为免疫原性减低。来自于法国Villejuif的Gustave Roussy研究院的科学家们解释道。
“有人认为逆转录病毒，假如它们具有活性，可能在这个过程中发挥作用。” Julien Pothlichet博士和他的共同作者在8月15日《国际癌症杂志》上写道。
为了支持这个观点，法国研究小组发现神经2a鼠神经母细胞瘤细胞系产生一个有功能的和传染性的逆转录病毒。这个逆转录病毒“可能来自于2个鼠内源性逆转录病毒成分中充足成分。”他们报道。
使用RNA干扰技术，研究小组也发现内源性逆转录病毒的表达在体内参与了肿瘤生长。在神经2a细胞系中敲除了内源性逆转录病毒，“将细胞移植物移入免疫活性鼠后，对细胞的转化表型没有影响，但是可使肿瘤生长延迟和延长了动物生存。”他们报道。
根据他们的研究，“2种内源性逆转录病毒的重组，合成成分的扩增和免疫抑制活性的高水平的表达可能是免疫编辑的步骤，引起一个侵袭性肿瘤。” Julien Pothlichet博士和他的同事推断道。
他们补充到，神经2a神经母细胞瘤细胞系对癌免疫编辑的持续研究“可能提供了一个有价值的模型。”
Endogenous Retrovirus in Mouse Neuroblastoma Involved in Tumor Growth
NEW YORK (Reuters Health) Aug 01 - Studies in a mouse neuroblastoma cell line suggest that an endogenous retrovirus expressed by tumor cells may play a key role in tumorigenesis by significantly reducing natural antitumor immune responses.
The theory of "cancer immunoediting" holds that tumor cells exhibit a reduced immunogenicity to escape eradication by the host immune system, explain scientists from Institut Gustave Roussy in Villejuif, France.
"It has been proposed that endogenous retroviruses -- provided that they are active -- could play a role in this process," Dr. Julien Pothlichet and co-authors write in the August 15 International Journal of Cancer.
In support of this, the French team found that the Neuro-2a mouse neuroblastoma tumor cell line produces a functional infectious endogenous retrovirus. This retrovirus "probably results from a recombination event between two mouse endogenous retroviral elements," they report.
Using RNA interference, the team also showed that expression of the endogenous retrovirus is involved in tumor growth in vivo. Knocking out the endogenous retrovirus in Neuro-2a cells has "no effect on the transformed phenotype of the cells, but results in delayed tumor growth and prolonged animal survival, following engraftment of the cells into immunocompetent mice," they report.
Based on their studies, "recombination between two endogenous retrovirus, amplification of the resulting element, and high-level expression of its immunosuppressive activity are therefore likely steps of an immunoediting process, leading to an invading tumor," Dr. Pothlichet and colleagues conclude.
The Neuro-2a neuroblastoma line, they add, "may constitute a valuable model" for continued studies of cancer immunoediting. [标签:content1][标签:content2]
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作者:admin@医学,生命科学 2011-02-07 05:14
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