美國西北大學(xué)研究人員日前稱,，他們找到了一種在保持動(dòng)物個(gè)體統(tǒng)一性上發(fā)揮重要作用的RNA片段。這種被稱為miR—7的微RNA對分子網(wǎng)絡(luò)的穩(wěn)定性至關(guān)重要,。研究人員稱，該發(fā)現(xiàn)或許能進(jìn)一步增加人們對癌細(xì)胞生存機(jī)制的認(rèn)識(shí),，以解釋癌細(xì)胞難以被人為控制的難題,。相關(guān)研究公布在《細(xì)胞》雜志網(wǎng)站上。
這項(xiàng)研究基于一種源于20世紀(jì)40年代的理論,，該理論認(rèn)為分子內(nèi)的細(xì)胞都是以網(wǎng)絡(luò)的方式進(jìn)行工作的,，而每個(gè)分子之間也相互聯(lián)系。負(fù)責(zé)該研究的美國西北大學(xué)文理學(xué)院細(xì)胞生物學(xué)教授理查德·卡休和歐文·庫恩說,，這種設(shè)計(jì)類似于一些產(chǎn)品中的安全裝置,。當(dāng)一些東西發(fā)生變化時(shí)，分子中的基因序列或是器官的溫度也會(huì)隨之改變,，這種網(wǎng)絡(luò)化的工作方式會(huì)對變化及時(shí)做出補(bǔ)償和修復(fù),，并使整體保持穩(wěn)定。
研究人員稱,，在動(dòng)物體內(nèi)的微RNA有數(shù)百種不同類型,，它們能抑制或關(guān)閉蛋白質(zhì)的生產(chǎn)。研究人員在其中發(fā)現(xiàn)了一種被稱為miR—7的微RNA,，它能抑制同一分子網(wǎng)絡(luò)中蛋白質(zhì)的生產(chǎn),。
在對果蠅的研究中,，當(dāng)研究人員去除miR—7時(shí)，相關(guān)網(wǎng)絡(luò)只有在統(tǒng)一的環(huán)境條件下才能保持完整性,；當(dāng)研究人員通過調(diào)整溫度擾亂統(tǒng)一環(huán)境時(shí),，網(wǎng)絡(luò)則不再能保持完整性，同時(shí)果蠅在發(fā)育上也會(huì)出現(xiàn)缺陷,；而在存有miR—7的情況下，無論外部的溫度如何變化,，果蠅都是正常和健康的,。研究人員發(fā)現(xiàn)微RNA在動(dòng)植物體內(nèi)廣泛存在，多細(xì)胞有機(jī)體在復(fù)雜多變的生存環(huán)境中能夠保持個(gè)體穩(wěn)定性可能都與此相關(guān),。
卡休說,，該研究很有建設(shè)性。癌細(xì)胞的復(fù)雜多樣性和難以控制眾所周知,，而有趣的是,，微RNA也是癌細(xì)胞突變最常見的目標(biāo)之一。那么,，癌細(xì)胞的多變和難以控制或許與微RNA的缺失有著某種關(guān)系,。（生物谷Bioon.com）
生物谷推薦原始出處：
Cell, Volume 137, Issue 2, 273-282, 17 April 2009 doi:10.1016/j.cell.2009.01.058
A MicroRNA Imparts Robustness against Environmental Fluctuation during Development
Xin Li1,2,3,Justin J. Cassidy1,2,Catherine A. Reinke1,Stephen Fischboeck1andRichard W. Carthew1,,
1 Department of Biochemistry, Molecular Biology and Cell Biology, 2205 Tech Drive, Northwestern University, Evanston, Illinois 60208, USA
2 These authors contributed equally to this work
3 Present address: Department of Biology, New York University, New York, NY 10003
The microRNA miR-7 is perfectly conserved from annelids to humans, and yet some of the genes that it regulates in Drosophila are not regulated in mammals. We have explored the role of lineage restricted targets, using Drosophila, in order to betterunderstand the evolutionary significance of microRNA-target relationships. From studies of twowell characterized developmental regulatory networks, we find that miR-7 functions in several interlocking feedback and feedforward loops, and propose that its role in these networks is to buffer them against perturbation. To directly demonstrate this function for miR-7, we subjected the networks to temperature fluctuation and found that miR-7 is essential for the maintenance of regulatory stability under conditions of environmental flux. We suggest that some conserved microRNAs like miR-7 may enter into novel genetic relationships to buffer developmental programs against variation and impart robustness to diverse regulatory networks.
