12月12日,,國(guó)際著名雜志《癌細(xì)胞》(Cancer Cell)刊登了英國(guó)西英格蘭大學(xué)布里斯托爾分校和布里斯托爾大學(xué)等機(jī)構(gòu)聯(lián)合的研究成果,他們發(fā)現(xiàn)在一種特殊腫瘤的基因變異中,,血管再生方式發(fā)生改變,,調(diào)控血管再生的主開(kāi)關(guān)被打開(kāi),為癌細(xì)胞建造運(yùn)輸營(yíng)養(yǎng)的血管通道,。而瞄準(zhǔn)這一主開(kāi)關(guān)就可能預(yù)防或阻止癌細(xì)胞再造血管,,切斷其營(yíng)養(yǎng)供給途徑,這一發(fā)現(xiàn)為研究癌癥療法開(kāi)辟了新方向,。
癌細(xì)胞能控制組織產(chǎn)生新血管,,為其運(yùn)輸氧氣和所需要的糖,所以長(zhǎng)得比正常細(xì)胞更快,。研究小組負(fù)責(zé)人邁克爾·雷多莫里解釋說(shuō),,控制血管再生對(duì)控制腫瘤生長(zhǎng)非常關(guān)鍵。血管再生是兩種同型的血管再生因子VEGF165(促血管再生因子)和VEGF165b(抗血管再生因子)之間的平衡,,制造這兩種蛋白要把不同的基因部分排列在一起,,這一過(guò)程稱為拼接,。
研究人員發(fā)現(xiàn),WT1(威爾姆腫瘤抑制基因)變異能控制拼接平衡,,讓細(xì)胞中的拼接主開(kāi)關(guān)拼接因子激酶SRPK1處于打開(kāi)狀態(tài),。SRPK1能促進(jìn)更多的血管再生因子拼接,使血管長(zhǎng)得更快,,進(jìn)而加速癌細(xì)胞的生長(zhǎng),。在實(shí)驗(yàn)?zāi)P椭校芯啃〗M用一種能抑制SRPK1主開(kāi)關(guān)的新藥,,就能預(yù)防和阻止血管生長(zhǎng),,遏制住癌細(xì)胞的生長(zhǎng)。
“瞄準(zhǔn)并控制病人體內(nèi)的拼接轉(zhuǎn)換,,就可能阻止腫瘤生長(zhǎng),。”雷多莫里說(shuō),“我們通過(guò)對(duì)拼接因子激酶SRPK1進(jìn)行轉(zhuǎn)錄控制,,發(fā)現(xiàn)WT1基因通過(guò)抑制SRPK1來(lái)調(diào)控拼接,,SRPK1可能作為一種抗血管再生療法的標(biāo)靶,通過(guò)基因和環(huán)境控制腫瘤中的拼接轉(zhuǎn)換能調(diào)控腫瘤生長(zhǎng),。”
此前,,英國(guó)科學(xué)家還曾發(fā)現(xiàn)一種通過(guò)限制癌細(xì)胞能量來(lái)源的方法來(lái)“餓死”癌細(xì)胞以幫助治療癌癥。相比之下,,新方法更像是一種道路控制,。布里斯托爾大學(xué)生理與藥理學(xué)院教授大衛(wèi)·貝特說(shuō):“這些發(fā)現(xiàn)能幫助我們開(kāi)發(fā)出一種瞄準(zhǔn)血管生長(zhǎng)的新藥,在癌癥,、失明,、腎病等疾病中都有廣闊前景。”(生物谷Bioon.com)
doi:10.1016/j.ccr.2011.10.016
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WT1 Mutants Reveal SRPK1 to Be a Downstream Angiogenesis Target by Altering VEGF Splicing
Elianna M. Amin, Sebastian Oltean, Jing Hua, Melissa V.R. Gammons, Maryam Hamdollah-Zadeh, Gavin I. Welsh, Man-Kim Cheung, Lan Ni, Satoru Kase, Emma S. Rennel, Kirsty E. Symonds, Dawid G. Nowak, Brigitte Royer-Pokora, Moin A. Saleem, Masatoshi Hagiwara, Valérie A. Schumacher, Steven J. Harper, David R. Hinton, David O. Bates, Michael R. Ladomery
Angiogenesis is regulated by the balance of proangiogenic VEGF165 and antiangiogenic VEGF165b splice isoforms. Mutations in WT1, the Wilms' tumor suppressor gene, suppress VEGF165b and cause abnormal gonadogenesis, renal failure, and Wilms' tumors. In WT1 mutant cells, reduced VEGF165b was due to lack of WT1-mediated transcriptional repression of the splicing-factor kinase SRPK1. WT1 bound to the SRPK1 promoter, and repressed expression through a specific WT1 binding site. In WT1 mutant cells SRPK1-mediated hyperphosphorylation of the oncogenic RNA binding protein SRSF1 regulated splicing of VEGF and rendered WT1 mutant cells proangiogenic. Altered VEGF splicing was reversed by wild-type WT1, knockdown of SRSF1, or SRPK1 and inhibition of SRPK1, which prevented in vitro and in vivo angiogenesis and associated tumor growth.