2012年1月3日,,據(jù)《每日科學(xué)》報(bào)道,,一項(xiàng)新的研究表明,,選擇性地靶向和阻斷肝癌中一個(gè)重要的特定microRNA是可能的,。這一發(fā)現(xiàn)可能提供一個(gè)針對(duì)肝癌的新療法,,每年全球估計(jì)有549000人死于肝癌,。
由俄亥俄州立大學(xué)綜合癌癥中心--Arthur G. James癌癥醫(yī)院和Richard J. Solove研究所(OSUCCC-James)及Mayo診所的研究人員開展的動(dòng)物實(shí)驗(yàn)研究,聚焦于microRNA - 221(miR - 221),,一種在肝癌中持續(xù)性地呈現(xiàn)異常高的水平的分子,。
為了控制這個(gè)問題分子,研究人員設(shè)計(jì)出了第二個(gè)分子作為第一個(gè)分子的一種鏡像,。這種鏡像分子被稱為反義寡核苷酸,,它選擇性地結(jié)合到并阻斷了在人體肝癌移植到小鼠體內(nèi)的miR - 221的作用。治療顯著地延長(zhǎng)了實(shí)驗(yàn)動(dòng)物的生命并有效促進(jìn)重要的抑癌基因的活性,。
"這項(xiàng)研究非常重要,,因?yàn)楦渭?xì)胞癌或肝癌,一般都預(yù)后不佳,,所以我們迫切需要新的治療策略,,"首席研究員Thomas Schmittgen說,俄亥俄州立大學(xué)藥學(xué)院副教授及主席,,同時(shí)也是OSUCCC-James實(shí)驗(yàn)治療項(xiàng)目的成員OSUCCC,。
該研究結(jié)果發(fā)表在"癌癥研究"雜志(Cancer Research)上。
在這項(xiàng)研究中,,Schmittgen和他的同事們,,將標(biāo)記了熒光素酶的肝癌細(xì)胞注射入小鼠的肝臟中。研究人員利用生物發(fā)光成像技術(shù)監(jiān)測(cè)腫瘤的生長(zhǎng),。
當(dāng)腫瘤長(zhǎng)到適當(dāng)?shù)拇笮?,他們給其中一組動(dòng)物注射能阻止miR - 221的分子,另一組接受對(duì)照分子,。
關(guān)鍵性的結(jié)果包括以下內(nèi)容:
1,、反義寡核苷酸治療后,有一半的實(shí)驗(yàn)動(dòng)物在10周時(shí)依然存活,,而對(duì)照全部死亡,。
2、反義寡核苷酸顯著降低了腫瘤和正常肝臟樣本中miR - 221的水平,。
3,、反義寡核苷酸治療引起3個(gè)重要的腫瘤抑制基因活性增加了3倍,而這三個(gè)基因在肝癌細(xì)胞中是被miR - 221阻斷的,。 (腫瘤抑制基因?yàn)镻27,,P57和PTEN,。)
"總的來說,這項(xiàng)研究為進(jìn)一步開發(fā)肝癌microRNA靶向療法提供了原理循證,,"Schmittgen說,。
這項(xiàng)研究得到了國(guó)家癌癥研究所和美國(guó)國(guó)立糖尿病、消化道和腎病研究所的資金支持,。
參與這項(xiàng)研究的其他研究人員,,還有 Jong-Kook Park, Jinmai Jiang, Lei He, Ji Hye Kim, Mitch A. Phelps, Tracey L. Papenfuss and Carlo M. Croce of Ohio State; Takayuki Kogure and Tushar Patel of Mayo Clinic, Jacksonville, Florida; and Gerard J. Nuovo。(生物谷bioon.com)
doi:10.1158/0008-5472.CAN-11-1144
PMC:
PMID:
miR-221 Silencing Blocks Hepatocellular Carcinoma and Promotes Survival
J.-K. Park, T. Kogure, G. J. Nuovo, J. Jiang, L. He, J. H. Kim, M. A. Phelps, T. L. Papenfuss, C. M. Croce, T. Patel, T. D. Schmittgen.
Abstract:Patients with advanced hepatocellular carcinoma (HCC) face a dismal prognosis because of a lack of any effective therapies. To address this situation, we conducted a preclinical investigation of the therapeutic efficacy of oligonucleotides directed against the oncogenic microRNA miR-221, which has been implicated in HCC. Of 9 chemistries evaluated, we determined that a 2′-O-methyl phosphorothioate-modified anti-miR-221 oligonucleotide was most effective at reducing proliferation in vitro. A cholesterol-modified isoform of anti-miR-221 (chol-anti-miR-221) exhibited improved pharmacokinetics and liver tissue distribution compared with unmodified oligonucleotide. Chol-anti-miR-221 significantly reduced miR-221 levels in liver within a week of intravenous administration and in situhybridization studies confirmed accumulation of the oligonucleotide in tumor cells in vivo. Within the same period, chol-anti-miR-221 reduced tumor cell proliferation and increased markers of apoptosis and cell-cycle arrest, elevating the tumor doubling time and increasing mouse survival. Taken together, our findings offer a preclinical proof of efficacy for chol-anti-miR-221 in a valid orthotopic mouse model of HCC, suggesting that this targeted agent could benefit treatment for patients with advanced HCC. Cancer Res; 71(24); 7608–16. ©2011 AACR.