日本廣島大學(xué)細(xì)胞分子生物學(xué)教授田原榮俊宣布,，他們的研究小組研究發(fā)現(xiàn),，一種存在于細(xì)胞和血液中、被稱為“微型核糖核酸（miR22）”的物質(zhì),，可以使乳腺癌和宮頸癌的癌細(xì)胞衰老,，從而具有抑制癌細(xì)胞增殖和轉(zhuǎn)移的功能。這一研究結(jié)果刊登在4月18日出版的美國(guó)科學(xué)雜志上,。
一般認(rèn)為微型RNA與調(diào)節(jié)細(xì)胞增殖,、細(xì)胞分化等各種生物現(xiàn)象有關(guān)，正常細(xì)胞老化停止分裂時(shí)微型RNA會(huì)增加,。
研究小組對(duì)不發(fā)生老化而進(jìn)化為癌癥的細(xì)胞中miR22的減少進(jìn)行了研究,。在培養(yǎng)的乳腺癌和宮頸癌的癌細(xì)胞中加入miR22，癌細(xì)胞老化程度加重,，分裂被抑制,。在小鼠的試驗(yàn)中同樣發(fā)現(xiàn)了乳腺癌的轉(zhuǎn)移被控制。
田原教授認(rèn)為,，細(xì)胞老化是生物體防止癌癥發(fā)生的自身防御機(jī)制,。細(xì)胞內(nèi)微型RNA減少會(huì)阻礙細(xì)胞老化,，從而促使癌細(xì)胞發(fā)生,，而加入miR22之后，機(jī)體內(nèi)老化程序恢復(fù),，進(jìn)而抑制了癌細(xì)胞的繁殖,。
田原教授說(shuō)，微型RNA是生物體內(nèi)制造的一種物質(zhì),，與目前的抗癌制劑相比具有副作用小的優(yōu)勢(shì),，有望用來(lái)研制下一代抗癌藥物。（生物谷Bioon.com）
生物谷推薦原文出處：
JCB doi: 10.1083/jcb.201010100
miR-22 represses cancer progression by inducing cellular senescence
Dan Xu1, Fumitaka Takeshita3, Yumiko Hino1, Saori Fukunaga1, Yasusei Kudo2, Aya Tamaki1, Junko Matsunaga1, Ryou-u Takahashi3, Takashi Takata2, Akira Shimamoto1, Takahiro Ochiya3, and Hidetoshi Tahara1
Abstract
Cellular senescence acts as a barrier to cancer progression, and microRNAs (miRNAs) are thought to be potential senescence regulators. However, whether senescence-associated miRNAs (SA-miRNAs) contribute to tumor suppression remains unknown. Here, we report that miR-22, a novel SA-miRNA, has an impact on tumorigenesis. miR-22 is up-regulated in human senescent fibroblasts and epithelial cells but down-regulated in various cancer cell lines. miR-22 overexpression induces growth suppression and acquisition of a senescent phenotype in human normal and cancer cells. miR-22 knockdown in presenescent fibroblasts decreased cell size, and cells became more compact. miR-22–induced senescence also decreases cell motility and inhibits cell invasion in vitro. Synthetic miR-22 delivery suppresses tumor growth and metastasis in vivo by inducing cellular senescence in a mouse model of breast carcinoma. We confirmed that CDK6, SIRT1, and Sp1, genes involved in the senescence program, are direct targets of miR-22. Our study provides the first evidence that miR-22 restores the cellular senescence program in cancer cells and acts as a tumor suppressor.
