8月28日，《科學(xué)》（Science）雜志發(fā)表的一項(xiàng)研究提示,，癌癥轉(zhuǎn)移并非癌癥進(jìn)展中的一個(gè)晚期事件,。癌細(xì)胞在體內(nèi)擴(kuò)散到新的地方，可能比過去所認(rèn)為的時(shí)間更早,。這一發(fā)現(xiàn)對(duì)為什么某些乳腺癌在最初的腫瘤已經(jīng)得到治療后很久,，還會(huì)發(fā)生轉(zhuǎn)移等問題給出了新的解釋。
癌癥轉(zhuǎn)移是最終引起大多數(shù)癌癥患者死亡的疾病進(jìn)程,。學(xué)術(shù)界一直認(rèn)為轉(zhuǎn)移是癌癥進(jìn)展中的一個(gè)晚期事件,，即在原發(fā)腫瘤細(xì)胞積累了一系列的基因變更之后才啟動(dòng)了癌癥基因。然而,，美國(guó)學(xué)者Katrina Podsypanina及其同事開展的動(dòng)物實(shí)驗(yàn)結(jié)果提示,，腫瘤的轉(zhuǎn)移可能肇端于疾病早期。它們?cè)谄鞴俚霓D(zhuǎn)移處保持休眠狀態(tài),，直到癌癥基因被啟動(dòng)時(shí)變身為癌細(xì)胞,。
研究人員給小鼠注射了通過實(shí)驗(yàn)處理的正常乳腺細(xì)胞，使其在注射后的不同時(shí)間,，激活其中的某些癌癥基因（或稱腫瘤基因）,。研究發(fā)現(xiàn)，這些正常的乳腺細(xì)胞能夠通過血液循環(huán)行進(jìn)到肺部,，并可在那里存活長(zhǎng)達(dá)16個(gè)星期,，但不表達(dá)任何的腫瘤基因。這些細(xì)胞在腫瘤基因被激活前,，在肺中不會(huì)活躍生長(zhǎng),。Katrina Podsypanina提出，對(duì)癌癥轉(zhuǎn)移過程的每一步驟進(jìn)行調(diào)查,，包括那些正常細(xì)胞的轉(zhuǎn)移,，可能會(huì)使科學(xué)家找到摧毀引起癌癥轉(zhuǎn)移細(xì)胞的新策略。（生物谷Bioon.com）
生物谷推薦原始出處：
Science,，DOI: 10.1126/science.1161621,，Katrina Podsypanina，Harold Varmus
Seeding and Propagation of Untransformed Mouse Mammary Cells in the Lung
Katrina Podsypanina , Yi-Chieh Nancy Du , Martin Jechlinger , Levi J. Beverly , Dolores Hambardzumyan , Harold Varmus
Program in Cancer Biology and Genetics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
Acquisition of metastatic ability by tumor cells is considered a late event in the evolution of malignant tumors. Here we report that untransformed mouse mammary cells, engineered to express inducible oncogenic transgenes: MYC and KrasD12, or polyoma middle T, and introduced into the systemic circulation of a mouse, can bypass transformation at the primary site and develop into metastatic pulmonary lesions upon immediate or delayed oncogene induction. Therefore, previously untransformed mammary cells may establish residence in the lung once they have entered the bloodstream, and may assume malignant growth upon oncogene activation. Mammary cells lacking oncogenic transgenes displayed a similar capacity for long-term residence in the lungs but did not form ectopic tumors.
