2015年2月4日 訊 /生物谷BIOON/ --近日,來自Norris Cotton綜合癌症研究中心的研究人員通過研究開發了一種治療ERBB2(人類表皮生長因子受體II)陽性乳腺癌的新型療法,該類乳腺癌通常會對療法產生強烈的耐藥性,相關研究刊登於國際雜誌Cell Cycle上,該研究為揭示新型的癌症耐藥機制提供了一定的線索。
研究者Kurokawa教授表示,目前大約有25%的乳腺癌會發生過表達,而且依賴於ERBB2來生存,當前的療法往往是通過利用靶向藥物如曲妥珠單抗或拉帕替尼來特異性地抑制ERBB2,但最終這些療法會隨著癌細胞產生耐藥性而失去作用。研究人員表示,ERBB4(HER4)是ERBB2陽性乳腺癌的驅動蛋白,ERBB2陽性乳腺癌會在第一輪或第二輪化療過程中產生耐藥性;當研究者發現pan-ERBB抑制劑依然對治療耐藥性的ERBB2陽性乳腺癌有效時,他們利用siRNA來敲除單一的ERBB成員從而發現ERBB4對於癌細胞的耐藥性的ERBB2陽性乳腺癌細胞非常關鍵,隨後研究者通過在小鼠機體中對拉帕替尼耐藥性的腫瘤進行免疫組化分析證實了ERBB4的重要性。
目前ERBB4在乳腺癌中扮演的角色一直處於爭議之中,有研究表明ERBB4在乳腺癌中並無作用,但也有研究表示其具有一種抗增殖的效應;本文研究發現,當ERBB2陽性的乳腺癌對抗ERBB2藥物產生耐藥性時,癌細胞就會將依賴性從ERBB2轉移到ERBB4,後者可以驅動癌症發展和癌細胞增殖。
ERBB4作為一種驅動蛋白促使ERBB2陽性的癌細胞對抗ERBB2的藥物產生耐藥性表明,抗ERBB4藥物或許對於那些在第一輪和第二輪治療中無反應的癌症患者具有較大的治療作用;而鑑別出癌症的驅動子對於開發癌症療法也至關重要。下一步研究人員計劃闡明為何ERBB2陽性的乳腺癌對ERBB2的依賴性會轉移到ERBB4上,研究者懷疑一種名為PI3K/AKT的途徑,該途徑和細胞增殖及生存直接相關,其可以在細胞水平上介導癌細胞的依賴性改變。相關研究由NIH提供資助。(生物谷Bioon.com)
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Receptor tyrosine kinase ERBB4 mediates acquired resistance to ERBB2 inhibitors in breast cancer cells.
Kaleigh Canfield, Jiaqi Li, Owen M. Wilkins, Meghan M. Morrison, Matthew Ung, Wendy Wells, Charlotte R. Williams, Karen T. Liby, Detlef Vullhorst, Andres Buonanno, Huizhong Hu, Rachel Schiff, Rebecca S. Cook, Manabu Kurokawa.
Approximately 25% of breast cancers overexpress and depend on the receptor tyrosine kinase ERBB2, one of four ERBB family members. Targeted therapies directed against ERBB2 have been developed and used clinically, but many patients continue to develop resistance to such therapies. Although much effort has been focused on elucidating the mechanisms of acquired resistance to ERBB2-targeted therapies, the involvement of ERBB4 remains elusive and controversial. We demonstrate that genetic ablation of ERBB4, but not ERBB1-3, led to apoptosis in lapatinib-resistant cells, suggesting that the efficacy of pan-ERBB inhibitors was, at least in part, mediated by the inhibition of ERBB4. Moreover, ERBB4 was upregulated at the protein level in ERBB2+ breast cancer cell lines selected for acquired lapatinib resistance in vitro and in MMTV-Neu mice following prolonged lapatinib treatment. Knockdown of ERBB4 caused a decrease in AKT phosphorylation in resistant cells but not in sensitive cells, suggesting that ERBB4 activated the PI3K/AKT pathway in lapatinib-resistant cells. Importantly, ERBB4 knockdown triggered apoptosis not only in lapatinib-resistant cells but also in trastuzumab-resistant cells. Our results suggest that although ERBB4 is dispensable for naïve ERBB2+ breast cancer cells, it may play a key role in the survival of ERBB2+ cancer cells after they develop resistance to ERBB2 inhibitors, lapatinib and trastuzumab.