β1-integrin via NF-κB signaling is essential for acquisition of invasiveness in a model of radiation treated in situ breast cancer
β1-integrin via NF-κB signaling is essential for acquisition of invasiveness in a model of radiation treated in situ breast cancer
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DOI：
10.1186/bcr3454
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发表时间：
2013-01-01
影响因子：
7.4
通讯作者：
Park, Catherine C.
中科院分区：
文献类型：
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作者：
Nam, Jin-Min;Ahmed, Kazi M.;Park, Catherine C.
导言：导管原位癌(DCIS)以乳腺导管内非侵袭性癌细胞生长为特征。虽然放射治疗是治疗DCIS的常用方法，但电离辐射(IR)对DCIS的影响及其分子机制尚不清楚，放射治疗后的侵袭性复发仍是一个重要的临床问题。本研究探讨IR对临床相关的Akt驱动的DCIS模型的影响，并确定存活细胞侵袭进展的可能分子机制。方法：采用免疫组织化学(IHC)方法检测一组人DCIS标本中磷酸化Akt(p-Akt)的水平，并将其与复发风险相关联。为了建立人DCIS的模型，我们使用了Akt高表达的人乳腺上皮细胞(MCF10A-Akt)，它在三维层粘连蛋白丰富的细胞外基质(IrECM)和体内形成器官型DCIS样病变，管腔由包含在完整基底膜内的多形细胞扩张。在三维lrECM中存活了大量IR剂量的细胞群体中，出现了恶性表型，创建了侵袭性复发的模型。结果：P-Akt在临床DCIS标本中上调，并与复发疾病有关。在三维lrECM中形成DCIS样结构的MCF10A-Akt细胞在IR后出现明显的细胞凋亡，主要发生在管腔内。值得注意的是，当在IR中存活的细胞在三维irECM中重新增殖时，出现了恶性表型，其特征是侵袭活性、纤维连接蛋白、α5β1整合素、基质金属蛋白酶9(MMP9)和E钙粘附素的表达上调。此外，IR诱导核因子-kappa B(NF-kappa B)与β1-整合素启动子区域的核移位和结合，与α5β1-整合素的上调有关。抑制核因子-kappaB或β1-整合素信号通路可抑制肿瘤的侵袭活性。结论：P-Akt在部分人DCIS病变中表达上调，可能与肿瘤复发有关。MCF10A-Akt细胞在三维IrECM和体内形成器官型DCIS样病变，是某些形式的人类DCIS的可行模型。在IR中存活的Akt驱动的类DCIS球体群体在β1整合素和NF-kappa B信号介导的三维lrECM中进展为侵袭性表型。
Introduction: Ductal carcinoma in situ (DCIS) is characterized by non-invasive cancerous cell growth within the breast ducts. Although radiotherapy is commonly used in the treatment of DCIS, the effect and molecular mechanism of ionizing radiation (IR) on DCIS are not well understood, and invasive recurrence following radiotherapy remains a significant clinical problem. This study investigated the effects of IR on a clinically relevant model of Akt-driven DCIS and identified possible molecular mechanisms underlying invasive progression in surviving cells.Methods: We measured the level of phosphorylated-Akt (p-Akt) in a cohort of human DCIS specimens by immunohistochemistry (IHC) and correlated it with recurrence risk. To model human DCIS, we used Akt overexpressing human mammary epithelial cells (MCF10A-Akt) which, in three-dimensional laminin-rich extracellular matrix (lrECM) and in vivo, form organotypic DCIS-like lesions with lumina expanded by pleiomorphic cells contained within an intact basement membrane. In a population of cells that survived significant IR doses in three-dimensional lrECM, a malignant phenotype emerged creating a model for invasive recurrence.Results: P-Akt was up-regulated in clinical DCIS specimens and was associated with recurrent disease. MCF10A-Akt cells that formed DCIS-like structures in three-dimensional lrECM showed significant apoptosis after IR, preferentially in the luminal compartment. Strikingly, when cells that survived IR were repropagated in three-dimensional lrECM, a malignant phenotype emerged, characterized by invasive activity, up-regulation of fibronectin, alpha 5 beta 1-integrin, matrix metalloproteinase-9 (MMP-9) and loss of E-cadherin. In addition, IR induced nuclear translocation and binding of nuclear factor-kappa B (NF-kappa B) to the beta 1-integrin promoter region, associated with up-regulation of alpha 5 beta 1-integrins. Inhibition of NF-kappa B or beta 1-integrin signaling abrogated emergence of the invasive activity.Conclusions: P-Akt is up-regulated in some human DCIS lesions and is possibly associated with recurrence. MCF10A-Akt cells form organotypic DCIS-like lesions in three-dimensional lrECM and in vivo, and are a plausible model for some forms of human DCIS. A population of Akt-driven DCIS-like spheroids that survive IR progresses to an invasive phenotype in three-dimensional lrECM mediated by beta 1-integrin and NF-kappa B signaling.