Department of Oral and Craniofacial Biology, School of Dentistry, Louisiana State University Health Sciences Center-New Orleans, New Orleans, Louisiana, United States of America.
PLoS One. 2011;6(6):e21496. doi: 10.1371/journal.pone.0021496. Epub 2011 Jun 24.
Extracellular matrix factors within the tumor microenvironment that control resistance to chemotherapeutics are poorly understood. This study focused on understanding matrix adhesion pathways that control the oral carcinoma response to cisplatin. Our studies revealed that adhesion of HN12 and JHU012 oral carcinomas to carcinoma matrix supported tumor cell proliferation in response to treatment with cisplatin. Proliferation in response to 30 µM cisplatin was not observed in HN12 cells adherent to other purified extracellular matrices such as Matrigel, collagen I, fibronectin or laminin I. Integrin β₁ was important for adhesion to carcinoma matrix to trigger proliferation after treatment with cisplatin. Disruption of talin expression in HN12 cells adherent to carcinoma matrix increased cisplatin induced proliferation. Pharmacological inhibitors were used to determine signaling events required for talin deficiency to regulate cisplatin induced proliferation. Pharmacological inhibition of NF-kB reduced proliferation of talin-deficient HN12 cells treated with 30 µM cisplatin. Nuclear NF-kB activity was assayed in HN12 cells using a luciferase reporter of NF-kB transcriptional activity. Nuclear NF-kB activity was similar in HN12 cells adherent to carcinoma matrix and collagen I when treated with vehicle DMSO. Following treatment with 30 µM cisplatin, NF-kB activity is maintained in cells adherent to carcinoma matrix whereas NF-kB activity is reduced in collagen I adherent cells. Expression of talin was sufficient to trigger proliferation of HN12 cells adherent to collagen I following treatment with 1 and 30 µM cisplatin. Talin overexpression was sufficient to trigger NF-kB activity following treatment with cisplatin in carcinoma matrix adherent HN12 cells in a process disrupted by FAK siRNA. Thus, adhesions within the carcinoma matrix create a matrix environment in which exposure to cisplatin induces proliferation through the function of integrin β₁, talin and FAK pathways that regulate NF-kB nuclear activity.
肿瘤微环境中的细胞外基质因子控制着对化疗药物的耐药性，但人们对此知之甚少。本研究专注于了解控制口腔癌细胞对顺铂反应的基质黏附途径。我们的研究表明，HN12 和 JHU012 口腔癌细胞与癌基质的黏附支持肿瘤细胞在顺铂治疗下的增殖。HN12 细胞黏附在其他纯化的细胞外基质（如 Matrigel、I 型胶原、纤维连接蛋白或层粘连蛋白 I）上时，不会对 30µM 顺铂产生增殖反应。β₁ 整联蛋白对于与癌基质的黏附以触发顺铂治疗后的增殖是重要的。在黏附于癌基质的 HN12 细胞中破坏 talin 的表达会增加顺铂诱导的增殖。使用药理学抑制剂来确定 talin 缺乏调节顺铂诱导增殖所需的信号事件。NF-κB 的药理学抑制减少了用 30µM 顺铂处理的 talin 缺陷 HN12 细胞的增殖。使用 NF-κB 转录活性的荧光素酶报告基因检测 HN12 细胞中的核 NF-κB 活性。在用 DMSO 处理时，HN12 细胞在癌基质和 I 型胶原上的 NF-κB 活性相似。在用 30µM 顺铂处理后，NF-κB 活性在黏附于癌基质的细胞中得以维持，而在黏附于 I 型胶原的细胞中 NF-κB 活性降低。在用 1µM 和 30µM 顺铂处理后，talin 的表达足以触发黏附于 I 型胶原的 HN12 细胞的增殖。在经顺铂处理后，在癌基质黏附的 HN12 细胞中，talin 的过表达足以触发 NF-κB 活性，而这一过程被 FAK siRNA 破坏。因此，癌基质中的黏附创建了一个基质环境，其中顺铂的暴露通过整合素 β₁、talin 和 FAK 途径调节 NF-κB 核活性来诱导增殖。
