Price Daniel J, Avraham Shalom, Feuerstein Joseph, Fu Yigong, Avraham Hava Karsenty
Division of Experimental Medicine, Beth Israel-Deaconess Medical Center, Harvard Institutes of Medicine, Boston, MA 02115, USA.
Cell Commun Adhes. 2002 Mar-Apr;9(2):87-102. doi: 10.1080/15419060214147.
We studied the invasion of HMT-3522 breast epithelial cells in response to epidermal growth factor (EGF), and the associated signaling pathways. HMT-3522 T4-2 cells were shown to invade Matrigel-coated Transwell membranes in response to EGF while HMT-3522 S-1 cells failed to invade when treated with EGF. Studies utilizing specific molecular inhibitors showed the importance of beta1 integrin, phosphatidylinositol 3 kinase (PI 3-kinase), p38, extracellular regulated kinase 1, 2 (Erk 1,2) MAP kinases, and metalloproteinases in invasion and motility. T4-2 cell invasion was shown to be time-dependent and also gene transcription-dependent as shown by inhibition with Actinomycin D. T4-2 cells exhibited an increased activation of MAP kinases Erk 1,2 (2-fold), EGF receptor (3-fold), and PI 3-kinase (3- to 4-fold) when compared to the S-1 cells. In response to EGF, T4-2 cells showed a 5-fold greater secretion of matrix metalloproteinase-9 (MMP-9) as compared to S-1 cells, and this increase was largely dependent on the activity of PI 3-kinase. These findings indicate that expression of the invasive phenotype in these breast epithelial cells requires increased EGF receptor signaling, involving both PI 3-kinase and Erk 1,2 activities, which leads to multiple downstream effects, including enhanced secretion of MMP-9 and transcription of invasion-related genes.
我们研究了HMT-3522乳腺上皮细胞对表皮生长因子（EGF）的侵袭反应以及相关的信号通路。结果显示，HMT-3522 T4-2细胞在EGF刺激下能够侵袭基质胶包被的Transwell小室膜，而HMT-3522 S-1细胞在EGF处理时则无法侵袭。利用特异性分子抑制剂的研究表明，β1整合素、磷脂酰肌醇3激酶（PI 3-激酶）、p38、细胞外调节激酶1、2（Erk 1,2）丝裂原活化蛋白激酶和金属蛋白酶在侵袭和迁移过程中具有重要作用。如放线菌素D抑制实验所示，T4-2细胞的侵袭呈时间依赖性且也依赖于基因转录。与S-1细胞相比，T4-2细胞中丝裂原活化蛋白激酶Erk 1,2（2倍）、EGF受体（3倍）和PI 3-激酶（3至4倍）的激活增加。在EGF刺激下，与S-1细胞相比，T4-2细胞中基质金属蛋白酶-9（MMP-9）的分泌增加了5倍，且这种增加在很大程度上依赖于PI 3-激酶的活性。这些发现表明，这些乳腺上皮细胞侵袭表型的表达需要增强EGF受体信号传导，涉及PI 3-激酶和Erk 1,2的活性，这会导致多种下游效应，包括MMP-9分泌增加和侵袭相关基因的转录。
