Bernhard E J, Hagner B, Wong C, Lubenski I, Muschel R J
Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia 19104-6072.
Int J Cancer. 1995 Mar 3;60(5):718-24. doi: 10.1002/ijc.2910600525.
The expression of MMP-9 in rat embryo fibroblasts (REF) transformed with Ha-ras or with Ha-ras and v-myc is associated with metastatic behavior. In contrast, REF transformed with Ha-ras and the adenovirus E1A genes (E1A) are tumorigenic, do not release MMP-9 and are rarely metastatic. In this report, we establish that E1A expression results in decreased levels of MMP-9 mRNA in an Ha-ras and v-myc transformed cell line and examine which of the functional domains of E1A participate in the inhibition of MMP-9 expression and which contribute to the suppression of metastasis. The metastatic 2.10 REF line, derived by co-transfection with v-myc and Ha-ras, constitutively expresses high levels of MMP-9 (92 kDa gelatinase). Transfection of E1A wild-type plasmids into this cell line eliminates detectable MMP-9 mRNA expression and greatly reduces MMP-9 activity. Transfection of 2.10 with E1A plasmids encoding mutations in conserved region 2 (CR2) retained inhibition of MMP-9 similar to the inhibition seen with wild-type E1A. Transfection with E1A containing mutations in CRI or the amino terminal region diminished, but did not fully inhibit, MMP-9 expression. In contrast, inhibition of MMP-9 was lost in with E1A mutations in CR3. Cells transfected with E1A mutants in CR1, the amino terminal region or CR3 retained metastatic behavior. Our findings delineate the regions of E1A responsible for MMP-9 inhibition and further define the domains of E1A responsible for inhibition of metastasis.
用Ha-ras或Ha-ras与v-myc转化的大鼠胚胎成纤维细胞（REF）中MMP-9的表达与转移行为相关。相比之下，用Ha-ras和腺病毒E1A基因（E1A）转化的REF具有致瘤性，不释放MMP-9，很少发生转移。在本报告中，我们证实E1A的表达导致Ha-ras和v-myc转化的细胞系中MMP-9 mRNA水平降低，并研究E1A的哪些功能域参与MMP-9表达的抑制以及哪些有助于转移的抑制。通过与v-myc和Ha-ras共转染获得的转移性2.10 REF细胞系持续高水平表达MMP-9（92 kDa明胶酶）。将E1A野生型质粒转染到该细胞系中可消除可检测到的MMP-9 mRNA表达，并大大降低MMP-9活性。用编码保守区域2（CR2）突变的E1A质粒转染2.10细胞，对MMP-9的抑制作用与野生型E1A相似。用在CRI或氨基末端区域含有突变的E1A转染可减少但不能完全抑制MMP-9的表达。相比之下，CR3中E1A突变则失去了对MMP-9的抑制作用。用CR1、氨基末端区域或CR3中E1A突变体转染的细胞保留了转移行为。我们的研究结果确定了E1A中负责抑制MMP-9的区域，并进一步明确了E1A中负责抑制转移的结构域。
