mda-7 (IL-24) mediates selective apoptosis in human melanoma cells by inducing the coordinated overexpression of the GADD family of genes by means of p38 MAPK
mda-7 (IL-24) mediates selective apoptosis in human melanoma cells by inducing the coordinated overexpression of the GADD family of genes by means of p38 MAPK
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DOI：
10.1073/pnas.152327199
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发表时间：
2002-07-23
影响因子：
11.1
通讯作者：
Fisher, PB
中科院分区：
文献类型：
--
作者：
Sarkar, D;Su, ZZ;Fisher, PB
差减杂交鉴定出黑色素瘤分化相关基因7（mda-7）是在人黑色素瘤细胞终末分化过程中诱导表达的基因。基于结构、染色体定位和类白细胞介素性质，mda-7被归类为IL-24。通过无复制能力的腺病毒（Ad.mda-7）施用mda-7/IL-24在多种人类癌细胞中选择性地诱导凋亡，而在正常成纤维细胞或上皮细胞中不诱导有害作用。本研究探讨了这种差异性凋亡效应的机制。感染黑色素瘤细胞，但不是正常的永生黑色素细胞，与Ad.mda-7诱导的时间和剂量依赖性增加的表达，mRNA和蛋白质，一个家庭的生长停滞和DNA损伤（GADD）诱导基因，这与诱导细胞凋亡。在GADD基因家族的成员中，GADD 153、GADD 45 α和GADD 34显示出显著的诱导，GADD 45 γ显示出最小的诱导。SB 203580是一种p38丝裂原活化蛋白激酶（MAPK）通路的选择性抑制剂，用SB 203580处理黑色素瘤细胞可有效抑制Ad.mda-7诱导的细胞凋亡。通过使用表达p38 MAPK显性失活突变体的腺病毒，证明了p38 MAPK通路参与Ad.mda-7介导的细胞凋亡的额外支持。Ad.mda-7感染增加了黑色素瘤细胞中p38 MAPK和热休克蛋白27的磷酸化，但在正常永生黑色素细胞中没有。此外，SB 203580以时间和密切依赖的方式有效抑制Ad.mda-7介导的GADD家族基因的诱导，并有效阻断Ad.mda-7介导的抗凋亡蛋白BCL-2的下调。单独或联合使用反义方法抑制GADD基因也有效地阻断了Ad.mda-7诱导的黑色素瘤细胞凋亡。这些结果支持以下假设：Ad.mda-7通过p38 MAPK途径介导GADD家族基因的诱导，从而导致人黑素瘤细胞中细胞凋亡的选择性诱导。
Subtraction hybridization identified melanoma differentiation-associated gene-7 (mda-7) as a gene induced during terminal differentiation in human melanoma cells. On the basis of structure, chromosomal localization and cytokine-like properties, mda-7 is classified as IL-24. Administration of mda-7/IL-24 by means of a replication-incompetent adenovirus (Ad.mda-7) induces apoptosis selectively in diverse human cancer cells without inducing harmful effects in normal fibroblast or epithelial cells. The present studies investigated the mechanism underlying this differential apoptotic effect. Infection of melanoma cells, but not normal immortal melanocytes, with Ad.mda-7 induced a time- and dose-dependent increase in expression, mRNA and protein, of a family of growth arrest and DNA damage (GADD)-inducible genes, which correlated with induction of apoptosis. Among the members of the GADD family of genes, GADD153, GADD45alpha, and GADD34 displayed marked, and GADD45gamma showed minimal induction. Treatment of melanoma cells with SB203580, a selective inhibitor of the p38 mitogen-activated protein kinase (MAPK) pathway, effectively inhibited Ad.mda-7-induced apoptosis. Additional support for an involvement of the p38 MAPK pathway in Ad.mda-7-mediated apoptosis was documented by using an adenovirus expressing a dominant negative mutant of p38 MAPK. Infection with Ad.mda-7 increased the phosphorylation of p38 MAPK and heat shock protein 27 in melanoma cells but not in normal immortal melanocytes. In addition, SB203580 effectively inhibited Ad.mda-7-mediated induction of the GADD family of genes in a time- and close-dependent manner, and it effectively blocked Ad.mda-7-mediated down-regulation of the antiapoptotic protein BCL-2. inhibition of GADD genes by an antisense approach either alone or in combination also effectively blocked Ad.mda-7-induced apoptosis in melanoma cells. These results support the hypothesis that Ad.mda-7 mediates induction of the GADD family of genes by means of the p38 MAPK pathway, thereby resulting in the selective induction of apoptosis in human melanoma cells.