The immunocytokine scFv23/TNF sensitizes HER-2/neu-overexpressing SKBR-3 cells to tumor necrosis factor (TNF) via up-regulation of TNF receptor-1
The immunocytokine scFv23/TNF sensitizes HER-2/neu-overexpressing SKBR-3 cells to tumor necrosis factor (TNF) via up-regulation of TNF receptor-1
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DOI：
10.1158/1535-7163.mct-05-0014
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发表时间：
2005-08-01
影响因子：
5.7
通讯作者：
Rosenblum, MG
中科院分区：
文献类型：
--
作者：
Lyu, MA;Rosenblum, MG
过表达HER-2/neu可增强细胞对肿瘤坏死因子(TNF)介导的细胞毒作用的抵抗力。为了了解HER-2/neu表达与肿瘤坏死因子耐药之间的关系，我们研究了免疫细胞因子scFv23/TNF在肿瘤坏死因子耐药的SKBR-3-LP细胞中的细胞毒作用。我们发现，用scFv23/TNF处理高表达HER-2/neu的SKBR-3-LP细胞48h后，肿瘤坏死因子受体-1的表达水平增加了5-7倍。此外，用scFv23/TNF处理SKBR-3-LP细胞后，Akt的磷酸化水平下调，并通过caspase-8、caspase-3和聚(ADP-核糖)聚合酶的裂解而诱导细胞凋亡。通过阻断scFv23/肿瘤坏死因子与肿瘤坏死因子受体-1的结合，抑制ScFv23/肿瘤坏死因子诱导的细胞毒作用，并依赖于caspase-8和caspase-3的激活。这些结果表明，免疫细胞因子scFv23/TNF通过过度表达肿瘤坏死因子受体-1，使高表达肿瘤坏死因子耐药的HER-2/neu的SKBR-3-LP细胞对肿瘤坏死因子诱导的细胞凋亡增敏，提示肿瘤坏死因子受体-1的过表达在HER-2/neu过表达癌细胞对肿瘤坏死因子的敏感性中起重要作用。靶向HER-2/neu的ScFv23/TNF可能是对抗HER-2/neu过表达的癌细胞的有效细胞毒剂，这些癌细胞对肿瘤坏死因子具有天然的耐药性。
Overexpression of HER-2/neu confers cellular resistance to tumor necrosis factor (TNF)-mediated cytotoxicity to SKBR-3 breast cancer cell lines. To understand the correlation between HER-2/neu expression and TNF resistance, we examined the unique signaling pathways associated with the cytotoxic effects of the immunocytokine scFv23/TNF, recombinant single-chain antibody fusion constructs containing TNF and targeting HER-2/neu, in TNF-resistant SKBR-3-LP cells. We found that treatment of HER-2/neu overexpressing SKBR-3-LP cells with scFv23/TNF resulted in a 5- to 7-fold higher level of TNF receptor-1 expression 48 hours after exposure. In addition, treatment of SKBR-3-LP cells with scFv23/TNF resulted in down-regulation of Akt phosphorylation and induced apoptosis through cleavage of caspase-8, caspase-3, and poly(ADP-ribose) polymerase. ScFv23/TNF-induced cytotoxicity was inhibited by blocking of the binding of the TNF component of scFv23/TNF to TNF receptor-1 and was dependent on activation of caspase-8 and caspase-3. These results indicate that the immunocytokine scFv23/TNF sensitizes TNF-resistant HER-2/neu overexpressing SKBR-3-LP cells to TNF-induced apoptosis via the overexpression of TNF receptor-1 and suggest that the overexpression of TNF receptor-1 plays a crucial role in TNF sensitivity in HER-2/neu - overexpressing cancer cells. ScFv23/TNF targeting the HER-2/neu may be an effective cytotoxic agent against HER-2/neu - overexpressing cancer cells, which are inherently resistant to TNF.