Upregulation of the truncated basic hair keratin 1(hHb1-ΔN) in carcinoma cells by Epstein-Barr virus (EBV)
Upregulation of the truncated basic hair keratin 1(hHb1-ΔN) in carcinoma cells by Epstein-Barr virus (EBV)
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DOI：
10.1002/ijc.11289
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发表时间：
2003-11-20
影响因子：
6.4
通讯作者：
Szekely, L
中科院分区：
文献类型：
--
作者：
Nishikawa, J;Kiss, C;Szekely, L
为了探讨EB病毒在上皮性肿瘤中的作用，我们比较了EB病毒感染的胃癌细胞株NU-GC-3和未感染的对照细胞基因的表达模式。消减抑制杂交(SSH)与高密度DNA阵列筛选相结合，筛选差异表达基因。我们发现，EBV感染上调了人类基本毛发角蛋白1(hHb1-Deltan)的截短变体，该基因以前在转移性乳腺癌中被发现。我们通过Northern杂交验证了hHb1-Deltan在3个独立的EBV阳性和阴性的Nu-GC-3克隆中的差异表达。我们进一步通过RT-PCR验证了EBV依赖的hHb1-Deltan在另外3个癌细胞系(AGS、TWO_3和DLD1)中的上调。5-aza-CDR抑制CpG甲基化可诱导EBV阴性克隆中hHb1-Deltan的表达，但不改变EBV阳性克隆中hHb1-Deltan的表达。免疫荧光和Western blotting检测到EBV阳性克隆中hHb1-Deltan蛋白的表达，而蛋白酶体抑制剂(MG132)处理后，EBV阴性的NU-GC-3克隆中未检测到hHb1-Deltan蛋白的表达。HHb1-Deltan蛋白在细胞质中形成纤维状结构，并聚集在细胞核常染色区的不同核体中。我们认为，不稳定的hHb1-Deltan蛋白可能抑制角蛋白细胞骨架的某些功能和/或干扰转录调节。它还可能在EBV和携带病毒的癌症的低分化或间变性状态之间建立联系。(C)2003年Wiley-Liss，Inc.
To investigate the role of Epstein-Barr virus (EBV) in epithelial tumors, we compared the expression pattern of cellular genes in the EBV-infected gastric carcinoma cell line, NU-GC-3, and its uninfected control. Subtractive suppression hybridization (SSH) was combined with high-density DNA array screening to identify differentially expressed genes. We have discovered that EBV infection upregulated a truncated variant of human basic hair keratin 1 (hHb1-DeltaN), a gene that had previously been identified in metastatic breast carcinoma. We verified the differential expression of hHb1-DeltaN in 3 independent EBV-positive and -negative NU-GC-3 clones by Northern blotting. We further verified the EBV-dependent upregulation of hHb1-DeltaN in 3 other carcinoma cell lines (AGS, TWO3 and DLD1) by RT-PCR. Inhibition of CpG methylation by 5-Aza-CdR induced hHb1-DeltaN mRNA expression in the EBV-negative clones but did not alter the expression in the EBV-positive clones. The expression of hHb1-DeltaN protein was detectable by immunofluorescence and Western blotting in EBV-positive but not in EBV-negative NU-GC-3 clones after proteasome inhibitor (MG132) treatment. hHb1-DeltaN protein formed fibrous structures in the cytoplasm and accumulated in distinct nuclear bodies in the euchromatic areas of the cell nucleus. We suggest that the unstable hHb1-DeltaN protein may inhibit some of the functions of the keratin cytoskeleton and/or interfere with transcription regulation. It also may establish a link between EBV and the low differentiated or anaplastic status of the carcinomas that carry the virus. (C) 2003 Wiley-Liss, Inc.