The latency-associated nuclear antigen of Kaposi's sarcoma-associated herpesvirus modulates cellular gene expression and protects lymphoid cells from p16 INK4A-induced cell cycle arrest
The latency-associated nuclear antigen of Kaposi's sarcoma-associated herpesvirus modulates cellular gene expression and protects lymphoid cells from p16 INK4A-induced cell cycle arrest
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DOI：
10.1074/jbc.m407435200
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发表时间：
2005-02-04
影响因子：
4.8
通讯作者：
Renne, R
中科院分区：
文献类型：
--
作者：
An, FQ;Compitello, N;Renne, R
潜伏感染的卡波西肉瘤相关疱疹病毒（KSHV）相关肿瘤细胞具有内皮和淋巴起源，并表达一组有限的潜伏病毒基因。一个这样的基因，ORF 73，编码潜伏相关核抗原（拉娜），一种多功能蛋白，在病毒DNA复制，附加体维持和转录调控中发挥作用。拉娜与参与转录调节的细胞蛋白相互作用，例如肿瘤抑制因子、视网膜母细胞瘤（Rb）和p53以及RING 3家族成员。尽管存在关于特定LANA调节启动子的几个报告，但只有有限的数据可用于解决KSHV感染细胞中的拉娜表达如何全面影响细胞基因表达，从而可能导致KSHV致病性。为了研究这个问题，我们产生了一个EB病毒阴性伯基特淋巴瘤细胞系，表达拉娜从四环素诱导型启动子（BJAB/Tet-On/拉娜），我们进行了基于微阵列的基因表达谱。诱导后不同时间点的表达谱显示，在拉娜存在下，186个基因被激活或抑制超过2倍。在这些基因中，41个在Rb/E2 F通路中受到调节，而7个与p53信号传导有关。为了确定这些基因表达变化是否转化为细胞周期调控中的LANA依赖性变化，我们过表达p16 INK 4a，这是一种CDK 4/6抑制剂，可有效诱导Rb阳性细胞的细胞周期停滞。在这些条件下，拉娜表达保护淋巴细胞免于p16 INK 4a诱导的细胞周期停滞并诱导S期进入。
Latently infected Kaposi's sarcoma-associated herpesvirus (KSHV)-associated tumor cells have both endothelial and lymphoid origins and express a limited set of latent viral genes. One such gene, ORF73, encodes the latency-associated nuclear antigen (LANA), a multifunctional protein that plays roles in viral DNA replication, episome maintenance, and transcriptional regulation. LANA interacts with cellular proteins involved in transcriptional regulation such as the tumor suppressors, retinoblastoma (Rb) and p53, and RING3 family members. Although several reports about specific LANA-regulated promoters exist, only limited data are available that address how LANA expression in KSHV-infected cells globally affects cellular gene expression, thereby potentially contributing to KSHV pathogenicity. To investigate this question, we generated an Epstein-Barr virus-negative Burkitts lymphoma line that expresses LANA from a tetracycline-inducible promoter (BJAB/Tet-On/LANA), and we performed microarray-based gene expression profiling. Expression profiling at different time points post-induction revealed that 186 genes were activated or repressed over 2-fold in the presence of LANA. Of these genes, 41 are regulated in the Rb/E2F pathway, whereas 7 are related to p53 signaling. To determine whether these gene expression changes translate into LANA-dependent changes in cell cycle regulation, we overexpressed p16 INK4a, a CDK4/6 inhibitor that efficiently induces cell cycle arrest in Rb-positive cells. Under these conditions, LANA expression protects lymphoid cells from p16 INK4a-induced cell cycle arrest and induces S-phase entry.