Identification of unique MEK-dependent genes in GNAQ mutant uveal melanoma involved in cell growth, tumor cell invasion, and MEK resistance.
Identification of unique MEK-dependent genes in GNAQ mutant uveal melanoma involved in cell growth, tumor cell invasion, and MEK resistance.
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DOI：
10.1158/1078-0432.ccr-11-3086
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发表时间：
2012-07-01
期刊：
影响因子：
--
通讯作者：
Schwartz GK
中科院分区：
文献类型：
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作者：
Ambrosini G;Pratilas CA;Qin LX;Tadi M;Surriga O;Carvajal RD;Schwartz GK
转移性葡萄膜黑色素瘤（UM）是最常见的眼内恶性肿瘤，预后极差且没有有效的治疗方法。约 85% 的葡萄膜黑色素瘤中存在 G 蛋白 α 亚基 q 和 11 的致癌突变，并导致组成性激活。 GNAQ/11 激活会诱导多种信号传导途径，其中包括 MEK/ERK 激酶级联。我们分析了用 MEK 抑制剂处理的细胞系的转录谱，以确定激活的 GNAQ 的基因靶标并评估这些基因在 UM 中的生物学重要性。我们对经 MEK 抑制剂 selumetinib 处理的具有 GNAQ 突变的 UM 细胞系进行了微阵列分析。为了进行比较，我们使用携带 BRAFV600E 的细胞和没有任何突变的细胞。然后通过实时 qPCR 和免疫印迹证实所选基因表达的变化。我们发现 GNAQ 突变细胞具有 MEK 依赖性转录输出，并鉴定了一组独特的基因，这些基因会因 MEK 抑制而下调，包括 RNA 解旋酶 DDX21 和细胞周期蛋白依赖性激酶调节剂 CDK5R1，同时 JUN 被诱导。我们提供的证据表明这些基因分别与细胞增殖、肿瘤细胞侵袭和耐药性有关。此外，我们发现司美替尼治疗可调节转移性 GNAQ/11 突变葡萄膜黑色素瘤患者肿瘤组织中这些基因的表达。结论：我们的研究结果定义了 GNAQ 突变细胞中司美替尼转录调控基因的子集，并为理解 MEK 抑制在该疾病中的生物学效应提供了新的见解。
Metastatic uveal melanoma (UM) represents the most common intraocular malignancy with very poor prognosis and no effective treatments. Oncogenic mutations in the G protein alpha subunit q and 11 have been described in about 85% of uveal melanomas and confer constitutive activation. Multiple signaling pathways are induced as a consequence of GNAQ/11 activation, which include the MEK/ERK kinase cascade. We analyzed the transcriptional profile of cell lines treated with a MEK inhibitor to identify gene targets of activated GNAQ and evaluate the biological importance of these genes in UM. We performed microarray analysis of UM cell lines with GNAQ mutations treated with the MEK inhibitor selumetinib. For comparison, we used cells carrying BRAFV600E and cells without either mutation. Changes in the expression of selected genes were then confirmed by real-time qPCR and immunoblotting. We found that GNAQ mutant cells have a MEK-dependent transcriptional output and identified a unique set of genes that are down-regulated by MEK inhibition, including the RNA helicase DDX21 and the cyclin dependent kinase regulator CDK5R1, while JUN was induced. We provide evidence that these genes are involved in cell proliferation, tumor cell invasion and drug resistance, respectively. Furthermore, we show that selumetinib treatment regulates the expression of these genes in tumor tissues of patients with metastatic GNAQ/11 mutant uveal melanoma. Conclusions: Our findings define a subset of transcriptionally regulated genes by selumetinib in GNAQ mutant cells and provide new insights into understanding the biologic effect of MEK inhibition in this disease.