Nucleoporin NUP205-driven Novel Pathway in Melanoma Tumor Growth and Metastasis

 描述（由申请方提供）：大分子的核质运输是一种高度特异性和严格调控的过程，仅通过核孔复合物（NPC）发生。NPC由大约30种称为核孔蛋白的蛋白质组成，它们在几种生物过程中发挥关键作用。虽然在血液恶性肿瘤中观察到涉及一些核孔蛋白的染色体易位，但是，它们在实体瘤中的作用尚不清楚。因此，为了研究核孔蛋白在黑色素瘤肿瘤生长和转移中的作用，我们通过将癌症基因组图谱（TCGA）黑色素瘤样本数据集分析与体内RNA干扰（RNAi）筛选的功能基因组学方法相结合，开发了一种整合基因组学方法。该方法将NUP 205鉴定为BRAF和NRAS突变型黑色素瘤的肿瘤生长和转移所必需的唯一核孔蛋白。另外的实验表明，NUP 205赋予失巢凋亡抗性并刺激MAK激酶和WNT信号通路。基于这些结果，我们假设NUP 205通过调节MAP激酶和WNT信号通路驱动黑色素瘤肿瘤生长和转移。总体目标是确定NUP 205在肿瘤生长和转移中的作用和机制，并测试NUP 205驱动的通路是否可以靶向治疗黑色素瘤。在目标1中，我们将确定NUP 205在黑色素瘤肿瘤生长和转移中的体内作用。为此，我们将使用黑色素瘤肿瘤生长的体内小鼠模型和黑色素瘤转移的器官特异性和自发性小鼠模型，确定NUP 205在促进黑色素瘤肿瘤生长和转移中的作用。在目标2中，我们将确定NUP 205的作用机制。基于我们的结果，我们将测试NUP 205通过Raf激酶抑制蛋白（RKIP）刺激MAP激酶和/或通过硫酸乙酰肝素2-O-磺基转移酶1（HS 2ST 1）刺激WNT信号传导途径的能力是否是其赋予失巢凋亡抗性和促进黑素瘤肿瘤生长和转移所必需的。在目标3中，我们将确定靶向NUP 205调节通路用于黑色素瘤治疗的效用。首先，我们将测试通过小分子抑制剂对NUP 205下游效应子HS 2ST 1酶的药理学抑制是否可以在体内阻断转移性肿瘤生长。此外，由于NUP 205蛋白稳定化可赋予对BRAFV 600 E抑制剂维罗非尼的耐药性，因此，我们将确定抑制其下游效应子HS 2ST 1是否可恢复对维罗非尼的敏感性并防止耐药性的出现。这些结果的临床意义将通过分析维罗非尼治疗前和治疗后黑色素瘤患者样品的NUP 205及其下游效应物的表达来确定。总的来说，我们希望发现一种新的NUP 205驱动的可药物化的遗传脆弱性途径，可以靶向治疗转移性和耐药性黑色素瘤。

 DESCRIPTION (provided by applicant): Nucleocytoplasmic trafficking of macromolecules is a highly specific and tightly regulated process that occurs exclusively through the nuclear pore complex (NPC). NPC is composed of approximately 30 proteins, termed nucleoporins, which play crucial roles in several biological processes. Although, chromosomal translocation involving some nucleoporins are observed in hematological malignancies, however, their role in solid tumors is not known. Therefore, to study the role of nucleoporins in melanoma tumor growth and metastasis, we developed an integrative genomics approach by combining The Cancer Genome Atlas (TCGA) melanoma sample dataset analyses with functional genomics approach of an in vivo RNA interference (RNAi) screening. This approach identified NUP205 as the only nucleoporin that is essential for tumor growth and metastasis of BRAF- and NRAS-mutant melanoma. Additional experiments revealed that NUP205 confers anoikis resistance and stimulates MAK kinase and WNT signaling pathways. Based on these results, we hypothesize that NUP205 by regulating MAP kinase and WNT signaling pathways drives melanoma tumor growth and metastasis. The overall objective is to determine the role and mechanism of NUP205 in tumor growth and metastasis and test if NUP205-driven pathway can be targeted to treat melanoma. In Aim 1, we will determine the in vivo role of NUP205 in melanoma tumor growth and metastasis. To this end, using in vivo mouse models of melanoma tumor growth and organ-specific and spontaneous mouse models of melanoma metastasis, we will determine the role of NUP205 in facilitating melanoma tumor growth and metastasis. In Aim 2, we will determine the mechanism of NUP205 action. Based on our results, we will test whether the ability of NUP205 to stimulate MAP kinase via Raf kinase inhibitory protein (RKIP) and/or WNT signaling pathway via heparan sulfate 2-O-sulfotransferase 1 (HS2ST1) is required for it to confer anoikis resistance and promote melanoma tumor growth and metastasis. In Aim 3, we will determine the utility of targeting NUP205 regulated pathway for melanoma therapy. First, we will test if pharmacological inhibition of NUP205 downstream effector HS2ST1 enzyme by small molecule inhibitors can block metastatic tumor growth in vivo. Additionally, because NUP205 protein stabilization can confer resistance to BRAFV600E inhibitor vemurafenib, therefore, we will determine if inhibition of its downstream effector HS2ST1 can restore sensitivity to vemurafenib and prevent emergence of drug resistance. Clinical significance of these results will be established by analyzing pre- and post- vemurafenib treatment melanoma patient samples for the expression of NUP205 and its downstream effectors. Collectively, we expect to uncover a novel NUP205-driven druggable genetic vulnerability pathway that can be targeted for treating metastatic and drug resistant melanoma.