Growth factor receptor-Src-mediated suppression of GRK6 dysregulates CXCR4 signaling and promotes medulloblastoma migration.
Growth factor receptor-Src-mediated suppression of GRK6 dysregulates CXCR4 signaling and promotes medulloblastoma migration.
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生长因子受体-SRC介导的GRK6抑制作用抑制CXCR4信号传导并促进髓母细胞瘤的迁移。
DOI：
10.1186/1476-4598-12-18
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发表时间：
2013-03-05
期刊：
影响因子：
37.3
通讯作者：
MacDonald TJ
中科院分区：
文献类型：
--
作者：
Yuan L;Zhang H;Liu J;Rubin JB;Cho YJ;Shu HK;Schniederjan M;MacDonald TJ
髓母细胞瘤（MB）的转移与生存率低有关。最近的遗传学研究显示MB包括不同的分子亚组，包括表现出相对较高的进展率的音刺猬（SHH）亚组。为了确定针对转移的靶向治疗剂，需要更好地理解MB细胞迁移的调节。G蛋白偶联受体激酶（GRKs）通过调节参与生长因子（GF）介导的细胞迁移的G蛋白偶联受体（GPCR）参与癌症转移。然而，GRKs在MB中的具体作用和调节尚未研究。应用基因芯片技术检测29例MB细胞中GRK、GPCR和GFs的mRNA表达，并采用真实的时间RT-PCR检测MB细胞中GRK 6的表达。MB细胞的慢病毒或逆转录病毒感染以及siRNA或shRNA转染分别用于过表达和敲低靶基因。蛋白质印迹用于确认改变的蛋白质表达。通过Boyden小室测定和xCELLigence迁移测定来确定改变的靶蛋白对细胞迁移的影响。我们观察到PDGFRA、CXCR 4和CXCL 12在SHH MB亚型中的共过表达与非SHH MB相比（分别高5、7和5倍）。GRK 6通常作为CXCR 4信号传导的负调节剂，相对于其他GRK，在MB中下调，而GRK 6表达的百分比在有转移的MB肿瘤中（22%）低于无转移的MB肿瘤（43%）。在SHH反应性MB细胞中，PDGFR的功能性阻断消除了CXCR 4介导的信号传导。shPDGFR转染的MB细胞显示GRK 6表达增加，而天然MB细胞的PDGF或10%FBS处理通过诱导其蛋白体降解而降低GRK 6的稳定性。Src是GF受体/PDGFR信号传导的关键介质，其过表达或下调分别类似地抑制或诱导GRK 6表达。GRK 6的siRNA下调增强了CXCR 4信号传导并促进了MB迁移，而慢病毒GRK 6过表达抑制了CXCR 4信号传导，增强了CXCR 4拮抗剂AMD 3100的作用并损害了迁移。我们的研究结果证明了GF受体/PDGFR-Src介导的CXCR 4信号转导失调的新机制，其促进MB细胞迁移，这可能用于SHH MB的治疗靶向。
Metastasis in medulloblastoma (MB) is associated with poor survival. Recent genetic studies revealed MB to comprise distinct molecular subgroups, including the sonic hedgehog (SHH) subgroup that exhibits a relatively high rate of progression. To identify targeted therapeutics against metastasis, a better understanding of the regulation of MB cell migration is needed. G protein-coupled receptor kinases (GRKs) have been implicated in cancer metastasis through their regulation of G-protein coupled receptors (GPCRs) involved in growth factor (GF)-mediated cell migration. However, the specific roles and regulation of GRKs in MB have not been investigated. Microarray mRNA analysis was performed for GRKs, GPCRs, and GFs in 29 human MB, and real time RT-PCR was used to detect GRK6 expression in MB cells. Lenti- or retro-virus infection, and siRNA or shRNA transfection, of MB cells was used to overexpress and knockdown target genes, respectively. Western blot was used to confirm altered expression of proteins. The effect of altered target protein on cell migration was determined by Boyden chamber assay and xCELLigence migration assays. We observed co-overexpression of PDGFRA, CXCR4, and CXCL12 in the SHH MB subtype compared to non-SHH MB (5, 7, and 5-fold higher, respectively). GRK6, which typically acts as a negative regulator of CXCR4 signaling, is downregulated in MB, relative to other GRKs, while the percentage of GRK6 expression is lower in MB tumors with metastasis (22%), compared to those without metastasis (43%). In SHH-responsive MB cells, functional blockade of PDGFR abolished CXCR4-mediated signaling. shPDGFR transfected MB cells demonstrated increased GRK6 expression, while PDGF or 10% FBS treatment of native MB cells reduced the stability of GRK6 by inducing its proteosomal degradation. Overexpression or downregulation of Src, a key mediator of GF receptor/PDGFR signaling, similarly inhibited or induced GRK6 expression, respectively. siRNA downregulation of GRK6 enhanced CXCR4 signaling and promoted MB migration, while lentiviral-GRK6 overexpression suppressed CXCR4 signaling, potentiated the effect of AMD3100, a CXCR4 antagonist, and impaired migration. Our findings demonstrate a novel mechanism of GF receptor/PDGFR-Src-mediated dysregulation of CXCR4 signaling that promotes MB cell migration, which could potentially be exploited for therapeutic targeting in SHH MB.
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DOI：
10.1073/pnas.2235846100
发表时间：
2003-11-11
影响因子：
11.1
作者：
Rubin, JB;Kung, AL;Segal, RA
通讯作者：
Segal, RA
影响因子：
12.7
作者：
Taylor MD;Northcott PA;Korshunov A;Remke M;Cho YJ;Clifford SC;Eberhart CG;Parsons DW;Rutkowski S;Gajjar A;Ellison DW;Lichter P;Gilbertson RJ;Pomeroy SL;Kool M;Pfister SM
通讯作者：
Pfister SM
DOI：
10.1007/978-1-61779-108-6_6
发表时间：
2011-01-01
期刊：
MAMMALIAN CELL VIABILITY: METHODS AND PROTOCOLS
影响因子：
--
作者：
Ke, Ning;Wang, Xiaobo;Abassi, Yama A.
通讯作者：
Abassi, Yama A.
影响因子：
30.8
作者：
MacDonald, TJ;Brown, KM;Stephan, DA
通讯作者：
Stephan, DA
影响因子：
11.5
作者：
Teicher, Beverly A.;Fricker, Simon P.
通讯作者：
Fricker, Simon P.