Regulator of G-protein signalling expression and function in ovarian cancer cell lines.
Regulator of G-protein signalling expression and function in ovarian cancer cell lines.
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DOI：
10.2478/s11658-008-0040-7
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发表时间：
2009
影响因子：
8.3
通讯作者：
Hooks SB
中科院分区：
文献类型：
--
作者：
Hurst JH;Mendpara N;Hooks SB
g蛋白信号传导调节因子（RGS）2蛋白通过加速异源三聚体g蛋白的失活，对g蛋白偶联受体（gpcr）启动的信号级联反应进行关键调控。溶血磷脂酸（LPA）是主要的生长因子，通过激活卵巢癌细胞中表达的特异性gpcr和g蛋白来驱动卵巢癌的进展。我们最近报道了在SKOV-3卵巢癌细胞中内源性表达的RGS蛋白显著减弱LPA刺激的细胞信号传导。本研究的目的有两个：首先，确定SKOV-3细胞中表达的候选RGS蛋白，这些RGS蛋白可能解释了已报道的g蛋白信号的负调控；其次，确定这些RGS蛋白转录物在常用的卵巢癌细胞系和非癌卵巢癌细胞系中是否存在差异表达。逆转录- pcr检测了22个主要RGS亚型在SKOV-3、OVCAR-3和Caov-3卵巢癌细胞系和非癌性永生化卵巢表面上皮（IOSE）细胞中转录的表达情况。在SKOV-3细胞系中检测到15个RGS转录本。为了比较这些细胞系的相对表达水平，对选择的转录本进行了定量实时RT-PCR。RGS19/GAIP在所有四种细胞系中表达水平相似，而RGS2转录物在卵巢癌细胞中的表达水平略低于loss细胞。RGS4和RGS6转录本在卵巢癌细胞系中的表达水平与在loss细胞中的表达水平有显著差异。RGS4转录物在IOSE中的表达量比其在卵巢癌细胞系中的表达量高几千倍，而RGS6转录物在SKOV-3细胞中的表达量比IOSE细胞高5倍，在OVCAR-3和Caov-3细胞中的表达量比IOSE细胞高1000倍以上。RGS 2、6和19/GAIP的功能研究是通过测量它们对LPA刺激的肌醇磷酸产生的影响来进行的。在表达单个外源性LPA受体的COS-7细胞中，RGS2和RSG19/GAIP减弱LPA1、LPA2或LPA3启动的信号传导，而RGS6仅抑制LPA2受体启动的信号传导。在SKOV-3卵巢癌细胞中，RGS2而不是RGS6或RGS19/GAIP抑制LPA刺激的肌醇磷酸生成。相反，在CAOV-3细胞中，RGS19/GAIP强烈减弱LPA信号。因此，多种RGS蛋白在癌变卵巢细胞和正常卵巢细胞的细胞中以显著不同的水平表达，至少有两种候选RGS转录本已被确定，以解释卵巢癌细胞中LPA信号通路的调节。
Regulator of G-protein signalling (RGS)2 proteins critically regulate signalling cascades initiated by G-protein coupled receptors (GPCRs) by accelerating the deactivation of heterotrimeric G-proteins. Lysophosphatidic acid (LPA) is the predominant growth factor that drives the progression of ovarian cancer by activating specific GPCRs and G-proteins expressed in ovarian cancer cells. We have recently reported that RGS proteins endogenously expressed in SKOV-3 ovarian cancer cells dramatically attenuate LPA stimulated cell signalling. The goal of this study was twofold: first, to identify candidate RGS proteins expressed in SKOV-3 cells that may account for the reported negative regulation of G-protein signalling, and second, to determine if these RGS protein transcripts are differentially expressed among commonly utilized ovarian cancer cell lines and non-cancerous ovarian cell lines. Reverse transcriptase-PCR was performed to determine transcript expression of 22 major RGS subtypes in RNA isolated from SKOV-3, OVCAR-3 and Caov-3 ovarian cancer cell lines and non-cancerous immortalized ovarian surface epithelial (IOSE) cells. Fifteen RGS transcripts were detected in SKOV-3 cell lines. To compare the relative expression levels in these cell lines, quantitative real time RT-PCR was performed on select transcripts. RGS19/GAIP was expressed at similar levels in all four cell lines, while RGS2 transcript was detected at levels slightly lower in ovarian cancer cells as compared to IOSE cells. RGS4 and RGS6 transcripts were expressed at dramatically different levels in ovarian cancer cell lines as compared to IOSE cells. RGS4 transcript was detected in IOSE at levels several thousand fold higher than its expression level in ovarian cancer cells lines, while RGS6 transcript was expressed fivefold higher in SKOV-3 cells as compared to IOSE cells, and over a thousand fold higher in OVCAR-3 and Caov-3 cells as compared to IOSE cells. Functional studies of RGS 2, 6, and 19/GAIP were performed by measuring their effects on LPA stimulated production of inositol phosphates. In COS-7 cells expressing individual exogenous LPA receptors, RGS2 and RSG19/GAIP attenuated signalling initiated by LPA1, LPA2, or LPA3, while RGS6 only inhibited signalling initiated by LPA2 receptors. In SKOV-3 ovarian cancer cells, RGS2 but not RGS6 or RGS19/GAIP, inhibited LPA stimulated inositol phosphate production. In contrast, in CAOV-3 cells RGS19/GAIP strongly attenuated LPA signalling. Thus, multiple RGS proteins are expressed at significantly different levels in cells derived from cancerous and normal ovarian cells and at least two candidate RGS transcripts have been identified to account for the reported regulation of LPA signalling pathways in ovarian cancer cells.
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影响因子：
15.9
作者：
Heximer, SP;Knutsen, RH;Blumer, KJ
通讯作者：
Blumer, KJ
影响因子：
3.6
作者：
Ishii, I;Contos, JJA;Chun, J
通讯作者：
Chun, J
影响因子：
4.8
作者：
Chatterjee, TK;Liu, ZY;Fisher, RA
通讯作者：
Fisher, RA
影响因子：
3.6
作者：
Hains, Melinda D.;Wing, Michele R.;Harden, T. Kendall
通讯作者：
Harden, T. Kendall
DOI：
10.1152/ajpheart.01391.2006
发表时间：
2007-05-01
影响因子：
4.8
作者：
Fu, Ying;Huang, Xinyan;Neubig, Richard R.
通讯作者：
Neubig, Richard R.