Critical Role of Gα12 and Gα13 for Human Small Cell Lung Cancer Cell Proliferation In vitro and Tumor Growth In vivo
Critical Role of Gα12 and Gα13 for Human Small Cell Lung Cancer Cell Proliferation In vitro and Tumor Growth In vivo
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DOI：
10.1158/1078-0432.ccr-09-1873
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发表时间：
2010-03-01
影响因子：
11.5
通讯作者：
Aigner, Achim
中科院分区：
文献类型：
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作者：
Grzelinski, Marius;Pinkenburg, Olaf;Aigner, Achim
目的：在小细胞肺癌细胞（SCLC）中，各种自分泌刺激导致G（q/11）和G（12/13）蛋白的平行激活。虽然G（q/11）-磷脂酶C-β级联对SCLC细胞中促有丝分裂作用的贡献已得到充分证实，但G（12/13）信号传导的相关性仍难以理解。在其他肿瘤实体中，G（12/13）活化促进侵袭性而不影响细胞增殖。在这里，我们研究了G（12/13）依赖性信号在SCLC中的作用。实验设计：我们在H69和H209细胞中使用小发夹RNA介导的G α（12）、G α（13）或两者的靶向，并分析了G α（12）和/或G α（13）敲低对体外肿瘤细胞、体内肿瘤生长、结果：慢病毒表达的小发夹RNA导致了G α（12）和G α（13）的稳定和特异性敲低，并显著抑制细胞增殖、集落形成和缓激肽促进的细胞生长刺激。分析所有三个主要MAPK家族的激活状态，揭示了G α（12）和G α（13）在SCLC中的非冗余功能，以及在G α（12）/G α（13）敲低后显著的p42/p44激活。在一个s.c.在肿瘤异种移植小鼠模型中，由于肿瘤细胞增殖减少，G α（12）或G α（13）下调导致肿瘤生长减少。结论：G α（12）和G α（13）在SCLC中发挥着复杂的非冗余作用，与其他肿瘤类型不同，SCLC细胞的体外增殖和体内致瘤性主要依赖于G（12/13）信号。由于我们的研究完全消除了致瘤性，RNAi介导的双敲低可能为SCLC治疗提供一个有希望的新途径。临床癌症研究; 16（5）; 1402-15。（C）2010年AACR。
Purpose: In small cell lung cancer cells (SCLC), various autocrine stimuli lead to the parallel activation of G(q/11) and G(12/13) proteins. Although the contribution of the G(q/11)-phospholipase C-beta cascade to mitogenic effects in SCLC cells is well established, the relevance of G(12/13) signaling is still elusive. In other tumor entities, G(12/13) activation promotes invasiveness without affecting cellular proliferation. Here, we investigate the role of G(12/13)-dependent signaling in SCLC.Experimental Design: We used small hairpin RNA-mediated targeting of G alpha(12), G alpha(13), or both in H69 and H209 cells and analyzed the effects of G alpha(12) and/or G alpha(13) knockdown on tumor cells in vitro, tumor growth in vivo, and mitogen-activated protein kinase (MAPK) activation.Results: Lentiviral expression of small hairpin RNAs resulted in robust and specific G alpha(12) and G alpha(13) knockdown as well as markedly inhibited proliferation, colony formation, and bradykinin-promoted stimulation of cell growth. Analyzing the activation status of all three major MAPK families revealed nonredundant functions of G alpha(12) and G alpha(13) in SCLC and a marked p42/p44 activation upon G alpha(12)/G alpha(13) knockdown. In a s.c. tumor xenograft mouse model, G alpha(12) or G alpha(13) downregulation led to decreased tumor growth due to reduced tumor cell proliferation. More importantly, G alpha(12)/G alpha(13) double knockdown completely abolished H69 tumorigenicity in mice.Conclusions: G alpha(12) and G alpha(13) exert a complex pattern of nonredundant effects in SCLC, and in contrast to other tumor types, SCLC cell proliferation in vitro and tumorigenicity in vivo critically depend on G(12/13) signaling. Due to the complete abolishment of tumorgenicity in our study, RNAi-mediated double knockdown may provide a promising new avenue in SCLC treatment. Clin Cancer Res; 16(5); 1402-15. (C)2010 AACR.