Chen Zhan, Zhang Yong, Wu Xiang, Zhang Ji, Xu Wei, Shen Cheng, Zheng Bing
Department of Urology, The Second Affiliated Hospital of Nantong University, Nantong, People's Republic of China.
Medical Research Center, The Second Affiliated Hospital of Nantong University, Nantong, People's Republic of China.
Onco Targets Ther. 2021 May 4;14:2941-2952. doi: 10.2147/OTT.S298102. eCollection 2021.
Renal cell carcinoma (RCC) accounts for about 2-3% of all adult malignancies. G protein alpha inhibitory subunit 1 (Gαi1) plays a key role in mediating PI3K-Akt signaling upon activation of receptor tyrosine kinases (RTKs). However, little is known about its expression, regulation and biological function in RCC.
Gαi1 expression in RCC tissues and cells was detected by quantitative real-time PCR (qRT-PCR), Western blot and immunohistochemistry (IHC). The effect of Gαi1 silence on cell proliferation and apoptosis of 786-O and ACHN cells was detected by CCK-8 assay and flow cytometry. Wound-healing assay and Transwell assays were used to detect the cell invasion in RCC cells. The expression of CDK4, cyclin D1, MMP-2, MMP-9, Bax, Bcl-2, p/t-Akt, p/t-S6 and p/t-Erk was detected by Western blot and qRT-PCR. Furthermore, a nude mouse subcutaneous xenograft model was used to further evaluate the potential effects of Gail in vivo.
In the present study, our data showed that Gαi1 expression was dramatically increased in RCC tissues compared with normal renal tissues. In addition, knocking down the expression of Gαi1 subsequently inhibited proliferation, migration and invasion of RCC cells in vivo and vitro. Furthermore, the expression of CDK4, cyclin D1, MMP-2 and MMP-9 was significantly reduced upon Gαi1 inhibition. Gαi1 positively regulates the activation of the mTOR and Erk pathways.
In conclusion, this study reveals Gαi1 promoted proliferation via activating the Akt-mTOR and Erk-MAPK signaling pathways in RCC, and Gαi1 may be a therapeutic and prognostic target for RCC.
肾细胞癌（RCC）约占所有成人恶性肿瘤的2%-3%。G蛋白α抑制亚基1（Gαi1）在受体酪氨酸激酶（RTK）激活后介导PI3K-Akt信号传导中起关键作用。然而，关于其在RCC中的表达、调控及生物学功能知之甚少。
采用定量实时PCR（qRT-PCR）、蛋白质免疫印迹法和免疫组织化学（IHC）检测RCC组织和细胞中Gαi1的表达。通过CCK-8法和流式细胞术检测Gαi1沉默对786-O和ACHN细胞增殖和凋亡的影响。采用划痕实验和Transwell实验检测RCC细胞的侵袭能力。通过蛋白质免疫印迹法和qRT-PCR检测细胞周期蛋白依赖性激酶4（CDK4）、细胞周期蛋白D1（cyclin D1）、基质金属蛋白酶2（MMP-2）、基质金属蛋白酶9（MMP-9）、凋亡相关蛋白Bax、Bcl-2、磷酸化/总蛋白Akt（p/t-Akt）、磷酸化/总蛋白核糖体蛋白S6（p/t-S6）及磷酸化/总蛋白细胞外信号调节激酶（p/t-Erk）的表达。此外，利用裸鼠皮下异种移植模型进一步评估Gαi1在体内的潜在作用。
在本研究中，我们的数据显示，与正常肾组织相比，RCC组织中Gαi1表达显著增加。此外，敲低Gαi1表达随后在体内外抑制了RCC细胞的增殖、迁移和侵袭。此外，抑制Gαi1后，CDK4、cyclin D1、MMP-2和MMP-9的表达显著降低。Gαi1正向调节mTOR和Erk信号通路的激活。
总之，本研究揭示Gαi1通过激活RCC中的Akt-mTOR和Erk-MAPK信号通路促进增殖，Gαi1可能是RCC的治疗和预后靶点。
