GNAS 通过促进 STAT3 激活促进炎症相关的肝细胞癌进展。

GNAS promotes inflammation-related hepatocellular carcinoma progression by promoting STAT3 activation.

机构信息

1Department of General Surgery, Shengjing Hospital of China Medical University, No. 36 Sanhao Road, Shenyang, 110004 China.

2Department of Otolaryngology Head and Neck Surgery, Shengjing Hospital of China Medical University, No. 36 Sanhao Road, Shenyang, 110004 China.

出版信息

Cell Mol Biol Lett. 2020 Feb 24;25:8. doi: 10.1186/s11658-020-00204-1. eCollection 2020.

DOI:10.1186/s11658-020-00204-1

PMID:32123532

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7038622/

Abstract

BACKGROUND

Hepatocellular carcinoma (HCC) is still the most common cause of cancer-related mortality worldwide and accumulating studies report that HCC is frequently linked to chronic inflammation. G-protein alpha-subunit (GNAS)-activating mutations have recently been reported to form a rare subgroup of inflammatory liver tumors. In this study, we investigated the roles of GNAS in inflammation-related HCC progression and its underlying mechanism.

METHODS

Lipopolysaccharides (LPS) and diethylnitrosamine were employed to stimulate HCC cells to an induced inflammatory response. qRT-PCR, immunohistochemistry and immunoblotting were performed to detect the expression of GNAS in HCC tissues and cell lines. Expression levels of proinflammatory cytokines were detected by qRT-PCR and ELISA. N6-methyladenosine (m6A) methylation of GNAS mRNA was detected by RNA-binding protein immunoprecipitation (RIP). Transcription factors activation profiling plate array was performed to investigate the underlying mechanism in GNAS promoting interleukin-6 (IL-6) expression in HCC cells. HCC cell invasion was determined by transwell assay in vitro, and tumorigenesis was assessed with a subcutaneous xenograft mouse model of HCC.

RESULTS

We found that LPS stimulation promotes GNAS expression in HCC cells through increasing m6A methylation of GNAS mRNA. The high expression level of GNAS promotes LPS-induced HCC cell growth and invasion by interacting with signal transducer and activator of transcription 3 (STAT3). Furthermore, GNAS knockdown inhibits LPS induced-IL-6 expression in HCC cells by suppressing STAT3 activation. Moreover, we found that GNAS promotes LPS-induced STAT3 activation in HCC cells through inhibiting long non-coding RNA TPTEP1 interacting with STAT3. In addition, GNAS expression promotes HCC development in mice and is related to poor survival.

CONCLUSIONS

Our findings for the first time indicate a tumor-promoting role of GNAS in inflammation-related HCC progression and provide a novel potential target for HCC therapy.

摘要

背景

肝细胞癌（HCC）仍然是全球癌症相关死亡的最常见原因，越来越多的研究报告称 HCC 常与慢性炎症有关。G 蛋白α亚单位（GNAS）激活突变最近被报道形成一种罕见的炎症性肝肿瘤亚群。在这项研究中，我们研究了 GNAS 在炎症相关 HCC 进展中的作用及其潜在机制。

方法

使用脂多糖（LPS）和二乙基亚硝胺刺激 HCC 细胞产生诱导性炎症反应。通过 qRT-PCR、免疫组织化学和免疫印迹检测 HCC 组织和细胞系中 GNAS 的表达。通过 qRT-PCR 和 ELISA 检测促炎细胞因子的表达水平。通过 RNA 结合蛋白免疫沉淀（RIP）检测 GNAS mRNA 的 N6-甲基腺苷（m6A）甲基化。进行转录因子激活谱板分析，以研究 GNAS 在 HCC 细胞中促进白细胞介素 6（IL-6）表达的潜在机制。通过体外 Transwell 测定法测定 HCC 细胞的侵袭性，通过 HCC 的皮下异种移植小鼠模型评估肿瘤发生情况。

结果

我们发现 LPS 刺激通过增加 GNAS mRNA 的 m6A 甲基化来促进 HCC 细胞中的 GNAS 表达。高表达水平的 GNAS 通过与信号转导和转录激活因子 3（STAT3）相互作用促进 LPS 诱导的 HCC 细胞生长和侵袭。此外，GNAS 敲低通过抑制 STAT3 激活抑制 LPS 诱导的 HCC 细胞中 IL-6 的表达。此外，我们发现 GNAS 通过抑制长非编码 RNA TPTEP1 与 STAT3 相互作用来促进 LPS 诱导的 HCC 细胞中 STAT3 的激活。此外，GNAS 的表达促进了小鼠中 LPS 诱导的 STAT3 激活，并与较差的存活率相关。