Department of Hepatobiliary & Pancreatic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, 430071, PR China; Clinical Medicine Research Center for Minimally Invasive Procedure of Hepatobiliary & Pancreatic Diseases of Hubei Province, Hubei, PR China.
Mol Metab. 2022 Sep;63:101540. doi: 10.1016/j.molmet.2022.101540. Epub 2022 Jul 5.
Emerging studies suggest that long non-coding RNAs (lncRNAs) play crucial roles in hepatocellular carcinoma (HCC). A rapidly increasing number of studies have shown that metabolic changes including lipid metabolic reprogramming play a significant role in the progression of HCC. But it remains to be elucidated how lncRNAs affect tumor cell metabolism.
Through analysis and screening of The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) dataset, we found a novel lncRNA RP11-386G11.10 was overexpressed, related to prognosis, conserved and non-protein-coding in HCC and related to poor prognosis. Then, CCK-8, colony formation, Transwell invasion, wound healing assays were performed and nude mouse subcutaneous tumour formation and lung metastasis models were established to explore the effect of RP11-386G11.10 on HCC tumour growth and metastasis. Chromatography-mass spectrometry (GC-MS) and Nile red staining detected the effect of RP11-386G11.10 on lipid metabolism in HCC. Mechanistically, we clarified the RP11-386G11.10/miR-345-3p/HNRNPU signalling pathway through dual luciferase reporter, RNA immunoprecipitation (RIP) and chromatin immunoprecipitation (ChIP) assays and identified ZBTB7A as a transcription factor of RP11-386G11.10.
RP11-386G11.10 was overexpressed in HCC and positively correlated with tumour size, TNM stage, and poor prognosis in HCC patients. RP11-386G11.10 promoted the proliferation and metastasis of HCC cells in vitro and in vivo. Mechanistically, RP11-386G11.10 acted as a competing endogenous RNA (ceRNA) for miR-345-3p to regulate the expression of HNRNPU and its downstream lipogenic enzymes, leading to lipid accumulation in HCC cells and promoting their growth and metastasis. In addition, we identified ZBTB7A as a transcription factor of RP11-386G11.10. Moreover, HNRNPU promoted the expression of ZBTB7A in HCC cells, thereby increasing the transcriptional activity of RP11-386G11.10, and forming a positive feedback loop, ultimately leading continuous lipid accumulation, growth and metastasis in HCC cells.
Our results indicated that the lncRNA RP11-386G11.10 was a novel oncogenic lncRNA that was strongly correlated with the poor prognosis of HCC. The ZBTB7A-RP11-386G11.10-HNRNPU positive feedback loop promoted the progression of HCC by regulating lipid anabolism. RP11-386G11.10 may become a new diagnostic and prognostic biomarker and therapy target for HCC.
新兴研究表明，长非编码 RNA（lncRNA）在肝细胞癌（HCC）中发挥关键作用。越来越多的研究表明，代谢变化包括脂质代谢重编程在 HCC 的进展中起着重要作用。但是，lncRNA 如何影响肿瘤细胞代谢仍有待阐明。
通过对癌症基因组图谱-肝肝细胞癌（TCGA-LIHC）数据集的分析和筛选，我们发现一种新型 lncRNA RP11-386G11.10 在 HCC 中过度表达，与预后相关，保守且无蛋白编码，并与不良预后相关。然后，进行 CCK-8、集落形成、Transwell 侵袭、划痕愈合测定，并建立裸鼠皮下肿瘤形成和肺转移模型，以探讨 RP11-386G11.10 对 HCC 肿瘤生长和转移的影响。通过色谱-质谱（GC-MS）和尼罗红染色检测 RP11-386G11.10 对 HCC 脂质代谢的影响。通过双荧光素酶报告、RNA 免疫沉淀（RIP）和染色质免疫沉淀（ChIP）测定，我们阐明了 RP11-386G11.10/miR-345-3p/HNRNPU 信号通路，并确定 ZBTB7A 是 RP11-386G11.10 的转录因子。
RP11-386G11.10 在 HCC 中过度表达，并与 HCC 患者的肿瘤大小、TNM 分期和不良预后呈正相关。RP11-386G11.10 促进 HCC 细胞在体外和体内的增殖和转移。机制上，RP11-386G11.10 作为 miR-345-3p 的竞争性内源 RNA（ceRNA），调节 HNRNPU 及其下游生脂酶的表达，导致 HCC 细胞中脂质积累，并促进其生长和转移。此外，我们确定 ZBTB7A 是 RP11-386G11.10 的转录因子。此外，HNRNPU 促进 HCC 细胞中 ZBTB7A 的表达，从而增加 RP11-386G11.10 的转录活性，并形成正反馈环，最终导致 HCC 细胞中持续的脂质积累、生长和转移。
我们的研究结果表明，lncRNA RP11-386G11.10 是一种新型致癌 lncRNA，与 HCC 的不良预后密切相关。ZBTB7A-RP11-386G11.10-HNRNPU 正反馈环通过调节脂质合成代谢促进 HCC 的进展。RP11-386G11.10 可能成为 HCC 的新的诊断和预后标志物和治疗靶点。
