Chen Huaping, Chen Siyuan, Chen Chen, Li Aifeng, Wei Zhixiao
Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China.
Department of Nuclear Medicine, First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China.
Front Genet. 2022 Jul 25;13:900951. doi: 10.3389/fgene.2022.900951. eCollection 2022.
: Leucine zipper downregulated in cancer 1 (LDOC1) inhibits tumor growth in several cancers. However, the expression and function of LDOC1 in hepatocellular carcinoma (HCC) remain unknown. In this study, we aimed to investigate how LDOC1 influenced tumor progression and the biological functions of HCC. : The transcription levels of LDOC1 were determined using the GEPIA and UALCAN online databases and a real-time polymerase chain reaction. Western blot and immunohistochemistry were used to validate the protein levels of LDOC1. The online Kaplan-Meier Plotter was applied for survival analysis. Then lentivirus transfection was used to construct LDOC1 exogenous overexpression cell lines. Proliferation, clone formation, cell cycle, apoptosis, and migration assays were performed with the LDOC1-upregulated Huh7 and Hep3B cell lines. The phosphorylated and total levels of AKT and mTOR were determined using a Western blot to explore the potential molecular mechanism of LDOC1. : In the GEPIA and UALCAN analyses, LDOC1 was lowly expressed in tumors, had high expression in normal tissue samples ( < 0.05), and negatively correlated with tumor grade progression. The down-regulation of LDOC1 in HCC was validated with real-time polymerase chain reaction, Western blot, and immunohistochemistry (all < 0.05). LDOC1 transcription levels were negatively associated with overall, progression-free, recurrence-free, and disease-specific survival (all < 0.05). The functional experiments suggested that the overexpression of LDOC1 contributed to increased G1 and G2 stages in Huh7, while increased G2 stage in Hep3B, and decreased cell proliferation, clone formation, and migration, as well as increased the apoptosis rate compared with the control group (all < 0.05). Furthermore, LDOC1 up-regulation reduced the p-AKT/AKT and p-mTOR/mTOR, which indicates an inactivation of the AKT/mTOR pathway. : The tumor-suppressor LDOC1 varied in HCC and non-HCC tissues, which can serve as a candidate prognostic biomarker. LDOC1 influenced survival by affecting proliferation, colony formation, cell cycle, apoptosis, and migration ability, which might be attributed to the AKT/mTOR inhibition in HCC.
亮氨酸拉链在癌症中下调1（LDOC1）抑制多种癌症的肿瘤生长。然而，LDOC1在肝细胞癌（HCC）中的表达和功能仍不清楚。在本研究中，我们旨在探讨LDOC1如何影响HCC的肿瘤进展和生物学功能。：使用GEPIA和UALCAN在线数据库以及实时聚合酶链反应测定LDOC1的转录水平。采用蛋白质免疫印迹法和免疫组织化学法验证LDOC1的蛋白水平。应用在线Kaplan-Meier Plotter进行生存分析。然后使用慢病毒转染构建LDOC1外源性过表达细胞系。对LDOC1上调的Huh7和Hep3B细胞系进行增殖、克隆形成、细胞周期、凋亡和迁移检测。使用蛋白质免疫印迹法测定AKT和mTOR的磷酸化水平和总水平，以探讨LDOC1的潜在分子机制。：在GEPIA和UALCAN分析中，LDOC1在肿瘤中低表达，在正常组织样本中高表达（<0.05），且与肿瘤分级进展呈负相关。通过实时聚合酶链反应、蛋白质免疫印迹法和免疫组织化学法验证了HCC中LDOC1的下调（均<0.05）。LDOC1转录水平与总生存期、无进展生存期、无复发生存期和疾病特异性生存期呈负相关（均<0.05）。功能实验表明，与对照组相比，LDOC1的过表达导致Huh7细胞的G1期和G2期增加，而Hep3B细胞的G2期增加，细胞增殖、克隆形成和迁移减少，凋亡率增加（均<0.05）。此外，LDOC1上调降低了p-AKT/AKT和p-mTOR/mTOR，这表明AKT/mTOR通路失活。：肿瘤抑制因子LDOC1在HCC组织和非HCC组织中存在差异，可作为候选的预后生物标志物。LDOC1通过影响增殖、集落形成、细胞周期、凋亡和迁移能力影响生存，这可能归因于HCC中对AKT/mTOR的抑制作用。
