Objectives: To investigate the expression and mechanism of the long non-coding RNA (lncRNA) HCG22 in oral squamous cell carcinoma (OSCC).
Methods: HCG22 levels were detected in the OSCC and adjacent tissues, OSCC cells, and normal oral keratinocytes. HCG22 expression in SCC-25 and HSC-3 cells was upregulated by transfection of the overexpressing plasmi dvector. Methyl thiazolyl tetrazolium (MTT) assay, flow cytometry, and Transwell assay were employed to detect changes in cell proliferation, apoptosis, migration, and invasion ability, while Western blotting was used to detect the expression of epithelial-mesenchymal transformation-related proteins. The expression level of miR-650 in the cells was detected by real-time quantitative polymerase chain reaction (RT-qPCR), and dual-luciferase reporter gene assay was applied to assess the targeting relationship between HCG22 and miR-650.
Results: Compared with that in adjacent tissues, the expression of HCG22 significantly decreased in OSCC tissues (P<0.05). Moreover, the prognostic survival of patients in the low-HCG22 expression group was significantly lower than that in the high-expression group (P<0.05). Compared with that in HOK cells, the expression of HCG22 was significantly lower in SCC-25, HN13, HSC-3, and CAL-27 cells (P<0.05). Upregulation of HCG22 expression could inhibit the proliferation, migration, invasion, and apoptosis of SCC-25 and HSC-3 cells, upregulatethe expression of E-cadherin, and downregulate the expression of N-cadherin and vimentin (P<0.05). miR-650 mimics could reduce the luciferase activity of HCG22 wild-type plasmid cells (P<0.05), and the expression of miR-650 in SCC-25 and HSC-3 cells decreased after upregulation of HCG22 expression (P<0.05).
Conclusions: HCG22 is expressed at low levels in OSCC. Upregulation of the expression of this lncRNA can inhibit the proliferation, migration, invasion, and epithelial-mesenchymal transition of OSCC cells. The mechanism of action of HCG22 may be related to its targeted regulation of miR-650.
目的: 探讨长链非编码RNA（lncRNA）HCG22在口腔鳞状细胞癌（OSCC）中的表达及作用机制。方法: 检测OSCC组织和对应癌旁组织、OSCC细胞和正常口腔角质细胞HOK中HCG22的水平；转染过表达载体质粒上调SCC-25和HSC-3细胞中HCG22的表达，采用甲基噻唑基四唑（MTT）法、流式细胞仪、Transwell小室检测细胞的增殖、凋亡，迁移和侵袭能力变化，Western blotting检测细胞上皮间质转化相关蛋白的表达；荧光定量聚合酶链反应（RT-qPCR）检测细胞中微小RNA-650（miR-650）表达水平；双荧光素酶报告基因实验检测HCG22和miR-650靶向关系。结果: 与癌旁组织比较，OSCC组织中HCG22表达明显降低（P<0.05），且HCG22低表达患者预后生存期显著低于高表达组（P<0.05）；与HOK细胞比较，SCC-25、HN13、HSC-3和CAL-27细胞中HCG22表达明显下调（P<0.05）；上调HCG22表达可抑制SCC-25和HSC-3细胞增殖、迁移、侵袭，诱导细胞凋亡，上调上皮间质转化蛋白上皮细胞钙黏蛋白（E-cadherin）和下调N-钙黏着蛋白（N-cadherin）、波形蛋白（Vimentin）蛋白表达（P<0.05）。miR-650模拟物可使转染HCG22野生型质粒细胞的荧光素酶活性降低（P<0.05），且上调HCG22表达后SCC-25和HSC-3细胞中miR-650表达下降（P<0.05）。结论: HCG22在OSCC中低表达，上调其表达可抑制OSCC细胞的增殖、迁移、侵袭和上皮间质转化，其作用机制可能与对miR-650的靶向调控有关。.
Keywords: cell invasion; cell migration; long non-coding RNA HCG22; microRNA-650; oral squamous cell carcinoma.