Department of Pulmonary and Critical Care Medicine, Taihe Hospital, Hubei University of Medicine, Shiyan, China.
Eur Rev Med Pharmacol Sci. 2019 Jan;23(2):690-698. doi: 10.26355/eurrev_201901_16882.
Previous studies have shown that long non-coding RNA (lncRNA) FOXC2-AC1 is one of cancer-promoting genes. However, the role of FOXC2-AC1 in lung cancer (LCa) has not been reported. This study aimed to investigate the expression characteristics of FOXC2-AC1 in LCa, and to further explore the mechanism by which it accelerates the metastasis of LCa.
Quantitative Real-time polymerase chain reaction (qRT-PCR) was used to detect the level of FOXC2-AC1 in 62 pairs of LCa tissues and adjacent normal tissues, and the relationship between FOXC2-AC1 and LCa pathological parameters as well as the prognosis of patients were analyzed. Meanwhile, FOXC2-AC1 level was further verified in LCa cells by qRT-PCR. In addition, FOXC2-AC1 knockdown and overexpression models were constructed using lentivirus in LCa cell lines including H1299 and SPCA1, and the effect of FOXC2-AC1 on the biological function of LCa cells was analyzed by cell counting kit-8 (CCK-8) test along with transwell invasion and migration assay. Finally, the potential mechanism was explored using Western blotting assay.
In this study, qRT-PCR results indicated that the expression level of FOXC2-AC1 in LCa was considerably higher than that in normal tissues, with statistically significant differences. Compared with patients with low expression of FOXC2-AC1, patients with high expression of FOXC2-AC1 had higher incidence of distant metastasis and lower overall survival rate. Compared with the control group, the cell proliferation, invasion and metastasis capacities of FOXC2-AC1 overexpressing group were considerably enhanced, while opposite results were observed in the FOXC2-AC1 silencing group. In addition, miR-107 expression was found significantly reduced no matter in LCa cell lines or in tissues and showed a negative correlation with FOXC2-AC1. Subsequently, luciferase reporter gene assay demonstrated that overexpression of miR-107 significantly attenuated the luciferase activity of the wild-type FOXC2-AC1 vector without reducing the activity of the mutant vector or empty vector, further proving that FOXC2-AC1 could be targeted by miR-107 through this binding site. In addition, rescue experiment also found that FOXC2-AC1 and miR-107 have mutual regulation, which jointly affected the malignant progression of LCa.
These studies indicate that LncRNA FOXC2-AC1 is notably upregulated in LCa and is significantly correlated with LCa distant metastasis as well as poor prognosis. Therefore, it is suggested that lncRNA FOXC2-AC1 may promote malignant progression of LCa through the mutual regulation of miR-107.
先前的研究表明，长链非编码 RNA（lncRNA）FOXC2-AC1 是一种促进癌症的基因。然而，FOXC2-AC1 在肺癌（LCa）中的作用尚未被报道。本研究旨在探讨 FOXC2-AC1 在 LCa 中的表达特征，并进一步探讨其加速 LCa 转移的机制。
采用实时定量聚合酶链反应（qRT-PCR）检测 62 对 LCa 组织和相邻正常组织中 FOXC2-AC1 的水平，分析 FOXC2-AC1 与 LCa 病理参数及患者预后的关系。同时，通过 qRT-PCR 进一步验证 LCa 细胞中 FOXC2-AC1 的水平。此外，利用慢病毒构建了 LCa 细胞系 H1299 和 SPCA1 中的 FOXC2-AC1 敲低和过表达模型，通过细胞计数试剂盒-8（CCK-8）试验和 Transwell 侵袭和迁移试验分析 FOXC2-AC1 对 LCa 细胞生物学功能的影响。最后，通过 Western blot 试验探讨潜在的机制。
本研究中，qRT-PCR 结果表明，FOXC2-AC1 在 LCa 中的表达水平明显高于正常组织，差异具有统计学意义。与 FOXC2-AC1 低表达的患者相比，FOXC2-AC1 高表达的患者远处转移发生率更高，总生存率更低。与对照组相比，FOXC2-AC1 过表达组的细胞增殖、侵袭和转移能力明显增强，而 FOXC2-AC1 沉默组则出现相反的结果。此外，miR-107 的表达在 LCa 细胞系或组织中均明显降低，与 FOXC2-AC1 呈负相关。随后，荧光素酶报告基因检测证实，miR-107 的过表达显著降低了野生型 FOXC2-AC1 载体的荧光素酶活性，而不降低突变型载体或空载体的活性，进一步证明 FOXC2-AC1 可以通过该结合位点被 miR-107 靶向。此外，挽救实验还发现，FOXC2-AC1 和 miR-107 存在相互调节，共同影响 LCa 的恶性进展。
这些研究表明，lncRNA FOXC2-AC1 在 LCa 中显著上调，与 LCa 远处转移和不良预后显著相关。因此，提示 lncRNA FOXC2-AC1 可能通过 miR-107 的相互调节促进 LCa 的恶性进展。
