Cancer Biomark. 2018;23(2):185-191. doi: 10.3233/CBM-181198.
Long non-coding RNAs (lncRNAs) were recently identified as crucial regulators of papillary thyroid cancer (PTC). However, the clinical role and regulatory functions of lncRNA cancer susceptibility candidate 2 (CASC2) in PTC remain unknown.
LncRNA CASC2 expression was examined in plasma samples from 68 PTC patients and 39 patients with nodular goiter (NG). Cell proliferation, migration and invasion abilities were evaluated using CCK8 assay and transwell migration and invasion assay. QRT-PCR and western blot analysis were performed to detect the expression of epithelial-to-mesenchymal (EMT) markers ZEB1, E-cadherin and vimentin in PTC cells.
We demonstrated that lncRNA CASC2 expression was significantly downregulated in tumor tissues and plasma samples in patients with PTC compared with those in nodular goiters (P< 0.05). Decreased plasma lncRNA CASC2 expression associated with lymph node metastasis (LNM) of PTC patients and was identified as an independent risk for patients with LNM (P< 0.05). Furthermore, functional assays demonstrated that overexpression of lncRNA CASC2 inhibited cell proliferation, migration and invasion of PTC. Moreover, we demonstrated that overexpression of lncRNA CASC2 suppressed cell epithelial-mesenchymal transition (EMT) process of PTC by increasing the E-cadherin expression, but downregulating ZEB1 and N-cadherin expression.
Thus, these results indicated that lncRNA CASC2 was a predictor for LNM of PTC patients and may serve as a potential target of PTC treatment.
长链非编码 RNA（lncRNAs）最近被鉴定为甲状腺乳头状癌（PTC）的关键调控因子。然而，lncRNA 癌症易感性候选物 2（CASC2）在 PTC 中的临床作用和调控功能仍不清楚。
检测了 68 例 PTC 患者和 39 例结节性甲状腺肿（NG）患者血浆样本中的 lncRNA CASC2 表达。通过 CCK8 测定和 Transwell 迁移和侵袭测定评估细胞增殖、迁移和侵袭能力。采用 QRT-PCR 和 Western blot 分析检测 PTC 细胞中上皮-间充质（EMT）标志物 ZEB1、E-钙粘蛋白和波形蛋白的表达。
我们证明与结节性甲状腺肿相比，PTC 患者肿瘤组织和血浆样本中 lncRNA CASC2 的表达明显下调（P<0.05）。PTC 患者血浆 lncRNA CASC2 表达降低与淋巴结转移（LNM）相关，并且被鉴定为 LNM 患者的独立危险因素（P<0.05）。此外，功能测定表明，lncRNA CASC2 的过表达抑制了 PTC 细胞的增殖、迁移和侵袭。此外，我们通过增加 E-钙粘蛋白的表达，下调 ZEB1 和 N-钙粘蛋白的表达，证明了 lncRNA CASC2 的过表达抑制了 PTC 的上皮-间充质转化（EMT）过程。
因此，这些结果表明 lncRNA CASC2 是 PTC 患者 LNM 的预测因子，可能作为 PTC 治疗的潜在靶点。
