Department of Head and Neck Surgery, Hunan Cancer Hospital and Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, No.283, Tongzipo Road, Yuelu District, Changsha, 410013, Hunan Province, People's Republic of China.
BMC Cancer. 2019 Apr 25;19(1):391. doi: 10.1186/s12885-019-5605-5.
Oral cancer has been estimated as the sixth most frequent solid cancer all over the world, in which tongue squamous cell carcinoma (TSCC) is the most common type of oral cancers. However, the mechanism of TSCC metastasizing to lymph node and distant sites has not been completely understood.
In this study, RT-qPCR method was used to detect the mRNA level of Numb, PTEN and Notch1 genes, as well as EMT-associated genes. Western blot assay was utilized to detect protein level of these genes. In addition, we determined cell proliferation by MTT assay and employed transwell invasion assay and wound healing assay to probe the abilities of invasion and migration, respectively. To investigate the role of PTEN, its inhibitor VO-Ohpic trihydrate was used to treat SCC-4 and CAL27 cells.
We found that Numb expression was downregulated in SCC-9 and CAL-27 cells compared to NHOK cells. Instead, Notch1 level in SCC-9 and CAL-27 cells were higher than that in NHOK cells. Furthermore, the results showed that Numb overexpression significantly suppressed proliferation, migration and invasion of SCC-9 and CAL-27 cells via regulating Notch1 signaling and EMT-related genes expression. By contrast, we observed that RBP-Jκ knockdown had an inhibitory role in proliferation, migration and invasion of SCC-9 and CAL-27 cells. In cells with Numb overexpression or RBP-Jκ knockdown, p-FAK and EMT-related genes were remarkably regulated.
Our findings provide new mechanism of understanding the metastasis of TSCC and help develop therapeutic strategies for treating tongue cancer.
口腔癌已被估计为全球第六大常见实体癌，其中舌鳞状细胞癌（TSCC）是最常见的口腔癌类型。然而，TSCC 转移到淋巴结和远处部位的机制尚未完全了解。
在这项研究中，使用 RT-qPCR 方法检测 Numb、PTEN 和 Notch1 基因以及 EMT 相关基因的 mRNA 水平。Western blot 检测这些基因的蛋白水平。此外，我们通过 MTT 测定法确定细胞增殖，并用 Transwell 侵袭测定法和划痕愈合测定法分别探测侵袭和迁移能力。为了研究 PTEN 的作用，我们使用其抑制剂 VO-Ohpic 三水合物处理 SCC-4 和 CAL27 细胞。
与 NHOK 细胞相比，我们发现 SCC-9 和 CAL-27 细胞中的 Numb 表达下调，而 SCC-9 和 CAL-27 细胞中的 Notch1 水平高于 NHOK 细胞。此外，结果表明，Numb 过表达通过调节 Notch1 信号和 EMT 相关基因表达，显著抑制 SCC-9 和 CAL-27 细胞的增殖、迁移和侵袭。相比之下，我们观察到 RBP-Jκ 敲低对 SCC-9 和 CAL-27 细胞的增殖、迁移和侵袭具有抑制作用。在 Numb 过表达或 RBP-Jκ 敲低的细胞中，p-FAK 和 EMT 相关基因被显著调节。
我们的研究结果为理解 TSCC 转移提供了新的机制，并有助于开发治疗舌癌的治疗策略。
