Department of Clinical Laboratory, Fudan University, Shanghai Cancer Center, Shanghai 200032, China.
Biochem Biophys Res Commun. 2012 Mar 9;419(2):274-80. doi: 10.1016/j.bbrc.2012.02.008. Epub 2012 Feb 10.
Human epididymis protein 4 (HE4) is a novel and specific biomarker for epithelial ovarian cancer (EOC). We previously demonstrated that serum HE4 levels were significantly elevated in the majority of EOC patients but not in subjects with benign disease or healthy controls. However, the precise mechanism of HE4 protein function is unknown. In this study, we generated HE4-overexpressing SKOV3 cells and found that stably transduced cells promoted cell adhesion and migration. Knockdown of HE4 expression was achieved by stable transfection of SKOV3 cells with a construct encoding a short hairpin DNA directed against the HE4 gene. Correspondingly, the proliferation and spreading ability of HE4-expressed cells were inhibited by HE4 suppression. Mechanistically, impaired EGFR and Erk1/2 phosphorylation were observed in cells with HE4 knockdown. The phosphorylation was restored when the knockdown cells were cultured in conditioned medium containing HE4. Moreover, in vivo tumorigenicity showed that HE4 suppression markedly inhibited the growth of tumors. This suggests that expression of HE4 is associated with cancer cell adhesion, migration and tumor growth, which can be related to its effects on the EGFR-MAPK signaling pathway. Our results provide evidence of the cellular and molecular mechanisms that may underlie the motility-promoting role of HE4 in EOC progression. The role of HE4 as a target for gene-based therapy might be considered in future studies.
人附睾蛋白 4（HE4）是一种新型的上皮性卵巢癌（EOC）特异性标志物。我们之前的研究表明，在大多数 EOC 患者中，血清 HE4 水平显著升高，但在良性疾病或健康对照者中则不升高。然而，HE4 蛋白功能的确切机制尚不清楚。在本研究中，我们生成了 HE4 过表达 SKOV3 细胞，发现稳定转染的细胞促进了细胞黏附和迁移。通过用针对 HE4 基因的短发夹 DNA 构建体稳定转染 SKOV3 细胞，实现了 HE4 表达的下调。相应地，下调 HE4 表达抑制了 HE4 表达细胞的增殖和扩展能力。在机制上，观察到 HE4 下调的细胞中 EGFR 和 Erk1/2 磷酸化受损。当将敲低细胞在含有 HE4 的条件培养基中培养时，磷酸化得到恢复。此外，体内肿瘤发生表明，下调 HE4 明显抑制了肿瘤的生长。这表明 HE4 的表达与癌细胞黏附、迁移和肿瘤生长有关，这可能与其对 EGFR-MAPK 信号通路的影响有关。我们的研究结果为 HE4 在 EOC 进展中促进运动的作用的细胞和分子机制提供了证据。在未来的研究中，可以考虑将 HE4 作为基因治疗的靶标。
