Department of Pathology, Shanghai Jiaotong University Affiliated Shanghai First People's Hospital, NO.85, Wujin Road, Shanghai 200080, People's Republic of China.
J Cancer Res Clin Oncol. 2012 Oct;138(10):1703-15. doi: 10.1007/s00432-012-1249-4. Epub 2012 Jun 8.
N-myc downstream-regulated gene 1 (NDRG1) reportedly regulates tumor progression in various cancers. Our previous studies showed that NDRG1 was aberrantly overexpressed in human endometrial cancer tissues. The purpose of the present study was to investigate the role of NDRG1 in endometrial carcinogenesis.
A short hairpin RNA (shRNA)-mediated gene silencing strategy was employed to stably suppress the expression of NDRG1 in endometrial cancer Ishikawa cells. The influence of NDRG1 silencing on cancer cell biological behaviors was examined through observing in vitro tumor cell proliferation, colony formation, cell migration and invasion. Moreover, the mammalian NDRG1 expression vector pcDNA3.1(+)/NDRG1 was constructed to determine the effects of NDRG1 overexpression on cell proliferation and migration. Additionally, gene expression microarray analysis was conducted to identify NDRG1 downstream target genes after NDRG1 knockdown.
It was demonstrated that NDRG1 knockdown significantly enhanced Ishikawa cell proliferation and dramatically promoted cell migration and invasion. Furthermore, overexpression of NDRG1 in Ishikawa cells greatly inhibited cell proliferation and migration. Through microarray analysis and data mining, a large cohort of NDRG1-repressed target genes were identified. Additionally, through comparing the current microarray results with those obtained previously in studies of cervical and ovarian cancer cells conducted by us, 19 more specific common downstream target genes were identified.
It was demonstrated that NDRG1 might carry out a tumor suppressor function during endometrial carcinogenesis. The identification of downstream target genes should afford meaningful hints for prospective investigations. The tumor suppressor function of NDRG1 may open a new window for the target therapy of endometrial cancer.
据报道，N- myc 下游调节基因 1（NDRG1）可调节多种癌症中的肿瘤进展。我们之前的研究表明，NDRG1 在人子宫内膜癌组织中异常过表达。本研究的目的是探讨 NDRG1 在子宫内膜癌发生中的作用。
采用短发夹 RNA（shRNA）介导的基因沉默策略，稳定抑制子宫内膜癌细胞 Ishikawa 中 NDRG1 的表达。通过观察体外肿瘤细胞增殖、集落形成、细胞迁移和侵袭，研究 NDRG1 沉默对癌细胞生物学行为的影响。此外，构建了哺乳动物 NDRG1 表达载体 pcDNA3.1(+)/NDRG1，以确定 NDRG1 过表达对细胞增殖和迁移的影响。此外，进行基因表达微阵列分析，以鉴定 NDRG1 敲低后 NDRG1 的下游靶基因。
结果表明，NDRG1 敲低显著增强了 Ishikawa 细胞的增殖，并显著促进了细胞迁移和侵袭。此外，NDRG1 在 Ishikawa 细胞中的过表达极大地抑制了细胞增殖和迁移。通过微阵列分析和数据挖掘，鉴定出大量 NDRG1 受抑制的靶基因。此外，通过将当前微阵列结果与我们之前在宫颈癌和卵巢癌细胞研究中获得的结果进行比较，鉴定出 19 个更具体的共同下游靶基因。
结果表明，NDRG1 可能在子宫内膜癌发生过程中发挥肿瘤抑制功能。下游靶基因的鉴定应为进一步的研究提供有意义的线索。NDRG1 的肿瘤抑制功能可能为子宫内膜癌的靶向治疗开辟新的窗口。
