Department of Pathology, the First Affiliated Hospital and College of Basic Medical Sciences of China Medical University, Shenyang 110001, China.
J Transl Med. 2013 Sep 26;11:232. doi: 10.1186/1479-5876-11-232.
Oct4 is a major transcription factor related to stem cell self-renewal and differentiation. To fulfill its functions, it must be able to enter the nucleus and remain there to affect transcription. KPNA2, a member of the karyopherin family, plays a central role in nucleocytoplasmic transport. The objective of the current study was to examine the association between Oct4 and KPNA2 expression levels with regard to both the clinicopathological characteristics and prognoses of patients with non-small-cell lung cancer (NSCLC).
Immunohistochemistry was used to detect the expression profile of Oct4 and KPNA2 in NSCLC tissues and adjacent noncancerous lung tissues. Real-time polymerase chain reaction and western blotting were used to detect the mRNA and protein expression profiles of Oct4 and KPNA2 in lung cancer cell lines. Small interfering RNAs were used to deplete Oct4 and KPNA2 expressions. Double immunofluorescence was used to detect Oct4 expression in KPNA2 knockdown cells. Co-immunoprecipitation was used to detect the interaction of Oct4 and KPNA2.
Oct4 was overexpressed in 29 of 102 (28.4%) human lung cancer samples and correlated with differentiation (P = 0.002) and TNM stage (P = 0.003). KPNA2 was overexpressed in 56 of 102 (54.9%) human lung cancer samples and correlated with histology (P = 0.001) and differentiation (P = 0.045). Importantly, Oct4 and KPNA2 expression levels correlated significantly (P < 0.01). Expression of Oct4 and KPNA2 was associated with short overall survival. In addition, depleting Oct4 and KPNA2 expression using small interfering RNAs inhibited proliferation in lung cancer cell lines. Real-time polymerase chain reaction and western blotting analysis indicated that reduction of KPNA2 expression significantly reduced mRNA and nucleoprotein levels of Oct4. Double immunofluorescence analysis revealed that nuclear Oct4 signals were reduced significantly in KPNA2 knockdown cells. Co-immunoprecipitation experiments revealed that KPNA2 interacts with Oct4 in lung cancer cell lines.
Oct4 and KPNA2 play an important role in NSCLC progression. Oct4 nuclear localization may be mediated by its interaction with KPNA2.
Oct4 是一种与干细胞自我更新和分化相关的主要转录因子。为了发挥其功能，它必须能够进入细胞核并保持在那里以影响转录。KPNA2 是核孔蛋白家族的成员，在核质转运中起着核心作用。本研究的目的是研究 Oct4 和 KPNA2 表达水平与非小细胞肺癌 (NSCLC) 患者的临床病理特征和预后之间的关系。
采用免疫组织化学法检测 NSCLC 组织及相邻非癌肺组织中 Oct4 和 KPNA2 的表达谱。实时聚合酶链反应和 Western blot 检测肺癌细胞系中 Oct4 和 KPNA2 的 mRNA 和蛋白表达谱。用小干扰 RNA 耗竭 Oct4 和 KPNA2 的表达。双免疫荧光法检测 KPNA2 敲低细胞中 Oct4 的表达。免疫共沉淀检测 Oct4 和 KPNA2 的相互作用。
在 102 例人肺癌样本中，有 29 例（28.4%）Oct4 过度表达，且与分化（P=0.002）和 TNM 分期（P=0.003）相关。在 102 例人肺癌样本中，有 56 例（54.9%）KPNA2 过度表达，且与组织学（P=0.001）和分化（P=0.045）相关。重要的是，Oct4 和 KPNA2 的表达水平呈显著相关（P<0.01）。Oct4 和 KPNA2 的表达与总生存期短有关。此外，用小干扰 RNA 耗竭 Oct4 和 KPNA2 的表达抑制了肺癌细胞系的增殖。实时聚合酶链反应和 Western blot 分析表明，KPNA2 表达的降低显著降低了 Oct4 的 mRNA 和核蛋白水平。双免疫荧光分析显示，KPNA2 敲低细胞中核 Oct4 信号显著减少。免疫共沉淀实验表明，KPNA2 与肺癌细胞系中的 Oct4 相互作用。
Oct4 和 KPNA2 在 NSCLC 进展中起重要作用。Oct4 的核定位可能是通过其与 KPNA2 的相互作用介导的。
