Li Mei, Zhang Chi, Zhong Yi, Zhao Jiyuan
Zhejiang Key Laboratory of Pathophysiology, Medical School, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China; Ningbo Institute of Medical Sciences, Ningbo, Zhejiang 315020, People's Republic of China.
Zhejiang Key Laboratory of Pathophysiology, Medical School, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China.
Biochem Biophys Res Commun. 2017 Aug 19;490(2):492-498. doi: 10.1016/j.bbrc.2017.06.068. Epub 2017 Jun 15.
ATBF1, a large transcription factor, was normally localized in nuclei, and its mislocalization to cytoplasm was reported in multiple cancers. However, localization of ATBF1 in breast epithelial cells and its potential functions were unknown. Here, we investigated ATBF1 localization via immunofluorescence staining in different kinds of breast epithelial cells. In MCF10A cells and normal mice mammary gland tissues, ATBF1 was mainly localized in nuclei. Knockdown of ATBF1 expression in MCF10A cells by siRNA promoted cell proliferation. Moreover, ATBF1 was co-localized with chromosome during mitosis, indicating its potential function in mitosis. In an estrogen receptor (ER)-positive breast cancer cell line (MCF7), estrogen induced ATBF1 translocation from cytoplasm to nuclei in an ER dependent pathway. In ER-negative cells (Hs578T and MDA-MB-231), ATBF1 was co-localized with GM130 in cytoplasm, indicating ATBF1 localization was associated with protein modification in golgi body. The results were beneficial for intensive investigation of ATBF1's function with different cellular localization in breast cancer.
ATBF1是一种大型转录因子，通常定位于细胞核，在多种癌症中均有报道其错误定位于细胞质。然而，ATBF1在乳腺上皮细胞中的定位及其潜在功能尚不清楚。在此，我们通过免疫荧光染色研究了ATBF1在不同类型乳腺上皮细胞中的定位。在MCF10A细胞和正常小鼠乳腺组织中，ATBF1主要定位于细胞核。通过小干扰RNA（siRNA）敲低MCF10A细胞中ATBF1的表达可促进细胞增殖。此外，ATBF1在有丝分裂期间与染色体共定位，表明其在有丝分裂中的潜在功能。在雌激素受体（ER）阳性乳腺癌细胞系（MCF7）中，雌激素通过依赖ER的途径诱导ATBF1从细胞质转运至细胞核。在ER阴性细胞（Hs578T和MDA-MB-231）中，ATBF1与GM130在细胞质中共定位，表明ATBF1的定位与高尔基体中的蛋白质修饰有关。这些结果有助于深入研究ATBF1在乳腺癌中不同细胞定位的功能。
