Department of Liberal Arts and Sciences, Toyama Prefectural University, Toyama 939‑0398, Japan.
Department of Ophthalmology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930‑0194, Japan.
Mol Med Rep. 2018 Oct;18(4):4138-4146. doi: 10.3892/mmr.2018.9383. Epub 2018 Aug 10.
Bcl‑2‑associated athanogene (BAG) 3, is a member of the BAG protein family and a known co‑chaperone of heat shock protein (HSP) 70. BAG3 serves a role in regulating a variety of cellular functions, including cell growth, proliferation and cell death including apoptosis. BAG3 is a stress‑inducible protein, however the constitutive expression level of BAG3 is increased in cancer cells compared with healthy cells. Recent proteomics technology combined with bioinformatics has revealed that BAG3 participates in an interactome with a number of proteins other than its typical partner HSP70. The functional types represented in the interactome included nucleic acid binding proteins and transcription factors, as well as chaperones, which indicated that overexpression of BAG3 may contribute to proliferation and cell survival through the alteration of gene transcription. While an increasing number of studies have addressed the function of BAG3 as a co‑chaperone protein, BAG3‑dependent alteration of gene transcription has not been studied extensively. The present study established two BAG3 knockout human cervical cancer HeLa cell clones and addressed the role of BAG3 in cell proliferation and survival through gene transcription, using DNA microarray‑based transcriptome analysis and bioinformatics. The present study also identified two genetic networks associated with 'cellular growth and proliferation' and 'cell death and survival', which are dysregulated in the absence of BAG3, and may therefore be linked to BAG3 overexpression in cancer. These findings provide a molecular basis for understanding of BAG3‑dependent cell proliferation and survival from the aspect of alteration of gene expression.
Bcl-2 相关抗凋亡基因(BAG)3 是 BAG 蛋白家族的一员,也是热休克蛋白(HSP)70 的已知共伴侣。BAG3 在调节多种细胞功能中发挥作用,包括细胞生长、增殖和细胞死亡,包括细胞凋亡。BAG3 是一种应激诱导蛋白,然而与健康细胞相比,癌细胞中 BAG3 的组成型表达水平增加。最近的蛋白质组学技术与生物信息学相结合,揭示了 BAG3 与 HSP70 等其典型伴侣以外的许多蛋白质参与相互作用。相互作用组中代表的功能类型包括核酸结合蛋白和转录因子,以及伴侣蛋白,这表明 BAG3 的过表达可能通过改变基因转录来促进增殖和细胞存活。虽然越来越多的研究已经解决了 BAG3 作为共伴侣蛋白的功能,但 BAG3 依赖性基因转录改变尚未得到广泛研究。本研究建立了两个 BAG3 敲除人宫颈癌 HeLa 细胞克隆,并通过 DNA 微阵列转录组分析和生物信息学,研究了 BAG3 在细胞增殖和存活中的基因转录作用。本研究还确定了两个与“细胞生长和增殖”和“细胞死亡和存活”相关的遗传网络,这些网络在缺乏 BAG3 的情况下失调,因此可能与癌症中 BAG3 的过表达有关。这些发现为从基因表达改变的角度理解 BAG3 依赖性细胞增殖和存活提供了分子基础。