p62/SQSTM1 Is Required for Cell Survival of Apoptosis-Resistant Bone Metastatic Prostate Cancer Cell Lines
p62/SQSTM1 Is Required for Cell Survival of Apoptosis-Resistant Bone Metastatic Prostate Cancer Cell Lines
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DOI：
10.1002/pros.22737
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发表时间：
2014-02-01
期刊：
影响因子：
2.8
通讯作者：
Delk, Nikki A.
中科院分区：
文献类型：
--
作者：
Chang, Megan A.;Morgado, Micaela;Delk, Nikki A.
背景：骨髓基质细胞(BMSC)旁分泌因子(S)可诱导骨转移性前列腺癌(PCa)细胞发生凋亡。方法用BMSC条件培养液培养PCa细胞株，用定量聚合酶链式反应(QPCR)、免疫印迹或免疫荧光等方法分析p62(也称为隔离组-1/SQSTM1)、微管相关蛋白1轻链3B(LC3B)或溶酶体相关膜蛋白1(LAMP1)的表达。小干扰RNA(SiRNA)用于确定p62是否是PCa细胞存活所必需的。结果：旁分泌信号上调了一部分PCa细胞系p62mRNA和蛋白的表达。对BMSC诱导的细胞凋亡和自噬诱导不敏感的PCa细胞株基础p62mRNA和蛋白水平升高。在BMSC不敏感的PCa细胞系中，p62的siRNA被敲除具有细胞毒性，免疫染色显示自溶酶体在核周聚集。然而，在BMSC敏感的PCa细胞系中，p62 siRNA没有明显的细胞毒性，也不影响自溶酶体的亚细胞定位。结论出现了这样的模式：BMSC敏感的PCa细胞系是成骨细胞，并表达雄激素受体，而BMSC不敏感的PCa细胞系具有溶骨作用，不表达雄激素受体。此外，骨髓间充质干细胞不敏感的PCa可能已经进化出对p62细胞生存的依赖，这可以被利用来靶向和杀死这些骨中的抗凋亡的PCA细胞。前列腺癌74：149-163,2014。(C)2013年威利期刊公司。
BACKGROUNDBone marrow stromal cell (BMSC) paracrine factor(s) can induce apoptosis in bone metastatic prostate cancer (PCa) cell lines. However, the PCa cells that escape BMSC-induced apoptosis can upregulate cytoprotective autophagy.METHODSC4-2, C4-2B, MDA PCa 2a, MDA PCa 2b, VCaP, PC3, or DU145 PCa cell lines were grown in BMSC conditioned medium and analyzed for mRNA and/or protein accumulation of p62 (also known as sequestome-1/SQSTM1), Microtubule-associated protein 1 light chain 3B (LC3B), or lysosomal-associated membrane protein 1 (LAMP1) using quantitative polymerase chain reaction (QPCR), Western blot, or immunofluorescence. Small interfering RNA (siRNA) was used to determine if p62 is necessary PCa cell survival.RESULTSBMSC paracrine signaling upregulated p62 mRNA and protein in a subset of the PCa cell lines. The PCa cell lines that were insensitive to BMSC-induced apoptosis and autophagy induction had elevated basal p62 mRNA and protein. In the BMSC-insensitive PCa cell lines, siRNA knockdown of p62 was cytotoxic and immunostaining showed peri-nuclear clustering of autolysosomes. However, in the BMSC-sensitive PCa cell lines, p62 siRNA knockdown was not appreciably cytotoxic and did not affect autolysosome subcellular localization.CONCLUSIONSA pattern emerges wherein the BMSC-sensitive PCa cell lines are known to be osteoblastic and express the androgen receptor, while the BMSC-insensitive PCa cell lines are characteristically osteolytic and do not express the androgen receptor. Furthermore, BMSC-insensitive PCa may have evolved a dependency on p62 for cell survival that could be exploited to target and kill these apoptosis-resistant PCa cells in the bone. Prostate 74:149-163, 2014. (c) 2013 Wiley Periodicals, Inc.