Rajendra Jacinth, Ghorai Atanu, Dutt Shilpee
Shilpee Dutt Laboratory, Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre, Navi Mumbai, India.
Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400085, India.
Heliyon. 2021 Nov 12;7(11):e08371. doi: 10.1016/j.heliyon.2021.e08371. eCollection 2021 Nov.
Glioblastoma (GBM) is the most lethal primary brain tumour with a median survival of only 15 months. We have previously demonstrated the generation of an therapy resistance model that captures the residual resistant (RR) disease cells of GBM post-radiation. We also reported the proteomic landscape of parent, residual, and relapse cells using iTRAQ based quantitative proteomics of glioma cells. The proteomics data revealed significant up-regulation (fold change >1.5) of 14-3-3ζ, specifically in GBM RR cells. This was further confirmed by western blots in residual cells generated from GBM cell lines and patient sample-derived short-term primary culture. ShRNA-mediated knockdown of 14-3-3ζ radio-sensitized GBM cells and further stimulated therapy-induced senescence (TIS) and multinucleated giant cells (MNGCs) phenotype in RR cells. Intriguingly, 14-3-3ζ knockdown residual cells also showed a significantly higher number of mitochondria and increased mtDNA content. Indeed, GST pull-down mass spectrometry analysis of GST tagged 14-3-3ζ from RR cells identified novel interacting partners of 14-3-3ζ involved in cellular metabolism. Taken together, here we identified novel interacting partners of 14-3-3ζ and proposed an unconventional function of 14-3-3ζ as a negative regulator of TIS and mitochondrial biogenesis in residual resistant cells and loss of which also radio-sensitize GBM cells.
胶质母细胞瘤（GBM）是最致命的原发性脑肿瘤，中位生存期仅为15个月。我们之前已经建立了一种治疗抗性模型，该模型捕获了放疗后GBM的残留抗性（RR）疾病细胞。我们还使用基于iTRAQ的胶质瘤细胞定量蛋白质组学报告了亲本、残留和复发细胞的蛋白质组概况。蛋白质组学数据显示，14-3-3ζ显著上调（倍数变化>1.5），特别是在GBM RR细胞中。这在GBM细胞系和患者样本来源的短期原代培养产生的残留细胞的蛋白质免疫印迹中得到了进一步证实。shRNA介导的14-3-3ζ敲低使GBM细胞对放疗敏感，并进一步刺激RR细胞中的治疗诱导衰老（TIS）和多核巨细胞（MNGC）表型。有趣的是，14-3-3ζ敲低的残留细胞还显示出线粒体数量显著增加和线粒体DNA含量增加。事实上，对RR细胞中GST标记的14-3-3ζ进行GST下拉质谱分析，确定了参与细胞代谢的14-3-3ζ的新相互作用伙伴。综上所述，我们在此鉴定了14-3-3ζ的新相互作用伙伴，并提出了14-3-3ζ作为残留抗性细胞中TIS和线粒体生物发生的负调节因子的非常规功能，其缺失也使GBM细胞对放疗敏感。
