Data_Sheet_1_Oncogenic Role of Guanylate Binding Protein 1 in Human Prostate Cancer.ZIP

The Guanylate binding proteins (GBPs) are a family of large GTPases and the most studied GBP family member is the guanylate binding protein 1 (GBP1). Earlier studies revealed that GBP1 expression was inflammatory cytokines-inducible, and most of the studies focused on inflammation diseases. Increasing number of cancer studies began to reveal its biological role in cancers recently, although with contradictory findings in literature. It was discovered from our earlier prostate cancer cell line models studies that when prostate cancer cells treated with either ethidium bromide or a cell cycle inhibitor flavopiridol for a long-term, the treatment-survived tumor cells experienced metabolic reprogramming toward Warburg effect pathways with greater aggressive features, and one common finding from these cells was the upregulation of GBP1. In this study, possible role of GBP1 in two independent prostate cancer lines by application of CRISR/Cas9 gene knockout (KO) technology was investigated. The GBP1 gene KO DU145 and PC3 prostate cancer cells were significantly less aggressive in vitro, with less proliferation, migration, wound healing, and colony formation capabilities, in addition to a significantly lower level of mitochondrial oxidative phosphorylation and glycolysis. At the same time, such GBP1 KO cells were significantly more sensitive to chemotherapeutic reagents. Xenograft experiments verified a significantly slower tumor growth of the GBP1 KO cells in nude mouse model. Furthermore, GBP1 protein expression in clinical prostate cancer sample revealed its aggressive clinical feature correlation and shorter overall survival association. Collectively, our results indicate a pro-survival or oncogenic role of GBP1 in prostate cancer.

鸟苷酸结合蛋白（guanylate binding proteins, GBPs）是一类大型GTP酶家族，目前研究最为深入的家族成员为鸟苷酸结合蛋白1（guanylate binding protein 1, GBP1）。早期研究表明，GBP1的表达可被炎症细胞因子诱导，既往多数研究均聚焦于炎症性疾病。近年来，越来越多的癌症研究开始揭示其在肿瘤中的生物学功能，但相关文献报道存在相悖的研究结论。我们早期基于前列腺癌细胞系模型的研究发现，当前列腺癌细胞经溴化乙锭或细胞周期抑制剂黄酮哌啶醇长期处理后，经处理存活的肿瘤细胞会发生代谢重编程，转向瓦伯格效应（Warburg effect）通路，侵袭性显著增强，且这类细胞的共同特征之一为GBP1的上调表达。本研究采用CRISPR/Cas9基因敲除（gene knockout, KO）技术，探究了GBP1在两株独立前列腺癌细胞系中的潜在作用。结果显示，GBP1基因敲除的DU145和PC3前列腺癌细胞在体外的侵袭能力显著减弱，增殖、迁移、划痕愈合及集落形成能力均下降，同时线粒体氧化磷酸化与糖酵解水平也显著降低。此外，此类GBP1敲除细胞对化疗药物的敏感性显著升高。异种移植实验证实，在裸鼠模型中，GBP1敲除细胞的肿瘤生长速度显著减慢。进一步针对临床前列腺癌样本的检测发现，GBP1蛋白的表达与肿瘤侵袭性临床特征呈正相关，且与患者更短的总生存期显著相关。综上，本研究结果表明GBP1在前列腺癌中发挥促存活或致癌的作用。