Table2_Identification and Characterization of Key Differentially Expressed Genes Associated With Metronomic Dosing of Topotecan in Human Prostate Cancer.docx

Repetitive, low-dose (metronomic; METRO) drug administration of some anticancer agents can overcome drug resistance and increase drug efficacy in many cancers, but the mechanisms are not understood fully. Previously, we showed that METRO dosing of topotecan (TOPO) is more effective than conventional (CONV) dosing in aggressive human prostate cancer (PCa) cell lines and in mouse tumor xenograft models. To gain mechanistic insights into METRO-TOPO activity, in this study we determined the effect of METRO- and CONV-TOPO treatment in a panel of human PCa cell lines representing castration-sensitive/resistant, androgen receptor (+/−), and those of different ethnicity on cell growth and gene expression. Differentially expressed genes (DEGs) were identified for METRO-TOPO therapy and compared to a PCa patient cohort and The Cancer Genome Atlas (TCGA) database. The top five DEGs were SERPINB5, CDKN1A, TNF, FOS, and ANGPT1. Ingenuity Pathway Analysis predicted several upstream regulators and identified top molecular networks associated with METRO dosing, including tumor suppression, anti-proliferation, angiogenesis, invasion, metastasis, and inflammation. Further, the top DEGs were associated with increase survival of PCa patients (TCGA database), as well as ethnic differences in gene expression patterns in patients and cell lines representing African Americans (AA) and European Americans (EA). Thus, we have identified candidate pharmacogenomic biomarkers and novel pathways associated with METRO-TOPO therapy that will serve as a foundation for further investigation and validation of METRO-TOPO as a novel treatment option for prostate cancers.

重复低剂量节律性给药（METRO）的部分抗肿瘤药物方案，可在多种癌症中克服肿瘤耐药性并提升药物疗效，但其具体作用机制尚未完全阐明。此前我们的研究证实，在侵袭性人前列腺癌（PCa）细胞系及小鼠肿瘤异种移植模型中，拓扑替康（TOPO）的节律性（METRO）给药方案，其抗肿瘤疗效优于传统（CONV）给药方案。为深入解析METRO-TOPO疗法的作用机制，本研究针对一组涵盖去势敏感/抵抗、雄激素受体（±）表型及不同种族背景的人前列腺癌细胞系，探究了METRO-TOPO与CONV-TOPO两种给药方案对细胞生长及基因表达的影响。我们鉴定了METRO-TOPO疗法相关的差异表达基因（DEGs），并将其与前列腺癌患者队列及癌症基因组图谱（TCGA）数据库的数据进行了比对分析。筛选得到的前5个核心差异表达基因为SERPINB5、CDKN1A、TNF、FOS及ANGPT1。Ingenuity通路分析（Ingenuity Pathway Analysis, IPA）预测了多个上游调控因子，并鉴定出与METRO给药方案相关的核心分子网络，涵盖肿瘤抑制、抗增殖、血管生成、侵袭、转移及炎症相关通路。此外，基于TCGA数据库的分析显示，上述核心差异表达基因与前列腺癌患者的总生存期延长相关，且在非裔美国人（AA）与欧裔美国人（EA）来源的患者及细胞系中，基因表达模式存在显著种族差异。综上，本研究鉴定出了与METRO-TOPO疗法相关的候选药物基因组学生物标志物及全新通路，可为后续开展METRO-TOPO作为前列腺癌新型治疗方案的验证研究提供重要理论基础。