PO.TB07.01 · 肿瘤生物学
研究TWEAK介导的卵巢癌细胞存活调控
Investigating TWEAK-mediated regulation of ovarian cancer cell survival
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
高级别浆液性卵巢癌（HGSOC）仍是女性健康领域的一个突出问题，90%的患者最终会对标准治疗化疗产生耐药。研究表明，一个被称为癌症干样细胞（CSC）的静止、多能细胞亚群参与了耐药和复发。我们此前已鉴定出肿瘤坏死因子样凋亡弱诱导剂（TWEAK）——一种促炎细胞因子——在化疗后的肿瘤微环境中高度富集，并通过激活NFkB信号增加存活，是CSC的关键介导因子。我们还发现，在TWEAK存在的情况下，一个不具备CSC特征的细胞亚群对化疗更为敏感，提示TWEAK具有双重作用。传统上，TWEAK影响细胞分化；然而这一作用在卵巢癌中尚不明确。我们假设TWEAK在卵巢癌中诱导非CSC的化疗敏感性和CSC的化疗耐药性。为在重现肿瘤微环境的免疫健全小鼠模型中研究这一信号，我们使用了小鼠卵巢表面上皮细胞系ID8（p53突变型和p53野生型）。在两种细胞系中研究了Carboplatin和Paclitaxel的联合IC50值，以确保准确给药。通过流式细胞术评估了一组表面标志物的基线表达，包括TWEAK受体Fn14（27%），以及CSC标志物LGR5（3.19%）、GRP78（29%）、CD117（70%）和alphaVbeta3（0.27%）。GRP78被鉴定为p53突变型ID8细胞系中一个有前景的CSC标志物，其基线表达为29%，化疗后显著增加至53%。对GRP78+富集组分进行FACS分选后，其干性基因SOX2、OCT4和NANOG的基线表达较高。为评估TWEAK对CSC特征的诱导作用，在GRP78+和GRP78-组分中进行TWEAK预处理后，化疗处理后的总体活力增加，提示化疗前进行TWEAK处理可能提供存活优势。目前的工作正采用体外试验研究GRP78+ ID8细胞对TWEAK刺激的应答，包括球体形成、极限稀释法和化疗耐药性。将采用体内小鼠复发模型来检验TWEAK在维持GRP78+细胞和复发潜能中的作用。未来的研究将阐明TRAF蛋白在指导TWEAK-Fn14活性下游效应中的作用。总之，这些研究为化疗耐药的潜在机制提供了宝贵的洞见。
查看英文原文 English abstract
High-Grade Serous Ovarian Cancer (HGSOC) remains a salient concern in women's health, with 90% of patients eventually experiencing resistance to standard-of-care chemotherapies. Research implicates a subpopulation of quiescent, multipotent cells termed Cancer Stem-like Cells (CSCs) in contributing to resistance and relapse. We previously identified Tumor Necrosis Factor-Like Weak Inducer of Apoptosis (TWEAK), a pro-inflammatory cytokine, as highly enriched in the tumor microenvironment following chemotherapy and a critical mediator of CSCs by activating NFkB signaling to increase survival. We also found that a subpopulation of cells without CSC features were more sensitized to chemotherapy in the presence of TWEAK, suggesting a dual role for TWEAK. Canonically, TWEAK influences cell differentiation; however, this role is ill-defined in ovarian cancer. We hypothesize that TWEAK induces chemosensitivity in non-CSCs and chemoresistance in CSCs in ovarian cancer. To study this signaling in an immunocompetent mouse model recapitulating the tumor microenvironment, the murine ovarian surface epithelial cell line ID8 (p53-mutant and p53-wild type) were used. Combination IC50 of Carboplatin and Paclitaxel was studied in both cell lines for accurate drug dosing. A panel of surface markers was assessed for baseline expression by flow cytometry, including the TWEAK receptor Fn14 (27%), and CSC markers LGR5 (3.19%), GRP78 (29%), CD117 (70%), and alphaVbeta3(0.27%). GRP78 was identified as a promising CSC marker in the p53-mutant ID8 cell line, with baseline expression of 29% increasing significantly to 53% post-chemotherapy. FACS sorting of GRP78+ enriched fractions to have high baseline expression of stem genes SOX2,OCT4, and NANOG. To assess TWEAK induction of CSC features, pre-treatment of TWEAK in GRP78 + and GRP78- factions showed an overall increase in viability after chemotherapy treatment, suggesting TWEAK treatment before chemotherapy may provide an advantage in survival. Current work is investigating GRP78+ ID8 cells using in vitro assays for spheroid formation, extreme limiting dilution, and chemoresistance in response to TWEAK stimulation. An in vivo murine relapse model will be used to test the role of TWEAK in maintaining GRP78+ cells and relapse potential. Future studies will elucidate the role of TRAF proteins in directing the downstream effects of TWEAK-Fn14 activity. Together, these investigations provide valuable insights into the mechanisms underlying chemoresistance.
利益披露 Disclosure
H. Sapre, None..
M. Robinson, None..
C. House, None.