■滑膜肉瘤(SS)是SS18-SSX融合基因驱动的软组织肉瘤,具有间充质特征,与由于频繁转移到远处器官而导致的不良预后相关,比如肺。组蛋白去乙酰化酶(HDAC)抑制剂(HDACis)作为有效的分子靶向药物而出现,当HDACi治疗破坏SS癌蛋白复合物时,其中包括HDAC,除了一般的HDACi效应。为HDACi治疗的优势及其由于SS细胞微环境诱导的耐药性而导致的局限性提供进一步的分子证据。我们结合二维(2D)和3D培养条件检查了细胞对HDACi治疗的反应。
■使用几种SS细胞系,生化和细胞生物测定是用罗米地辛进行的,HDAC1/2选择性抑制剂。SN38同时用作罗米地辛治疗的改善药物。细胞停滞,凋亡诱导,监测和MHCI类多肽相关序列A/B(MICA/B)诱导以评价药物功效。除了常规的2D培养条件,采用球体培养来评估细胞团微环境对化学抗性的影响。
■通过在SS细胞中使用romidepsin和/或SN38监测细胞行为,我们观察到每个细胞系的反应性不同。在凋亡诱导细胞中,与SN38共同处理增强了细胞死亡。在非凋亡可诱导细胞中,观察到细胞停滞和MICA/B诱导,和SN38进一步改善MICA/B诱导。作为SN38的新功效,我们揭示了SS细胞中的TWIST1抑制。在球体(3D)条件下,罗米地辛在TWIST1阳性细胞中的功效受到严重限制。我们证明了TWIST1下调即使在球体形式下也能恢复romidepsin的功效,伴随SN38处理与罗米地辛一起再现了反应。
■当前的研究证明了在2D和3D培养条件下使用HDACi进行SS治疗的益处和关注点,并提供了分子证据,表明伴随SN38治疗可以通过抑制TWIST1表达来克服对HDACi的耐药性。
UNASSIGNED: Synovial sarcoma (SS) is an SS18-SSX fusion gene-driven soft tissue sarcoma with mesenchymal characteristics, associated with a poor prognosis due to frequent metastasis to a distant organ, such as the lung. Histone deacetylase (HDAC) inhibitors (HDACis) are arising as potent molecular targeted drugs, as HDACi treatment disrupts the SS oncoprotein complex, which includes HDACs, in addition to general HDACi effects. To provide further molecular evidence for the advantages of HDACi treatment and its limitations due to drug resistance induced by the microenvironment in SS cells, we examined cellular responses to HDACi treatment in combination with two-dimensional (2D) and 3D culture conditions.
UNASSIGNED: Using several SS cell lines, biochemical and cell biological assays were performed with romidepsin, an HDAC1/2 selective inhibitor. SN38 was concomitantly used as an ameliorant drug with romidepsin treatment. Cytostasis, apoptosis induction, and MHC class I polypeptide-related sequence A/B (MICA/B) induction were monitored to evaluate the drug efficacy. In addition to the conventional 2D culture condition,
spheroid culture was adopted to evaluate the influence of cell-mass microenvironment on chemoresistance.
UNASSIGNED: By monitoring the cellular behavior with romidepsin and/or SN38 in SS cells, we observed that responsiveness is diverse in each cell line. In the apoptotic inducible cells, co-treatment with SN38 enhanced cell death. In nonapoptotic inducible cells, cytostasis and MICA/B induction were observed, and SN38 improved MICA/B induction further. As a novel efficacy of SN38, we revealed TWIST1 suppression in SS cells. In the
spheroid (3D) condition, romidepsin efficacy was severely restricted in TWIST1-positive cells. We demonstrated that TWIST1 downregulation restored romidepsin efficacy even in
spheroid form, and concomitant SN38 treatment along with romidepsin reproduced the reaction.
UNASSIGNED: The current study demonstrated the benefits and concerns of using HDACi for SS treatment in 2D and 3D culture conditions and provided molecular evidence that concomitant treatment with SN38 can overcome drug resistance to HDACi by suppressing TWIST1 expression.