Romidepsin overcomes cell adhesion-mediated drug resistance in multiple myeloma cells.
Romidepsin overcomes cell adhesion-mediated drug resistance in multiple myeloma cells.
复制标题
罗米地辛克服了多发性骨髓瘤细胞中细胞粘附介导的耐药性。
DOI：
10.1159/000357213
复制
发表时间：
2014
影响因子：
2.4
通讯作者：
Ozawa K
中科院分区：
文献类型：
--
作者：
Sripayap P;Nagai T;Hatano K;Kikuchi J;Furukawa Y;Ozawa K
多发性骨髓瘤（MM）是一种恶性造血系统疾病，目前仍无法治愈。基于新药物的开发，包括蛋白酶体抑制剂、免疫调节剂、抗体和小分子化合物如组蛋白脱乙酰酶抑制剂（HDIs），该疾病的治疗策略已迅速取得进展;然而，耐药性仍然是一个主要挑战[1]。众所周知，当MM细胞与基质细胞相互作用时，会发生细胞粘附介导的耐药性（CAM-DR）[2]。具体而言，MM细胞表达与基质细胞上的相应配体结合的表面粘附受体分子。这种相互作用导致MM细胞免受抗骨髓瘤药物的细胞毒性作用。我们先前发现MM细胞表达多种粘附分子，包括CD 29（β1-整联蛋白）、CD 49 d（α4-整联蛋白，VLA-4的亚基）、CD 54（细胞间粘附分子-1）、CD 138（多配体蛋白聚糖-1）、CD 184（CXC趋化因子受体-4）和CD 44。此外，其中CD 49 d对于CAM-DR对于常规抗骨髓瘤药物如硼替佐米和地塞米松至关重要[3]。因此，抑制CD 49 d表达以克服CAM-DR是非常重要的。HDI和DNA甲基化剂通过表观遗传学上重新表达各种基因而显示抗肿瘤活性[4，5]。这些效应可能最终影响包括转录因子在内的各种细胞内分子的表达和功能。因此，我们假设这些药物影响MM细胞中粘附分子的表达水平。为了验证这一假设，我们研究了HDI罗米地辛和DNA甲基化剂阿扎胞苷对CD 49 d和其他两种代表性粘附分子CD 29和CD 138表达水平的影响，通过流式细胞术分析两种人MM细胞系RPMI 8226和U266。令人惊讶且重要的是，罗米地辛在两种细胞系中均以统计学显著性抑制CD 49 d的表达水平（图1a、B）。加入罗米地辛后，CD 49 d mRNA水平也显著降低，表明罗米地辛在mRNA水平上抑制CD 49 d表达（图1c）。相反，罗米地辛对CD 29和CD 138的表达水平没有显著影响（图1a，B）。在RPMI 8226细胞中，阿扎胞苷也抑制CD 49 d以及CD 138（图1a）。然而，在U266细胞中，它对所有三种测试的粘附分子，包括CD 49 d没有影响（图1 B）。由于阿扎胞苷不能破坏DNA甲基转移酶，这是它的主要目标，在U266细胞中[unpubl.数据]，阿扎胞苷可能对这些细胞的病理生理学没有影响。
Multiple myeloma (MM) is a malignant hematopoietic disease that remains incurable. Therapeutic strategies for this disease have been rapidly progressing based on the development of new drugs, including proteasome inhibitors, immunomodulatory agents, antibodies and small molecular compounds such as histone deacetylase inhibitors (HDIs); however, drug resistance remains a major challenge [1]. It is well known that cell adhesion-mediated drug resistance (CAM-DR) occurs when MM cells interact with stromal cells [2]. Specifically, MM cells express surface adhesion receptor molecules which bind with corresponding ligands on stromal cells. Such interaction results in protection of MM cells from the cytotoxic effects of anti-myeloma drugs. We previously found that MM cells express various adhesion molecules, including CD29 (β1-integrin), CD49d (α4-integrin, a subunit of VLA-4), CD54 (intercellular adhesion molecule-1), CD138 (syndecan-1), CD184 (CXC chemokine receptor-4), and CD44. Furthermore, among them CD49d was crucial for CAM-DR to conventional anti-myeloma drugs such as bortezomib and dexamethasone [3]. Thus, it is of great importance to suppress CD49d expression to overcome CAM-DR.HDI-and DNA-methylating agents show anti-tumor activity by epigenetically re-expressing various genes [4, 5]. These effects might ultimately affect the expression and function of various intracellular molecules, including transcription factors. We therefore hypothesized that these agents influence the expression levels of adhesion molecules in MM cells. To verify this hypothesis, we examined the effect of the HDI romidepsin and DNA-methylating agent azacitidine on the expression levels of CD49d and two other representative adhesion molecules, CD29 and CD138, by flow cytometry analyses in two human MM cell lines, RPMI8226 and U266. Surprisingly and importantly, romidepsin repressed the expression levels of CD49d with statistical significance in both cell lines (fig. 1 a, b). Levels of CD49d mRNA also markedly decreased after addition of romidepsin, suggesting that romidepsin suppresses CD49d expression at the mRNA level (fig. 1 c). In contrast, romidepsin had no significant effect on the expression levels of CD29 and CD138 (fig. 1 a, b). In RPMI8226 cells, azacitidine also repressed CD49d as well as CD138 (fig. 1 a). However, in U266 cells it had no influence on all three adhesion molecules tested, including CD49d (fig. 1 b). Since azacitidine failed to disrupt DNA methyltransferases, which are its main targets, in U266 cells [unpubl. data], it is possible that azacitidine had no effect on the pathophysiology of these cells.