Purpose

Bone marrow stromal cells (BMSCs) have been implicated in multiple myeloma (MM) progression. However, the underlying mechanisms remain largely elusive. Therefore, we aimed to explore key factors in BMSCs that contribute to MM development.

Methods

RNA-sequencing was used to perform gene expression profiling in BMSCs. Enzyme-linked immunosorbent assays (ELISAs) were performed to determine the concentrations of PGE2 and TNFα in sera and conditioned media (CM). Western blotting, qRT-PCR and IHC were used to examine the expression of cyclooxygenase 2 (COX2) in BMSCs and to analyze the regulation of TNFα by COX2. Cell growth and adhesion assays were employed to explore the function of COX2 in vitro. A 5T33MMvt-KaLwRij mouse model was used to study the effects of COX2 inhibition in vivo.

Results

COX2 was found to be upregulated in MM patient-derived BMSCs and to play a critical role in BMSC-induced MM cell proliferation and adhesion. Administration of PGE2 to CM derived from BMSCs promoted MM cell proliferation and adhesion. Conversely, inhibition of COX2 in BMSCs greatly compromised BMSC-induced MM cell proliferation and adhesion. PCR array-based analysis of inflammatory cytokines indicated that COX2 upregulates the expression of TNFα. Subsequent rescue assays showed that an anti-TNFα monoclonal antibody could antagonize COX2-mediated MM cell proliferation and adhesion. Administration of NS398, a specific COX2 inhibitor, inhibited in vivo tumor growth and improved the survival of 5TMM mice.

Conclusions

Our results indicate that COX2 contributes to BMSC-induced MM proliferation and adhesion by increasing the secretion of PGE2 and TNFα. Targeting COX2 in BMSCs may serve as a potential therapeutic approach of treating MM.

中文翻译：

---

COX2 赋予骨髓基质细胞促进 TNFα/TNFR1β 介导的骨髓瘤细胞生长和粘附

目的

骨髓基质细胞 (BMSC) 与多发性骨髓瘤 (MM) 的进展有关。然而，潜在的机制在很大程度上仍然难以捉摸。因此，我们旨在探索 BMSCs 中有助于 MM 发展的关键因素。

方法

RNA 测序用于在 BMSC 中进行基因表达谱分析。进行酶联免疫吸附测定 (ELISA) 以确定血清和条件培养基 (CM) 中 PGE2 和 TNFα 的浓度。使用蛋白质印迹、qRT-PCR 和 IHC 检测 BMSC 中环氧合酶 2 (COX2) 的表达并分析 COX2 对 TNFα 的调节。细胞生长和粘附试验被用来探索体外 COX2 的功能。5T33MMvt-KaLwRij 小鼠模型用于研究体内 COX2 抑制的影响。

结果

发现 COX2 在 MM 患者来源的 BMSC 中上调，并在 BMSC 诱导的 MM 细胞增殖和粘附中起关键作用。向源自 BMSC 的 CM 施用 PGE2 可促进 MM 细胞增殖和粘附。相反，BMSC 中 COX2 的抑制极大地损害了 BMSC 诱导的 MM 细胞增殖和粘附。基于 PCR 阵列的炎性细胞因子分析表明 COX2 上调 TNFα 的表达。随后的救援试验表明，抗 TNFα 单克隆抗体可以拮抗 COX2 介导的 MM 细胞增殖和粘附。NS398 是一种特定的 COX2 抑制剂，可抑制体内肿瘤生长并提高 5TMM 小鼠的存活率。

结论

我们的结果表明，COX2 通过增加 PGE2 和 TNFα 的分泌促进 BMSC 诱导的 MM 增殖和粘附。靶向 BMSC 中的 COX2 可作为治疗 MM 的潜在治疗方法。