MicroRNAs (miRs/miRNAs) play a key role in posttranscriptional regulation of gene expression and are implicated in a number of physiological and pathological conditions, including cellular malignant transformation. In the current study, we investigated the role of miR-3148 in regulating human stromal (mesenchymal) stem cell (hMSC) differentiation and transformation. Stable expression of miR-3148 in telomerized hMSC (hMSC-miR-3148) led to significant increase in in vitro adipocytic differentiation and suppression of osteoblastic differentiation. Concordantly, global gene expression profiling revealed significant enrichment in cholesterol biosynthesis pathway, and pathways related to enhanced cell movement and survival, whereas processes related to bone and connective tissue developments, cell death, apoptosis, and necrosis were downregulated. Global proteomic analysis using 2D-DIGE followed by mass spectrometry (MS) revealed significant changes in protein expression in hMSC-miR-3148 and enrichment in protein networks associated with carcinogenesis. Functional studies revealed that hMSC-miR-3148 exhibited enhanced in vitro cell proliferation, colony formation, migration, invasion, sphere formation, doxorubicin resistance, and increased active number of cells in S and G2/M cell cycle phases and formed sarcoma-like tumors with adipocyte infiltration when implanted into immunocompromised mice. SMAD2 was identified as bone fide gene target for miR-3148 using qRT-PCR, Western blotting, and UTR-based reporter assay. In agreement with our data, SMAD2 expression was downregulated in 47% of patients with soft tissue sarcoma. Bioinformatics analysis revealed that elevated miR-3148 expression correlates with poor prognosis in several human cancer types, including sarcoma. Our study identified miR-3148 as factor regulating hMSC differentiation and is involved in promoting malignant transformation of telomerized hMSC.

MicroRNA (miR/miRNA) 在基因表达的转录后调控中发挥着关键作用，并与许多生理和病理条件有关，包括细胞恶性转化。在本研究中，我们研究了 miR-3148 在调节人基质（间充质）干细胞（hMSC）分化和转化中的作用。miR-3148 在端粒化 hMSC (hMSC-miR-3148) 中的稳定表达导致体外脂肪细胞分化显着增加并抑制成骨细胞分化。一致地，全局基因表达谱显示胆固醇生物合成途径以及与增强细胞运动和存活相关的途径显着富集，而与骨和结缔组织发育、细胞死亡、细胞凋亡和坏死相关的过程被下调。使用 2D-DIGE 和质谱 (MS) 进行的整体蛋白质组学分析揭示了 hMSC-miR-3148 中蛋白质表达的显着变化以及与癌发生相关的蛋白质网络的富集。功能研究表明，hMSC-miR-3148 表现出体外细胞增殖、集落形成、迁移、侵袭、球体形成、阿霉素耐药性增强，S 和 G2/M 细胞周期期细胞活跃数量增加，形成肉瘤样肿瘤当植入免疫功能低下的小鼠体内时，会出现脂肪细胞浸润。使用 qRT-PCR、蛋白质印迹和基于 UTR 的报告基因检测，将 SMAD2 确定为 miR-3148 的真实基因靶标。与我们的数据一致，47% 的软组织肉瘤患者中 SMAD2 表达下调。生物信息学分析表明，miR-3148 表达升高与多种人类癌症类型（包括肉瘤）的不良预后相关。我们的研究发现miR-3148是调节hMSC分化的因子，并参与促进端粒化hMSC的恶性转化。