胃癌外泌体来源的miR-151-3p诱导巨噬细胞M2型极化并促进肿瘤生长

miR-151-3p derived from gastric cancer exosomes induces M2-phenotype polarization of macrophages and promotes tumor growth

目的 探索胃癌细胞来源的外泌体是否可以通过微小RNA-151-3p(miR-151-3p)来影响肿瘤微环境中的巨噬细胞极化。方法 采用实时定量PCR检测胃癌患者癌组织和正常组织miR-151-3p的表达,实时定量PCR检测手术后胃液中miR-151-3p水平;构建过表达miR-151-3p的胃癌细胞系,分离外泌体并进行鉴定;流式细胞术检测与携带miR-151-3p的外泌体共孵育的RAW264.7细胞上CD11b和CD163的表达;在裸鼠移植瘤模型中评价携带miR-151-3p的外泌体对肿瘤生长的影响及对肿瘤相关巨噬细胞CD86和CD163的影响。结果 与正常组织相比,胃癌患者癌组织miR-151-3p高表达,且多数患者手术后的胃液中miR-151-3p的含量较术前有所降低;所分离的过表达miR-151-3p的肿瘤细胞外泌体中miR-151-3p的含量也较未转染细胞显著升高;携带miR-151-3p的外泌体与RAW264.7细胞共孵育可以诱导其向M2型极化,同样的,裸鼠皮下移植瘤实验也显示携带miR-151-3p的外泌体可以诱导肿瘤相关巨噬细胞向M2型极化,并促进肿瘤生长。结论 胃癌外泌体来源的miR-151-3p可以诱导巨噬细胞M2型极化,促进胃癌的生长。

Objective To investigate whether exosomes derived from gastric cancer cells can affect macrophages in tumor microenvironment through miR-151-3p. Methods The expression of miR-151-3p in tumor tissues of patients with gastric cancer and normal tissues was detected by real time quantitative PCR;Gastric cancer cells overexpressing miR-151-3p were constructed, and exosomes were isolated and identified. The expression of CD11b and CD163 markers on RAW264.7 cells co-incubated with exosomes were detected by flow cytometry, and the effects of exosome carrying miR-151-3p on tumor growth and tumor-associated macrophages were evaluated in mice transplanted tumor model. Results The results of real time quantitative PCR showed that the level of miR-151-3p in gastric tumor tissues was significantly higher than that in normal tissues, and the content of miR-151-3p in gastric juice of most patients after operation was lower than that before operation;The content of miR-151-3p in exosomes of tumor cells overexpressing miR-151-3p was also significantly higher than that of untransfected cells. Exosomes carrying miR-151-3p can induce phenotypic differentiation of M2 in co-incubation with RAW264.7 cells. Similarly, tumor transplantation model also showed that exosomes carrying miR-151-3p can induce tumor-associated macrophages to polarize to M2 and promote tumor growth. Conclusion miR-151-3p derived from gastric cancer exosomes can induce the polarization of M2 macrophages and promote the growth of gastric cancer. The treatment of miR-151-3p may destroy the tumor microenvironment of immunosuppression, which assists the anti-tumor immunotherapy.