ABSTRACT

The ability of small extracellular vesicles (sEVs) to reprogram cancer cells is well established. However, the specific sEV components able to mediate aberrant effects in cancer cells have not been characterized. Integrins are major players in mediating sEV functions. We have previously reported that the αVβ3 integrin is detected in sEVs of prostate cancer (PrCa) cells and transferred into recipient cells. Here, we investigate whether sEVs from αVβ3-expressing cells affect tumour growth differently than sEVs from control cells that do not express αVβ3. We compared the ability of sEVs to stimulate tumour growth, using sEVs isolated from PrCa C4-2B cells by iodixanol density gradient and characterized with immunoblotting, nanoparticle tracking analysis, immunocapturing and single vesicle analysis. We incubated PrCa cells with sEVs and injected them subcutaneously into nude mice to measure in vivo tumour growth or analysed in vitro their anchorage-independent growth. Our results demonstrate that a single treatment with sEVs shed from C4-2B cells that express αVβ3, but not from control cells, stimulates tumour growth and induces differentiation of PrCa cells towards a neuroendocrine phenotype, as quantified by increased levels of neuroendocrine markers. In conclusion, the expression of αVβ3 integrin generates sEVs capable of reprogramming cells towards an aggressive phenotype.

摘要

细胞外小囊泡 (sEVs) 重新编程癌细胞的能力已得到充分证实。然而，能够在癌细胞中介导异常效应的特定 sEV 成分尚未得到表征。整合素是介导 sEV 功能的主要参与者。我们之前曾报道在前列腺癌 (PrCa) 细胞的 sEV 中检测到 αVβ3 整合素并转移到受体细胞中。在这里，我们研究了来自表达 αVβ3 的细胞的 sEV 对肿瘤生长的影响是否与来自不表达 αVβ3 的对照细胞的 sEV 不同。我们比较了 sEVs 刺激肿瘤生长的能力，使用通过碘克沙醇密度梯度从 PrCa C4-2B 细胞中分离的 sEVs，并通过免疫印迹、纳米粒子追踪分析、免疫捕获和单囊泡分析进行表征。体内肿瘤生长或体外分析它们不依赖锚定的生长。我们的结果表明，用从表达 αVβ3 的 C4-2B 细胞而非对照细胞中脱落的 sEVs 进行单一治疗，可刺激肿瘤生长并诱导 PrCa 细胞向神经内分泌表型分化，如通过神经内分泌标记物水平增加所量化的。总之，αVβ3 整合素的表达产生能够将细胞重新编程为侵袭性表型的 sEV。