Purpose

Gemcitabine (GEM)-based chemotherapy is the first-line treatment for locally advanced pancreatic cancer. GEM resistance, however, remains a significant clinical challenge. Here, we investigated whether exosomes derived from GEM-resistant pancreatic cancer stem cells (CSCs) mediate cell-cell communication between cells that are sensitive or resistant to GEM and, by doing so, regulate drug resistance.

Methods

GEM-sensitive BxPC-3-derived Bx_S and PANC-1 pancreatic cancer cells were cultured with exosomes extracted from CSCs isolated from GEM-resistant BxPC-3-derived Bx_R cells (Bx_R-CSC). The effect of exosomes on drug resistance, cell cycle progression, apoptosis and miRNA expression was evaluated in Bx_S and PANC-1 cells. Relevant miRNAs associated with GEM resistance were identified and the role of miR-210 in conferring drug resistance was examined in vitro and in vivo.

Results

Bx_R-CSC-derived exosomes induced GEM resistance, inhibited GEM-induced cell cycle arrest, antagonized GEM-induced apoptosis, and promoted tube formation and cell migration in Bx_S and PANC-1 cells. Elevated miR-210 expression levels were detected in Bx_R-CSCs and Bx_R-CSC-derived exosomes compared to those in Bx_S-CSCs and Bx_S-CSC-derived exosomes. In addition, increased expression levels of miR-210 were observed in Bx_S and PANC-1 cells cultured with Bx_R-CSC-derived exosomes upon exposure to GEM in a dose-dependent manner. Also, a series of biological changes was observed in Bx_S cells after transfection with miR-210 mimics, including activation of the mammalian target of rapamycin (mTOR) signaling pathway, and these changes were similar to those triggered by Bx_R-CSC-derived exosomes.

Conclusions

Our findings suggest that exosomes derived from GEM-resistant pancreatic cancer stem cells mediate the horizontal transfer of drug-resistant traits to GEM-sensitive pancreatic cancer cells by delivering miR-210.

中文翻译：

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源自对吉西他滨耐药的胰腺癌细胞的癌症干细胞的外泌体通过递送miR-210增强了耐药性。

目的

基于吉西他滨（GEM）的化疗是局部晚期胰腺癌的一线治疗。然而，GEM抗性仍然是重大的临床挑战。在这里，我们调查了源自GEM抗性胰腺癌干细胞（CSC）的外泌体是否介导对GEM敏感或具有抗性的细胞之间的细胞间通讯，并以此来调节药物抗性。

方法

将GEM敏感的BxPC-3衍生的Bx _S和PANC-1胰腺癌细胞与外泌体一起培养，该外泌体是从从GEM耐药的BxPC-3衍生的Bx _R细胞（Bx _R -CSC）分离的CSC中提取的。在Bx _S和PANC-1细胞中评估了外泌体对耐药性，细胞周期进程，凋亡和miRNA表达的影响。鉴定了与GEM抗性相关的相关miRNA，并在体外和体内检查了miR-210在赋予抗药性中的作用。

结果

Bx _R -CSC衍生的外泌体诱导GEM抵抗，抑制GEM诱导的细胞周期停滞，拮抗GEM诱导的细胞凋亡，并促进Bx _S和PANC-1细胞的管形成和细胞迁移。与Bx _S -CSCs和Bx _S -CSC衍生的外泌体相比，在Bx _R -CSCs和Bx _R -CSC衍生的外泌体中检测到的miR-210表达水平升高。此外，增加的在Bx的观察的miR-210的表达水平_小号和PANC-1细胞培养Bx的_ř -CSC衍生的外来体在暴露以剂量依赖的方式GEM。此外，在Bx _S中观察到一系列生物学变化miR-210模拟物转染后的细胞，包括激活雷帕霉素（mTOR）哺乳动物靶标信号通路，这些变化与Bx _R -CSC衍生的外泌体触发的变化相似。

结论

我们的发现表明，来自GEM耐受性胰腺癌干细胞的外泌体通过传递miR-210介导耐药性状向GEM敏感的胰腺癌细胞的水平转移。