Exosomal connexin 43 regulates the resistance of glioma cells to temozolomide.
Exosomal connexin 43 regulates the resistance of glioma cells to temozolomide.
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DOI：
10.3892/or.2021.7995
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发表时间：
2021-04
期刊：
影响因子：
4.2
通讯作者：
Jiang LP
中科院分区：
文献类型：
--
作者：
Yang ZJ;Zhang LL;Bi QC;Gan LJ;Wei MJ;Hong T;Tan RJ;Lan XM;Liu LH;Han XJ;Jiang LP
胶质母细胞瘤是最常见和最具侵袭性的脑肿瘤，其特征在于高死亡率。替莫唑胺（TMZ）是一种有效的胶质母细胞瘤化疗药物，但对TMZ的耐药性已成为一个主要的临床问题，其潜在的机制尚未阐明。在本研究中，外泌体连接蛋白43（Cx43）在胶质瘤细胞对TMZ的抗性和细胞迁移中的作用进行了研究。首先，与TMZ敏感的U251 s细胞相比，TMZ耐药的U251（U251 r）细胞中检测到更高的Cx43表达水平。分离来自U251 s或U251 r细胞的外来体（分别为sExo和rExo）。结果发现，rExo细胞中Cx43的表达明显高于sExo细胞，而rExo处理后U251 s细胞中Cx43的表达增加。此外，使用双十八烷基氧碳菁（Dio）染色的外泌体来观察神经胶质瘤细胞对外泌体的摄取。结果表明，U251 s细胞对Dio染色的rExo的摄取明显高于Dio染色的sExo，而针对Cx43的缝隙连接模拟肽37，43 Gap 27则明显抑制了rExo的摄取。rExo可增加U251 s细胞对TMZ的IC 50，增加U251 s细胞的集落形成和Bcl-2表达，降低Bax和Caspase-3的表达。37，43 Gap 27有效地抑制rExo对U251 s细胞的这些作用。最后，伤口愈合和Transwell测定的结果显示，rExo显著增强了U251 s细胞的迁移，而37，43 Gap 27显著减弱了rExo诱导的细胞迁移。综上所述，这些结果表明外泌体Cx43在胶质瘤细胞的化疗耐药性和迁移中起着至关重要的作用，并表明Cx43可能有望成为胶质母细胞瘤未来的治疗靶点。
Glioblastoma is the most common and aggressive brain tumor and it is characterized by a high mortality rate. Temozolomide (TMZ) is an effective chemotherapy drug for glioblastoma, but the resistance to TMZ has come to represent a major clinical problem, and its underlying mechanism has yet to be elucidated. In the present study, the role of exosomal connexin 43 (Cx43) in the resistance of glioma cells to TMZ and cell migration was investigated. First, higher expression levels of Cx43 were detected in TMZ-resistant U251 (U251r) cells compared with those in TMZ-sensitive (U251s) cells. Exosomes from U251s or U251r cells (sExo and rExo, respectively) were isolated. It was found that the expression of Cx43 in rExo was notably higher compared with that in sExo, whereas treatment with rExo increased the expression of Cx43 in U251s cells. Additionally, exosomes stained with dioctadecyloxacarbocyanine (Dio) were used to visualized exosome uptake by glioma cells. It was observed that the uptake of Dio-stained rExo in U251s cells was more prominent compared with that of Dio-stained sExo, while 37,43Gap27, a gap junction mimetic peptide directed against Cx43, alleviated the rExo uptake by cells. Moreover, rExo increased the IC50 of U251s to TMZ, colony formation and Bcl-2 expression, but decreased Bax and cleaved caspase-3 expression in U251s cells. 37,43Gap27 efficiently inhibited these effects of rExo on U251s cells. Finally, the results of the wound healing and Transwell assays revealed that rExo significantly enhanced the migration of U251s cells, whereas 37,43Gap27 significantly attenuated rExo-induced cell migration. Taken together, these results indicate the crucial role of exosomal Cx43 in chemotherapy resistance and migration of glioma cells, and suggest that Cx43 may hold promise as a therapeutic target for glioblastoma in the future.