CD133^+卵巢癌干细胞通过CXCL16/CXCR6维持其侵袭迁移能力

CD133^+ ovarian cancer stem cells maintain high abilities of invasion and migration via CXCL16 / CXCR6 axis

目的探讨人卵巢癌干细胞(ovarian cancer stem cells,OCSCs)自分泌趋化因子CXCL16对OCSCs增殖及侵袭迁移能力的影响。方法采用Real-time PCR、ELISA及流式细胞仪检测A2780细胞株诱导的CD133+OCSCs和CD133-非卵巢癌干细胞(non ovarian cancer stem cells,n OCSCs)中CXCL16及CXCR6的表达;用CCK-8法检测阻断CXCL16对OCSCs增殖能力的影响;利用Transwell迁移、侵袭实验检测分别阻断CXCL16或CXCR6及shRNA沉默CXCL16对OCSCs侵袭迁移能力的影响。结果与n OCSCs比较,OCSCs中CXCL16及CXCR6 mRNA均表达上调(P<0.01)。ELISA结果显示OCSCs的CXCL16分泌量远远高于n OCSCs[(2 434.00±204.65)vs(129.33±31.64)ng/m L,P<0.01]。流式细胞仪检测发现OCSCs表面CXCR6表达率显著高于n OCSCs(60.6%vs 2.4%,P<0.01)。与对照组比较,中和抗体阻断CXCL16对OCSCs增殖无明显影响(P>0.05),然而阻断CXCL16或CXCR6能明显抑制OCSCs的侵袭迁移能力(P<0.01)。shRNA沉默CXCL16同样能显著抑制OCSCs的侵袭迁移能力(P<0.01)。结论 CD133+卵巢癌干细胞自分泌CXCL16,后者与CXCR6结合可维持卵巢癌干细胞高侵袭迁移能力。

Objective To determine the effect of CXCL16 /CXCR6 axis on the proliferation,invasion and migration of ovarian cancer stem cells（ OCSCs）. Methods CD133^＋OCSCs were isolated from ovarian cancer cell line A2780 by serum-free culture selection. The difference of CXCL16 and CXCR6 expression between CD133^＋OCSCs and CD133^-non-ovarian cancer stem cells（ n OCSCs） was detected by real-time PCR,enzyme linked immunosorbent assay and flow cytometry. CCK-8 assay was used to assess the effect of CXCL16 on proliferation of OCSCs. Transwell migration assay and Matrigel invasion assay were used to determine invasion and migration ability of OCSCs after blocking CXCL16 or CXCR6 with neutralizing antibody or short hairpin RNA（ shRNA）. Results Compared with n OCSCs,CXCL16 and CXCR6 at mRNA expression level were increased in OCSCs（ P〈0. 01）. OCSCs had more CXCL16 secretion（ 2 434. 00 ±204. 65 ng / mL） than n OCSCs（ 129. 33 ± 31. 64 ng / mL）（ P〈0. 01）. And the CXCR6 expression in OCSCs（ 60. 6%） was higher than that in n OCSCs（ 2. 4%）（ P〈0. 01）. CCK-8 assay showed that the proliferation of OCSCs was not affected after blocking CXCL16 with neutralizing antibody（ P〉0. 05）. When CXCL16 or CXCR6 was blocked with neutralizing antibody,OCSCs showed decrease of invasion and migration ability（ P〈0. 01）. Invasion and migration ability of OCSCs was also significantly inhibited when blocking CXCL16 with shRNA（ P〈0. 01）. Conclusion Autocrine chemokine CXCL16 can bind to CXCR6 to maintain high ability of invasion and migration of CD133^＋OCSCs.