Wang Hao, Li Wei, Tan Guolin
Department of Otolaryngology-Head and Neck Surgery, Third Xiangya Hospital of Central South University, Changsha 410013, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2019 Mar 30;39(3):357-363. doi: 10.12122/j.issn.1673-4254.2019.03.15.
To explore the role of long non-coding RNA (lncRNA) X inactive specific transcript (XIST) in modulating cisplatin (DDP) resistance of human nasopharyngeal carcinoma cells and investigate the possible mechanism.
Realtime PCR was performed to detect the expression of XIST in cisplatin-resistant human nasopharyngeal carcinoma cell line HNE1/DDP. The effects of up-regulation and down-regulation of XIST on DDP resistance, proliferation and apoptosis of HNE1/ DDP cells were assessed using MTT assay, EdU assay and flow cytometry. Western blotting was used to detect the changes in the expressions of programmed cell death 4 (PDCD4) and Fas ligand (Fas-L) proteins in the cells in response to up-regulation or down-regulation of XIST.
The expression of XIST was significantly up-regulated in HNE1/DDP cells in comparison with HNE1 cells (0.57±0.06 0.1±0.02, < 0.05). Down-regulation of XIST significantly decreased while up-regulation of XIST obviously increased DDP resistance of HNE1/DDP cells ( < 0.05). Down-regulation of XIST significantly reduced the proliferation (6.17 ± 1.93 16.59 ± 4.86, < 0.05) and enhanced apoptosis [(18.04 ± 4.72)% (4.22 ± 1.65)%, < 0.05], while upregulating XIST enhanced the proliferation (25.40±7.21 13.16±3.95, < 0.05) and inhibited apoptosis [(2.82±0.88)% (6.46± 1.75)%, < 0.05] in HNE1/DDP cells. Down-regulation of XIST significantly increased the protein expressions of PDCD4 and Fas-L ( < 0.05) in HNE1/DDP cells, and up-regulation of XIST resulted in reverse changes in PDCD4 and Fas-L expressions ( < 0.05).
XIST is up-regulated in HNE1/DDP cells, and down-regulation and up-regulation of XIST expression reduce and increase DDP resistance of the cells, respectively, possibly as a result of changes in the expressions of PDCD4 and Fas-L.
探讨长链非编码RNA（lncRNA）X染色体失活特异性转录本（XIST）在调节人鼻咽癌顺铂（DDP）耐药中的作用并研究其可能机制。
采用实时定量聚合酶链反应（Realtime PCR）检测顺铂耐药人鼻咽癌细胞系HNE1/DDP中XIST的表达。运用MTT法、EdU法和流式细胞术评估上调和下调XIST对HNE1/DDP细胞顺铂耐药性、增殖和凋亡的影响。采用蛋白质免疫印迹法检测上调或下调XIST后细胞中程序性细胞死亡4（PDCD4）和Fas配体（Fas-L）蛋白表达的变化。
与HNE1细胞相比，HNE1/DDP细胞中XIST的表达显著上调（0.57±0.06对0.1±0.02，P<0.05）。下调XIST显著降低，而上调XIST明显增加HNE1/DDP细胞的顺铂耐药性（P<0.05）。下调XIST显著降低增殖（6.17±1.93对16.59±4.86，P<0.05）并增强凋亡[（18.04±4.72）%对（4.22±1.65）%，P<0.05]，而上调XIST则增强HNE1/DDP细胞的增殖（25.40±7.21对13.16±3.95，P<0.05）并抑制凋亡[（2.82±0.88）%对（6.46±1.75）%，P<0.05]。下调XIST显著增加HNE1/DDP细胞中PDCD4和Fas-L的蛋白表达（P<0.05），而上调XIST导致PDCD4和Fas-L表达出现相反变化（P<0.05）。
HNE1/DDP细胞中XIST上调，下调和上调XIST表达分别降低和增加细胞的顺铂耐药性，可能是由于PDCD4和Fas-L表达变化所致。
