MEDLINE/PubMed Journal Browser Search

Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

Title: [Effect of CASC19 on proliferation, apoptosis and radiation sensitivity of cervical cancer cells by regulating miR-449b-5p expression].
Author: Liu YJ, Guo RX, Han LP, Gu H, Liu MZ.
Journal: Zhonghua Fu Chan Ke Za Zhi; 2020 Jan 25; 55(1):36-44. PubMed ID: 32074771.
Abstract:
Objective: To investigate the effects of cancer susceptibility candidate gene 19 (CASC19) regulating the expression of microRNA-449b-5p (miR-449b-5p) on the proliferation, apoptosis and radiation sensitivity of cervical cancer cells. Methods: (1) HeLa cells of cervical cancer cell line were cultured. HeLa cells were irradiated with X-ray at different doses (0, 2, 4, 6, 8 Gy, respectively), then the expression level of CASC19 mRNA and miR-449b-5p were detected by real-time quantitative PCR. (2) HeLa cell proliferation, apoptosis, radiation sensitivity (expressed as a survival fraction) and its related protein expression included cyclin D1, cleaved-caspase-3, and histone variant H2AX (γ-H2AX) were examined after different treatment including silencing CASC19 expression, over-expressing miR-449b-5p, down-regulating miR-449b-5p and silencing CASC19 expression. (3) The dual luciferase reporter gene experiment and real-time quantitative PCR technology were used to verify the targeting relationship between CASC19 and miR-449b-5p. Results: (1) With the increase of X-ray irradiation different dose (0, 2, 4, 6, 8 Gy), the expression level of CASC19 mRNA in HeLa cells gradually increased (F=502.681, P=0.000), and the expression level of miR-449b-5p gradually decreased (F=202.936, P=0.000).(2) After silencing CASC19 expression or over-expressing miR-449b-5p, the survival rate of HeLa cells was significantly reduced (P<0.05), the apoptosis rate was significantly increased (P<0.05), the survival fraction was significantly reduced (P<0.05), the expression level of cyclin D1 protein was significantly reduced (P<0.05), and the expression levels of cleaved-caspase-3 and γ-H2AX protein were significantly increased (P<0.05). After down-regulating miR-449b-5p and silencing CASC19 expression, the survival rate of HeLa cells was significantly reduced (P<0.05), the apoptosis rate was significantly increased (P<0.05), the survival fraction was significantly reduced (P<0.05), the expression levels of cyclin D1 and γ-H2AX protein were significantly increased (P<0.05), and the expression level of cleaved-caspase-3 was significantly decreased (P<0.05). (3) Over expression of miR-449b-5p could significantly reduce the luciferase activity of CASC19 wild type (1.00±0.09 versus 0.37±0.05, P<0.01), but there were no significant effect on the luciferase activity of CASC19 mutant type (0.92±0.07 versus 0.94±0.05, P>0.05). After the expression of CASC19 was silenced, the expression level of miR-449b-5p in HeLa cells increased significantly (1.00±0.12 versus 4.84±0.49, P<0.05). After overexpression of CASC19, the expression level of miR-449b-5p in HeLa cells was significantly reduced (1.00±0.09 versus 0.38±0.04, P<0.05). Conclusion: CASC19 in HeLa cells negatively regulates the expression of miR-449b-5p, and down-regulating the expression of miR-449b-5p could partially reverse the effects of silencing CASC19 on HeLa cell proliferation, apoptosis and radiation sensitivity. 目的： 探讨癌易感性候选基因19（CASC19）调控微小RNA-449b-5p（miR-449b-5p）的表达后对子宫颈癌细胞增殖、凋亡和辐射敏感性的影响。 方法： （1）培养子宫颈癌细胞系HeLa细胞，予不同剂量（分别为0、2、4、6、8 Gy）的X线照射，实时荧光定量PCR技术检测HeLa细胞中CASC19 mRNA和miR-449b-5p的表达水平。（2）不同条件处理后HeLa细胞增殖、凋亡、辐射敏感性及其相关蛋白表达的检测，其中，不同处理条件包括沉默CASC19表达、过度表达miR-449b-5p、下调miR-449b-5p并沉默CASC19表达，相关蛋白包括细胞周期蛋白D1（cyclin D1）、活化的半胱氨酸天冬氨酸蛋白酶3（cleaved-caspase-3）和组蛋白变异体H2AX（γ-H2AX）；采用四甲基偶氮唑蓝（MTT）比色法检测细胞增殖情况，流式细胞仪检测细胞凋亡情况，细胞克隆形成实验检测细胞的辐射敏感性（以存活分数表示）。（3）采用双荧光素酶报告基因实验（结果以荧光素酶活性表示）和实时荧光定量PCR技术验证CASC19和miR-449b-5p之间的靶向调控关系。 结果： （1）随着X线照射剂量（0、2、4、6、8 Gy）的增加，HeLa细胞中CASC19 mRNA的表达水平逐渐升高（F=502.681，P=0.000），miR-449b-5p的表达水平逐渐降低（F=202.936，P=0.000）。（2）沉默CASC19表达、过度表达miR-449b-5p后，HeLa细胞的存活率显著降低（P<0.05），凋亡率显著升高（P<0.05），存活分数显著降低（P<0.05），cyclin D1蛋白的表达水平显著降低（P<0.05），cleaved-caspase-3和γ-H2AX蛋白的表达水平显著升高（P<0.05）；下调miR-449b-5p并沉默CASC19表达后，HeLa细胞的存活率显著升高（P<0.05），凋亡率显著降低（P<0.05），存活分数显著升高（P<0.05），cyclin D1、γ-H2AX蛋白的表达水平显著升高（P<0.05），cleaved-caspase-3的表达水平显著降低（P<0.05）。（3）与对照比较，过度表达miR-449b-5p可显著降低CASC19基因野生型HeLa细胞的荧光素酶活性（分别为1.00±0.09、0.37±0.05，P<0.01），而对CASC19基因突变型HeLa细胞的荧光素酶活性无显著影响（分别为0.92±0.07、0.94±0.05，P>0.05）。与对照比较，沉默CASC19表达后HeLa细胞中miR-449b-5p的表达水平显著升高（分别为1.00±0.12、4.84±0.49，P<0.05），过度表达CASC19后HeLa细胞中miR-449b-5p的表达水平显著降低（分别为1.00±0.09、0.38±0.04，P<0.05）。 结论： HeLa细胞中CASC19可负调控miR-449b-5p的表达，下调miR-449b-5p表达可部分逆转沉默CASC19对HeLa细胞增殖、凋亡及辐射敏感性的影响。.

[Abstract] [Full Text] [Related] [New Search]