大分割与小分割X线放疗方案对乳腺癌MCF-7细胞lncRNA GATA6-AS1基因表达的影响

Effect of hypofractionated and hyperfrationated X-ray radiotherapy on lncRNA GATA6-AS1 gene expression in breast cancer MCF-7 cells

目的探讨大分割与小分割X线放疗方案对乳腺癌MCF-7细胞长链非编码RNA GATA6反义RNA 1(GATA6-AS1)基因表达的影响。方法给予MCF-7细胞4Gy X线照射,分为小分割组(每次0.5 Gy,共8次)、大分割组(每次2 Gy,共2次),以未照射组为对照组。利用CCK-8实验检测各组MCF-7细胞的增殖能力,流式细胞仪检测各组MCF-7细胞凋亡,qRT-PCR法检测各组MCF-7细胞GATA6-AS1基因表达变化,进一步通过Westernblot法检测其邻近基因表达产物GATA6的表达情况。结果通过CCK-8实验发现,X线照射能够抑制MCF-7细胞的增殖,大分割组MCF-7细胞增殖抑制较小分割组更明显,72 h抑制率可达(57.0±8.86)%,而小分割组仅为(25.0±4.15)%,差异有统计学意义(P<0.05);流式细胞仪检测发现大分割组MCF-7细胞的凋亡较小分割组更明显,48 h凋亡率达(19.07±2.38)%,而小分割组仅为(13.22±2.71)%,差异有统计学意义(P<0.05);qRT-PCR法检测发现,X线照射会引起MCF-7细胞内GATA6-AS1基因表达增强,大分割组GATA6-AS1基因表达增强更明显,达到对照组的(2.13±0.19)倍,差异具有统计学意义(P<0.05);Western blot法检测发现,X线照射可下调GATA6-AS1基因邻近蛋白GATA6的表达,大分割组-GATA6蛋白下调更明显。结论大分割法X线照射能够明显抑制乳腺癌MCF-7细胞增殖并促进细胞凋亡,增强乳腺癌MCF-7细胞GATA6-AS1基因表达,并下调其邻近基因表达产物GATA6的表达。

Objective To investigate the effect of hypofractionated and hyperfrationated X-ray radiotherapy on the expression of GATA6 antisense RNA 1(GATA6-AS1)gene in breast cancer MCF-7 cells.Methods MCF-7 cells were given 4Gy X-ray irradiation,which were divided into hyperfrationated radiotherapy groups(0.5 Gy,8 times)and hypofrationated radiotherapy groups(2 Gy,twice),and the non-irradiation groups were used as controls.The proliferation ability of MCF-7 cells was detected by CCK-8 assays,the cell apoptosis was detected by flow cytometry,the expression of GATA6-AS1 gene was detected by qRT-PCR,and the expression of the adjacent gene expression product GATA6 was further detected by western blot.Results CCK-8 assays showed that X-ray irradiation inhibited the proliferation of MCF-7 cells,and the proliferation inhibition of MCF-7 cells in the hypofrationated radiotherapy group was more significant than that of hyperfrationated radiotherapy group after the treatment for 72 h:(57.0±8.86)%vs(25.0±4.15)%,P<0.05.Flow cytometry analysis revealed that the apoptosis of MCF-7 cells was more significantly promoted in hypofrationated radiotherapy group than that of hyperfrationated radiotherapy group after the treatment for 48 h:(19.07±2.38)%vs(13.22±2.71)%,P<0.05.Results from qRT-PCR showed that X-ray irradiation increased the expression of GATA6-AS1 gene in MCF-7 cells,and the expression of GATA6-AS1 gene was more significant in hypofrationated radiotherapy group than that of hyperfrationated radiotherapy group(FC=2.13±0.19,P<0.05).Results from western blot showed that X-ray irradiation reduced the expression of GATA6 protein adjacent to GATA6-AS1 gene,and the down-regulation of GATA protein was more significant in hypofrationated radiotherapy group.Conclusion X-ray irradiation with hypofrationated radiotherapy obviously inhibits the proliferation of breast cancer MCF-7 cells,promotes cell apoptosis,enhances the expression of GATA6-AS1 gene,and reduces the expression of the adjacent gene expression product GATA6 in MCF-7 cells.