Objective: To explore the molecular mechanism of circDDX17 regulating the proliferation and apoptosis of non-small cell lung cancer cells by targeting the miR-223-3p/RIP3 molecular axis. Methods: The expression levels of circDDX17, miR-223-3p, and RIP3 in human normal lung epithelial cell lines BEAS-2B and non-small cell lung cancer cells H1299, A549, and H446 were detected by reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR). The plasmids of pcDNA, pcDNA-circDDX17, anti-miR-con, anti-miR-223-3p, pcDNA-circDDX17 and miR-con, pcDNA-circDDX17 and miR-223-3p mimics were transfected into H1299 cells. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MTT) assay was used to detect the cell proliferation. Flow cytometry was used to detect the cell cycle and cell apoptosis. Plate cloning experiment was used to detect cell proliferation ability. The dual luciferase report experiment was applied to verify the targeting relationship between miR-223-3p with circDDX17 and RIP3. Western blot was used to detect the protein expression of cyclinD1, CDK2, cleaved caspase-3 and Bax. Results: The expression levels of circDDX17 and RIP3 mRNA in H1299, A549, and H446 cells were significantly reduced (P<0.05), the expression level of miR-223-3p mRNA was significantly increased (P<0.05) compared with BEAS-2B. The cell viability [(69.46±4.68)%], the number of cell clones (83.49±7.86), the proportion of cells in S phase [(22.52±1.41) %], the protein expression levels of cyclinD1 and CDK2 in PCDNa-CircDDX17 group were lower than those in pcDNA group [(97.54±7.72)%, 205.03±13.37, (28.69±1.49)%, respectively, P<0.05], while the percentage of G0/G1 phase cells [(64.45±3.56)%], apoptosis rate [(18.36±1.63)%], the protein expression levels of cleaved caspase-3 and Bax in pcDNA-circDDX17 group were higher than those of pcDNA group [(51.33±2.76) % and (5.21±0.54) %, respectively, P<0.05]. The viability [(72.64±5.44)%], the number of cell clones (78.16±8.23), the proportion of S-stage cells [(21.34±1.59) %], the protein expression levels of CyclinD1 and CDK2 in anti-miR-223-3p group were lower than those in anti-miR-con group [(103.47±6.25)%, 169.32±14.53, (28.43±1.26)%, respectively, P<0.05]. Percentage of G0/G1 phase cells [(62.86±3.28)%], apoptosis rate [(14.64±1.67)%], the protein expression levels of cleaved caspase-3 and Bax in the anti-miR-223-3p group were higher than those of anti-miR-con group [(51.33±2.71)% and (4.83±0.39)%, respectively, P<0.05]. MiR-223-3p has complementary sites with circDDX17 or RIP3. The viability [(135.45±9.28)%], the number of cell clones (174.64±10.68), the proportion of S-phase cells [(26.39±2.25)%], the protein expression levels of cyclinD1 and CDK2 in pcDNA-circDDX17+miR-223-3p group were higher than those in pcDNA-circDDX17+miR-con group [(101.56±6.68)%, 107.65±7.62, (21.64±1.72)%, P<0.05]. Percentage of G0/G1 phase cells [(56.64±2.76)%], apoptosis rate [(8.34±0.76)%], the protein expression levels of cleaved caspase-3 and Bax in pcDNA-circDDX17+miR-223-3p group were lower than those of pcDNA-circDDX17+miR-con group [(64.03±3.48)% and (15.21±1.18)%, respectively, P<0.05]. Conclusion: circDDX17 could inhibit the proliferation and induce apoptosis of non-small cell lung cancer cells via targeting the miR-223-3p / RIP3 molecular axis.
目的： 探讨circDDX17通过靶向miR-223-3p/RIP3分子轴调控非小细胞肺癌细胞增殖及凋亡的分子机制。 方法： 采用实时荧光定量聚合酶链反应（qRT-PCR）检测人正常肺上皮细胞株BEAS-2B和非小细胞肺癌H1299、A549、H446细胞中circDDX17、miR-223-3p、受体相互作用蛋白3（RIP3）的表达水平。分别将pcDNA、pcDNA-circDDX17、anti-miR-con、anti-miR-223-3p、pcDNA-circDDX17与miR-con、pcDNA-circDDX17与miR-223-3p mimics转染至H1299细胞。采用四甲基偶氮唑蓝法检测细胞增殖情况，流式细胞术检测细胞周期和细胞凋亡情况，平板克隆实验检测细胞增殖能力，双荧光素酶报告实验验证circDDX17与miR-223-3p、miR-223-3p与RIP3的靶向关系，Western blot法检测CyclinD1、CDK2、Cleaved caspase-3、Bax蛋白的表达水平。 结果： 与BEAS-2B比较，H1299、A549、H446细胞中circDDX17 mRNA表达水平降低，miR-223-3p mRNA表达水平升高，RIP3 mRNA的表达水平降低（均P＜0.05）。pcDNA-circDDX17组细胞活力［（69.46±4.68）%］、细胞克隆数［（83.49±7.86）个］、S期细胞比例［（22.52±1.41）%］、CyclinD1、CDK2蛋白表达水平均低于pcDNA组［分别为（97.54±7.72）%、（205.03±13.37）个、（28.69±1.49）%，均P＜0.05］，pcDNA-circDDX17组细胞G0/G1期细胞比例［（64.45±3.56）%］、细胞凋亡率［（18.36±1.63）%］、Cleaved caspase-3、Bax蛋白表达水平均高于pcDNA组［分别为（51.33±2.76）%和（5.21±0.54）%，均P＜0.05］；anti-miR-223-3p组细胞活力［（72.64±5.44）%］、细胞克隆数［（78.16±8.23）个］、S期细胞比例［（21.34±1.59）%］、CyclinD1、CDK2蛋白表达水平均低于anti-miR-con组［分别为103.47±6.25、（169.32±14.53）个、（28.43±1.26）%，均P＜0.05］，anti-miR-223-3p组细胞G0/G1期细胞比例［（62.86±3.28）%］、细胞凋亡率［（14.64±1.67）%］、Cleaved caspase-3、Bax蛋白表达水平均高于anti-miR-con组［分别为（51.33±2.71）%和（4.83±0.39）%，均P＜0.05］。circDDX17与miR-223-3p存在结合位点，miR-223-3p与RIP3存在结合位点。pcDNA-circDDX17+miR-223-3p组细胞活力［（135.45±9.28）%］、细胞克隆数［（174.64±10.68）个］、S期细胞比例［（26.39±2.25）%］、CyclinD1、CDK2蛋白表达水平均高于pcDNA-circDDX17+miR-con组［分别为（101.56±6.68）%、（107.65±7.62）个、（21.64±1.72）%，均P＜0.05］，pcDNA-circDDX17+miR-223-3p组细胞G0/G1期细胞比例［（56.64±2.76）%］、细胞凋亡率［（8.34±0.76）%］、Cleaved caspase-3、Bax蛋白表达水平均低于pcDNA-circDDX17+miR-con组［分别为（64.03±3.48）%和（15.21±1.18）%，均P＜0.05］。 结论： circDDX17可靶向调控miR-223-3p/RIP3分子轴从而抑制非小细胞肺癌细胞增殖及诱导细胞凋亡。.