环状RNA hsacirc0000231与HnRNPK相互作用对乳腺癌增殖、迁移及凋亡的影响

Effect of circular RNA hsa_irc_000231 interacting with HnRNPK on proliferation, migration, and apoptosis in breast cancer

目的 研究环状RNA hsa_circ_0000231与HnRNPK相互作用对乳腺癌增殖、迁移及凋亡的影响。方法 采用微阵列分析技术对4对乳腺癌组织及其癌旁组织的环状RNA表达谱进行分析。选取重庆医科大学附属第一医院2019年9月至2021年1月收治的乳腺癌患者癌组织标本35例,qRT-PCR验证hsa_circ_0000231的相对表达量,FISH实验检测其在细胞中的定位与表达。转染干扰质粒后,通过划痕、CCK-8、EdU、克隆形成、Hoechst33342、TUNEL、流式细胞仪和Transwell实验检测hsa_circ_0000231在乳腺癌细胞迁移、侵袭、增殖和细胞凋亡中的作用,Western blot检测CCND2、CCND1和CDK4的表达变化;在裸鼠体内研究hsa_circ_0000231对移植瘤生长的影响。RNA pulldown实验检测与hsa_circ_0000231作用的相关蛋白表达,FISH-IF实验观察hsa_circ_0000231与HnRNPK的亚细胞定位,qRT-PCR和Western blot检测c-Myc的表达变化。结果 hsa_circ_0000231在乳腺癌组织(P<0.001)和乳腺癌细胞(P<0.01)中高表达,敲低hsa_circ_0000231能抑制乳腺癌细胞的增殖、迁移和侵袭,诱导细胞凋亡及细胞周期G;期阻滞,CCND2、CCND1和CDK4蛋白表达明显下降。裸鼠移植瘤实验结果表明敲低hsa_circ_0000231可抑制移植瘤生长。HnRNPK蛋白与hsa_circ_0000231共定位于细胞核,且与hsa_circ_0000231相互作用能促进c-Myc的表达。结论 敲低hsa_circ_0000231能抑制乳腺癌细胞的增殖、迁移和侵袭,诱导细胞凋亡,阻滞细胞周期,并在体内抑制移植瘤生长,hsa_circ_0000231能够与HnRNPK相互作用增强c-Myc的表达,从而促进乳腺癌的发生和发展。

Objective To explore the effects of the interaction between circular RNA hsa_circ_0000231 and HnRNPK on the proliferation, migration and apoptosis in breast cancer. Methods Microarray analysis was used to investigate the expression profile of circRNAs in 4 pairs of breast cancer tissues and corresponding adjacent normal tissues. A total of 35 breast cancer tissue specimens were collected from the patients admitted in the First Affiliated Hospital of Chongqing Medical University from September 2019 to January 2021. qRT-PCR was carried out to detect the relative expression of hsa_circ_0000231, and fluorescence in situ hybridization(FISH) assay was performed to observe its location and expression in the cells. Breast cancer MCF-7 and SK-BR-3 cells were transfected with the interference vector of hsa_circ_0000231 respectively. Then cell wound healing assay, CCK-8 assay, EdU cell proliferation assay, clone formation experiment, hoechst33342 staining, TUNEL, flow cytometry and Transwell assay were adopted to determine cell migration, invasion, proliferation and apoptosis, and Western blotting was employed to measure the expression of CCND2, CCND1 and CDK4 after the knockdown. The effect of hsa_circ_0000231 on the growth of transplanted tumors was observed in nude mice. RNA pulldown assay was performed to identify hsa_circ_0000231-associated proteins, and FISH-immunofluorescence(IF) assay were employed to clarify the subcellular localization of hsa_circ_0000231 and HnRNPK. qRT-PCR and Western blotting were conducted to detect the expression of c-Myc. Results Circular RNA hsa_circ_ 0000231 was highly expressed in breast cancer tissues(P<0.001) and breast cancer cells(P<0.01). Down-regulation of hsa_ circ_ 0000231 inhibited the proliferation, migration and invasion of breast cancer cells, induced cell apoptosis, led to cell cycle arrest in G;phase, and obviously decreased the expression of CCND2, CCND1 and CDK4. The results of in vivo experiments showed that knockdown of hsa_circ_0000231 inhibited the growth of tumor xenograft. HnRNPK was co-localized in the nucleus with hsa_circ_0000231, and interacted with hsa_circ_0000231 to promote c-Myc expression. Conclusion Knockdown of hsa_ circ_ 0000231 could suppress the proliferation, migration and invasion of breast cancer cells, induce cell apoptosis and cell cycle arrest, and inhibit tumor growth in vivo. The interaction of hsa_circ_0000231 with HnRNPK enhances the expression of c-Myc, and thus promotes the occurrence and development of breast cancer.