Objective To analyze the effects of circular RNA CSPP1(circCSPP1)and microRNA-642a-5p(miR-642a-5p)on the biological behaviors of retinoblastoma Y-79 cells.Methods A total of 47 patients with retinoblastoma(47 eyes)who were admitted at Zhengzhou Central Hospital from June 2019 to October 2022 were included in this study,and the tumor tissues and paraneoplastic tissues of these patients were collected during surgery.The human retinoblastoma cell line Y-79 was cultured in vitro and then divided into seven groups based on different transfectants:the Con group(nor-mally cultured Y-79 cells),sh-NC group(transfected with sh-NC),sh-circCSPP1 group(transfected with sh-circCSPP1),miR-NC group(transfected with miR-NC),miR-642a-5p group(transfected with miR-642a-5p mimics),sh-circCSPP1+an-ti-miR-NC group(co-transfected with sh-circCSPP1 and anti-miR-NC),and sh-circCSPP1+anti-miR-642a-5p group(co-transfected with sh-circCSPP1 and anti-miR-642a-5p).The real-time quantitative polymerase chain reaction(RT-qPCR)was used to measure the expression level of circCSPP1 and miR-642a-5p in retinoblastoma tissues,paraneoplastic tissues,and Y-79 cells.The proliferation,migration,and invasion of Y-79 cells were assessed via the cell counting kit-8(CCK-8)assay,scratch wound healing assay,and Transwell chamber assay,respectively.The targeting relationship between cir-cCSPP1 and miR-642a-5p was verified by the dual-luciferase reporter assay.Western blot was performed to quantify the ex-pression level of E-cadherin and N-cadherin.Results Compared with paraneoplastic tissues,the expression of circCSPP1 was up-regulated,that of miR-642a-5p was downregulated in retinoblastoma tissues,and the differences were statistically significant(both P＜0.05).Compared with the Con group and the sh-NC group,the sh-circCSPP1 group showed a reduced scratch healing rate,decreased invasive cell count,up-regulated relative protein expression of E-cadherin,and down-regu-lated relative protein expression of N-cadherin,and the differences were statistically significant(all P＜0.05).Compared with the Con group and the miR-NC group,the miR-642a-5p group exhibited a reduced scratch healing rate,decreased in-vasive cell count,up-regulated protein expression of E-cadherin,and down-regulated protein expression of N-cadherin,and the differences were statistically significant(all P＜0.05).The dual luciferase reporter assay demonstrated that cir-cCSPP1 negatively regulated the expression level of miR-642a-5p.Compared with the sh-circCSPP1+anti-miR-NC group,the sh-circCSPP1+anti-miR-642a-5p group displayed an increased scratch healing rate,increased invasive cell count,down-regulated protein expression of E-cadherin,and up-regulated protein expression of N-cadherin,and the differences were statistically significant(all P＜0.05).Conclusion Silencing circCSPP1 may suppress the proliferation,migration,and invasion of Y-79 cells by up-regulating the expression of miR-642a-5p,suggesting that circCSPP1 may become a poten-tial therapeutic target for retinoblastoma.

Objective To analyze the effects of circular RNA CSPP1(circCSPP1)and microRNA-642a-5p(miR-642a-5p)on the biological behaviors of retinoblastoma Y-79 cells.Methods A total of 47 patients with retinoblastoma(47 eyes)who were admitted at Zhengzhou Central Hospital from June 2019 to October 2022 were included in this study,and the tumor tissues and paraneoplastic tissues of these patients were collected during surgery.The human retinoblastoma cell line Y-79 was cultured in vitro and then divided into seven groups based on different transfectants:the Con group(nor-mally cultured Y-79 cells),sh-NC group(transfected with sh-NC),sh-circCSPP1 group(transfected with sh-circCSPP1),miR-NC group(transfected with miR-NC),miR-642a-5p group(transfected with miR-642a-5p mimics),sh-circCSPP1+an-ti-miR-NC group(co-transfected with sh-circCSPP1 and anti-miR-NC),and sh-circCSPP1+anti-miR-642a-5p group(co-transfected with sh-circCSPP1 and anti-miR-642a-5p).The real-time quantitative polymerase chain reaction(RT-qPCR)was used to measure the expression level of circCSPP1 and miR-642a-5p in retinoblastoma tissues,paraneoplastic tissues,and Y-79 cells.The proliferation,migration,and invasion of Y-79 cells were assessed via the cell counting kit-8(CCK-8)assay,scratch wound healing assay,and Transwell chamber assay,respectively.The targeting relationship between cir-cCSPP1 and miR-642a-5p was verified by the dual-luciferase reporter assay.Western blot was performed to quantify the ex-pression level of E-cadherin and N-cadherin.Results Compared with paraneoplastic tissues,the expression of circCSPP1 was up-regulated,that of miR-642a-5p was downregulated in retinoblastoma tissues,and the differences were statistically significant(both P＜0.05).Compared with the Con group and the sh-NC group,the sh-circCSPP1 group showed a reduced scratch healing rate,decreased invasive cell count,up-regulated relative protein expression of E-cadherin,and down-regu-lated relative protein expression of N-cadherin,and the differences were statistically significant(all P＜0.05).Compared with the Con group and the miR-NC group,the miR-642a-5p group exhibited a reduced scratch healing rate,decreased in-vasive cell count,up-regulated protein expression of E-cadherin,and down-regulated protein expression of N-cadherin,and the differences were statistically significant(all P＜0.05).The dual luciferase reporter assay demonstrated that cir-cCSPP1 negatively regulated the expression level of miR-642a-5p.Compared with the sh-circCSPP1+anti-miR-NC group,the sh-circCSPP1+anti-miR-642a-5p group displayed an increased scratch healing rate,increased invasive cell count,down-regulated protein expression of E-cadherin,and up-regulated protein expression of N-cadherin,and the differences were statistically significant(all P＜0.05).Conclusion Silencing circCSPP1 may suppress the proliferation,migration,and invasion of Y-79 cells by up-regulating the expression of miR-642a-5p,suggesting that circCSPP1 may become a poten-tial therapeutic target for retinoblastoma.

Objective　To investigate the protective effect and mechanism of the derivative NIM811 on hypoxia/reoxygenation injury of rat hippocampal neuron (HT22) induced by sodium disulfite (Na2S2O4).Methods　The hypoxia/reoxygenation cell model was prepared with mouse HT22 cultured cells.The experiment was divided into normal control group,Na2S2O4 group,Na2S2O4+NIM811 group,and NIM811 group.Cell survival rate was detected by CCK-8,flow cytometry was used to detect apoptosis,mitochondrial membrane potential was detected by JC-1 reagent,calcium ion level in mitochondria was observed by Rhod-2 AM,and reactive oxygen species (ROS) was detected by DCFH-DA method.Results　Compared with the Na2S2O4 group,after NIM811 treatment:(1)Cell activity increased by 38% (P<0.01);(2)Apoptosis decreased by 27% (P<0.01);(3)Mitochondrial membrane potential increased (P<0.01);(4)The level of calcium ions in the mitochondria decreased (P<0.01);(5)The level of reactive oxygen species (ROS) decreased (P<0.01).Conclusion　NIM811 has a protective effect on the hypoxia/reoxygenation injury of mouse hippocampal neurons caused by Na2S2O4.The mechanism may be related to the maintenance of mitochondrial homeostasis and inhibition of cell apoptosis.NIM811 has therapeutic potential for future clinical treatment of ischemic stroke.