Objective: To further explore the role and mechanism of hsa_circ_0001776 and mir-1265 in lung squamous carcinoma by verifying the expression level of hsa_circ_0001776 in plasma, tissues, and cells of lung squamous carcinoma. Methods: Plasma was collected from patients with lung squamous carcinoma treated at Tangshan People's Hospital and healthy individuals from 2020 to 2022. Lung squamous carcinoma tissue microarrays purchased from Shanghai Xinchao Biotechnology Company in 2022. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression of hsa_circ_0001776 in lung squamous carcinoma plasma, tissues, and cells, and fluorescence in situ hybridization was used to verify the expression of hsa_circ_0001776 in lung squamous carcinoma. The localization of hsa_circ_0001776 in NCI-H1703 was verified by fluorescence in situ hybridization. The lung squamous carcinoma cells NCI-H1703 and NCI-H226 were cultured in vitro and divided into the circ-negative control (NC) group, hsa_circ_0001776 overexpression group, miR-NC group, miR-1265 mimic group, hsa_circ_0001776+miR-NC group, and hsa_circ_0001776+miR-1265 mimic group.The cell proliferation, motility and apoptosis were detected by the cell counting kit-8 (CCK-8) method, clone formation, Transwell invasion and migration, and scratch assay, and flow cytometry, respectively. The downstream of hsa_circ_0001776 was predicted by circular RNA interactome website, and the interaction between hsa_circ_0001776, miR-1265 was further determined by dual luciferase reporter gene assay, and nude mice subcutaneous tumorigenesis assay detected the growth of transplanted tumors. Results: Fluorescence in situ hybridization results showed that the fluorescence intensity of hsa_circ_0001776 in lung squamous carcinoma tissues was lower than that in paracancerous tissues, and the fluorescence intensity of miR-1265 in lung squamous carcinoma tissues was higher than that in paracancerous tissues (both P＜0.05). The expression level of hsa_circ_0001776 in the plasma of lung squamous carcinoma patients was lower than that in the plasma of healthy people, and the expression level of miR-1265 was higher than that in the plasma of healthy people (both P＜0.05). The expression levels of hsa_circ_0001776 in lung squamous carcinoma cells NCI-H1703, NCI-H226 and SK-MES-1 were lower than that in bronchial epithelial cells BEAS-2B (all P＜0.05), and the relative expression levels of miR-1265 in NCI-H1703 and NCI-H226 were higher than that in human bronchial epithelial cells BEAS -2B (all P＜0.05). The expression of hsa_circ_0001776 was correlated with age, lymph node metastasis, clinical stage, and tumor stage in patients with lung squamous carcinoma (all P＜0.05). Fluorescence in situ hybridization results showed that hsa_circ_0001776 was mainly expressed in the cytoplasm. The results of dual-luciferase reporter assay showed complementary binding of miR-1265 to hsa_circ_0001776. The absorbance values of the hsa_circ_0001776 overexpression group in NCI-H1703 and NCI-H226 cells were lower than that of the circ-NC group (P＜0.05). The number of cell clones in the hsa_circ_0001776 overexpressed group was (52±3) and (53±4), the number of migrating cells was (476±17) and (113±7), the number of invading cells was (100±2) and (184±2), and the cell migration rate was (25.00±4.36)% and (36.02±5.55)%, which were lower than those of the circ-NC group [(104±4) and (106±2), (783±29) and (517±16), (657±45) and (473±9), (48.95±8.69)% and (48.70±1.57)%, all P＜0.05]. The apoptosis rates in the overexpression hsa_circ_0001776 group were (24.77±2.303)% and (19.67±1.16)%, respectively, both higher than those in the circ-NC group [(11.83±1.15)% and (9.50±0.66)%, respectively, both P＜0.05]. MiR-1265 mimic group had a higher apoptotic rate in the NCI-H1703 and NCI-H226 than those of the miR-NC groups (P＜0.05). miR-1265 mimic group had (56±13) and (51±8) cell clones, (556±13) and (405±6) migrating cells, (486±6) and (359±7) invading cells, cell migration rates of (68.56±5.51)%, (81.74±8.04)%, were higher than those of miR-NC group [(31±4) and (21±8), (154±19) and (186±5), (227±6) and (176±7), (25.83±4.26)% and (53.12±4.14) %, all P＜0.05]. The apoptotic rates in the miR-1265 mimic group were (11.83±2.55)% and (17.50±1.05)%, respectively, which were lower than those in the miR-NC group [(32.67±4.44)% and (39.90±2.88)%, respectively, both P<0.05]. The absorbance values of NCI-H1703 and NCI-H226 in the overexpression of hsa_circ_0001776+miR-1265 mimic group were higher than those of the overexpression of hsa_circ_0001776+miR-NC group (P<0.05). The overexpression of hsa_circ_0001776+miR-1265 mimic group had (128±15) and (133±8) cell clones, (623±10) and (310±7) migrating cells, (643±16) and (420±7) invading cells, (66.39±4.46)% cell migration rate and (68.60±3.53)%, were higher than those of the hsa_circ_0001776+miR-NC group [(86±7) and (80±16), (380±11) and (115±5), (152±7) and (94±4), respectively, (31.41±5.91)% and (30.94±0.67)%, all P＜0.05]. The apoptotic rates in the overexpression of hsa_circ_0001776+miR-1265 mimic group were (19.27±0.15)% and (11.53±0.75)%, respectively, both lower than those in the overexpression of hsa_circ_0001776+miR-NC group [(27.77±1.29)% and (18.43±0.71)%, both P＜0.05]. The results of the subcutaneous tumorigenesis assay in nude mice showed that the volume of tumors in the overexpression of hsa_circ_0001776 group was lower than that in the circ-NC group (P＜0.05). Conclusion: hsa_circ_0001776 is downregulated in lung squamous cell carcinoma, and hsa_circ_0001776 can inhibit the development of lung squamous cell carcinoma by targeting miR-1265.
目的： 探讨hsa_circ_0001776与miR-1265在肺鳞状细胞癌（鳞癌）中的作用及机制。 方法： 收集2020—2022年于唐山市人民医院治疗的肺鳞癌患者血浆和健康人血浆。肺鳞癌组织芯片和癌旁正常组织芯片于2022年购自上海芯超生物科技有限公司。采用实时定量聚合酶链式反应检测hsa_circ_0001776在肺鳞癌血浆、组织及细胞中的表达情况，荧光原位杂交验证hsa_circ_0001776在肺鳞癌细胞NCI-H1703中的定位。体外培养肺鳞癌细胞NCI-H1703、NCI-H226，分为circ-NC组、过表达hsa_circ_0001776组、miR-NC组、miR-1265 mimic组、过表达hsa_circ_0001776+miR-NC组和过表达hsa_circ_0001776+miR-1265 mimic组，采用细胞计数试剂盒8法、细胞克隆形成实验、Transwell实验和划痕实验以及流式细胞术分别检测过表达hsa_circ_0001776、过表达miR-1265以及过表达hsa_circ_0001776和miR-1265 mimic的挽救实验对肺鳞癌细胞NCI-H1703和NCI-H226的增殖、克隆、侵袭、迁移和凋亡的影响。通过circular RNA Interactome网站预测hsa_circ_0001776下游的miR-1265，双荧光素酶报告基因实验确定hsa_circ_0001776、miR-1265之间的相互作用，裸鼠皮下成瘤实验检测稳定过表达hsa_circ_0001776的NCI-H1703细胞对移植瘤生长的影响。 结果： 荧光原位杂交结果显示，肺鳞癌组织中hsa_circ_0001776的荧光强度低于癌旁组织，肺鳞癌组织中miR-1265荧光强度高于癌旁组织（均P＜0.05）。肺鳞癌患者血浆中hsa_circ_0001776的表达水平低于健康人血浆，miR-1265表达水平高于健康人血浆（均P＜0.05）。肺鳞癌细胞NCI-H1703、NCI-H226和SK-MES-1中hsa_circ_0001776的表达水平均低于支气管上皮细胞BEAS-2B（均P＜0.05），miR-1265在NCI-H1703、NCI-H226中的相对表达水平高于人支气管上皮细胞BEAS-2B（均P＜0.05）。hsa_circ_0001776低表达与肺鳞癌患者的年龄、淋巴结转移、临床分期以及肿瘤分期有关（均P＜0.05）。荧光原位杂交结果显示，hsa_circ_0001776主要在细胞质中表达。双荧光素酶报告实验结果表明，miR-1265与hsa_circ_0001776存在互补结合位点。过表达hsa_circ_0001776组NCI-H1703、NCI-H226细胞吸光度值均低于circ-NC组（均P＜0.05）。过表达hsa_circ_0001776组细胞克隆数为（52±3）个、（53±4）个，迁移细胞数为（476±17）个、（113±7）个，侵袭细胞数为（100±2）个、（184±2）个，细胞迁移率为（25.00±4.36）%、（36.02±5.55）%，均低于circ-NC组［分别为（104±4）个和（106±2）个，（783±29）个和（517±16）个，（657±45）个和（473±9）个，（48.95±8.69）%和（48.70±1.57）%，均P＜0.05］。过表达hsa_circ_0001776组细胞凋亡率分别为（24.77±2.30）%和（19.67±1.16）%，均高于circ-NC组［分别为（11.83±1.15）%和（9.50±0.66）%，均P＜0.05］。miR-1265 mimic组NCI-H1703、NCI-H226细胞吸光度值均高于miR-NC组（均P＜0.05）。miR-1265 mimic组细胞克隆数为（56±13）个和（51±8）个，迁移细胞数为（556±13）个、（405±6）个，侵袭细胞数为（486±6）个、（359±7）个，细胞迁移率为（68.56±5.51）%、（81.74±8.04）%，均高于miR-NC组［分别为（31±4）个和（21±8）个，（154±19）个和（186±5）个，（227±6）个和（176±7）个，（25.83±4.26）%和（53.12±4.14）%，均P＜0.05］。miR-1265 mimic组细胞凋亡率分别为（11.83±2.55）%、（17.50±1.05）%，均低于miR-NC组［分别为（32.67±4.44）%、（39.90±2.88）%，均P＜0.05］。过表达hsa_circ_0001776+miR-1265 mimic组中NCI-H1703、NCI-H226吸光度值均高于过表达hsa_circ_0001776+miR-NC组（均P＜0.05）。过表达hsa_circ_0001776+miR-1265 mimic组细胞克隆数为（128±15）个和（133±8）个，迁移细胞数为（623±10）个和（310±7）个，侵袭细胞数为（643±16）个和（420±7）个，细胞迁移率为（66.39±4.46）%和（68.60±3.53）%，均高于过表达hsa_circ_0001776+miR-NC组［分别为（86±7）个和（80±16）个，（380±11）个和（115±5）个，（152±7）个和（94±4）个，（31.41±5.91）%和（30.94±0.67）%，均P＜0.05］。过表达hsa_circ_0001776+miR-1265 mimic组细胞凋亡率分别为（19.27±0.15）%和（11.53±0.75）%，均低于过表达hsa_circ_0001776+miR-NC组［分别为（27.77±1.29）%和（18.43±0.71）%，均P＜0.05］。裸鼠皮下成瘤实验结果显示，过表达hsa_circ_0001776组肿瘤的体积低于circ-NC组（P＜0.05）。 结论： 肺鳞癌中hsa_circ_0001776呈低表达，hsa_circ_0001776通过靶向miR-1265可抑制肺鳞癌的发展。.