Hsa_circ_0000670 promoted the progression of gastric cancer through the miR-515-5p/SIX1 molecular axis / 中华肿瘤杂志

Objective: To explore whether hsa_circ_0000670 promotes the progression of gastric cancer by regulating the miR-515-5p/SIX1 molecular axis. Methods: The gastric cancer and adjacent normal tissues of 35 gastric cancer patients admitted to Rugao Hospital Affiliated to Nantong University from 2014 to 2015 were collected. The expression levels of circ_0000670, miR-515-5p and Sine oculis homeobox 1 (SIX1) in gastric cancer tissues and cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. The correlations between circ_0000670 and miR-515-5p, miR-515-5p and SIX1, circ_0000670 and SIX1 were analyzed by the Pearson method. Patients were divided into low circ_0000670 expression group (17 cases) and high circ_0000670 expression group (18 cases) based on the median of circ_0000670 expression level, and Kaplan-Meier was used to analyze the 5-year survival of patients. Cell proliferation was assessed via clone formation assay. Cell cycle and apoptosis were detected by flow cytometry. Wound healing and Transwell assays were used to detect cell migration and invasion ability. The targeting relationship between miR-515-5p and circ_0000670 or SIX1 was confirmed by the dual luciferase reporter assay. Nude mice were injected into HGC-27 cells transfected with sh-NC or sh-circ_0000670, and the volume and weight of the transplanted tumor were measured, also, the levels of circ_0000670, miR-515-5p and SIX1 in the transplanted tumor tissue were detected. Results: The expression levels of circ_0000670 and SIX1 in gastric cancer tissues and cell lines were significantly increased (P<0.05), while the expression levels of miR-515-5p were significantly decreased (P<0.05). The survival rate of patients in the low circ_0000670 expression group (82.4%) was significantly higher than that in the high circ_0000670 expression group (28.7%, P=0.034). Circ_0000670 was negatively correlated with miR-515-5p (r=-0.846, P<0.001), and miR-515-5p was negatively correlated with SIX1 (r=-0.615, P<0.001), but circ_0000670 was positively correlated with SIX1 (r=0.814, P<0.001). Transfection of si-circ_0000670 or miR-515-5p mimic could significantly reduce the number of clone-forming cells, migration distance, migration and invasion cells (P<0.05), and increase the ratio of G(0)/G(1) phase cells, apoptosis rate and the protein level of E-cadherin (P<0.05), decreased the proportion of S-phase cells and the protein level of Vimentin (P<0.05). The dual luciferase report assay confirmed that circ_0000670 could target miR-515-5p, and miR-515-5p could bind to SIX1. Co-transfection of si-circ_0000670 and miR-515-5p inhibitor could significantly attenuate the effects of si-circ_0000670 on cell proliferation, migration, invasion, cell cycle and apoptosis (P<0.05). Co-transfection of miR-515-5p mimic and pcDNA-SIX1 could significantly reduce the effects of miR-515-5p mimic on cell proliferation, migration, invasion, cell cycle and apoptosis (P<0.05). Compared with the sh-NC group [volume=(596.20±125.46) mm(3) and weight=(538.00±114.39) g], the volume and weight of transplanted tumors in the sh-circ_0000670 group [volume=(299.20±47.58) mm 3 and weight=(289.80±48.73 g)] were significantly reduced (P<0.05), the expression levels of circ_0000670 and SIX1 were significantly reduced (P<0.05), and the expression level of miR-515-5p was significantly increased (P<0.05). Conclusion: Knockdown of circ_0000670 could inhibit cell proliferation, migration, invasion of gastric cancer cells, induce cell cycle arrest in G(0)/G(1) phase and promote cell apoptosis by regulating the miR-515-5p/SIX1 axis.

The effects of circFBXL5 on the malignant biological behaviors of bladder cancer T24 cells by targeting miR-515-5p and its molecular mechanisms / 中国肿瘤生物治疗杂志

@#[摘 要] 目的：探讨circFBXL5通过靶向miR-515-5p影响膀胱癌T24细胞的增殖、迁移、侵袭及其分子机制。方法： 收集2020年4月至2020年6月间在苏州市中西医结合医院手术切除的41例膀胱癌组织及其癌旁组织，采用qPCR法检测circFBXL5、miR-515-5p的表达；双荧光素酶报告实验验证circFBXL5与miR-515-5p之间的靶向关系，体外培养人膀胱癌T24细胞，实验分为si-NC组、si-circFBXL5组、anti-miR-NC+si-circFBXL5组和si-circFBXL5+anti-miR-515-5p组；MTT法、细胞克隆形成实验、FCM、Transwell实验和WB法分别检测转染后T24细胞的增殖、细胞克隆形成、迁移、侵袭和凋亡及BAX、Bcl-2蛋白水平。结果：膀胱癌组织中circFBXL5呈高表达，miR-515-5p呈低表达（均P<0.05）；circFBXL5靶向且负向调控miR-515-5p的表达；敲减circFBXL5后T24细胞的增殖抑制率、凋亡率和BAX蛋白水平均显著增高（均P<0.05），细胞克隆形成数和迁移、侵袭细胞数均显著减少（均P<0.05），Bcl-2蛋白水平显著降低（P<0.05）；同时敲减circFBXL5和miR-515-5p可部分逆转敲减circFBXL5对T24细胞增殖的抑制作用。结论：circFBXL5通过调控miR-515-5p表达影响膀胱癌T24细胞的增殖、迁移、侵袭，circFBXL5和miR-515-5p可能膀胱癌治疗的潜在分子靶标。

Long non-coding RNA DLGAP1-AS1 promotes the progression of gastric cancer via miR-515-5p/MARK4 axis

Long non-coding RNA (lncRNA) is an essential regulator of carcinogenesis and cancer progression. In the study, we explored the role of lncRNA DLGAP1-AS1 in gastric cancer (GC). qRT-PCR was carried out to detect DLGAP1-AS1 expression in GC tissues and cell lines. CCK-8 assay, EdU assay, and transwell experiments were employed to detect the malignant biological behaviors of GC cells with DLGAP1-AS1 knockdown or overexpression. Bioinformatics and dual-luciferase report assay were used to confirm the binding relationship between DLGAP1-AS1 and miR-515-5p. MARK4 expression was detected by western blot after DLGAP1-AS1/miR-515-5p was selectively regulated. DLGAP1-AS1 was up-regulated in GC tissues and cell lines, and its high expression was closely associated with larger tumor size, higher TNM stage, and lymph node metastasis. Furthermore, DLGAP1-AS1 overexpression enhanced cell proliferation, migration, and invasion, and miR-515-5p could reverse these effects. DLGAP1-AS1 participated in the regulation of the MARK4 signaling pathway by targeting miR-515-5p. DLGAP1-AS1 promoted GC progression through miR-515-5p/MARK4 signaling pathway.