circ_ARF3 regulates the pathogenesis of osteosarcoma by sponging miR-1299 to maintain CDK6 expression.
Circ_ARF3 通过海绵 miR-1299 维持 CDK6 表达调控骨肉瘤发病机制
- 作者列表："Gao AM","Yuan C","Hu AX","Liu XS
:Increasing evidence suggests that circular RNAs are emerging biomarkers or targets for early cancer diagnosis and treatment. However, the studies of circular RNA in osteosarcoma (OS) are limited. In this study we found that circ_ARF3 were highly expressed in osteosarcoma cell lines and tumor tissues. Knocking down circ_ARF3 greatly ceased OS cell growth, impaired cell colony formation and halted cell cycle transition from G1 to S phase. Bioinformatic analysis suggested that miR-1299 is the target of circ_ARF3. Luciferase assay and biotin labeled circ_ARF3 pull down assay confirmed their interactions in OS cells. The regulatory roles of circ_ARF3 on miR-1299 was also investigated. Further bioinformatic analysis showed that CDK6 is the target of miR-1299. Overexpressing miR-1299 in OS cells decreased CDK6 expression and arrested OS cell growth and cell cycle progression. However, the roles of miR-1299 in regulating CDK6 expression, OS cell growth and cell cycle progression were greatly impaired in the presence of circ_ARF3. In general, our study demonstrated that in the OS, highly expressed circ_ARF3 acts as a sponge of miR-1299 to inhibit miR-1299 mediated CDK6 downregulation which further promoted OS pathogenesis. circ_ARF3 could be a potential target for OS treatment in the future.
: 越来越多的证据表明，环状 rna 是早期癌症诊断和治疗的新兴生物标志物或靶点。然而，环状 RNA 在骨肉瘤 (OS) 中的研究有限。在本研究中，我们发现 circ_ARF3 在骨肉瘤细胞系和肿瘤组织中高表达。敲低 circ_ARF3 大大停止了 OS 细胞生长，细胞集落形成受损，细胞周期从 G1 期向 S 期转变。生物信息学分析表明，miR-1299 是 circ_ARF3 的靶点。荧光素酶测定和生物素标记的 circ_ARF3 pull down 测定证实了它们在 OS 细胞中的相互作用。研究了 circ_ARF3 对 miR-1299 的调控作用。进一步的生物信息学分析表明，CDK6 是 miR-1299 的靶点。在 OS 细胞中过表达 miR-1299 可降低 CDK6 的表达，阻滞 OS 细胞生长和细胞周期进程。然而，在存在 circ_ARF3 的情况下，miR-1299 在调节 CDK6 表达、 OS 细胞生长和细胞周期进程中的作用大大受损。总的来说，我们的研究表明，在 OS 中，高表达的 circ_ARF3 作为 miR-1299 的海绵，抑制 miR-1299 介导的 CDK6 下调，进一步促进 OS 发病。circ_ARF3 可能是未来 OS 治疗的潜在靶点。
METHODS:BACKGROUND:Osteosarcoma is the most common primary bone malignancy in children and adolescents. In order to find factors related to its recurrence, and thus improve recovery prospects, a powerful clinical signature is needed. Long noncoding RNAs (lncRNAs) are essential in osteosarcoma processes and development, and here we report significant lncRNAs to aid in earlier diagnosis of osteosarcoma. METHODS:A univariate Cox proportional hazards regression analysis and a multivariate Cox regression analysis were used to analyze osteosarcoma patients' lncRNA expression data from the Therapeutically Applicable Research To Generate Effective Treatments (TARGET), a public database. RESULTS:A lncRNA signature consisting of three lncRNAs (RP1-261G23.7, RP11-69E11.4 and SATB2-AS1) was selected. The signature was used to sort patients into high-risk and low-risk groups with meaningful recurrence rates (median recurrence time 16.80 vs. >128.22 months, log-rank test, P143.80 months, log-rank test, P=0.006). A multivariate Cox regression analysis showed that the significant lncRNA was an independent prognostic factor for osteosarcoma patients. Functional analysis suggests that these lncRNAs were related to the PI3K-Akt signaling pathway, the Wnt signaling pathway, and the G-protein coupled receptor signaling pathway, all of which have various, important roles in osteosarcoma development. The significant 3-lncRNA set could be a novel prediction biomarker that could aid in treatment and also predict the likelihood of recurrence of osteosarcoma in patients.
METHODS::Long non-coding RNAs (lncRNAs) regulates the initiation and progression of osteosarcoma (OS), specifically lncRNA RP11-361F15.2 has been shown to play prominent roles in tumorigenesis. Previously, M2-Like polarization of tumor-associated macrophages (TAMs) has been identified to play a key role in cancer migration/invasion. Hence, it is essential to understand the role of RP11-361F15.2 in tumorigenesis and its association with M2-Like polarization of TAMs. The results indicate that RP11-361F15.2 is significantly increased in OS tissues, and its expression is positively correlated with cytoplasmic polyadenylation element binding protein 4 (CPEB4) expression and negatively associated with miR-30c-5p expression. Further, overexpression of RP11-361F15.2 increased OS cell migration/invasion and M2-Like polarization of TAMs in vitro, as well as promoted xenograft tumor growth in vivo. Mechanistically, luciferase reporter assays indicated that RP11-361F15.2 upregulated CPEB4 expression by competitively binding to miR-30c-5p. Further, we have identified that RP11-361F15.2 promotes CPEB4-mediated tumorigenesis and M2-Like polarization of TAMs through miR-30c-5p in OS. We also identified that RP11-361F15.2 acts as competitive endogenous RNA (ceRNA) against miR-30c-5p thereby binding and activating CPEB4. This RP11-361F15.2/miR-30c-5p/CPEB4 loop could be used as a potential therapeutic strategy for the treatment of OS.
METHODS:PURPOSE:The objective of this study was to investigate potential correlations between pathologic fractures (PFs) and prognosis of patients with primary central high-grade osteosarcoma of the extremities. METHODS:We retrospectively analyzed 2,847 patients registered in the Consecutive Cooperative Osteosarcoma Study Group database with primary central high-grade osteosarcoma of the extremities, treated between 1980 and 2010. Intended treatment included pre- and postoperative chemotherapy and surgery. Univariable and multivariable survival analyses were performed for all patients and then differentiated for adult and pediatric (≤ 18 years at time of diagnosis) patients. RESULTS:A total of 2,193 patients were ≤ 18 years of age; 11.3% of all patients had PFs. In the overall cohort, presence of PF correlated significantly with tumor site, histologic subtype, relative tumor size, and primary metastases, but not with body mass index or local surgical remission. In univariable analysis, 5-year overall survival (OAS) of patients with and without PF was 63% versus 71%, respectively (P = .007), and 5-year event-free survival (EFS) was 51% versus 58% (P = .026). In pediatric patients, OAS and EFS did not differ significantly between patients with and without PF. In adults, 5-year OAS in patients with and without PF was 46% versus 69% (P < .001), and 5-year EFS was 36% versus 56% (P < .001). In multivariable analysis, PF was not a statistically significant factor for OAS or EFS in the total cohort or in pediatric patients. In adult patients, PF remained an independent prognostic factor for OAS (P = .013; hazard ratio [HR], 1.893). It was not a significant prognostic factor for EFS (P = .263; HR, 1.312). CONCLUSION:In this largest study to date with extremity osteosarcomas, we observed the occurrence of PF to correlate with inferior OAS expectancies in adult but not in pediatric patients.