Mir ‑ 181b ‑ p53 负反馈轴调控骨肉瘤细胞增殖和侵袭。
- 作者列表："Wan J","Long F","Zhang C","Liu Y
:Osteosarcoma (OS) is one of the most common malignant tumors in young adults and has a high distant metastasis rate. The p53 protein, a potent prognostic biomarker for patients with OS, is altered in ~50% of OS cases. p53 was reported to exert its effects through regulating the transcription of microRNAs (miRNAs/miRs) and other genes. In the present study, the expression of miR‑181b, a critical OS oncomiR, was shown to be significantly upregulated whereas p53 expression was downregulated within OS tissues and cells; in tissue samples, miR‑181b and p53 were negatively correlated. p53 inhibited the transcription of miR‑181b via targeting its promoter region, whereas miR‑181b bound the TP53 3'‑untranslated region (UTR) to inhibit p53 expression. miR‑181b silencing considerably increased p53, p21, and epithelial‑Cadherin protein levels but decreased Cyclin D1 protein levels in OS cells. In addition, miR‑181b inhibition reduced OS cell proliferation and invasion. In contrast, p53 knockdown had the opposite effects on these proteins and OS cell proliferation and invasion. Above all, p53 knockdown significantly attenuated the effects of miR‑181b inhibition. Moreover, OS cell xenograft assays further confirmed the roles of the miR‑181b/p53 axis in OS growth. In conclusion, miR‑181b and p53 are negatively regulated by one another and therefore form a negative feedback axis that regulates the proliferation and invasion abilities of OS cells. Targeting miR‑181b to inhibit its abnormal upregulation might be a potent strategy for OS treatment.
: 骨肉瘤 (OS) 是青壮年最常见的恶性肿瘤之一，有较高的远处转移率。P53 蛋白是 OS 患者的有效预后生物标志物，在 ~ 50% 的 OS 病例中发生了改变。据报道，p53 通过调控 microRNAs (miRNAs/miRs) 和其他基因的转录发挥其作用。在本研究中，mir181b (一种关键的 OS oncomiR) 的表达显著上调，而 p53 在 OS 组织和细胞内表达下调; 在组织样本中,mir ‑ 181b 与 p53 呈负相关。p53 通过靶向其启动子区抑制 mi ‑ 181b 的转录,而 mi ‑ 181b 结合 TP53 3 '‑ 非翻译区 (UTR) 抑制 p53 表达。mir ‑ 181b 沉默显著增加了 OS 细胞中 p53 、 p21 和上皮钙粘蛋白的蛋白水平，但降低了细胞周期蛋白 D1 的蛋白水平。此外，mi ‑ 181b 抑制降低 OS 细胞增殖和侵袭。相反，p53 敲除对这些蛋白和 OS 细胞的增殖和侵袭有相反的作用。最重要的是，p53 敲除显著减弱了 mi ‑ 181b 抑制的作用。此外，OS 细胞异种移植试验进一步证实了 mir ‑ 181b/p53 轴在 OS 生长中的作用。总之，mi ‑ 181b 和 p53 相互负调控，因此形成负反馈轴，调节 OS 细胞的增殖和侵袭能力。靶向 mi ‑ 181b 抑制其异常上调可能是 OS 治疗的有效策略。
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.