MicroRNA-212 suppresses the proliferation and migration of osteosarcoma cells by targeting forkhead box protein A1

Identification and Validation of a Potent Multi-miRNA Signature for Prediction of Prognosis of Osteosarcoma Patients

Background

Osteosarcoma, the most common solid malignancy, has high incidence and mortality rates. We constructed a miRNA-based signature that can be used to assess the prognosis of osteosarcoma patients.

Material/Methods

The miRNA profile was derived from the Gene Expression Omnibus (GEO) website, with matched clinical records. The miRNA-based overall survival (OS)-predicting signature was established by LASSO Cox regression analysis. Receiver operating characteristic (ROC) curve and Kaplan-Meier (K-M) analyses were performed to examine the stability and discriminatory ability of the OS-predicting signatures. Pathway enrichment analyses were performed to uncover potential mechanisms.

Results

Three miRNAs (miR-153, miR-212, and miR-591) independently related to the OS were extracted to build a risk score formula. The ROC curve and K-M analyses revealed good discrimination ability of the OS signature for osteosarcoma patients in both the training cohort (P=0.00015, AUC=0.962) and the validation cohort (P=0.0065, AUC=0.793). As shown in multivariate analysis, the classifier showed favorable predictive accuracy similar to the recurrence status to be an independent risk factor for osteosarcoma. Furthermore, the nomogram showed a synergistic effect by combining the clinicopathological features with our classifier. Also, the enrichment analyses of the target genes may contribute to improved treatment of osteosarcoma.

Conclusions

The 3-miRNA-based classifier serves as an effective prognosis-predicting signature for osteosarcoma patients.

The functions and targets of miR-212 as a potential biomarker of cancer diagnosis and therapy

Cancer is a major health problem worldwide. An increasing number of researchers are studying the diagnosis, therapy and mechanisms underlying the development and progression of cancer. The study of noncoding RNA has attracted a lot of attention in recent years. It was found that frequent alterations of miRNA expression not only have various functions in cancer but also that miRNAs can act as clinical markers of diagnosis, stage and progression of cancer. MiR-212 is an important example of miRNAs involved in cancer. According to recent studies, miR-212 may serve as an oncogene or tumour suppressor by influencing different targets or pathways during the oncogenesis and the development and metastasis of cancer. Its deregulation may serve as a marker for the diagnosis or prognosis of cancer. In addition, it was recently reported that miR-212 was related to the sensitivity or resistance of cancer cells to chemotherapy or radiotherapy. Here, we summarize the current understanding of miR-212 functions in cancer by describing the relevant signalling pathways and targets. The role of miR-212 as a biomarker and its therapeutic potential in cancer is also described. The aim of this review was to identify new methods for the diagnosis and treatment of human cancers.

Signification of forkhead box A1 (FOXA1) expression in thyroid cancers

BACKGROUND

Forkhead box A1 (FOXA1) plays an important role in several tumors. This study investigated the potential role of FOXA1 expression in thyroid tumors. We conducted a retrospective study of 110 thyroid lesions and tumors diagnosed during 1995-2018. The expression of FOXA1 was analyzed by immunohistochemistry on archival material.

RESULTS

No FOXA1 immunostaining was observed in all cases of Graves' disease, Hashimoto's disease, multi-nodular goiter, and adenoma. FOXA1 expression was absent as well in all papillary and follicular carcinomas, Hurthle cell carcinoma, and undifferentiated sarcoma. Only three anaplastic carcinomas exhibited focally FOXA1 staining. However, FOXA1 was expressed in all medullary carcinomas. No significant correlation was found with all clinicopathological features (p > 0.05 for all). The pattern of FOXA1 staining was similar to that of calcitonin and chromogranin A (p = 0.04 and p = 0.003, respectively).

CONCLUSIONS

FOXA1 is expressed mostly in all medullary thyroid carcinomas. Hence, FOXA1 could serve as an additional marker for refining the diagnosis of medullary thyroid carcinoma.

Long noncoding RNA NR2F1-AS1 enhances the malignant properties of osteosarcoma by increasing forkhead box A1 expression via sponging of microRNA-483-3p

The long noncoding RNA NR2F1-AS1 has been found to promote the development of hepatocellular carcinoma and endometrial cancer. In this study, we measured NR2F1-AS1 expression in osteosarcoma (OS), determined the involvement of NR2F1-AS1 in the malignant properties of OS, and investigated the underlying mechanisms. NR2F1-AS1 was found to be upregulated in OS tumors and cell lines. The increased NR2F1-AS1 level was closely associated with advanced clinical stage and distant metastasis in patients with OS. Patients with OS in an NR2F1-AS1 high-expression group demonstrated significantly shorter overall survival than did patients in an NR2F1-AS1 low-expression group. NR2F1-AS1 knockdown inhibited OS cell proliferation, migration, and invasion and promoted cell cycle arrest and apoptosis in vitro and slowed tumor growth in vivo. NR2F1-AS1 was found to function as a competing endogenous RNA by directly sponging microRNA-483-3p (miR-483-3p) and upregulating its target oncogene forkhead box A1 (FOXA1). Finally, rescue experiments revealed that knockdown of miR-483-3p and recovery of FOXA1 expression both attenuated the influence of the NR2F1-AS1 knockdown on OS cells. Thus, NR2F1-AS1 plays an oncogenic role in OS through sponging miR-483-3p and thereby upregulating FOXA1, suggesting an additional target for osteosarcoma therapeutics.

miRNA signatures in childhood sarcomas and their clinical implications

Progresses in multimodal treatments have significantly improved the outcomes for childhood cancer. Nonetheless, for about one-third of patients with Ewing sarcoma, rhabdomyosarcoma, or osteosarcoma steady remission has remained intangible. Thus, new biomarkers to improve early diagnosis and the development of precision-targeted medicine remain imperative. Over the last decade, remarkable progress has been made in the basic understanding of miRNAs function and in interpreting the contribution of their dysregulation to cancer development and progression. On this basis, this review focuses on what has been learned about the pivotal roles of miRNAs in the regulation of key genes implicated in childhood sarcomas.

Silencing of long noncoding RNA SBF2-AS1 inhibits proliferation, migration and invasion and contributes to apoptosis in osteosarcoma cells by upregulating microRNA-30a to suppress FOXA1 expression

Objectives: Long noncoding RNA (lncRNA) SBF2-AS1 was found to be related to some tumors. Nevertheless, the role of SBF2-AS1 in osteosarcoma (OS) is still needed to be elaborated. This study is conducted to examine the expression of lncRNA SBF2-AS1 in OS with the involvement of microRNA-30a (miR-30a) and FOXA1. Methods: OS tissues and its corresponding adjacent normal tissues were obtained for the detection of SBF2-AS1 expression and its relations with clinical phenotypes. OS cells with most significant expression of SBF2-AS1 were selected for subsequent experiments. Moreover, a series of experiments were performed to detect proliferation, invasion, migration, colony formation, cell cycle distribution and apoptosis of OS cells. Furthermore, the binding site between SBF2-AS1 and miR-30a as well as between miR-30a and FOXA1 was verified. Results: SBF2-AS1 was overexpressed in tissues and cells of OS. Additionally, silencing of SBF2-AS1 and miR-30a overexpression inhibited the proliferation, migration and invasion of OS cells and promoted their apoptosis. Moreover, lncRNA SBF2-AS1 regulated miR-30a by serving as a ceRNA, thus promoting FOXA1 expression. Furthermore, interfered SBF2-AS1 or upregulated miR-30a restrained the growth of OS. Conclusion: Our study confirms that silencing of SBF2-AS1 represses proliferation, migration and invasion of OS cells and promotes their apoptosis by binding to miR-30a and inhibiting FOXA1 expression.

SP1-mediated upregulation of lncRNA ILF3-AS1 functions a ceRNA for miR-212 to contribute to osteosarcoma progression via modulation of SOX5

Long noncoding RNA ILF3-AS1 (ILF3-AS1) has been reported to be abnormally expressed in several tumors. However, its expression pattern and function in osteosarcoma have not been investigated. In this study, we showed that ILF3-AS1 expression was significantly up-regulated in both osteosarcoma tissues and cell lines. We first reported that ILF3-AS1 upregulation was induced by nuclear transcription factor SP1. Clinical assays revealed that higher expression of ILF3-AS1 was associated with advanced clinical stage, distant metastasis and shorter overall survival. in multivariate analysis, ILF3-AS1 expression level was found to be an independent prognostic factor for osteosarcoma patients. Functional investigations showed that knockdown of ILF3-AS1 suppressed the proliferation, migration and invasion of osteosarcoma cells, and promoted apoptosis. Bioinformatic software predicted that miR-212 both targeted the 3'-UTR of ILF3-AS1 and SOX5, which was confirmed using luciferase reporter assay, RT-PCR and Western blot. Taken together, ILF3-AS1 displayed its tumor-promotive roles in the progression of osteosarcoma through miR-212/SOX5 axis. Our findings help to elucidate the tumorigenesis of osteosarcoma, and future study will provide a novel therapeutic target for osteosarcoma.

microRNA-200a functions as a tumor suppressor by targeting FOXA1 in glioma

microRNAs (miRs) serve primary roles in certain human malignancies; however, the detailed regulatory mechanism of miR-200a in glioma progression is yet to be fully elucidated. The current study aimed to assess the expression of miR-200a in glioma as well as the regulatory mechanism of miR-200a in glioma cell proliferation, survival and invasion. RT-qPCR and western blotting were performed to examine mRNA and protein expression. An MTT assay, an EdU incorporation cell proliferation assay and a transwell assay were utilized to assess cell survival, proliferation and invasion. The results indicated that the miR-200a levels were significantly reduced in glioma tissues compared with normal brain tissues. Levels were also downregulated in glioma cell lines when compared with those in normal human astrocyte cells. Furthermore, low miR-200a expression was associated with advanced progression of glioma. The overexpression of miR-200a inhibited glioma cell proliferation, survival and invasion. Results also identified that FOXA1 was a target gene of miR-200a in glioma cells and that the increased expression of FOXA1 was negatively correlated to the decreased expression of miR-200a in glioma tissues. Furthermore, FOXA1 expression was negatively mediated by miR-200a in glioma cells and the overexpression of FOXA1 eliminated the inhibitory effects of miR-200a on the survival, proliferation and invasion of glioma cells. In conclusion, the current study demonstrated that miR-200a functions acts as a tumor suppressor in glioma by directly targeting FOXA1 and may thus be a potential candidate for the treatment of glioma.

Long non-coding RNA TUG1 promotes osteosarcoma cell proliferation and invasion through inhibition of microRNA-212-3p expression

Taurine upregulated gene 1 (TUG1), a long non-coding RNA (lncRNA), has recently been suggested to be associated with the development of osteosarcoma (OS), but the underlying molecular mechanism still remains largely unclear. In the present study, it was revealed that TUG1 was significantly upregulated whereas miR-212-3p was significantly downregulated in OS tissues and cell lines, when compared with adjacent non-tumor tissues and normal osteoblasts cell lines, respectively. An inverse association between the TUG1 and miR-212-3p expression was also observed in OS tissues. Furthermore, TUG1 directly interacted with miR-212-3p and negatively regulated the expression of miR-212-3p in OS cells. In vitro experiments further indicated that inhibition of TUG1 suppressed the proliferation and invasion of OS cells. Furthermore, knockdown of miR-212-3p eliminated the suppressive effects of TUG1 inhibition on the proliferation and invasion of OS cells. Taken together, these findings demonstrate that TUG1 promotes OS cell proliferation and invasion by inhibition of miR-212-3p expression, thus suggesting that TUG1 may become a potential therapeutic target for OS.

MicroRNA-935 Inhibits Proliferation and Invasion of Osteosarcoma Cells by Directly Targeting High Mobility Group Box 1

Numerous studies have suggested that microRNAs (miRNAs) are dysregulated in osteosarcoma (OS), implicating miRNAs in OS initiation and progression. Therefore, knowledge of aberrantly expressed miRNAs in OS may provide novel mechanistic insights into the tumorigenesis and tumor development of OS and facilitate therapeutic methods for patients with this aggressive bone neoplasm. In this study, data obtained from reverse transcription quantitative polymerase chain reaction (RT-qPCR) revealed that miR-935 was significantly decreased in OS tissues and cell lines. Restoration expression of miR-935 obviously restricted proliferation and invasion of OS cells. In addition, high-mobility group box 1 (HMGB1) was predicted to be a putative target of miR-935. Subsequent dual-luciferase reporter assay, RT-qPCR, and Western blot analysis confirmed that miR-935 could directly target the 3′-untranslated region of HMGB1 and negatively regulated HMGB1 expression in OS cells. Furthermore, a significant negative association was found between miR-935 and HMGB1 mRNA expression in OS tissues. Rescue experiments showed that recovery of HMGB1 expression partially rescued miR-935-induced suppression of cell proliferation and invasion in OS. These results provide the first evidence for the suppressive roles of miR-935 in OS by directly targeting HMGB1, suggesting that miR-935 may be a potential candidate for the treatment of patients with this disease.