Noncancerous Bone Tissues Research Articles

Evaluating the local expression pattern of IGF-1R in tumor tissues and the circulating levels of IGF-1, IGFBP-1, and IGFBP-3 in the blood of patients with different primary bone tumors.

The present study tried to provide insights into the expression pattern and diagnostic significance of the IGF-1 axis main mediators in three main primary bone tumor types with different degrees of severity. The real-time qRT-PCR (to analyze IGF-1R gene expression), the immunohistochemistry (to measure IGF-1R protein), and the ELISA assay (to assess the circulating level of IGF-1, IGFBP-1, and IGFBP-3) were applied to confirm this hypothesis. A total number of 180 bone tissues (90 tumors and 90 noncancerous adjacent tissues) and 120 blood samples drained from 90 patients with bone tumors and 30 healthy controls were enrolled in the study. The association of insulin-like growth factor (IGF)-1 axis expression pattern with the patient's clinical pathological characteristics and tumor aggressive features, the diagnostic and predictive values were assessed for all tumor groups. A significantly elevated level of IGF-1R gene and protein was detected in bone tumors compared to the noncancerous bone tissues that were prominent in osteosarcoma and Ewing sarcoma compared to the GCT group. The positive association of the IGF-1R gene and protein level with tumor grade, metastasis, and recurrence was detected in the osteosarcoma and Ewing sarcoma groups. The circulating level of IGF-1, IGFPB-1, and IGFBP-3 were increased in osteosarcoma and Ewing sarcoma and GCT groups that were correlated significantly to the tumor severity. The ability of the IGF-1 axis to discriminate between bone tumors also malignant and benign tumors was considerable. In summary, our data suggested that IGF-1R, IGF-1, IGFBP-1, and IGFBP-3 levels are associated with bone tumor malignancy, metastasis, and recurrence that might serve as biomarkers for osteosarcoma and Ewing sarcoma recurrence.

Evaluation of the expression pattern and diagnostic value of PPARγ in malignant and benign primary bone tumors

PurposeThe quantifiable description of PPARγ expression pattern beside mechanistic in-vitro evidence will provide insights into the involvement of this mediator in tumor pathogenesis. This study is focused on illuminating the PPARγ gene and protein expression pattern, its association with tumor deterioration and its diagnostic value in different types of primary bone tumors.MethodsThe expression pattern of PPARγ was investigated in the 180 bone tissues including 90 bone tumor tissues and 90 non-cancerous bone tissues. The local PPARγ expression level was assessed using real-time qRT-PCR and the PPARγ protein expression pattern was measured using immunohistochemistry. The correlation of PPARγ expression level with patients’ clinic-pathological features, also the value of the variables in predicting PPARγ expression level in tumors and the value of PPARγ to discriminate tumor subtypes were assessed.ResultsThe mean PPARγ mRNA expression was significantly higher in bone tumors compared to healthy bone tissues, also the malignant tumors including osteosarcoma and Ewing sarcoma had the elevated level of PPARγ mRNA compared to GCT tumors. Consistently, the protein expression of PPARγ in the tumor site was significantly higher in the bone tumors and malignant tumors compared to non-cancerous and benign tumors, respectively. The PPARγ protein could predict malignant tumor features including tumor grade, metastasis and recurrence significantly. Moreover, PPARγ could potentially discriminate the patients from the controls also malignant tumors from benign tumors with significant sensitivity and specificity.ConclusionsPPARγ might be involved in primary bone tumor pathogenesis and determining its molecular mechanism regarding bone cancer pathogenesis is of grave importance.

Elevated expression of microRNA-328-3p suppresses aggressive malignant behaviors via targeting matrix metalloprotease 16 in osteosarcoma.

BackgroundA previous study indicated that microRNA(miR)-328-3p upregulation might be critical for resveratrol-mediated suppression of metastatic ability in human osteosarcoma, implying its potential role in this malignancy. However, the clinical significance and the biological functions of miR-328-3p in osteosarcoma remain unclear.MethodsmiR-328-3p expression in 88 pairs of osteosarcoma and matched non-cancerous bone tissues were detected by quantitative real-time PCR. Then, the associations of miR-328-3p expression with various clinicopathological features of osteosarcoma patients were statistically analyzed. Cell Counting Kit-8 and scratch-wound healing were performed to evaluate roles of miR-328-3p in human osteosarcoma cells. After that, luciferase reporter assay, western blot analysis and rescue assay were applied to determine the underlying molecular mechanisms of miR-328-3p in osteosarcoma cells.ResultsmiR-328-3p expression in osteosarcoma tissues was significantly lower than those in non-cancerous bone tissues (P<0.001). miR-328-3p downregulation was significantly associated with advanced surgical stage, positive metastasis and recurrence (all P<0.05). Functionally, enforced expression of miR-328-3p efficiently suppressed cell proliferation and migration in vitro. Moreover, matrix metalloprotease 16 (MMP16) was identified as a direct target of miR-328-3p in osteosarcoma cells. Notably, MMP16 overexpression partially reversed the miR-328-3p-inhibited cell proliferation and migration of osteosarcoma cells.ConclusionsOur data indicated that the aberrant expression of miR-328-3p may play a crucial role in malignant progression of human osteosarcoma. More importantly, miR-328-3p may function as a tumor suppressor inhibiting osteosarcoma cell proliferation and migration partially mediated by regulating of MMP16.

CLDN10 promotes a malignant phenotype of osteosarcoma cells via JAK1/Stat1 signaling.

In our previous study, the expression profile of tight junction (TJ) protein claudins (CLDNs) in human osteosarcoma (OS) cells was examined, and the data found the CLDN10 was high expressed in OS cells versus fetal osteoblast cells. Hence, we aim to determine the impacts and the molecular mechanisms of CLDN10 in the metastatic phenotype of OS. The exact expression profiles of CLDN10 and phosphorylated Janus kinase 1 (JAK1) in noncancerous bone tissues and OS tissues were detected via a western blotting and immunohistochemistry method. The OS cells with CLDN10 or JAK1 silencing was established via an RNA interference (RNAi) method, and an osteoblast cell line stably expressing CLDN10 was established via cell transfection. Then, the transfection effects and activation states of JAK1/ signal transducer and activator of transcription1 (Stat1) pathway in OS and osteoblast cells were detected via a western blotting assay. Moreover, the metastatic ability of osteoblast cells and OS cells in vitro were evaluated by means of a cell counting kit-8 (CCK8) assay, colony formation assay in soft agar, transwell assay and wound-healing experiment. The present data revealed that CLDN10 and phospho-JAK1 were up-regulated in OS tissues compared with noncancerous bone tissues. Genetic loss of CLDN10 or JAK1 inhibited the activation of the Stat1 and the malignant phenotype in OS cells. To sum up, our study suggested the CLDN10 enhanced the metastatic phenotype of OS cells via the activation of the JAK1/Stat1 signaling pathway.

High levels of long non-coding RNA DICER1-AS1 are associated with poor clinical prognosis in patients with osteosarcoma.

Long noncoding RNA DICER1-AS1 (DICER1-AS1) has been reported to be upregulated in osteosarcoma cells and to serve as a tumor promoter. However, the clinical significance of DICER1-AS1 in osteosarcoma remains unclear. The aim of this study was to investigate the association of DICER1-AS1 expression with prognosis of osteosarcoma. The expression of DICER1-AS1 was measured in 214 osteosarcoma samples and normal bone samples by using Real-time PCR. The correlations between DICER1-AS1 expression and clinical features were statistically analyzed. Overall survival (OS) and disease-free survival (DFS) were examined using Kaplan-Meier curves. Multivariate analyses were performed to analyze the prognostic significance of DICER1-AS1 expression. It was found that the expression levels of DICER1-AS1 in osteosarcoma tissues were significantly higher than those in corresponding noncancerous bone tissues (p < 0.01). Higher DICER1-AS1 had significant association with clinical stage (p = 0.005) and distant metastasis (p = 0.000). Kaplan-Meier survival analysis showed that patients with high DICER1-AS1 expression had a shorter OS and DFS compared with the low DICER1-AS1 expression group (p = 0.007 and p < 0.0001). In a multivariate Cox model, our results showed that DICER1-AS1 expression was an independent poor prognostic factor for both 5-year OS (HR = 3.236, 95% CI: 1.148-5.347; p = 0.004) and 5-year DFS (HR = 3.935, 95% CI: 1.556-6.349; p = 0.001). DICER1-AS1 is up-regulated in osteosarcoma and may serve as a potential prognostic biomarker for osteosarcoma.

Expression of circ_001569 is upregulated in osteosarcoma and promotes cell proliferation and cisplatin resistance by activating the Wnt/β-catenin signaling pathway.

Circular RNAs (circRNAs), a type of non-coding RNAs derived from back-splicing, have been reported to function as gene expression regulators involved in tumor development of multiple human tumors. However, the clinical significance and underlying molecular mechanisms of circ_001569 in osteosarcoma still be unknown. In the study, we found that circ_001569 expression was significantly overexpressed in osteosarcoma tissues compared with adjacent noncancerous bone tissues. Higher circ_001569 expression significantly correlated with distant metastasis and advanced tumor stage of osteosarcoma patients. Gain-function and loss-function assays showed that circ_001569 knockdown significantly inhibited osteosarcoma cell proliferation and cell colon formation capacities. Moreover, upregulation of circ_001569 significantly promoted osteosarcoma cell resistance to cisplatin by activating Wnt/β-catenin signaling pathway. Thus, these results indicated that circ_001569 represented a novel potentially therapeutic target of osteosarcoma.

Reduced expression of miR-564 is associated with worse prognosis in patients with osteosarcoma.

MiR-564 has been reported to be involved in the development of several types of cancers. However, its clinical significance in osteosarcoma (OS) has not been investigated. We aimed to explore the prognostic value of miR-564 in OS patients. Quantitative RT-PCR assay was used to detect the expression levels of miR-564 in OS tissues and matched normal bone tissues. The correlation between miR-564 expression and clinicopathological features was analyzed by Pearson's χ2-test. The disease-free survival and overall survival rates of OS patients were calculated by the Kaplan-Meier method. Cox regression analysis was used to assess factors related to survival. We observed that the level of miR-564 was significantly reduced in OS tissues compared with that in the paired noncancerous bone tissues (p < 0.01). In addition, low miR-564 expression was found to be closely correlated with advanced clinical stage (p = 0.000) and distant metastasis (p = 0.003). Furthermore, survival analyses showed that patients with low expression of miR-564 had a shorter overall survival (p = 0.001) and disease-free survival (p = 0.001) than those with high expression of miR-564. Finally, we showed that miR-564 was an independent poor prognostic factor for both 5-year overall survival (p = 0.001) and 5-year disease-free survival (p = 0.001) through multivariate analysis. Overall, our data for the first time suggest that downregulated miR-564 may be used as a novel prognosis predictor of OS.

Role of taurine upregulated gene 1 as a predictor of poor outcome in osteosarcoma.

Previous studies have found that long noncoding RNA taurine upregulated gene 1 (TUG1) can regulate osteosarcoma cells apoptosis and proliferation; the aim of this study was to investigate the clinical significance of TUG1 in osteosarcoma. The expression of TUG1 was detected by real-time and quantitative polymerase chain reaction assay in 94 pairs of tumor tissues and corresponding noncancerous bone tissues of osteosarcoma patients. Its correlations with clinicopathologic features were analyzed, and the significance of TUG1 as a prognostic factor was determined. This study shows that the expression of TUG1 in osteosarcoma tissues was significantly higher than that in adjacent normal bone tissues. Upregulation of TUG1 was significantly correlated with the larger tumor size and advanced tumor-node-metastases stage of osteosarcoma patients. Kaplan-Meier curve showed a decreased overall survival time of osteosarcoma patients with high TUG1 expression. Moreover, univariate and multivariate analyses suggested that low-expression level of TUG1 was an independent poor prognostic indicator for osteosarcoma patients. In conclusion, our data support TUG1 as a potential prognostic predictor and gene therapy target with its high expression in tumor tissues and its association with carcinogenesis and progression in osteosarcoma.

Histone Demethylase JARID1B Is Overexpressed in Osteosarcoma and Upregulates Cyclin D1 Expression via Demethylation of H3K27me3.

JARID1B has been proven to be upregulated in many human malignancies and is correlated with tumor progression. However, its expression and clinical significance in osteosarcoma are still unclear. Thus, the aim of this study was to explore the effects of JARID1B in osteosarcoma tumorigenesis and development. In this study, we found that the expression levels of JARID1B in osteosarcoma tissues were significantly higher than those in corresponding noncancerous bone tissues. In addition, JARID1B upregulation occurred more frequently in osteosarcoma specimens from patients with a poor prognosis. After JARID1B transfection in osteosarcoma cells, cell proliferation was significantly promoted in vitro and in vivo. On the contrary, knockdown of JARID1B inhibited cell proliferation in vitro and tumor growth in vivo. JARID1B can also decrease the G0/G1 phase cell numbers and increase the S and G2/M phase cell numbers. We further demonstrated that JARID1B regulates cyclin D1 expression through H3K27me3. These findings indicate that JARID1B may act not only as a novel diagnostic and prognostic marker but also as a potential target for molecular therapy in osteosarcoma.

Prognostic value of long non-coding RNA HOST2 expression and its tumor-promotive function in human osteosarcoma.

Aberrant expression of long noncoding RNA (lncRNA) is associated with carcinogenesis of various tumors. The aim of current study was to explore the clinical significance and biological function of long non-coding RNA HOST2 (lnc-HOST2) in patients with osteosarcoma. The expression of lnc-HOST2 was detected by quantitative Real-time PCR (qRT-PCR) in 163 osteosarcoma specimens and matched the normal tissues. The significance of lnc-HOST2 as a prognostic factor as well as its relationship with survival was determined. The effects of lnc-HOST2 expression on the biological behavior of osteosarcoma cells were investigated by MTT and flow cytometry. qRT-PCR and Western blot were used to evaluate the mRNA and protein expression of apoptosis-related factors. The expression levels of lnc-HOST2 in osteosarcoma tissues were significantly higher than those in corresponding noncancerous bone tissues (p < 0.01). Statistical assay indicated that the expression level of lnc-HOST2 was positively correlated with tumor stage (p = 0.003) and distant metastasis (p = 0.000). Furthermore, Kaplan-Meier analysis suggested that patients with high lnc-HOST2 showed poorer overall survival than those with low lnc-HOST2 (p = 0.000). The univariate and multivariate analysis further revealed that lnc-HOST2 expression was an independent prognostic factor for overall survival. Then, functionally, down-regulation of lnc-HOST2 suppressed proliferation and induced cell apoptosis in osteosarcoma cells. Notably, we confirmed that up-regulation of lnc-HOST2 led to Bcl-2 downregulation and Bax upregulation in osteosarcoma cells. We provided the first evidence that lnc-HOST2 may serve as a novel prognostic marker in osteosarcoma. Further, targeting lnc-HOST2 may represent an attractive target therapy for osteosarcoma.

MicroRNA-335 and its target Rock1 synergistically influence tumor progression and prognosis in osteosarcoma.

MicroRNA (miR)-335 and Rho-associated serine-threonine protein kinase 1 (Rock1) is ectopically expressed in multiple malignant tumors including osteosarcoma. The present study aimed to clarify whether the combined ectopically expressed miR-335 and Rock1 was correlated with clinicopathological features and prognosis in patients with osteosarcoma. The expression of miR-335 and Rock1 in 91 osteosarcoma tissue samples and 47 noncancerous bone tissues were determined respectively by in situ hybridization and immunohistochemistry. The association between miR-335 and Rock1 expression with the clinicopathological features of osteosarcoma was calculated using the Pearson's χ2 test. Spearman's correlation analysis was used to study the association between the miR-335 and Rock1 expression. Survival curves were drawn using the Kaplan-Meier method. Univariate and multivariate analysis was performed using the Cox's proportional hazard regression model to allow the prognostic values to be assessed. Expression levels of miR-335 were significantly reduced in osteosarcoma tissues (P<0.001), compared with that in noncancerous bone tissues, while Rock1 expression was significantly increased in osteosarcoma tissues (P<0.001). A strong correlation between miR-335 and Rock1 expression was also shown (P<0.001). Decreased miR-335 expression was identified to be positively associated with higher clinical stage (P=0.004) and distant metastasis (P=0.016), while elevated expression levels of Rock1 was positively associated with a larger tumor size (P=0.013), higher clinical stage (P=0.027) and distant metastasis (P=0.022). The combined high expression of Rock1 and low expression of miR-335 was clearly associated with distant metastasis (P=0.010) and a higher clinical stage (P=0.010). Patients with elevated Rock1 or decreased miR-335 expression exhibited a worse overall survival (OS) and disease-free survival (DFS) compared with patients with decreased Rock1 or increased miR-335 (P<0.001 for the two). In addition, patients with decreased miR-335 and increased Rock1 had the worst OS and DFS (P<0.001 for the two). In multivariate survival analysis, clinical stage (P=0.002 for DFS, P=0.015 for OS), distant metastasis (P=0.024 for DFS, P=0.002 for OS), low expression of miR-335 (P<0.001 for DFS, P=0.002 for OS) and combined depressed miR-335 and elevated Rock1 (P=0.021 for DFS, P=0.050 for OS) expression remained as the independent prognostic factors for DFS and OS. The present findings suggest that there may be an association between the combined downregulation of miR-335 and upregulation of Rock1 with tumor progression and adverse prognosis in patients with osteosarcoma.

Actin-like protein 6A is a novel prognostic indicator promoting invasion and metastasis in osteosarcoma

Osteosarcoma harbors highly metastatic properties, accounting for postoperative recurrence and metastasis. Actin-like protein 6A(ACTL6A) regulates cell proliferation, migration and differentiation. However, the biologic role of ACTL6A in osteosarcoma remains unknown. In this study, the results showed that, by analysis of frozen fresh primary tumor tissues, matched non-cancerous bone tissues(NCBTs) and biopsy lung metastatic nodule tissues from 30osteosarcoma patients after radical surgical resection, ACTL6A was overexpressed in osteosarcoma tissues compared with matched NCBTs, and its expression level was associated with osteosarcoma metastasis. Immunohistochemical analyses of osteosarcoma tissue samples from two independent cohorts of formaldehyde-fixed, paraffin-embedded osteosarcoma tissue samples from total of 186osteosarcoma patients showed that high ACTL6A expression correlated with malignant clinicopathological features such as larger tumor size, high Ennecking grade, high histologic grade, and advanced tumor node metastasis stage. High ACTL6A expression was associated with poor prognosis for patients with osteosarcoma, and an independent and significant risk factor for disease-free survival and overall survival after radical tumor resection. Both invitro and invivo assays showed that ACTL6A overexpression promoted osteosarcoma cell invasion and metastasis, whereas knockdown of ACTL6A expression reduced osteosarcoma cell malignant behavior such as invasion and metastasis. Furthermore, we proved that ACTL6A promoted osteosarcoma cells of metastasis through facilitating epithelial-mesenchymal transition(EMT). Inconclusion, data from the present study demonstrated that ACTL6A was associated with poor survival and promoted osteosarcoma cell metastasis through EMT, suggesting that ACTL6A may be a novel prognostic biomarker and therapeutic target for osteosarcoma.

Elevated expression of microRNA-19a predicts a poor prognosis in patients with osteosarcoma

MicroRNA (miR)-19a, a member of the miR-17-92 cluster, functions as an oncomiRNA in multiple kinds of cancers. However, its involvement in human osteosarcomas remains unclear. In this study, to analyze the expression pattern of miR-19a and to investigate its clinical implication in human osteosarcomas, quantitative reverse-transcription polymerase chain reaction was performed to detect expression levels of miR-19a in 166 self-pairs of osteosarcoma and noncancerous bone tissues. Associations between miR-19a expression and various clinicopathological parameters and patients' prognosis of osteosarcomas were further evaluated. As a results, miR-19a expression in osteosarcoma tissues was significantly higher than that in corresponding noncancerous bone tissues (P<0.001). Osteosarcoma patients with high miR-19a expression more frequently had large tumor size (P=0.03), advanced clinical stage (P=0.01), positive distant metastasis (P=0.008) and poor response to chemotherapy (P=0.01) than those with low miR-19a expression. Additionally, kaplan-Meier analysis showed that both overall and disease-free survivals of osteosarcoma patients with high miR-19a expression were shorter than those with low miR-19a expression (both P<0.001). Further multivariate analysis identified miR-19a expression as an independent prognostic factor for both overall (P=0.001) and disease-free (P=0.006) survivals. In conclusion, the aberrant expression of miR-19a may play a crucial role in development and progression of human osteosarcomas. MiR-19a may act as a novel prognostic marker for patients with this malignancy.

Retraction Note to: Downregulation of microRNA-217 and microRNA-646 acts as potential predictor biomarkers in progression, metastasis, and unfavorable prognosis of human osteosarcoma.

Despite the progress in therapeutic targets, it remains dissatisfactory for most osteosarcoma patients with metastasis or recurrence osteosarcoma. Therefore, it is required to determine the involved mechanisms of osteosarcoma. The aim of this study was to investigate the expression level of MiR-217 and miR-646 and also their association with clinicopathological features in patients with osteosarcoma. Total RNA was purified from patients with osteosarcoma and noncancerous bone tissues, and then quantitative real-time PCR was applied to evaluate the expression level of microRNAs. Our result suggested that miR-217 expression was remarkably deceased in osteosarcoma bone tissue when compared with noncancerous bone tissues (mean ± SD 5.32 ± 1.231, 2.01 ± 0.78; P = 0.024) and miR-646 expression decreased in osteosarcoma bone tissue in comparison with normal tissues (mean ± SD 4.56 ± 1.45, 1.76 ± 1.24; P = 0.041). Our findings indicated that decreased expression of MiR-217 and miR-646 was strongly correlated with high tumor, node, and metastasis (TNM) stage (P = 0.015, P = 0.002) and large cancer diameter (P = 0.041, P = 0.053). Kaplan-Meier survival and log-rank analysis indicated that shorter overall survival was strongly linked to decreased expression of miR-217 and miR-646 (log-rank test P = 0.034, P = 0.026). In terms of miR-217, multivariate Cox proportional hazards model analysis has showed that reduction of miR-217 expression (P = 0.001), TNM stage (P = 0.046), and lymph node metastasis (P = 0.006) were independently linked to a short-time survival of patients. In terms of miR-646, low expression of miR-646 (P = 0.021), TNM stage (P = 0.052), and tumor size (P = 0.043) were independently associated with poor survival of patients as prognostic factors. Our findings suggested that downregulation of MiR-217 and miR-646 was associated with progression of osteosarcoma. MiR-217 and miR-646 may play a key role in suppression of tumor in osteosarcoma and would be applied as a novel therapeutic agent.

Retraction note: Down-regulation of microRNA-26a and up-regulation of microRNA-27a contributes to aggressive progression of human osteosarcoma.

Osteosarcoma is the most common primary bone malignancy with high local aggressiveness and rapid metastasizing potential, resulting in poor survival. Increasing reports suggest that deregulated microRNAs (miRNAs) might provide novel therapeutic targets for cancers. However, the expression of miR-26a and miR-27a in osteosarcoma need further investigation in clinical samples. In our study, we evaluate the expression of these miRNAs in osteosarcoma tissues and compared with paired adjacent non-tumor bone tissues using RT-qPCR. Total RNA was purified from patients with osteosarcoma and noncancerous bone tissues. Real-time PCR was applied to quantify the expression level of miR-26a and miR-27a. Moreover, the correlation of these markers with clinicopathological characteristics was also evaluated in osteosarcoma patients. A cox proportional hazards model was performed to assess multivariate analyses of prognostic values. Our result suggested that miR-26aexpression level in osteosarcoma bone tissue was significantly lower than that in the paired noncancerous bone tissues. MiR-27a expression was higher in osteosarcoma bone tissue in comparison with paired noncancerous bone tissues. The results indicated that low expression level of miR-26a and high expression of miR-27a were associated with high TNM stage (P = 0.001; P = 0.012), tumor grade (P = 0.007; P = 0.016), and distant metastasis (P = 0.004; P = 0.001). Kaplan-Meier analysis and log-rank test indicated that patients with low expression of miR-26a and high expression of miR-27a had shorter overall survival (log-rank test: P < 0.001). Multivariate Cox proportional hazards model analysis showed that low expression of miR-26a and high expression of miR-27a (P = 0.021; P = 0.011), high TNM stage (P = 0.001; P = 0.003), tumor grade (P = 0.005; P = 0.01), and distant metastasis.(P = 0.002; P = 0.005) were independent prognostic factors for overall survival patients with osteosarcoma cancer. In conclusion, our findings suggested that expression level of miR-26a and miR-27a contributes to aggressive progression of this malignancy. Therefore, may have clinical potentials as a non-invasive diagnostic/prognostic biomarker for osteosarcoma patients.

MiR-21 predicts poor prognosis in patients with osteosarcoma

Background and aims: miR-21 has been demonstrated to play an important role in tumour progression. The aim of the present study was to analyse the correlation between miR-21 expression level and clinicopathologic features, as well as to assess the prognostic significance of miR-21 in osteosarcoma.Methods: Eighty-four pairs of osteosarcoma and corresponding non-cancerous bone tissues were obtained, and miR-21 expression levels were detected using quantitative real-time PCR (qRT-PCR). A χ2 test was used to assess the relationship between miR-21 expression and clinicopathological features. Overall survival (OS) and disease-free survival (DFS) rates were determined by the Kaplan–Meier method and analysed by the log-rank test. The Cox proportional hazards model was used for multivariate analysis.Results: qRT-PCR indicated that miR-21 expression in tumour tissues was strongly elevated compared with the adjacent corresponding non-cancerous bone tissue (7.88 ± 1.04 vs. 1.12 ± 0.37, respectively; P < 0.001). High miR-21 expression levels were linked to advanced clinical stage (P = 0.001), distant metastasis (P = 0.001), high tumour grade (P = 0.032) and large-sized tumours (P = 0.013). A higher miR-21 expression was significantly linked to shorter OS and DFS (both P < 0.001). Furthermore, a multivariate analysis confirmed that miR-21 was an independent and significant prognostic factor to predict poor OS and DFS (both P < 0.001).Conclusions: Upregulation of miR-21 was associated with poor clinicopathological characteristics. It is used as a marker of poor prognosis in patients with osteosarcoma.

Combined over-expression of the hypoxia-inducible factor 2α gene and its long non-coding RNA predicts unfavorable prognosis of patients with osteosarcoma

BackgroundLncRNA hypoxia-inducible factor-2α (HIF-2α) promoter upstream transcript (HIF2PUT) functions as a novel regulatory factor of osteosarcoma stem cells partly by controlling HIF-2α expression. The aim of this study was to investigate the clinical significance of HIF-2α and HIF2PUT in human osteosarcoma. Materials and methodsQuantitative real-time PCR was performed to detect the expression levels of HIF-2α mRNA and HIF2PUT in 82 surgical specimens of primary osteosarcoma and matched non-cancerous bone tissues. Then, the associations of HIF-2α and/or HIF2PUT expression with various clinicopathological features of osteosarcoma patients were statistically analyzed. Moreover, their prognostic value was further evaluated. ResultsCompared with non-cancerous bone tissues, HIF-2α mRNA and HIF2PUT expression were both significantly upregulated in osteosarcoma tissues (all P<0.001). Interestingly, the expression levels of HIF-2α mRNA in osteosarcoma tissues were positively correlated with those of HIF2PUT (r=0.28, P=0.009). Additionally, osteosarcoma patients with HIF-2α mRNA and/or HIF2PUT over-expression more frequently had large tumor size (all P<0.05), advanced clinical stage (all P<0.01) and positive distant metastasis (all P<0.01). Moreover, osteosarcoma patients with HIF-2α mRNA and/or HIF2PUT over-expression had a significantly shorter overall and disease-free survival (all P<0.05). Furthermore, Cox multivariate analysis identified that HIF-2α mRNA and/or HIF2PUT expression, clinical stage and distant metastasis were all independent and significant prognostic factors for both overall and disease-free survival (all P<0.05). ConclusionsHIF-2α and HIF2PUT upregulation may be a common feature in human osteosarcomas with aggressive potency. The over-expression of the two molecules, alone or combined, may predict poor prognosis in osteosarcoma patients.

Down-regulation of microRNA-182 and microRNA-183 predicts progression of osteosarcoma.

IntroductionThe aim of this study was to investigate the expression levels of microRNA-182 and microRNA-183 and their association with clinicopathological features in patients with osteosarcoma.Material and methodsTotal RNA was purified from samples and noncancerous bone tissues and then quantitative real-time polymerase chain reaction was applied to evaluate the expression levels of microRNAs, and their relationship with clinicopathological features and survival in osteosarcoma patients.ResultsOur findings showed that expression of MiR-182 was clearly lower in osteosarcoma bone tissue (mean ± SD: 2.84 ±.07) compared with noncancerous bone tissues (6.23 ±1.72, p = 0.004). On the other hand, lower expression of MiR-183 was seen in osteosarcoma bone tissue (1.43 ±0.59) when compared with normal tissues (4.36 ±2.47, p = 0.036). Decreased expression of MiR-182 was clearly correlated with advanced clinical stage (p = 0.001), metastasis or recurrence (p = 0.024), and large tumor size (p = 0.032). Decreased expression of MiR-183 was associated with advanced TNM stage (p = 0.004), and metastasis or recurrence (p = 0.002). A multivariate Cox proportional hazards model revealed that low expression of MiR-182 and MiR-183 (p = 0.02; p = 0.016), TNM stage (p = 0.04), and metastasis or recurrence (p = 0.03) were significantly associated with poor survival as independent prognostic factors.ConclusionsThese findings suggest that MiR-182 and MiR-183 may be associated with progression and metastasis of osteosarcoma.

Decreased microRNA-452 expression and its prognostic significance in human osteosarcoma.

BackgroundMicroRNA-452 (miR-452) was previously reported to be dysregulated in several types of human cancers and involved in tumor progression. The aim of this study was to investigate the clinical significance and prognostic value of miR-452 expression in human osteosarcoma.MethodsThe expression of miR-452 was detected in 95 pairs of osteosarcoma specimens and adjacent noncancerous bone tissues using quantitative RT-PCR (qRT-PCR) assay. Then, the association of miR-452 levels with clinicopathological features and prognosis was analyzed. The roles of miR-452 in regulating osteosarcoma cell proliferation, apoptosis, and invasion were evaluated in vitro.ResultsmiR-452 expression was significantly downregulated in osteosarcoma tissues than those in corresponding noncancerous bone tissues (P < 0.001). Decreased miR-452 expression was linked to larger tumor size, high tumor grade, advanced clinical stage, distant metastasis, and shorter overall survival. Multivariate Cox regression analysis confirmed that low level of miR-452 expression predicted poor prognosis independently. miR-452 overexpression in MG-63 cells suppressed cell proliferation, promoted cell apoptosis, inhibited cell invasion, and led to decreased BMI1 protein levels.ConclusionsThese findings suggest that miR-452 downregulation may be involved in osteosarcoma formation and progression and that miR-452 would serve as a novel prognostic biomarker for patients with this disease.

Aberrant expression of microRNA-99a and its target gene mTOR associated with malignant progression and poor prognosis in patients with osteosarcoma.

BackgroundThe mammalian target of rapamycin (mTOR) has been reported to act as a target gene of microRNA (miR)-99a in various cancer cells and identified as an independent prognostic marker of human osteosarcoma. The aim of this study was to investigate the clinical significance of miR-99a/mTOR axis in human osteosarcoma.MethodsA total of 130 pairs of osteosarcoma and matched noncancerous bone tissues were used to detect the expression levels of miR-99a and mTOR mRNA by quantitative real-time polymerase chain reaction. Then, associations of miR-99a and/or mTOR expression with clinico-pathological features and prognosis of patients with osteosarcoma were statistically analyzed.ResultsThe expression levels of miR-99a (tumor vs normal: 2.11±1.03 vs 4.69±1.21, P<0.001) and mTOR mRNA (tumor vs normal: 4.40±1.13 vs 1.74±0.85, P<0.001) in osteosarcoma tissues were, respectively, lower and higher than those in noncancerous bone tissues. The expression levels of miR-99a in osteosarcoma tissues were negatively correlated with those of mTOR mRNA. Additionally, miR-99a-low and/or mTOR-high expression were all significantly associated with advanced surgical stage, positive metastasis and recurrence, and poor response to chemotherapy (all P<0.05). Moreover, patients with osteosarcoma with miR-99a-low and/or mTOR-high expression had shorter overall and disease-free survivals than those in miR-99a-high and/or mTOR-low expression groups. Multivariate Cox analyses showed that miR-99a and/or mTOR expression were all independent prognostic factors of osteosarcoma.ConclusionOur data showed the crucial role of miR-99a/mTOR axis in the malignant progression of human osteosarcoma, implying that conjoined expression of miR-99a and mTOR may offer an attractive novel prognostic marker for this disease.