LncRNA expression and implication in osteosarcoma: a systematic review and meta-analysis

miR-939, as an important regulator in various cancers pathogenesis, has diagnostic, prognostic, and therapeutic values: a review

BACKGROUND

MicroRNAs (miRNAs or miRs) are highly conserved non-coding RNAs with a short length (18-24 nucleotides) that directly bind to a complementary sequence within 3'-untranslated regions of their target mRNAs and regulate gene expression, post-transcriptionally. They play crucial roles in diverse biological processes, including cell proliferation, apoptosis, and differentiation. In the context of cancer, miRNAs are key regulators of growth, angiogenesis, metastasis, and drug resistance.

MAIN BODY

This review primarily focuses on miR-939 and its expanding roles and target genes in cancer pathogenesis. It compiles findings from various investigations. MiRNAs, due to their dysregulated expression in tumor environments, hold potential as cancer biomarkers. Several studies have highlighted the dysregulation of miR-939 expression in human cancers.

CONCLUSION

Our study highlights the potential of miR-939 as a valuable target in cancer diagnosis, prognosis, and treatment. The aberrant expression of miR-939, along with other miRNAs, underscores their significance in advancing our understanding of cancer biology and their promise in personalized cancer care.

IncRNA MALAT1 Regulates the Proliferation, Apoptosis, Migration, and Invasion of Osteosarcoma Cells by Targeting miR-873-5p/ROCK1

The malignant bone tumor osteosarcoma (OS) was one of the most aggressive tumors. Despite breakthroughs in treatment options for OS recently, the survival rate of patients with metastasis or reoccurring disease has remained unchanged over the last 25 years, at around 20%. lncRNA expression dysregulation is linked to carcinogenesis, advancement, and metastasis. Additionally, the fundamental mechanism of lncRNAs in regulating OS cell biological activity and progression is still being investigated. The expression of miR-873-5p and MALAT1 were detected by quantitative real-time polymerase chain reaction (qRT-PCR) in OS. The relationship between the expression level of MALAT1 and the survival rate of OS individuals was evaluated by the Kaplan-Meier plotter. The tumor cell's capability of proliferation was determined using the CCK-8. Transwell was used to test the migratory and invasive properties of tumor cells. ROCK1 protein expression was analyzed by western blot, while qRT-PCR was used to detect ROCK1 mRNA expression. Targeted genes of MALAT1 or miR-873-5p were predicted by StarBase2.0. The target association among miR-873-5p and MALAT1 or ROCK1 was confirmed using the luciferase assay. The relationship between ROCK1 and MALAT1 or miR-873-5p expression in OS was investigated using Spearman's correlation analysis. MALAT1 was up-regulated and was linked to a lower survival rate of patients in OS. The malignant behaviors of cells were inhibited by down-regulated MALAT1 in vitro. Dual-luciferase gene experiments confirmed the presence of MALAT1/miR-873-5p/ROCK1 axis. The up-regulated miR-873-5p blocked the promoted effects of MALAT1 on cell behaviors. Over-expressed MALAT1 promoted the malignant behaviors of cells by miR-873-5p/ROCK1 axis in OS.

Hox transcript antisense RNA knockdown inhibits osteosarcoma progression by regulating the phosphoinositide 3-kinase/AKT pathway through the microRNA miR-6888-3p/spleen tyrosine kinase axis

Long non-coding RNA HOX transcript antisense RNA (lncRNA HOTAIR) is thought to be a key regulator of the occurrence and development of osteosarcoma (OS). The expression of HOTAIR, microRNA miR-6888-3p, spleen tyrosine kinase (SYK), and phosphoinositide 3-kinase/AKT (PI3K/AKT) pathway-related proteins in OS was detected by quantitative reverse transcription-PCR (qRT-PCR) and western blotting. Changes in the proliferation and migration of OS cells were detected by Cell Counting Kit-8 (CCK-8) and transwell assays after the knockdown of HOTAIR, miR-6888-3p, or SYK. Luciferase assays, RNA immunoprecipitation (RIP), and RNA pull-down assays were used to detect the relationship between miR-6888-3p and HOTAIR or SYK. We found that HOTAIR and SYK were highly expressed in OS, whereas miR-6888-3p expression was low. In addition, downregulation of HOTAIR or SYK significantly inhibited the growth and migration of OS cells and the PI3K/AKT pathway, both in vitro and in vivo. Additionally, downregulation of miR-6888-3p promoted the proliferation and migration of OS cells and activated the PI3K/AKT pathway. Mechanistically, these results suggest that the HOTAIR sponge, miR-6888-3p, regulates SYK expression. To summarize, HOTAIR regulates SYK by acting on miR-6888-3p, thereby promoting the proliferation and migration of OS cells.

LncRNA HULC as a potential predictor of prognosis and clinicopathological features in patients with digestive system tumors: a meta-analysis

Objective: This meta-analysis aimed to evaluate the correlation between lncRNA HULC, prognosis and clinicopathological characteristics in patients with digestive system tumors.

Methods: The relevant literatures were collected through PubMed, Web of Science and Embase up to February 2021. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to assess the prognostic value of HULC in patients with digestive system tumors. The clinicopathological characteristics of HULC in patients were estimated by odds ratios (ORs).

Results: A total of 14 studies involving 1312 patients were included. The up-regulated expression level of HULC was associated with poorer overall survival (OS) in patients with digestive system tumors (HR = 1.83, 95% CI: 1.05-3.19, P = 0.033). Subgroup analysis showed that cancer type (pancreatic cancer or gastric cancer), residence region (China, Japan or Korea), and specimen (serum) significantly associated between HULC and OS. In addition, high HULC expression significantly increased the risk of high TNM stage (OR = 2.51, 95%CI: 1.36-4.62, P < 0.05), poor differentiation (OR = 1.38, 95%CI: 1.02-1.87, P < 0.05) and lymphatic node metastasis (LNM, OR = 4.93, 95% CI: 3.47-6.99, P < 0.05).

Conclusions: High expression level of HULC is related to OS, TNM stage, differentiation and LNM. Therefore, HULC can be used as a new potential predictor for prognosis and clinicopathological features of patients with digestive system tumors.

LncRNA RUSC1-AS1 promotes osteosarcoma progression through regulating the miR-340-5p and PI3K/AKT pathway

Dysregulation of long noncoding RNA (lncRNA) is frequently involved in the progression and development of osteosarcoma. LncRNA RUSC1-AS1 is reported to be upregulated and acts as an oncogene in hepatocellular carcinoma, cervical cancer and breast cancer. However, its role in osteosarcoma has not been studied yet. In the present study, we investigated the role of RUSC1-AS1 in osteosarcoma both in vitro and in vivo. The results showed that the expression of RUSC1-AS1 was significantly upregulated in osteosarcoma cell line U2OS and HOS compared to that in human osteoblast cell line hFOB1.19. Similar results were found in human samples. Silencing RUSC1-AS1 by siRNA significantly inhibited U2OS and HOS cell proliferation and invasion, measured by CCK-8 and transwell assay. Besides, knockdown of RUSC1-AS1 increased cell apoptosis in osteosarcoma cell lines. In addition, RUSC1-AS1 promoted the epithelial-mesenchymal transition (EMT) process of osteosarcoma cells. In vivo experiments confirmed that RUSC1-AS1 knockdown had an inhibitory effect on osteosarcoma tumor growth. Mechanically, we showed that RUSC1-AS1 directly binds to and inhibits miR-340-5p and activates the PI3K/AKT signaling pathway. In conclusion, our study demonstrated that RUSC1-AS1 promoted osteosarcoma development both in vitro and in vivo through sponging to miR-340-5p and activating the PI3K/AKT signaling pathway. Therefore, RUSC1-AS1 becomes a potential therapeutic target for osteosarcoma.

Up-regulation of LINC00619 promotes apoptosis and inhibits proliferation, migration and invasion while promoting apoptosis of osteosarcoma cells through inactivation of the HGF-mediated PI3K-Akt signalling pathway

This study is performed to evaluate the role of long noncoding RNA (lncRNA) LINC00619 in osteosarcoma through the PI3K-Akt signalling pathway by binding to HGF. Osteosarcoma and osteochondroma tissues from patients were collected. The relationship between lncRNA LINC00619 and HGF was proved by the dual-luciferase reporter gene assay. The expression patterns of lncRNA LINC00619 as well as the levels of proliferating cell nuclear antigen (PCNA), hepatocyte growth factor (HGF), phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), Bax, Bcl-2, alkaline phosphatase (ALP), and osteopontin (OPN) were detected by RT-qPCR and Western blot analysis. In addition, MTT assay, flow cytometry, scratch test, and Transwell assay were performed to assess the cell proliferation, cell cycle distribution, apoptosis, cell migration, and invasion in each group, respectively. Osteosarcoma tissues presented with elevated positive expression rate of HGF, up-regulated expression levels of PCNA, HGF, PI3K, Akt, Bcl-2, ALP and OPN, and down-regulated expressions of Bax and LINC00619. HGF was verified as a target gene of lncRNA LINC00619. LINC00619 was found to down-regulate the expressions of PCNA, HGF, PI3K, Akt, Bcl-2, ALP, and OPN in osteosarcoma cells. Up-regulation of lncRNA LINC00619 decreased cell growth, migration intensity, and invasion ability, but enhanced the apoptosis rate of osteosarcoma cells. Our findings suggest that lncRNA LINC00619 inhibits proliferation, migration and invasion and improves apoptosis of osteosarcoma cells through the inhibition of the activation of the HGF-dependent PI3K-Akt signalling pathway.

lncRNA‑CASC15 promotes osteosarcoma proliferation and metastasis by regulating epithelial‑mesenchymal transition via the Wnt/β‑catenin signaling pathway

Osteosarcoma (OS) is a rare type of tumor and mostly occurs in children and adolescents. Approximately 10–25% of patients with OS have lung metastases, and lung damage caused by lung metastasis is the main cause of mortality. Therefore, studying the growth and metastasis of OS is key in reducing OS mortality and improving prognosis. The expression of long non-coding RNA (lncRNA) cancer susceptibility 15 (CASC15) in OS patients or OS cell lines were quantified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The expression of vimentin, E-cadherin, N-cadherin, and cyclin D were detected by RT-qPCR and western blotting. Mice were injected with OS cell lines via the tail vein to observe tumor formation in the lung. CCK-8 and EdU assays were utilized to evaluate cell proliferation. Both Ttranswell assay and cell scratch test detected cell migration. The results revealed that lncRNA-CASC15 was highly expressed in clinical samples and OS cells. In vitro verification experiments revealed that CASC15 promoted the growth of OS cells. Rescue experiments demonstrated that CASC15 affected the cell cycle by activating the Wnt/β-catenin pathway, thereby promoting cell proliferation. Furthermore, the transfection dose test indicated that lentiviruses expressing various doses of CASC15-overexpression (oe-CASC15) altered the proliferation and migration status of OS cells. CASC15 promoted OS cell metastasis both in vivo and in vitro. The overexpression of CASC15 revealed that the occurrence of metastasis was also related to the Wnt/β-catenin pathway. The western blotting results revealed that CASC15 could lead to β-catenin entering the nucleus via the Wnt pathway to promote the epithelial-mesenchymal transition (EMT) of OS cells. To sum up, CASC15 promoted the proliferation of OS cells in vitro and the growth of OS xenograft tumors in vivo. Moreover, CASC15 promoted the entry of β-catenin into the nucleus, thus activating the Wnt pathway and subsequently promoting the EMT of OS cells.

LINC01614 promotes osteosarcoma progression via miR-520a-3p/SNX3 axis

Long noncoding RNAs (lncRNAs) have been reported as essential regulators in osteosarcoma (OS), the most malignant bone tumor usually observed in children and adolescents. In the present study, we detected differentially expressed lncRNAs among OS tissues through RNA-sequencing. Then through bioinformatics analysis, we constructed the aberrant lncRNAs regulatory networks, and detected the key-lncRNAs. We identified LINC01614 was most significantly up-regulated among OS tissues, which was positively correlated with the worse prognosis. Through related in vitro experiments, we confirmed that knockdown of LINC01614 could inhibit the proliferation, invasion, and metastasis activities of OS cells. Furthermore, we identified LINC01614 may promote the proliferation and invasion activities of OS cells, via binding miR-520a-3p and increase the expression of SNX3. In conclusion, we identified lncRNAs participate in various malignant behaviors in OS. We also proved that LINC01614 could function as competing endogenous RNAs and promote the proliferation, and invasion of OS cells through miR-520a-3p/SNX3 axis, and thus acts as a novel prognostic marker for OS in clinic.

The value of lncRNAs as prognostic biomarkers on clinical outcomes in osteosarcoma: a meta-analysis

Background

In recent years, emerging studies have demonstrated critical functions and potential clinical applications of long non-coding RNA (lncRNA) in osteosarcoma. To further validate the prognostic value of multiple lncRNAs, we have conducted this updated meta-analysis.

Methods

Literature retrieval was conducted by searching PubMed, Web of Science and the Cochrane Library (last update by October 2, 2019). A meta-analysis was performed to explore association between lncRNAs expression and overall survival (OS) of osteosarcoma patients. Relationships between lncRNAs expression and other clinicopathological features were also analyzed respectively.

Results

Overall, 4351 patients from 62 studies were included in this meta-analysis and 25 lncRNAs were identified. Pooled analyses showed that high expression of 14 lncRNAs connoted worse OS, while two lncRNAs were associated with positive outcome. Further, analysis toward osteosarcoma clinicopathologic features demonstrated that overexpression of TUG1 and XIST indicated poor clinical parameters of patients.

Conclusions

This meta-analysis has elucidated the prognostic potential of 16 lncRNAs in human osteosarcoma. Evidently, desperate expression and functional targets of these lncRNAs offer new approaches for prognosis and therapy of osteosarcoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07882-w.

LncRNA MHRT Promotes Cardiac Fibrosis via miR-3185 Pathway Following Myocardial Infarction

Long-chain noncoding RNA (lncRNA) is a new class of molecular regulators in heart development and disease. However, the role of specific lncRNA in cardiac fibrosis remains to be fully explored. This study aimed to investigate the role and potential mechanism of lncRNA MHRT in myocardial fibrosis after myocardial infarction (MI).Cardiac fibroblasts (CFs) were isolated from a mouse model of MI. The expression levels of MHRT and miR-3185 in the hearts of MI and CFs mice treated with transforming growth factor beta 1 (TGF-β1) were analyzed by qRT-PCR. The collagen expression was assessed using qRT-PCR and Western blot. Cell proliferation was assessed by performing MTT and EdU assays. The direct interaction between lncRNA and miRNA was analyzed by luciferase assay, RNA-binding protein immunoprecipitation (RIP) assay, and RNA pull-down assay.The expression levels of MHRT were raised in MI and CFs mice treated with TGF-β1. Overexpression of MHRT promoted collagen production and CF proliferation, while silencing of MHRT showed the opposite effect. MiR-3185 was a target gene of MHRT. In addition, overexpression of MHRT reduced the expression levels of miR-3185, and siMHRT reversed the inhibitory effect of TGF-β1 on the expression of miR-3185. Overexpression of miR-3185 inhibited the upregulation of Col I and Col III induced by TGF-β1.MHRT promoted cardiac fibrosis after MI through miR-3185 and increased myocardial collagen deposition and promoted myocardial fibrosis.

Risk Factors, Prognostic Factors, and Nomograms for Distant Metastasis in Patients With Newly Diagnosed Osteosarcoma: A Population-Based Study

BACKGROUND

Osteosarcoma is the most common bone cancer, mainly occurring in children and adolescents, among which distant metastasis (DM) still leads to a poor prognosis. Although nomogram has recently been used in tumor areas, there are no studies focused on diagnostic and prognostic evaluation of DM in primary osteosarcoma patients.

METHODS

The data of osteosarcoma patients diagnosed between 2004 and 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for DM in osteosarcoma patients, and univariate and multivariate Cox proportional hazards regression analyses were used to determine independent prognostic factors of osteosarcoma patients with DM. We then established two novel nomograms and the results were evaluated by receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA).

RESULT

A total of 1,657 patients with osteosarcoma were included, and 267 patients (16.11%) had DM at the time of diagnosis. The independent risk factors for DM in patients with osteosarcoma include age, grade, T stage, and N stage. The independent prognostic factors for osteosarcoma patients with DM are age, chemotherapy and surgery. The results of ROC curves, calibration, DCA, and Kaplan-Meier (K-M) survival curves in the training, validation, and expanded testing sets, confirmed that two nomograms can precisely predict occurrence and prognosis of DM in osteosarcoma patients.

CONCLUSION

Two nomograms are expected to be effective tools for predicting the risk of DM for osteosarcoma patients and personalized prognosis prediction for patients with DM, which may benefit clinical decision-making.

Development of a novel immune-related genes prognostic signature for osteosarcoma

Immune-related genes (IRGs) are responsible for osteosarcoma (OS) initiation and development. We aimed to develop an optimal IRGs-based signature to assess of OS prognosis. Sample gene expression profiles and clinical information were downloaded from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) and Genotype-Tissue Expression (GTEx) databases. IRGs were obtained from the ImmPort database. R software was used to screen differentially expressed IRGs (DEIRGs) and functional correlation analysis. DEIRGs were analyzed by univariate Cox regression and iterative LASSO Cox regression analysis to develop an optimal prognostic signature, and the signature was further verified by independent cohort (GSE39055) and clinical correlation analysis. The analyses yielded 604 DEIRGs and 10 hub IRGs. A prognostic signature consisting of 13 IRGs was constructed, which strikingly correlated with OS overall survival and distant metastasis (p < 0.05, p < 0.01), and clinical subgroup showed that the signature's prognostic ability was independent of clinicopathological factors. Univariate and multivariate Cox regression analyses also supported its prognostic value. In conclusion, we developed an IRGs signature that is a prognostic indicator in OS patients, and the signature might serve as potential prognostic indicator to identify outcome of OS and facilitate personalized management of the high-risk patients.

LncRNA-ROR/microRNA-185-3p/YAP1 axis exerts function in biological characteristics of osteosarcoma cells

AIM

The co-expression network of long non-coding RNA ROR (lncRNA-ROR) and microRNA-185-3p (miR-185-3p) has not been focused on osteosarcoma. Therein, this work was initiated to uncover lncRNA-ROR and miR-185-3p functions in osteosarcoma.

METHODS

LncRNA-ROR, miR-185-3p and Yes-associated protein 1 (YAP1) expression in osteosarcoma tissues and cells were detected. The screened cells (MG63 and U2OS) were transfected with decreased and/or increased lncRNA-ROR and miR-185-3p to explore osteosarcoma progression. Tumor growth was detected by tumor xenografts in mice.

RESULTS

Up-regulated lncRNA-ROR and YAP1 and down-regulated miR-185-3p were found in osteosarcoma. LncRNA ROR knockdown or miR-185-3p overexpression inhibited osteosarcoma cell progression while lncRNA ROR elevation or miR-185-3p inhibition presented the opposite effects. Function of lncRNA ROR was rescued by miR-185-3p and regulated the growth and metastasis of osteosarcoma cells via modulating YAP1, the target gene of miR-185-3p.

CONCLUSION

This work illustrates that lncRNA-ROR down-regulation or miR-185-3p up-regulation inhibits osteosarcoma progression via YAP1 repression.

LncRNA HULC induces the progression of osteosarcoma by regulating the miR-372-3p/HMGB1 signalling axis

Background

Osteosarcoma is a malignancy that normally affects children, adolescents, and young adults. Although accumulating evidence has demonstrated the importance of HULC in osteosarcoma, little is reported about its functional roles and molecular mechanisms.

Methods

The expression of HULC and miR-372-3p in osteosarcoma tissues was quantified by qRT-PCR. The regulatory roles of HULC and miR-372-3p on cell proliferation, apoptosis, migration and invasion were determined by CCK-8, colony formation, flow cytometry, wound healing, and transwell assays, respectively. The bioinformatics prediction software RAID v2.0 was used to predict the putative binding sites. The interactions among HULC, miR-372-3p and HMGB1 were explored by luciferase assay and western blot assay.

Results

Our results revealed elevated HULC and decreased miR-372-3p expression in both osteosarcoma tissues and cell lines. Overexpression of HULC or knockdown of miR-372-3p promoted osteosarcoma cell proliferation, migration and invasion and induced cell apoptosis. Bioinformatics and luciferase assays verified that HULC directly interacted with miR-372-3p to attenuate miR-372-3p binding to the HMGB1 3′-UTR. Furthermore, mechanistic investigations confirmed that activation of the miR-372-3p/HMGB1 regulatory loop by knockdown of miR-372-3p or overexpression of HMGB1 reversed the in vitro roles of HULC in promoting osteosarcoma cell proliferation, migration and invasion.

Conclusion

Our study is the first to demonstrate that HULC may act as a ceRNA to modulate HMGB1 expression by competitively sponging miR-372-3p, leading to the regulation of osteosarcoma progression, which provides new insight into osteosarcoma diagnosis and treatment.

LINC01354 Promotes Osteosarcoma Cell Invasion by Up-regulating Integrin β1

BACKGROUND AND AIMS

Long noncoding RNAs have been proved to play a key role in the development and progression of various tumors, including osteosarcoma (OS). However, the role and molecular mechanism of lncRNA in osteosarcoma metastasis remains unknown. Our purpose is to explore the clinical significance and biological function of LINC01354 in osteosarcoma.

METHODS

Expression of LINC01354 in OS tissues, serum and cell lines was measured and the association between LINC01354 expression and clinicopathological factors was analyzed. The functional effects of LINC01354 were examined in vitro by using transwell assays, western blot, immunohistochemistry (IHC) and in vivo in a xenograft tumor mouse model.

RESULTS

LINC01354 was overexpressed in OS tissues, serum and cells. LINC01354 overexpression promoted OS cells invasion, EMT and integrin β1 expression, while knockdown of LINC01354 inhibited OS cell invasion, epithelial-mesenchymal transition (EMT) and integrin β1 expression. In addition, integrin-β1 blockage with MAB13 antibody abrogated the effects of LINC01354 overexpression on promoting OS cells invasion and EMT. In addition, LINC01354 promoted OS cell metastasis in vivo.

CONCLUSION

LINC01354 promote OS cell EMT and invasion through up-regulating integrin β1. Our study suggested that LINC01354 may be regarded as a potential target for the clinical treatment of OS.

11 Long noncoding RNA UCA1 functions as miR-135a sponge to promote the epithelial to mesenchymal transition in glioma

The dysregulation of long noncoding (lncRNA) UCA1 may play an important role in tumor progression. However, the function in gliomas is unclear. Therefore, this experiment was designed to explore the pathogenesis of glioma based on lncRNA UCA1. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of lncRNA UCA1, miR-135a, and HOXD9 in gliomas tissues. The effect of lncRNA UCA1 and miR-135a on tumor cell proliferation and migration invasiveness was examined by CCK-8 and transwell assays. Target gene prediction and screening, luciferase reporter assay were used to verify downstream target genes of lncRNA UCA1. Expression of E-cadherin, N-cadherin, vimentin, and HOXD9 was detected by RT-qPCR and Western blotting. The tumor changes in mice were detected by in vivo experiments in nude mice. lncRNA UCA1 was highly expressed in glioma tissues and cell lines. lncRNA UCA1 expression was associated with significantly poor overall survival in gliomas. Moreover, lncRNA UCA1 significantly enhanced cell proliferation and migration, and promoted the occurrence of EMT. In addition, lncRNA UCA1 promoted the development of EMT by positively regulating HOXD9 expression as a miR-135a sponge. In vivo experiments indicated that UCA1 exerted its biological functions by modulating miR-135a and HOXD9. In conclusion, lncRNA UCA1 can induce the activation of HOXD9 by inhibiting the expression of miR-135a and promote the occurrence of EMT in glioma.

Knockdown of lncRNA GHET1 inhibits osteosarcoma cells proliferation, invasion, migration and EMT in vitro and in vivo

OBJECTIVE

Osteosarcoma is the most common primary malignant skeleton tumor that derives from mesenchymal cells. Emerging evidences have identified the vital role of long non-coding RNAs (lncRNAs) in the development of osteosarcoma. In this study, we aimed to investigate the role of lncRNA gastric carcinoma highly expressed transcript 1 (GHET1) in osteosarcoma progression.

METHODS

The expression levels of relevant genes in clinical samples and cell lines were determined by quantitative real-time PCR. Cell proliferation was determined by CCK8 and cell colony formation assays. Transwell assay was used to detect the invasion and migration of osteosarcoma cells. Cell apoptosis and cell cycle were detected by flow cytometry. Protein levels were detected by western blot. In vivo tumor growth was investigated in the xenograft nude mice model. To determine whether growth inhibition and apoptosis are responsible for antitumor activity of silencing GHET1, immunohistochemistry for proliferation and TUNEL assay was performed in xenograft tissues. In vivo lung metastasis was performed to detect the effect of GHET1 on cell metastasis ability.

RESULTS

Our results revealed that GHET1 was up-regulated in osteosarcoma tissues compared to normal tissues. GHET1 was also increased in osteosarcoma cell lines compared to normal osteoplastic cell line. The up-regulation of GHET1 was significantly associated with TNM stage, distant metastasis and lymph node metastasis in patients with osteosarcoma. In vitro studies showed that silencing GHET1 in MG-63 and U2OS cells inhibited cell proliferation, cell invasion and migration and epithelial-to-mesenchymal transition (EMT), promoted cell apoptotic rate, and also caused an increase in cell population at G0/G1 phase with a decrease in cell population at S phase. Overexpression of GHET1 promoted the proliferation, invasion and migration of osteosarcoma cells. Importantly, silencing GHET1 inhibited tumor growth and tumor metastasis in mice MG-63-xenograft model in association with changes of EMT-related genes, reduced expression of Ki-67 and promotion of apoptosis.

CONCLUSION

GHET1 was up-regulated in osteosarcoma tissues and cell lines, inhibited cell apoptosis, promoted cell proliferation, invasion and migration by affecting EMT in vitro, and was correlated with the tumor growth and metastasis in vivo. GHET1 may be a potential therapeutic target of osteosarcoma treatment.

NIMA-related kinase 2 overexpression is associated with poor survival in cancer patients: a systematic review and meta-analysis

Objective

NIMA-related kinase 2 (NEK2) has been reported to be overexpressed in various types of cancer and correlated with poor prognosis. The role(s) of NEK2 in cancer, however, is still uncertain. The aim of this study was to evaluate the prognostic value of NEK2 in human tumors.

Methods

A comprehensive literature search was performed for PubMed, Embase, Web of Science, and CNKI databases, and eligible studies were included based on the inclusion and exclusion criteria. A meta-analysis of the included studies was then carried out.

Results

Fifteen studies with 3,280 cancer patients were included in the present meta-analysis. All publications were of moderate to high quality, and had no significant heterogeneity (I^2=46%, P=0.03) or publication bias was discovered. The results showed that a high NEK2 level was associated with shorter overall survival (OS) in patients with various types of cancers (pooled HR=1.72, 95% CI 1.49–2.00, P<0.00001). However, the disease-free survival (DFS) had no significant association with NEK2 level (HR=1.13, 95% CI: 0.29–4.38, P=0.85). In the subgroup analyses, high NEK2 level was correlated with an increased risk of poor OS in patients with hepatocellular carcinoma (HR=1.62, 95% CI: 1.25–2.10, P=0.02) and lung cancer (HR=2.18, 95% CI: 1.40–3.38, P=0.0005). However, other factors, including sample size, follow-up period, HR estimation method, and country, also affect the association between NEK2 expression and OS. Analysis of clinicopathological parameters further showed that increased NEK2 level was correlated with younger age, male gender, better tumor differentiation, and lower number of tumor nodules.

Conclusion

The results of this study indicated that increased expression of NEK2 was associated with unfavorable survival of cancer patients and that NEK2 could be used as a prognostic predictor for cancers.

LncRNA BDNF-AS is associated with the malignant status and regulates cell proliferation and apoptosis in osteosarcoma

Long non-coding RNA (LncRNA) brain-derived neurotrophic factor antisense (BDNF-AS) has been found to be down-regulated and function in a tumor suppressive role in human cancers. However, the expression status and function of BDNF-AS is still unknown in osteosarcoma (OS). In our study, BDNF-AS expression was found to be decreased in OS tissues and cells. Moreover, BDNF-AS low expression was correlated with advanced Enneking stage, large tumor size and poor prognosis in OS patients. The multivariate analysis suggested low expression of BDNF-AS was an independent unfavorable prognostic factor for overall survival in OS patients. The in vitro studies indicated that BDNF-AS overexpression inhibits OS cell proliferation and promotes cell apoptosis through regulating cleaved caspase-3. In conclusion, BDNF-AS serves as a tumor suppressive lncRNA in OS.

Long noncoding RNA LINC00858 promotes osteosarcoma through regulating miR-139-CDK14 axis

Long noncoding RNAs (lncRNAs) have been identified to modulate the tumorigenesis of human cancers. The in-depth of lncRNAs on human osteosarcoma oncogenesis is still ambiguous. In present study, functional and mechanism experiments were conducted to investigate the role of long intergenic non-protein coding RNA 00858 (LINC00858) on human osteosarcoma tumorigenesis. Results demonstrated that LINC00858 expression was significantly upregulated in both osteosarcoma tissues and cell lines. Mechanism assays presented that LINC00858 silencing significantly repressed osteosarcoma cells' proliferation and invasion in vitro, and inhibited the tumor growth in vivo. In further experiments, LINC00858 was identified to sponge miR-139 to form RNA-induced silencing complex (RISC) using luciferase reporter assay and RNA immunoprecipitation (RIP). Besides, CDK14 was validated to be the target protein the miR-139. Rescue experiments confirmed the role of LINC00858/miR-139/CDK14 pathway on osteosarcoma cells' phenotype. In summary, these data prove that LINC00858/miR-139/CDK14 axis promotes the tumorigenesis of osteosarcoma, providing a new mechanism or target for osteosarcoma.

Prognostic role of long non-coding RNA HNF1A-AS1 in Chinese cancer patients: a meta-analysis

Background

Long non-coding RNAs (LncRNAs) play important roles in tumorigenesis and progression. Recent studies have demonstrated that LncRNA HNF1A antisense RNA 1 (HNF1A-AS1) is aberrantly expressed in several types of cancers and is associated with poor outcomes. This meta-analysis was conducted to investigate the relationship between HNF1A-AS1 expression and clinical outcomes in cancer patients.

Methods

We searched PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and Wan Fang databases (updated until December 31, 2017) for literature. A total of eight studies with 789 cancer patients were finally included in the present meta-analysis.

Results

The results showed that high expression of HNF1A-AS1 significantly predicted poor overall survival (HR=3.10, 95% CI: 1.58-6.11, P=0.001), which was further validated using The Cancer Genome Atlas (TCGA) dataset. Moreover, high HNF1A-AS1 expression was also associated with advanced TNM stage (OR=3.32, 95% CI: 2.28-4.83, P<0.001), lymph node metastasis (OR=3.08, 95% CI: 1.95-4.85, P<0.001), and distant metastasis (OR=5.53, 95% CI: 1.94-15.77, P=0.001).

Conclusion

Our results suggested that elevated HNF1A-AS1 was associated with poor clinical outcomes and might serve as a potential prognostic biomarker of cancer.

LncRNA TUG1 affects cell viability by regulating glycolysis in osteosarcoma cells

Osteosarcoma is an aggressive malignant neoplasm in teenagers and young adults. Long non-coding RNA (lncRNA) taurine-upregulated gene 1 (TUG1) is considered as an oncogene in osteosarcoma. However, the mechanism of TUG1 in regulating osteosarcoma has not been fully understood. We aimed to investigate whether the metabolic alteration is involved in the effect of TUG1 on osteosarcoma cells. Herein, we found that TUG1 was overexpressed in osteosarcoma cells compared with the normal osteoblastic cell line. Knockdown of TUG1 inhibited glucose consumption, lactate production and cell viability of osteosarcoma cells. Overexpression of TUG1 induced cell viability, whereas the induction was attenuated by 2-DG. The aberrant expression of TUG1 markedly affected the expression of hexokinase-2 (HK2). Knockdown of HK2 weakened the effect of TUG1 overexpression on glycolysis in osteosarcoma cells. We concluded that glycolysis was involved in the effect of TUG1 on cell viability of osteosarcoma cells. HK2 might be an important molecule by which TUG1 affected the glycolysis.

Prognostic value and clinical significance of long noncoding RNA CASC2 in human malignancies: a meta-analysis

Purpose

This meta-analysis aimed to assess the prognostic value of long noncoding RNA cancer susceptibility candidate 2 (CASC2) in human tumors.

Materials and methods

We searched the available databases up to December 2017. Pooled hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) were used to examine the prognostic impact of CASC2 on overall survival (OS) in patients diagnosed with malignancies.

Results

A total of eight studies with 663 cancer patients were enrolled. Our results showed that high CASC2 expression level was associated with a favorable OS (HR=0.437, 95% CI: 0.345-0.554). The significant results were not altered by stratified analysis according to cancer type, sample size, follow-up months, and HR estimation method. A significant association of glioma tumor stage with CASC2 expression was detected (III-IV vs I-II: odds ratio=2.126, 95% CI: 1.032-4.378). CASC2 could be used as an independent prognostic factor for OS (HR=0.450, 95% CI: 0.336-0.602). Sensitivity analysis showed that no single study changed the pooled results significantly. Begg's funnel plot and Egger's test showed that no publication bias was detected.

Conclusion

High expression level of CASC2 is associated with favorable survival outcome for cancer patients, and CASC2 could be used as a prognostic predictor for cancers.