Up-regulation of long noncoding RNA CCAL predicts poor patient prognosis and promotes tumor metastasis in osteosarcoma

Emerging roles of long non-coding RNAs in osteosarcoma

Osteosarcoma (OS) is a highly aggressive and lethal malignant bone tumor that primarily afflicts children, adolescents, and young adults. However, the molecular mechanisms underlying OS pathogenesis remain obscure. Mounting evidence implicates dysregulated long non-coding RNAs (lncRNAs) in tumorigenesis and progression. These lncRNAs play a pivotal role in modulating gene expression at diverse epigenetic, transcriptional, and post-transcriptional levels. Uncovering the roles of aberrant lncRNAs would provide new insights into OS pathogenesis and novel tools for its early diagnosis and treatment. In this review, we summarize the significance of lncRNAs in controlling signaling pathways implicated in OS development, including the Wnt/β-catenin, PI3K/AKT/mTOR, NF-κB, Notch, Hippo, and HIF-1α. Moreover, we discuss the multifaceted contributions of lncRNAs to drug resistance in OS, as well as their potential to serve as biomarkers and therapeutic targets. This review aims to encourage further research into lncRNA field and the development of more effective therapeutic strategies for patients with OS.

LncRNA MATN1-AS1 for Prediction of Prognosis in Osteosarcoma Patients and Its Cellular Function

Long non-coding RNAs show essential roles in various cancer processes. This study aimed at the expression features, prognosis significance, and biological effect of lnc MATN1-AS1 in osteosarcoma (OS). Five kinds of cell lines and 117 pairs of tissues were analyzed by qRT-PCR for quantification of lnc MATN1-AS1 and miR-1299 level. Clinical data were analyzed using Chi-Square Tests to show the association with lnc MATN1-AS1 level. Kaplan-Meier analysis and Cox regression were used to judge the prognostic value. Cell counting kit-8 and Transwell assay were conducted, respectively, to analyze the effect of lnc MATN1-AS1 on cell proliferation and metastasis. The target miRNA was predicted. lnc MATN1-AS1 level was significantly elevated in OS cells and tissues and related to Enneking staging, lung metastasis, and histologic type. Patients with high lnc MATN1-AS1 level showed a shorter overall survival and recurrence-free survival. Lnc MATN1-AS1 knockdown inhibited OS cell proliferation, migration, and invasion by sponging miR-1299. Lnc MATN1-AS1 has oncogenic features and prognostic significance in OS and is a novel therapeutic strategy for OS.

The Emerging Landscape of Long Non-Coding RNAs in Colorectal Cancer Metastasis

Colorectal cancer (CRC) is one of the most common gastrointestinal cancers, with extremely high rates of morbidity and mortality. The main cause of death in CRC is distant metastasis; it affects patient prognosis and survival and is one of the key challenges in the treatment of CRC. Long non-coding RNAs (lncRNAs) are a group of non-coding RNA molecules with more than 200 nucleotides. Abnormal lncRNA expression is closely related to the occurrence and progression of several diseases, including cancer. Recent studies have shown that numerous lncRNAs play pivotal roles in the CRC metastasis, and reversing the expression of these lncRNAs through artificial means can reduce the malignant phenotype of metastatic CRC to some extent. This review summarizes the major mechanisms of lncRNAs in CRC metastasis and proposes lncRNAs as potential therapeutic targets for CRC and molecular markers for early diagnosis.

LncRNA CCAL Promotes Angiogenesis Through Regulating the MiR-29b/ANGPTL4 Axis in Osteosarcoma

Purpose

The objective of this study was to detect the expression of the long noncoding RNA (lncRNA) colorectal cancer-associated lncRNA (CCAL) in osteosarcoma tissues and to investigate its role in angiogenesis and the potential molecular mechanisms associated with this effect in osteosarcoma.

Materials and Methods

CCAL expression in 40 osteosarcoma tissues and 40 noncancerous tissues was measured by qRT-PCR (quantitative real-time polymerase chain reaction). Tube formation assays were performed to explore the role of CCAL in angiogenesis in osteosarcoma. In addition, the regulatory interaction between CCAL, miR-29b, and ANGPTL4 was investigated via luciferase reporter assay and bioinformatics predictive analysis.

Results

Compared with noncancerous tissues, the expression of CCAL was markedly upregulated in osteosarcoma tissues. Higher CCAL expression levels were closely related to shorter overall survival in patients with osteosarcoma. Additionally, functional analysis indicated that CCAL could facilitate tumour angiogenesis in vitro and in vivo in osteosarcoma. Mechanistically, CCAL upregulated ANGPTL4 expression in osteosarcoma cells, and ANGPTL4 mediated angiogenic induction by CCAL in osteosarcoma. Moreover, CCAL directly targeted miR-29b in osteosarcoma. More importantly, we demonstrated that CCAL upregulated the expression of ANGPTL4 by sponging miR-29b, which promoted angiogenesis in osteosarcoma.

Conclusion

Our results show that CCAL promotes angiogenesis by regulating the miR-29b/ANGPTL4 axis in osteosarcoma.

lncRNA FLVCR-AS1 promotes osteosarcoma growth by targeting miR381-3p/CCND1

Purpose

This article reports on FLVCR-AS1 effects on osteosarcoma (OS) growth.

Methods

Tumor tissue and adjacent normal tissue of 48 OS patients were collected. HOS and 143B cells were transfected. Gene expression was examined with qRT-PCR and Western blot. CCK8 assays and cell cloning was performed to measure cell proliferation. Cell cycle and apoptosis were assessed. Luciferase-reporter gene assays and RNA pull-down tests were used to detect targeting relationships between genes.

Results

Prominently higher FLVCR-AS1 expression was found in OS tissue and cells, and was associated with poor prognosis (P<0.05, P<0.01, or P<0.001). Compared with the siCtrl group, 143B and HOS cells of the siFLVCR-AS1 group had significantly lower OD₄₅₀ values and clone numbers and obviously higher percentages of cells in the G₁ phase and apoptosis (P<0.01 or P<0.001). miR381-3p expression was directly inhibited by FLVCR-AS1, and CCND1 expression was directly suppressed by miR381-3p. Compared with the FLVCR-AS1 group, 143B cells of the FLVCR-AS1⁺ miR381-3p mimic group and FLVCR-AS1⁺ siCCND1 group showed remarkably lower OD₄₅₀ values and clone numbers obviously higher apoptosis and percentage of cells in the G₁ phase (P<0.05, P<0.01, or P<0.001).

Conclusion

FLVCR-AS1 promoted OS growth by upregulating CCND1 expression via downregulation of miR381-3p.

The lncRNA SNHG16 affects prognosis in hepatocellular carcinoma by regulating p62 expression

Long noncoding RNAs (lncRNAs) regulate tumor development and progression by promoting proliferation, invasion, and metastasis. The oncogenic role of lncRNA SNHG16 in hepatocellular carcinoma (HCC) has not been revealed. LncRNA SNHG16 is upregulated in HCC and correlates with poorer prognosis. Patients with high SNHG16 expression showed lower rates of overall and disease-free survival than patients with low SNHG16 expression. Multivariate Cox regression revealed that SNHG16 expression was an independent predictor of poor overall and disease-free survival. In vitro, SNHG16 promoted HCC cell proliferation, migration, and invasion while inhibiting apoptosis; in vivo, it accelerated tumor development. Altering SNHG16 expression altered levels of miR-17-5p, which in turn modified expression of p62, which has been shown to regulate the mTOR and NF-κB pathways. Indeed, altering SNHG16 expression in HCC cells activated mTOR and NF-κB signaling. These results reveal a potential mechanism for the oncogenic role of SNHG16 in HCC. SNHG16 may therefore be a promising diagnostic marker as well as therapeutic target in HCC.

Long non-coding RNA CCAL/miR-149/FOXM1 axis promotes metastasis in gastric cancer

Early evidence indicates that the long non-coding RNA CCAL plays a critical role in cancer progression and metastasis. However, the overall biological role and clinical significance of CCAL in gastric tumourigenesis and progression remain largely unknown. We observed that CCAL was upregulated in gastric cancer tissues and was associated with the tumour-node-metastasis stage. Functional experiments showed that CCAL promoted gastric cancer cell proliferation and metastasis in vitro and in vivo. Luciferase reporter assay indicated that CCAL directly bind to miR-149. Moreover, knockdown of CCAL significantly reduced the expression of FOXM1, a direct target of miR-149. We also showed that FOXM1 suppression by miR-149 could be partially rescued by CCAL overexpression. In addition, we identified a negative correlation between the mRNA expression of CCAL and miR-149 in gastric cancer tissues. Furthermore, we observed a negative correlation between the expression of miR-149 and FOXM1 and a positive correlation between CCAL and FOXM1 levels. These results demonstrated that the CCAL/miR-149/FOXM1 axis functions as a key regulator in gastric cancer metastasis and CCAL potentially represents a biomarker for diagnosis and potential target for therapy in the future.

Abnormally expressed long non-coding RNAs in prognosis of Osteosarcoma: A systematic review and meta-analysis

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High LncRNA expression was significantly correlated with the poorer OS prognosis in osteosarcoma patients. However, the cut-off values may be the source of heterogeneity.

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The expression level of LncRNA was positively correlated with alkaline phosphatase, tumor size, metastasis, distant metastasis and Enneking stage.

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This meta-analysis demonstrated that abnormal LncRNAs expression was correlated with advanced clinicopathological features and poor prognosis as a novel predictive biomarker in osteosarcoma.

Background

Numerous studies have reported the relationship between Long non-coding RNAs (LncRNAs) expression and prognosis of osteosarcoma, but less consensus has been reached. Our meta-analysis was conducted to quantitatively assess the relationship between the expression of LncRNAs, prognosis and clinical pathology in osteosarcoma development.

Methods

PubMed,Embase,Web of Science,The Cochrane Library,SionMed,CNKI and WanFang databases were carefully searched to identify eligible studies. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to evaluate the prognostic significance of LncRNAs expression in osteosarcoma. Moreover, meta-regression analysis and subgroup analysis were carried out to explore the potential sources of heterogeneity.

Results

A total of 20 studies comprising 1749 patients were included in present meta-analysis. The results showed that the over-expression of LncRNA had a significant correlation with overall survival (OS) (HR = 2.16, 95% CI:1.68–2.79), and was not related to disease free survival (DFS) (HR = 0.71, 95% CI:0.05–9.53). Subgroup analysis further indicated that LncRNA transcription level was significantly associated with alkaline phosphatase (HR = 2.13, 95% CI:1.58–2.88) , tumor size (< 8/ ≥ 8:HR = 1.97, 95% CI: 1.55–2.62) , metastasis (yes/no: HR = 2.14,95% CI:1.15–3.97) , distant metastasis(presence/absence: HR = 4.02, 95% CI:3.05–5.23) and Enneking stage(IIA /IIB-III:HR = 3.2, 95% CI:2.48–4.14), but not associated with age (≤ 25/ > 25:HR = 1.01, 95% CI:0.78–1.3), gender(female/male: HR = 1.15, 95% CI: 0.96–1.37), tumor site (femur,tibia/elsewhere:HR = 1.15, 95% CI:0.94–1.4) and chemotherapy (yes/no: HR = 1.45, 95% CI:0.46–4.63).

Conclusions

This study demonstrated that abnormal LncRNAs expression might be potential prognostic markers to predict worse overall survival in osteosarcoma patients. However, the cut-off values may be the source of heterogeneity.

Enhanced expression of the long non-coding RNA SNHG16 contributes to gastric cancer progression and metastasis

This paper aimed to probe into the expression of long non-coding RNA (lncRNA) SNHG16 in human gastric cancer (GC) and its potential tumor biological functions. The expression of lncRNA SNHG16 was detected in GC and adjacent tissues and GC cell lines using qRT-PCR. GC MGC-803 cells were transfected with siRNA of lncRNA SNHG16, as well as blank and negative control. A series of experiments including CCK-8, flow cytometry, transwell, and wound healing assay were adopted to evaluate the effects of lncRNA SNHG16 on cell growth and metastasis. Besides, the nude mouse xenograft tumor model was established to draw tumor growth curve and measure tumor volume during treatments. TUNEL staining was used to determine the apoptosis rate of tissues. The expression of lncRNA SNHG16 in GC tissue, significantly associated with invasion depth, lymph node metastasis, TNM stage and histological differentiation (all P< 0.05), was upregulated compared with adjacent tissues. Transfected with siRNA of lncRNA SNHG16 inhibited GC MGC-803 cell proliferation, and arrested cells in the G0/G1 phase, and then promoted apoptosis rate with reduced cell invasion and shortened migration distance. Additionally, the nude mice xenograft presented lower tumor growth rate and weight loss alongside elevated apoptosis rate of tumor tissues. LncRNA SNHG16 is highly expressed in GC, while suppression of SNHG16 expression can inhibit proliferation, weaken invasion and migration of GC cells, and enhance apoptosis, to be a novel target for GC clinical treatment.

Crosstalk mechanisms between the WNT signaling pathway and long non-coding RNAs

The WNT/β-catenin signaling pathway controls a plethora of biological processes throughout animal development and adult life. Because of its fundamental role during animal lifespan, the WNT pathway is subject to strict positive and negative multi-layered regulation, while its aberrant activity causes a wide range of pathologies, including cancer. At present, despite the inroads into the molecules involved in WNT-mediated transcriptional responses, the fine-tuning of WNT pathway activity and the totality of its target genes have not been fully elucidated. Over the past few years, long non-coding RNAs (lncRNAs), RNA transcripts longer that 200nt that do not code for proteins, have emerged as significant transcriptional regulators. Recent studies show that lncRNAs can modulate WNT pathway outcome by affecting gene expression through diversified mechanisms, from the transcriptional to post-translational level. In this review, we selectively discuss those lncRNA-mediated mechanisms we believe the most important to WNT pathway modulation.

Long Noncoding RNA CCAL Promotes Papillary Thyroid Cancer Progression by Activation of NOTCH1 Pathway

Long noncoding RNA CCAL has been reported to promote tumor progression in various human cancers, including hepatocellular carcinoma, osteosarcoma, and colorectal cancer. However, the role of CCAL in papillary thyroid cancer remains largely unknown. In the present study, we found that the expression of CCAL was upregulated in papillary thyroid tumor tissues compared to adjacent normal tissues. Moreover, the expression of CCAL was positively related with papillary thyroid cancer severity and TNM stage and predicated poor prognosis. Besides, we found that knockdown of CCAL significantly inhibited papillary thyroid cancer cell proliferation, migration, and invasion in vitro and reduced tumor growth and metastasis in vivo. We found that knockdown of CCAL dramatically decreased the expression of NOTCH1 and suppressed the activation of the NOTCH1 signaling pathway. Furthermore, overexpression of NOTCH1 rescued the proliferation, migration, and invasion in papillary thyroid cancer cells. Taken together, our data indicated that CCAL promoted papillary thyroid cancer development and progression by activation of the NOTCH1 pathway, which provided a new insight on the design of therapeutic targets.

Long non-coding RNA CCAL promotes hepatocellular carcinoma progression by regulating AP-2α and Wnt/β-catenin pathway

OBJECTIVE

Long non-coding RNAs are emerging as key molecules in cancer progression. LncRNA-CCAL has shown to be highly expressed and important in regulating CRC and osteosarcoma development. Nevertheless, the expression and mechanism of CCAL in HCC is still not well understood.

METHODS

qRT-PCR and ISH were used to evaluate CCAL expression in HCC tissues and cell lines. Histone H3 methylation and acetylation levels across CCAL promoter region were examined by chromatin immunoprecipitation assays. Transfection of Lv-CCAL-shRNAs into HCC cell lines was used to evaluate cellular invasion and proliferation. The influence of CCAL depletion on AP-2α expression and Wnt/β-catenin pathway was analyzed by qRT-PCR, western blot and immunofluorescence.

RESULTS

Higher expression of CCAL was found in HCC tumor tissues compared with normal tissues, and was associated with tumor metastasis and TNM stage. Furthermore, the decreased histone H3 methylation and increased histone H3 acetylation across CCAL promoter region contributed to the upregulation of CCAL in HCC. Moreover, the depletion of CCAL inhibited HCC cellular invasion and proliferation, and promoted cell apoptosis. In addition, CCAL depletion up-regulated AP-2α expression and inhibited Wnt/β-catenin pathway activation.

CONCLUSIONS

CCAL has an important role in hepatic carcinogenesis and may serve as a new target for HCC diagnosis and treatment.

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

Purpose

Osteosarcoma is the most prevalent primary bone tumor in children, adolescents, and older adults, typically presenting with poor survival outcomes. In recent years, ample evidence has shown that many long noncoding RNAs (lncRNAs) have been aberrantly expressed in osteosarcoma, demonstrating their potential to serve as prognostic markers. In this study, we performed a meta-analysis on four lncRNAs (TUG1, UCA1, BCAR4, and HULC) to systematically evaluate their prognostic value in osteosarcoma.

Materials and methods

The eligible articles were systematically searched in PubMed, Web of Science, Embase, and Elsevier ScienceDirect (up to September 22, 2017), and one meta-analysis concerning the association between lncRNA expression and the overall survival (OS) of osteosarcoma patients was performed. Survival outcomes were analyzed by OS. Subgroup analyses were performed.

Results

A total of 1,361 patients with osteosarcoma and 12 lncRNAs from 16 articles were included in the study. Of the listed lncRNAs, the high expression of 10 lncRNAs indicated worse survival outcomes, while only two lncRNAs were shown to positively affect patients’ OS.

Conclusion

This meta-analysis indicated that the abnormally expressed lncRNAs might significantly affect the survival of osteosarcoma patients. Combined use of these lncRNAs may serve as potential novel biomarkers for the indication of clinical outcomes of osteosarcoma patients as well as the selection of adjuvant chemotherapy strategies for clinical treatment of this disease.

LncRNA ODRUL Contributes to Osteosarcoma Progression through the miR-3182/MMP2 Axis

Recent findings have shown that lncRNA dysregulation is involved in many cancers, including osteosarcoma (OS). In a previous study, we reported a novel lncRNA, ODRUL, that could promote doxorubicin resistance in OS. We now report the function and underlying mechanism of ODRUL in regulating OS progression. We show that ODRUL is upregulated in OS tissues and cell lines and correlates with poor prognosis. ODRUL knockdown significantly inhibits OS cell proliferation, migration, invasion, and tumor growth in vitro and in vivo by decreasing matrix metalloproteinase (MMP) expression. A microarray screen combined with online database analysis showed that miR-3182 is upregulated and MMP2 is downregulated in sh-ODRUL-expressing MG63 cells and that miR-3182 harbors potential binding sites for ODRUL and the 3' UTR of MMP2 mRNA. In addition, miR-3182 expression and function are inversely correlated with ODRUL expression in vitro and in vivo. A luciferase reporter assay demonstrated that ODRUL could directly interact with miR-3182 and upregulate MMP2 expression via its competing endogenous RNA activity on miR-3182 at the posttranscriptional level. Taken together, our study has elucidated the role of oncogenic ODRUL in OS progression and may provide a new target in OS therapy.