Long intergenic non-protein coding RNA 1006 used as a potential novel biomarker of gastric cancer

LINC01006 regulates the proliferation, migration and invasion of hepatocellular carcinoma cells through regulating miR-433-3p/CBX3 axis

INTRODUCTION AND OBJECTIVES

LINC01006 has been verified to be correlated with several cancer types, whereas its biological function in hepatocellular carcinoma (HCC) is still elusive. This study aimed to elucidate the specific regulatory mechanism of LINC01006 in the tumorigenesis of HCC.

MATERIALS AND METHODS

The expression of LINC01006, miR-433-3p and CBX3 in HCC tissues and cells was assessed by qRT-PCR or Western blot. MTT, wound-healing, and transwell assays were used to evaluate the effects of LINC01006 on cell viability, migration, and invasion in vitro. A mouse xenograft model was established for in vivo assays. The relations among LINC01006, miR-433-3p, and CBX3 were analyzed by MS2-RNA immunoprecipitation (RIP) and Dual-luciferase reporter (DLR) assays.

RESULTS

The expression of LINC01006 was up-regulated in HCC tissues and cells. LINC01006 knockdown inhibited the viability, wound healing rate, and invasive cell number of HeP3B and SK-HeP-1 cells, and decreased the tumor volume and weight in a mouse xenograft model. MiR-433-3p was a target of LINC01006, and LINC01006 overexpression inhibited the viability, wound healing rate, and invasive cell number of HeP3B and SK-HeP-1 cells. In addition, CBX3 was a target of miR-433-3p, which was negatively regulated by miR-433-3p. CBX3 overexpression and miR-433-3p inhibition reversed the inhibiting effects of LINC01006 knockdown on the viability, migration, and invasion of HeP3B cells.

CONCLUSIONS

Silencing of LINC01006 inhibited the viability, migration, and invasion of HCC cells through regulating miR-433-3p/CBX3 axis.

LINC01006 and miR-3199 Serve as Novel Markers of Poor Prognosis in Colon Cancer and Regulate Cell Proliferation, Migration and Invasion

Purpose

Colon cancer is the most commonly diagnosed gastrointestinal cancer. This research intended to evaluate the prognostic values of LINC01006 and miR-3199 for colon cancer and their effects on cell physiology.

Patients and Methods

LINC01006 and miR-3199 expression levels were determined by RT-qPCR. Patients’ 5-year cumulative survival rate was analyzed by Kaplan–Meier curves with the Log rank test. Chi-square test and multivariate Cox regression analysis were used to access the clinical significance. CCK-8 assay, transwell assay, and TUNEL assays were used to monitor the change of cell proliferation, invasion, migration, and apoptosis.

Results

The expression level of LINC01006 was increased while miR-3199 was decreased in colon tissues and cells compared to normal ones. This dysregulated expression was correlated with T stage (P = 0.002) and N stage (P = 0.009). High LINC01006 level (HR = 4.048, 95%: 1.502–10.911, P = 0.006) or low miR-3199 level (HR = 3.421, 95% CI: 1.254–9.330, P = 0.016) was outstanding for predicting poor prognosis in patients with colon cancer. Downregulation of LINC01006 reduced cell proliferation, invasion, and migration but induced cell apoptosis (P < 0.05).

Conclusion

LINC01006 knockdown showed anti-proliferative, anti-metastatic, and apoptotic-induced effects on colon cancer cells. This study contributes to research on promising prognostic biomarkers of colon cancer and might give way to further investigation of alternative tumor targets.

Knockdown of long non-coding RNA LINC01006 represses the development of hepatocellular carcinoma by modulating the miR-194-5p/CADM1 axis

INTRODUCTION AND OBJECTIVES

Long non-coding RNAs (lncRNAs) have great potential as therapeutic targets in hepatocellular carcinoma (HCC). In this study, we aimed to uncover the function and molecular mechanism of long intergenic non-protein coding RNA 1006 (LINC01006) in HCC.

MATERIALS AND METHODS

Mice were injected with HCC cells in order to establish the HCC model. Quantitative reverse transcription polymerase chain reaction was used to determine the expression levels of LINC01006, cell adhesion molecule 1 (CADM1), and microRNA (miR)-194-5p in HCC tissues and cells. The cell proliferation, invasion, and migration abilities were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide, transwell, and wound healing assays. The interrelation between LINC01006, miR-194-5p, and CADM1 was confirmed by a dual-luciferase reporter assay. Western blotting was employed to assess the relative protein expression level of CADM1.

RESULTS

LINC01006 and CADM1 displayed upregulation, but miR-194-5p exhibited downregulation in HCC cells and tissues. Short hairpin (sh)-LINC01006 and miR-194-5p mimics repressed the proliferative, migratory, and invasive capacities of HCC cells, and injection of sh-LINC01006 restrained the growth of HCC tumours in mice. LINC01006 served as a competing endogenous RNA of miR-194-5p and was inversely correlated with miR-194-5p. CADM1 was targeted by miR-194-5p, inversely correlated with miR-194-5p, and positively associated with LINC01006. Furthermore, transfection of pcDNA-CADM1 or the miR-194-5p inhibitor reversed the suppressive effects of sh-LINC01006 on the proliferation, invasion, and migration abilities of HCC cells.

CONCLUSIONS

Downregulation of LINC01006 repressed the development of HCC by sponging miR-194-5p to modulate the expression of CADM1, implying its potential as a therapeutic target for HCC.

Long noncoding RNAs as diagnostic biomarkers for the early detection of digestive tract cancers: a systematic review and meta-analysis

BACKGROUND

long noncoding RNAs (lncRNAs) have attracted attention recently. However, many inconsistencies frequently appeared for the early diagnosis of digestive tract cancers (DTCs). We performed this meta-analysis to describe the diagnostic performance of lncRNAs in the discrimination of DTCs.

METHODS

data were extracted from PubMed, Web of Science, Embase, and Cochrane Library. Their quality was evaluated using the revised Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). Such parameters as sensitivity and specificity were included for pooled analyses. The STATA 12.0 and Meta-Disc 1.4 software packages were used to perform the statistical analysis.

RESULTS

sixty-nine papers were included in this meta-analysis. The pooled analysis of DTCs showed that lncRNAs had a sensitivity of 0.78 and a specificity of 0.80. The area under the summary ROC curve (AUC) was 0.86. For gastric cancer (GC), the pooled sensitivity and specificity were 0.77 (95 % CI: 0.72-0.81) and 0.75 (95 % CI: 0.71-0.79), respectively, and the AUC was 0.83. For colorectal cancer (CRC), these three parameters were 0.82 (95 % CI: 0.76-0.86), 0.84 (95 % CI: 0.79-0.88), and 0.90, respectively. For esophageal cancer (EC) sensitivity was 0.74 (95 % CI: 0.67-0.80) and specificity reached 0.86 (95 % CI: 0.72-0.93), with an AUC of 0.82.

CONCLUSIONS

LncRNAs show potential diagnostic value for discrimination between DTCs.

Long Noncoding RNA LINC01006 Facilitates Cell Proliferation, Migration, and Epithelial-Mesenchymal Transition in Lung Adenocarcinoma via Targeting the MicroRNA 129-2-3p/CTNNB1 Axis and Activating Wnt/β-Catenin Signaling Pathway

Lung adenocarcinoma (LUAD) is a common type of malignancy of lung cancers. Long intergenic noncoding RNAs (lincRNAs) have emerged as crucial regulators of various cancers, including LUAD. LINC01006 is a newly discovered long noncoding RNA (lncRNA) whose function in LUAD remains to be explored. This study is to explore the role of LINC01006 in LUAD. Quantitative real-time PCR (RT-qPCR) analysis and Western blotting were used to determine the expression levels and protein levels, respectively. Functional assays and animal experiments investigated the role of LINC01006 both in vivo and in vitro. Moreover, TOP/FOP assay was performed to detect the activation of the Wnt/β-catenin signaling pathway. The interaction between LINC01006 and microRNA 29-2-3-p (miR-29-2-3-p)/catenin beta 1 (CTNNB1) was explored by RNA binding protein immunoprecipitation (RIP), RNA pulldown, luciferase reporter assays, and rescue experiments. According to the results, LINC01006 was highly expressed in LUAD tissues and cell lines. LINC01006 knockdown significantly suppressed cell proliferative, migratory, and epithelial-mesenchymal transition (EMT) capacities and tumor development. Moreover, LINC01006 enhanced CTNNB1 via sequestering miR-129-2-3p and activated the Wnt/β-catenin pathway in LUAD. Overall, LINC01006 promotes LUAD development via activating the Wnt/β-catenin pathway, implying that LINC01006 might be a promising biomarker for LUAD treatment.

Long non‑coding RNA LINC01006 exhibits oncogenic properties in cervical cancer by functioning as a molecular sponge for microRNA‑28‑5p and increasing PAK2 expression

As previously reported, long intergenic non‑protein‑coding RNA 1006 (LINC01006) plays crucial roles in prostate, pancreatic and gastric cancers. However, whether it plays important roles in cervical cancer remains unclear. The present study thus aimed to determine the precise role of LINC01006 in cervical cancer and elucidate its regulatory mechanisms. The expression of LINC01006 in cervical cancer was examined by reverse transcription‑quantitative polymerase chain reaction. Cell proliferation assay, flow cytometric analysis, Transwell migration and invasion assays, and tumor xenograft model experiments were performed to elucidate the roles of LINC01006 in cervical cancer. Bioinformatics analysis, luciferase reporter assay, RNA immunoprecipitation and rescue experiments were performed for mechanistic analyses. The expression of LINC01006 was found to be upregulated in cervical cancer and to be associated with a poor prognosis. The absence of LINC01006 inhibited the proliferation, migration and invasion of cervical cancer cells, whereas it promoted cell apoptosis in vitro. The downregulation of LINC01006 impeded tumor growth in vivo. LINC01006 was verified as an endogenous 'sponge' that competed for microRNA‑28‑5p (miR‑28‑5p), which resulted in the upregulation of the miR‑28‑5p target P21‑activated kinase 2 (PAK2). Rescue experiments revealed that the suppression of miR‑28‑5p expression or the overexpression of PAK2 abrogated the effects of LINC01006 downregulation on malignant cellular functions in cervical cancer. On the whole, the present study demonstrates that LINC01006 exhibits tumor‑promoting functions in cervical cancer via the regulation of the miR‑28‑5p/PAK2 axis. These findings may provide the basis for the identification of LINC01006‑targeted clinical therapy.

LINC01006 facilitates cell proliferation, migration and invasion in prostate cancer through targeting miR-34a-5p to up-regulate DAAM1

Background

Prostate cancer (PCa) is a kind of malignancy occurring in the prostate gland. Substantial researches have proved the major role of long noncoding RNAs (lncRNAs) in PCa. However, the role of long intergenic non-protein coding RNA 1006 (LINC01006) in PCa has not been investigated yet.

Methods

RT-qPCR was used to examine the expression levels of LINC01006 and its downstream targets. The function of LINC01006 in PCa was tested by in vitro and in vivo assays. With application of RNA pull down, RNA immunoprecipitation (RIP) and luciferase reporter assays, the interaction among LINC01006, miR-34a-5p and disheveled associated activator of morphogenesis 1 (DAAM1) were verified.

Results

LINC01006 expression presented high in PCa cell lines. LINC01006 silencing suppressed cell proliferative, migratory, invasive capacities while accelerated apoptotic rate. Besides, LINC01006 knockdown also suppressed tumor growth and metastasis in vivo. Furthermore, miR-34a-5p, a tumor suppressor in PCa, was sponged by LINC01006. Moreover, DAAM1 was targeted by miR-34a-5p and promoted PCa progression. More intriguingly, rescue assays suggested that the inhibitory effect of LINC01006 knockdown on PCa development was offset by DAAM1 overexpression.

Conclusions

LINC01006 promoted PCa progression by sponging miR-34a-5p to up-regulate DAAM1, providing a novel target for PCa therapy.

Function and regulation annotation of up-regulated long non-coding RNA LINC01234 in gastric cancer

Background

Accumulated evidences indicate that long non‐coding RNAs (lncRNAs) participate in many biological mechanisms. Moreover, it acts as an essential regulator in various human diseases such as gastric cancer (GC). Nevertheless, the comprehensive regulatory roles and clinical significance of most lncRNAs in GC are not fully understood.

Methods

In this research, our aim was to investigate the underlying mechanism of lncRNA LINC01234 in GC. Firstly, the usage of qRT‐PCR helped to establish expression pattern of LINC01234 in GC tissues. Following this, appropriate statistical tests were applied to analyze the relation between expression level and clinicopathological factors. Ultimately, potential functions and regulatory network of LINC01234 were concluded via GSEA and a series of bioinformatics tools or databases, respectively.

Results

Consequently, at the end of research we found LINC01234 is up‐regulated in GC tissues in comparison with adjacent normal tissues. Furthermore, its expression level is correlated with differentiation of patients with GC. It is also important to highlight bioinformatics analysis revealed that LINC01234 is involved in cancer‐associated pathways such as cell cycle and mismatch repair. Also, regulatory network of LINC01234 presented a probability in the involvement of tumorigenesis through regulating cancer‐associated genes.

Conclusion

Overall, our results suggested that LINC01234 may play a crucial role in GC.

Long non-coding RNA signature in gastric cancer

Gastric cancer as a common human malignancy has been associated with aberrant expressions of several coding and non-coding genes. Long non-coding RNAs (lncRNAs) as regulators of gene expressions at different genomic, transcriptomic and post-transcriptomic levels are among putative biomarkers and therapeutic targets in gastric cancer. In the present study, we have searched available literature and listed lncRNAs that are involved in the pathogenesis of gastric cancer. In addition, we discuss associations between expressions of these lncRNAs and tumoral features or risk factors for gastric cancer. Based on the established role of lncRNAs in regulation of genomic stability, cell cycle, apoptosis, angiogenesis and other aspects of cell physiology, the potential of these transcripts as therapeutic targets in gastric cancer should be evaluated in future studies.

LINC01006 promotes cell proliferation and metastasis in pancreatic cancer via miR-2682-5p/HOXB8 axis

Background

Pancreatic cancer (PC) is one of the deadliest cancers about the digestive system. Recent researches have validated that long non-coding RNAs (lncRNAs) play vital roles in various cancers, while the function of LINC01006 in PC is rarely clarified.

Aim of the study

Investigation of the specific role of LINC01006 in PC.

Methods

LINC01006 expression was examined by RT-qPCR. CCK-8, EdU, transwell, wound healing, and western blot assays were carried out to explore the function of LINC01006 in PC. The interaction among LINC01006, miR-2682-5p and HOXB8 was verified by luciferase reporter, RIP and ChIP assays.

Results

The expression of LINC01006 was markedly upregulated in PC tissues and cells. Furthermore, LINC01006 knockdown inhibited PC cell proliferation, invasion and migration, and upregulation of LINC01006 led to the opposite results. Besides, miR-2682-5p expression was downregulated and negatively regulated by LINC01006 in PC. Meanwhile, LINC01006 could bind with miR-2682-5p in PC. Moreover, miR-2682-5p negatively regulated HOXB8 expression and there was a binding site between miR-2682-5p and HOXB8 in PC. Additionally, miR-2682-5p overexpression or HOXB8 knockdown rescued the promotive effects of LINC01006 upregulation on PC cell progression. Similarly, miR-2682-5p inhibition or HOXB8 overexpression countervailed the repressive role of LINC01006 downregulation in PC cell progression. In addition, the transcription factor HOXB8 could activate LINC01006 transcription in PC.

Conclusions

LINC01006 promotes cell proliferation and metastasis in pancreatic cancer via miR-2682-5p/HOXB8 axis, which may facilitate the treatment for PC.

LncRNA PCAT-1 in gastrointestinal cancers: A meta-analysis

BACKGROUND

Prostate-cancer-associated ncRNA transcript 1 (PCAT-1), a newly discovered lncRNA, was implicated in the progression of multiple tumors. We conducted a systematic review and meta-analysis to determine its prognostic potential for gastrointestinal cancers.

METHODS

A literature survey was conducted by searching the PubMed, Web of Science, Cochrane Library, Embase together with Wanfang, and China National Knowledge Infrastructure (CNKI) database for articles published as of October 15, 2017. Hazard ratio (HR) or odds ratio (OR) with 95% confidence intervals (95% CIs) were calculated to demonstrate prognostic value of PCAT-1 using Stata 12.0 software.

RESULTS

A total of 6 studies with 961 cases were pooled in the analysis to evaluate the prognostic value of PCAT-1 in gastrointestinal cancers. Increased PCAT-1 expression was significantly correlated with poor overall survival (OS) (HR = 1.04, 95% CI: 1.02-1.06). Statistical significance was also observed in subgroup meta-analysis stratified by cancer type, histology type, sample size, and analysis type. Additionally, high expression of PCAT-1 was significantly associated with deeper tumor invasion (OR = 4.46, 95% CI: 3.00-6.63), positive lymph node metastasis (OR = 3.76, 95% CI: 1.39-10.16), and advanced clinical stage (OR = 4.09, 95% CI: 1.55-10.82).

CONCLUSION

High expression of PCAT-1 was related to poor prognosis and could be a promising biomarker of clinicopathologic features in gastrointestinal cancers. More studies will be necessary to verify and strengthen the clinical value of PCAT-1 in gastrointestinal cancers.

Prognostic Significance of Pretreatment Apolipoprotein A-I as a Noninvasive Biomarker in Cancer Survivors: A Meta-Analysis

Background

Numerous studies have reported the prognostic significance of serum apolipoprotein A-I (ApoA-I) in various cancers, but the results have been inconsistent. The current meta-analysis was performed to investigate the association between ApoA-I level and prognosis in human malignancies.

Methods

A literature search was performed using the electronic platforms of the PubMed, Cochrane Library, Web of Science, Embase, Wanfang, and China National Knowledge Infrastructure (CNKI) databases to obtain eligible articles published up to May 20, 2018. Pooled hazard ratios (HRs) with 95% confidence intervals (95% CIs) were calculated to assess the prognostic values of the ApoA-I level in cancers using STATA 12.0 software.

Results

A total of 14 studies involving 9295 patients were included. The results indicated that low ApoA-I level was significantly associated with poor overall survival (OS) (HR = 0.52, 95% CI: 0.44-0.61). Significant relationships between the ApoA-I level and OS were specifically detected in nasopharyngeal carcinoma (NPC, HR = 0.63, 95% CI: 0.54-0.73), colorectal cancer (CRC, HR = 0.48, 95% CI: 0.19-0.76), and hepatocellular carcinoma (HCC, HR = 0.46, 95% CI: 0.27-0.65). The subgroup analyses for OS also further confirmed the prognostic significance of the ApoA-I level in cancers. Moreover, lower Apo A-I was associated with unfavorable cancer-specific survival (CSS, HR: 0.47, 95% CI: 0.19-0.76) in cancers, and low ApoA-I level was clearly associated with inferior total time to recurrence (TTR, HR: 0.43, 95% CI: 0.29-0.58) in HCC, poorer locoregional recurrence-free survival (LRFS) and distant metastasis-free survival (DMFS) (HR: 0.58, 95% CI: 0.42-0.74 for LRFS; HR: 0.65, 95% CI: 0.41-0.89 for DMFS) in NPC, and shorter disease-free survival (DFS, HR: 0.64, 95% CI: 0.43-0.84) in cancers. Conclusions. Low ApoA-I level might be an unfavorable prognostic factor in multiple malignancies, and serum ApoA-I could serve as a noninvasive marker to predict cancer prognosis.