LINC00261 suppresses human colon cancer progression via sponging miR-324-3p and inactivating the Wnt/β-catenin pathway

Growing evidence indicates long noncoding RNAs (lncRNAs) are significant regulators in the progression of various malignant tumors including colon cancer. Dysregulation of lncRNA LINC00261 has been identified in many cancers. Investigations on LINC00261 function have revealed that LINC00261 could act as a crucial tumor suppressor in various cancers. But, the biological involvement of LINC00261 in colon cancer is still barely known. Here, we found LINC00261 was reduced in colon cancer cells. Meanwhile, overexpressed LINC00261 repressed colon cancer cell viability and proliferation capacity. In addition, colony cancer cell colony formation was inhibited and apoptosis was enhanced by upregulation of LINC00261. Also, colon cancer cell migration and invasion both were restrained by LINC00261. miR-324-3p can exert important functions in several carcinomas, but its role in colon cancer is uninvestigated. In the current study, miR-324-3p was examined and miR-324-3p was greatly increased in colon cancer cells. Moreover, the association between miR-324-3p and LINC00261 was confirmed via performing RNA immunoprecipitation and RNA-pull-down experiments. In cancer biology, aberrant modulation of the Wnt signaling pathway remains a prevalent theme. Overexpression of LINC00261 obviously impaired colon cancer progression via inactivating the Wnt pathway. Furthermore, in the xenograft model assay, an increase of LINC00261 could suppress colon tumor growth via sponging miR-324-3p and inactivating the Wnt pathway. Overall, our results showed that LINC00261 repressed colon cancer progression via regulating miR-324-3p and the Wnt pathway. LINC00261 could be established as a novel therapeutic target for colon cancer.     

Up-regulation of long intergenic noncoding RNA 01296 in ovarian cancer impacts invasion,apoptosis and cell cycle distribution via regulating EMT

BackgroundRecently, long intergenic non-coding RNA 01296 (LINC01296) has been demonstrated to regulate the initiation and progression of several cancers, but the functions of LINC01296 in ovarian cancer still remain unclear. The objective of our study was to determine the expression, biological roles, and clinical significance of LINC01296 in ovarian cancer.MethodsLINC01296 expression was measured in ovarian cancer tissues or cell lines. Next, the relationships between LINC01296 levels and the clinical factors of ovarian cancer, such as progression-free survival and overall survival were analyzed. Additionally, cell proliferation, migration and invasion capacities, apoptosis, cell cycle distribution were investigated after silencing of LINC01296. To confirm whether LINC01296 mediates EMT initiation in ovarian cancer cells, the effect of LINC01296 silence on E-cadherin, N-cadherin and vimentin was assessed in SKOV3 and OVCAR3 cells.ResultsWe found that LINC01296 was over-expressed in ovarian cancer tissues and cell lines, when comparing with adjacent normal tissue samples and normal cells. Higher LINC01296 expression was significantly correlated with shorter progression-free survival and overall survival. For the functional experiments, knockdown of LINC01296 suppressed cell proliferation, inhibited colony formation ability, abrogated cell migration and invasion potential, and enhanced cell apoptosis. Cell cycle analysis suggested that LINC01296 positively regulated cell cycle progression in ovarian cancer cells. Moreover, western blotting analysis displayed that knockdown of LINC01296 significantly increased E-cadherin, but reduced N-cadherin and vimentin expressions in SKOV3 and OVCAR3 cells, compared with no-transfection cells.ConclusionsLINC01296 plays an important role in promoting the progression of ovarian cancer. Over-expression of LINC01296 might function as an indicator for diagnosis and prognosis of ovarian cancer patients.     

LINC01116 promotes proliferation and migration of endometrial stromal cells by targeting FOXP1 via sponging miR-9-5p in endometriosis

Endometriosis is a common multi-factorial gynaecological disease. Recent studies have revealed that long non-coding RNAs (lncRNAs) are involved in the pathogenesis of endometriosis. In the present study, the expression profiles of lncRNAs in 6 pairs of endometriosis ectopic endometrium (ecEM) and eutopic endometrium (euEM) tissues were analysed by RNA sequencing. From the profiles, LINC01116 was found to be up-regulated in ecEM tissues compared to euEM tissues and was verified by quantitative real-time PCR (qRT-PCR). Then, functional experiments demonstrated that LINC01116 promoted the proliferation and migration of ectopic primary endometrial stromal cells (ESCs), while miR-9-5p exerted the opposite effects. Dual-luciferase reporter assays verified that LINC01116 directly sponged miR-9-5p and relieved the suppression of its target, Forkhead box protein P1 (FOXP1). Rescue experiments further demonstrated that LINC01116 could promote proliferation and migration of ESCs by targeting FOXP1 via sponging miR-9-5p. Overall, our study illuminates that LINC01116 promotes the progression of endometriosis through the miR-9-5p/FOXP1 axis. This finding provides a novel therapeutic target for patients with endometriosis.     

LINC00857 contributes to hepatocellular carcinoma malignancy via enhancing epithelial-mesenchymal transition

Hepatocellular carcinoma (HCC) remains the fifth most frequent cancer with high mortality rate worldwide. However, the underlying molecular mechanisms of HCC progression are still barely known. Long noncoding RNAs (lncRNAs) have been recognized as significant therapeutic targets for HCC. Recently, the biological role of LINC00857 in several cancer types has been reported. Our present study was aimed to investigate the role of LINC00857 in HCC progression. We observed that LINC00857 was overexpressed in HCC cell lines (Huh7, Hep3B, HepG2, MHCC-97H, and SNU449). Knockdown of LINC00857 significantly repressed Hep-3B and SNU449 cell proliferation and inhibited the HCC cell colony formation. In addition, cell apoptosis was induced by the silence of LINC00857 and cell cycle progression was blocked in G1 phase. Besides these, downregulation of LINC00857 was able to restrain HCC cell migration and invasion capacity via enhancing epithelial-mesenchymal transition (EMT) process. As displayed, E-cadherin protein expression was increased by LINC00857 silence, while N-cadherin protein level was repressed by LV-shLINC00857 in HCC cells. Finally, the in vivo assays were used and the data indicated that LINC00857 could also obviously suppress the HCC tumor growth in vivo. In conclusion, our study revealed that LINC00857 might provide a novel perspective for the HCC treatment.     

Retracted: LINC00707 contributes to hepatocellular carcinoma progression via sponging miR-206 to increase CDK14

Recently, increasing numbers of long noncoding RNAs (lncRNAs) have been found to be aberrantly expressed in various cancers. However, the roles of lncRNAs in hepatocellular carcinoma (HCC) progression is largely unknown. In our current study, we identified that long intergenic nonprotein-coding RNA 707 (LINC00707) was remarkably elevated in HCC cells, indicating that LINC00707 was involved in HCC development. Subsequently, LINC00707 was significantly decreased in HepG2 and Huh7 cells. The in vitro functional assays demonstrated that knockdown of LINC00707 significantly reduced HCC cell proliferation, induced cell apoptosis, and blocked the cell cycle progression. In addition, HCC cell migration and invasion was also greatly inhibited by downregulation of LINC00707. Increasing evidence has indicated that lncRNAs can act as molecular sponges of microRNAs. Currently, we observed that microRNA-206 (miR-206) was dramatically inhibited in HCC cells and LINC00707 can modulate HCC development through sponging miR-206. The binding correlation between LINC00707 and miR-206 was confirmed by dual-luciferase reporter assay, RNA pull down and RNA immunoprecipitation assay in our study. Moreover, cyclin-dependent kinase 14 (CDK14) was predicted as a target of miR-206 and we found that miR-206 suppressed CDK14 levels in HCC cells. Finally, in vivo assays were used and it was proved that silence of LINC00707 can restrain HCC development through modulating miR-206 to upregulate CDK14. In conclusion, it was implied that LINC00707 can lead to HCC progression through sponging miR-206 and modulating CDK14.     

Long noncoding RNA LINC00978 promotes cancer growth and acts as a diagnostic biomarker in gastric cancer

Objectives

Long noncoding RNAs (lncRNAs) play important roles in cancer development and progression. The deregulated expression of LINC00978 has been reported in human cancers. However, the expression pattern and biological roles of LINC00978 in gastric cancer (GC) remain unclear. In this study, we investigated the potential roles and clinical value of LINC00978 in gastric cancer.

Materials and methods

QRT‐PCR was performed to investigate the expression of LINC00978 in gastric cancer cell lines, tissues and serum samples. Cell counting, colony formation, transwell migration and matrigel invasion assays were performed to determine the effects of shRNA‐mediated knockdown of LINC00978 on gastric cancer cell functions. In vivo tumour growth assay was also conducted. Flow cytometry, immunohistochemistry, western blot and qRT‐PCR were used for potential mechanism study.

Results

LINC00978 expression level was elevated in GC tumour tissues, serum samples and cell lines. The expression level of LINC00978 was significantly correlated with tumour size (P = 0.02), lymphatic metastasis (P = 0.009) and TNM stage (P = 0.009). LINC00978 knockdown inhibited the proliferation of GC cells by suppressing cell cycle progression and inducing apoptosis. LINC00978 knockdown also inhibited the migration and invasion of GC cells. In addition, LINC00978 knockdown inhibited the activation of TGF‐β/SMAD signalling pathway and the process of epithelial‐mesenchymal transition (EMT) in GC cells. Moreover, the in vivo tumorigenicity of LINC00978 knockdown GC cells in mice was significantly decreased.

Conclusions

LINC00978 promotes gastric cancer progression and may serve as a potential biomarker for GC.     

Long noncoding RNA LINC00473 drives the progression of pancreatic cancer via upregulating programmed death-ligand 1 by sponging microRNA-195-5p

Pancreatic cancer (PC) is a great health burden to patients owing to its poor overall survival rate. Long noncoding RNAs (lncRNAs) interact with microRNAs (miRs) to participate in tumorigenesis. Therefore, we aim to uncover the role and related mechanism of LINC00473 in PC through the modulation of miR-195-5p and programmed death-ligand 1 (PD-L1). Increased LINC00473 and PD-L1 but declined miR-195-5p were determined in PC tissues and cell lines, and it was found that LINC00473 mainly situated in the cytoplasm. Also, miR-195-5p was verified to bind with both LINC00473 and PD-L1. Next, with the aim to examine the ability of LINC00473, miR-195-5p, and PD-L1 on the PC progression, the expression of LINC00473, miR-195-5p and PD-L1 were altered with mimics, inhibitors, overexpression vectors or siRNAs in PC cells and cocultured CD8⁺ T cells. It was demonstrated that LINC00473 sponged miR-195-5p to upregulate PD-L1 expression. More important, the obtained results revealed that LINC00473 silencing or miR-195-5p upregulation elevated the expression of Bcl-2 associated X protein (Bax), interferon (IFN)-γ, and interleukin (IL)-4 but reduced the expression of B-cell lymphoma-2 (Bcl-2), matrix metalloproteinase (MMP)-2, MMP-9, and IL-10, thus inducing the enhancement of the apoptosis as along with the inhibition of proliferation, invasion, and migration of the PC cells. LINC00473 silencing or miR-195-5p elevation activated the CD8⁺ T cells. Taken together, LINC00473 silencing blocked the PC progression through enhancing miR-195-5p-targeted downregulation of PD-L1. This finding offers new therapeutic options for treating this devastating disease.     

LINC01311 exerts an inhibitory effect in thyroid cancer progression by targeting the miR-146b-5p/IMPA2 axis

BackgroundA growing body of research suggests that long non-coding RNA (lncRNA) play an important role during the tumorigenesis and progression of cancers, including thyroid cancer (TC). Herein, we intended to uncover the role and mechanisms of LINC01311 in TC.MethodsThe relative LINC01311, miR-146b-5p, and IMPA2 expressions were quantified by subjecting TC cells and tissues to western blotting and RT-qPCR. CCK-8 and scratch-wound healing assays were carried out for the evaluation of the proliferation and migration of TC cells. The apoptosis was evaluated by flow cytometry assay and western blotting of Bax and Bcl-2 proteins. Xenograft tumor model was also used to study how LINC01311 functions during TC cell growth. Luciferase reporter and RNA immunoprecipitation (RIP) assays were performed to ascertain miR-146b-5p's interactions with LINC01311 and IMPA2 3′UTR.ResultsThe TC cells and tissues exhibited a downregulation of LINC01311 and IMPA2 and an upregulation of miR-146b-5p. LINC01311 overexpression retarded TC cell growth in vitro as well as in vivo. The luciferase reporter and RIP assays verified that miR-146b-5p recognizes LINC01311 and IMPA2 3′UTR by base pairing. LINC01311 overexpression could counteract the oncogenic effect of miR-146b-5p in vitro. Moreover, IMPA2 upregulation could offset the tumor-promoting effect of miR-146b-5p.ConclusionLINC01311-mediated inhibition of TC cell growth was achieved by targeting the miR-146b-5p/IMPA2 axis. These findings support that targeting the LINC01311/miR-146b-5p/IMPA2 axis may be a promising approach against TC progression.     

Long noncoding RNA LINC00941 promotes pancreatic cancer progression by competitively binding miR-335-5p to regulate ROCK1-mediated LIMK1/Cofilin-1 signaling

An accumulation of evidence indicates that long noncoding RNAs are involved in the tumorigenesis and progression of pancreatic cancer (PC). In this study, we investigated the functions and molecular mechanism of action of LINC00941 in PC. Quantitative PCR was used to examine the expression of LINC00941 and miR-335-5p in PC tissues and cell lines, and to investigate the correlation between LINC00941 expression and clinicopathological features. Plasmid vectors or lentiviruses were used to manipulate the expression of LINC00941, miR-335-5p, and ROCK1 in PC cell lines. Gain or loss-of-function assays and mechanistic assays were employed to verify the roles of LINC00941, miR-335-5p, and ROCK1 in PC cell growth and metastasis, both in vivo and in vitro. LINC00941 and ROCK1 were found to be highly expressed in PC, while miR-335-5p exhibited low expression. High LINC00941 expression was strongly associated with larger tumor size, lymph node metastasis, and poor prognosis. Functional experiments revealed that LINC00941 silencing significantly suppressed PC cell growth, metastasis and epithelial–mesenchymal transition. LINC00941 functioned as a molecular sponge for miR-335-5p, and a competitive endogenous RNA (ceRNA) for ROCK1, promoting ROCK1 upregulation, and LIMK1/Cofilin-1 pathway activation. Our observations lead us to conclude that LINC00941 functions as an oncogene in PC progression, behaving as a ceRNA for miR-335-5p binding. LINC00941 may therefore have potential utility as a diagnostic and treatment target in this disease.Subject terms: Pancreatic cancer, Long non-coding RNAs     

LINC01133 aggravates the progression of hepatocellular carcinoma by activating the PI3K/AKT pathway

LncRNAs exhibit crucial roles in various pathological diseases, including hepatocellular carcinoma (HCC). Therefore, it is significant to recognize the dysregulated lncRNAs in HCC progression. Recently, LINC01133 has been identified in several tumors. However, the biological role of LINC01133 in HCC remains poorly understood. Currently, we focused on the function of LINC01133 in HCC development. We observed that LINC01133 was significantly increased in HCC cells including HepG2, Hep3B, MHCC-97L, SK-Hep-1, and MHCC-97H cells compared with the normal human liver cell line HL-7702. In addition, PI3K/AKT signaling was highly activated in HCC cells. Knockdown of LINC01133 was able to inhibit HCC cell proliferation, cell colony formation, cell apoptosis, and blocked cell cycle arrest in the G1 phase. For another, downregulation of LINC01133 repressed HCC cell migration and invasion. Subsequently, the PI3K/AKT signaling pathway was strongly suppressed by silence of LINC01133 in Hep3B and HepG2 cells. Then, in vivo tumor xenografts models were established using Hep3B cells to explore the function of LINC01133 in HCC progression. Consistently, our study indicated that knockdown of LINC01133 dramatically repressed HCC tumor progression through targeting the PI3K/AKT pathway in vivo. Taken these together, we revealed that LINC01133 contributed to HCC progression by activating the PI3K/AKT pathway.     

Long noncoding RNA LINC01234 promoted cell proliferation and invasion via miR-1284/TRAF6 axis in colorectal cancer

Colorectal cancer is one of the most common and leading malignancies globally. Long noncoding RNAs (lncRNAs) function as potentially critical regulator in colorectal cancer. LINC01234, a novel lncRNA in tumor biology, regulates the progression of various tumors. However, the tumorigenic mechanism of LINC01234 in colorectal cancer is still unclear. This study was performed with the aim to prospectively investigate clinical significance, effect, and mechanism of lncRNA LINC01234 in colorectal cancer. First, we found that LINC01234, localized in the cytoplasm, was increased in both colorectal cancer cell lines and tissues. Subsequent functional assays suggested LINC01234 knockdown suppressed cell proliferation, migration, and invasion of colorectal cancer cells, while blocked cell cycle and induced cell apoptosis. Moreover, we identified that miR-1284 was target of LINC01234, we further demonstrated a negative correlation with LINC01234 in colorectal cancer tissues and cells. Furthermore, miR-1284 targeted and suppressed tumor necrosis factor receptor–associated factor 6 (TRAF6). Loss-of-function assay revealed that LINC01234 silencing suppressed colorectal cancer progression through inhibition of miR-1284. In vivo subcutaneous xenotransplanted tumor model indicated LINC01234 knockdown inhibited in vivo tumorigenic ability of colorectal cancer via downregulation of TRAF6. Collectively, this study clarified the biological significance of LINC01234/miR-1284/TRAF6 axis in colorectal cancer progression, providing insights into LINC01234 as novel potential therapeutic target for colorectal cancer therapeutic from bench to clinic.     

LINC00961 restrains cancer progression via modulating epithelial–mesenchymal transition in renal cell carcinoma

Recently, long noncoding RNA have been identified as new gene regulators and prognostic biomarkers in various cancers, including renal cell carcinoma (RCC). The expression and biological roles of LINC00961 have been reported in many human cancers. However, up to date, no study of LINC00961 has been shown in RCC. Currently, we aimed to investigate the function of LINC00961 in RCC progression. Interestingly, we observed that LINC00961 could act as a novel biomarker in predicting the diagnosis of RCC. Then, we found that LINC00961 was greatly downregulated in RCC cell lines (Caki-1, Caki-2, 786-O, A498, and ACHN cells) compared with normal renal cell lines (HK-2 cells). Then, 786-O cells and ACHN cells were infected with LV-LINC00961. As displayed in our current study, LINC00961 overexpression could obviously suppress the proliferation and survival of RCC cells in vitro. In addition, RCC cell apoptosis was greatly induced and cell cycle progression was blocked in G1 phase by upregulation of LINC00961 in 786-O cells and ACHN cells. Subsequently, we found that LV-LINC00961 was able to restrain RCC cell migration and cell invasion capacity. Meanwhile, the messenger RNA and protein expression levels of epithelial–mesenchymal transition (EMT)-associated markers Slug and N-cadherin in RCC cell lines were dramatically inhibited by overexpressing LINC00961. Finally, the in vivo experiment was carried out and we observed that LINC00961 could inhibit RCC development through modulating EMT process. Taken these together, it was indicated in our study that LINC00961 was involved in RCC progression through targeting EMT pathway.