LncRNA LOXL1-AS1 facilitates the tumorigenesis and stemness of gastric carcinoma via regulation of miR-708-5p/USF1 pathway

Long noncoding RNA LINC01559 promotes pancreatic cancer progression by acting as a competing endogenous RNA of miR-1343-3p to upregulate RAF1 expression

Background: An increasing number of studies have shown that lncRNAs are involved in the biological processes of pancreatic cancer (PC). Hence, we investigated the role of a novel noncoding RNA, LINC01559, involved in PC progression.

Results: LINC01559 and RAF1 were highly expressed in PC, while miR-1343-3p had low expression. High expression of LINC01559 was significantly associated with large tumors, lymph node metastasis, and poor prognosis. Functional experiment results revealed that silencing of LINC01559 significantly suppressed PC cell proliferation and metastasis. Meanwhile, LINC01559 could act as a ceRNA to competitively sponge miR-1343-3p to up-regulate RAF1 and activate its downstream ERK pathway

Conclusions: LINC01559 functions as an oncogene in PC progression through acting as a ceRNA of miR-1343-3p. Hence, LINC01559 is a potential diagnostic and therapeutic target.

Methods: RT-qPCR was performed to determine the expression of LINC01559 and miR-1343-3p in PC. Individual patient data were collected to investigate the correlation between clinicopathological features and LINC01559 expression. Subsequently, the expression of LINC01559, miR-1343-3p, and RAF1 was altered using transfection of vectors or inhibitors. Gain- and loss-of-function assays and mechanistic assays were applied to verify the effects of LINC01559, miR-1343-3p, and RAF1 on PC cell proliferation and metastasis in vivo and in vitro.

Long non-coding RNAs in gastric cancer: New emerging biological functions and therapeutic implications

Gastric cancer (GC) is currently the fourth most common malignancy and the third leading cause of cancer-related deaths worldwide. Long non-coding RNAs (lncRNAs), transcriptional products with more than 200 nucleotides, are not as well-characterized as protein-coding RNAs. Accumulating evidence has recently revealed that maladjustments of diverse lncRNAs may play key roles in multiple genetic and epigenetic phenomena in GC, affecting all aspects of cellular homeostasis, such as proliferation, migration, and stemness. However, the full extent of their functionality remains to be clarified. Considering the lack of viable biomarkers and therapeutic targets, future research should be focused on unravelling the intricate relationships between lncRNAs and GC that can be translated from bench to clinic. Here, we summarized the state-of-the-art advances in lncRNAs and their biological functions in GC, and we further discuss their potential diagnostic and therapeutic roles. We aim to shed light on the interrelationships between lncRNAs and GC with respect to their potential therapeutic applications. With better understanding of these relationships, the biological functions of lncRNAs in GC development will be exploitable, and promising new strategies developed for the prevention and treatment of GC.

TMPO-AS1 promotes cell proliferation of thyroid cancer via sponging miR-498 to modulate TMPO

Background

Thyroid cancer (TC) is the most frequent endocrine malignancy. Long noncoding RNAs (lncRNAs) have been confirmed to act as significant roles in tumor development. The role of lncRNA TMPO-AS1 in TC is still unclear, so it remains to be explored. The aim of the research is to investigate the role and regulatory mechanism of TMPO-AS1 in TC.

Methods

TMPO-AS1 and TMPO expression in TC tumors and cells was detected by TCGA database and QRT-PCR assay respectively. CCK-8, EDU, TUNEL and western blot assays were conducted to identify the biological functions of TMPO-AS1 in TC. Luciferase reporter and RNA pull down assays were conducted to measure the interaction among TMPO-AS1, TMPO and miR-498.

Results

TMPO-AS1 was overexpressed in TC tissues and cell lines. Knockdown of TMPO-AS1 suppressed cell growth and accelerated cell apoptosis in TC. Furthermore, downregulation of TMPO-AS1 suppressed TMPO expression in TC. The data suggested that TMPO expression was upregulated in TC tissues and cell lines and was positively correlated with TMPO-AS1 expression in TC. Furthermore, the expression of miR-498 presented low expression in TC cells. And miR-498 expression was negatively regulated by TMPO-AS1, meanwhile, TMPO expression was negatively regulated by miR-498 in TC cells. Besides, it was confirmed that TMPO-AS1 could bind with miR-498 and TMPO in TC cells. In addition, it was validated that TMPO-AS1 elevated the levels of TMPO via sponging miR-498 in TC cells.

Conclusions

TMPO-AS1 promotes cell proliferation in TC via sponging miR-498 to modulate TMPO.

Long Noncoding RNA CCAT1 Functions as a Competing Endogenous RNA to Upregulate ITGA9 by Sponging MiR-296-3p in Melanoma

Background

Melanoma is aggressive and lethal melanocytic neoplasm, and its incidence has increased worldwide in recent decades. Accumulating evidence has showed that various long noncoding RNAs (lncRNAs) participated in occurrence of malignant tumors, including melanoma. The present study was designed to investigate function of lncRNA colon cancer-associated transcript-1 (CCAT1) in melanoma.

Methods

The expression levels of CCAT1, miR-296-3p and Integrin alpha9 (ITGA9) in melanoma tissues or cells were measured using real-time quantitative polymerase chain reaction (RT-qPCR). The concentrations of glucose and lactate were measured for assessing glycolysis of melanoma cells. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazol-3-ium bromide (MTT), flow cytometry, and transwell assays were conducted to assess proliferation, apoptosis, and migration of melanoma cells. Western blot assay was performed to measure the protein expression of ITGA9, hexokinase 2 (HK2), and epithelial–mesenchymal transition (EMT)-related proteins in melanoma tissues or cells. The relationship among CCAT1, miR-296-3p, and ITGA9 was predicted and confirmed by bioinformatics analysis, dual-luciferase reporter, and RNA immunoprecipitation (RIP) assay, respectively. A xenograft experiment was established to assess the effect of CCAT1 knockdown in vivo.

Results

CCAT1 was effectively increased in melanoma tissues and cells compared with matched controls, and deficiency of CCAT1 impeded cell glycolysis, proliferation, migration while induced apoptosis, which were abrogated by knockdown of miR-296-3p in melanoma cells. In addition, our findings revealed that ITGA9 overexpression abolished miR-296-3p overexpression-induced effects on melanoma cells. Importantly, CCAT1 regulated ITGA9 expression by sponging miR-296-3p. The results of xenograft experiment suggested that CCAT1 silencing inhibited melanoma cell growth in vivo.

Conclusion

LncRNA CCAT1 promoted ITGA9 expression by sponging miR-296-3p in melanoma.

Long non-coding RNA MINCR aggravates colon cancer via regulating miR-708-5p-mediated Wnt/β-catenin pathway

BACKGROUND

Increasing evidence has found that the dysregulation of long non-coding RNAs (lncRNAs) may be important indicators in tumorigenesis. MYC-induced long non-coding RNA (MINCR) has been found to be related with some cancers, such as non-small cell lung cancer and gallbladder cancer. Besides, MINCR has potentially prognostic value for colon cancer (CC) patients' prognosis, yet its function and molecular mechanism in CC are not explored.

METHODS

qRT-PCR evaluated gene expression, and western blot detected protein level. In vitro and in vivo experiments were adopted to understand the biological role of MINCR in CC. TOP/FOP Flash assay was performed to measure the activity of Wnt/β-catenin pathway. RNA pull down, luciferase reporter and RIP assays were utilized to analyze the relationship among genes. Immunohistochemistry and HE staining techniques were utilized to evaluate Ki67 staining in xenografts.

RESULTS

MINCR was up-regulated in CC cells. Knockdown of MINCR suppressed cell proliferation and migration. MINCR could up-regulate CTNNB1 via sequestering miR-708-5p, resulting in activated Wnt/β-catenin pathway. The addition of LiCl treatment, miR-708-5p inhibitor or pcDNA3.1/CTNNB1 abolished the inhibitory impacts induced by MINCR silence in CC progression.

CONCLUSION

MINCR sponges miR-708-5p to up-regulate CTNNB1 and activate Wnt/β-catenin pathway, thus promoting the development CC. Targeting MINCR might shed new light on the therapeutic strategies of CC.

Comprehensive analysis of competitive endogenous RNAs network reveals potential prognostic lncRNAs in gastric cancer

Long non-coding RNAs (lncRNAs) are key regulators of a range of human diseases, including various cancers, with multiple previous studies having explored lncRNA dysregulation in the context of gastric cancer (GC). The present study sought to expand upon these previous results by downloading lncRNA, mRNA, and microRNA (miRNA) expression profiles derived from 180 GC tissues and 24 normal control tissues within the Cancer Genome Atlas (TCGA) database. These datasets were then interrogated to identify GC-related differentially expressed (DE) RNAs (|fold change| ≥ 2, FDR< 0.01), leading to the identification of 1946 DE lncRNAs, 123 DE miRNAs, and 3159 DE mRNAs. These results were then used to generate a putative GC-related competitive endogenous RNA (ceRNA) network composed of 131 lncRNAs, 9 miRNAs, and 78 mRNAs. Subsequent survival analyses based upon this network revealed 17 of these lncRNAs to be significantly associated with GC patient survival (P < 0.05). Further multivariable Cox regression and lasso analyses allowed for the construction of an 8-lncRNA risk score that was able to effectively predict GC patient survival with good discriminative ability. The Kaplan-Meier Plotter database further confirmed that network hub genes that were related to these 8 lncRNAs were associated with GC patient prognosis (P < 0.05). As the ceRNA network in the present study was constructed with a focus on both disease stage and differential gene expression, it represents a key resource that will offer valuable insights into the mechanistic roles of ceRNA pathways in GC development and progression.

FTX contributes to cell proliferation and migration in lung adenocarcinoma via targeting miR-335-5p/NUCB2 axis

Background

Extensive studies revealed that long non-coding RNAs (lncRNAs) could act as a regulator in tumors, including lung adenocarcinoma (LUAD). LncRNA FTX transcript, XIST regulator (FTX) has been reported to regulate the biological behaviors of some cancers. Nevertheless, its functional role and molecular mechanism remain obscure in LUAD. Our current study concentrates on exploring the biological function of FTX in LUAD.

Methods

RT-qPCR was used to test the expression of FTX, miR-335-5p or NUCB2 in LUAD cells. The effect of FTX on LUAD progression was investigated by colony formation, EdU, flow cytometry, TUNEL, transwell and western blot assays. The interaction between microRNA-335-5p (miR-335-5p) and FTX or nucleobindin 2 (NUCB2) was confirmed by luciferase reporter assay.

Results

RT-qPCR showed that FTX expression was up-regulated in LUAD cell lines. Loss-of-function assay indicated that FTX accelerated cell proliferation, migration and invasion, while inhibited cell apoptosis in LUAD. Besides, miR-335-5p, lowly expressed in LUAD cells, was discovered to be sponged by FTX. Subsequently, NUCB2 was identified as a target gene of miR-335-5p. Additionally, it was confirmed that NUCB2 functioned as an oncogene in LUAD. Rescue assays indicated that LUAD progression inhibited by FTX knockdown could be restored by NUCB2 up-regulation.

Conclusion

FTX played an oncogenic role in LUAD and contributed to cancer development via targeting miR-335-5p/NUCB2 axis.

Non-coding RNA LOXL1-AS1 exhibits oncogenic activity in ovarian cancer via regulation of miR-18b-5p/VMA21 axis

Long non-coding RNAs (lncRNAs) exert critical effects in the process of malignant cancers and lncRNA LOXL1 Antisense RNA 1 (LOXL1-AS1) has been demonstrated to be a pro-oncogene in multiple tumor types. In the current study, we illuminated the precise roles of LOXL1-AS1 in the development of ovarian cancer. LOXL1-AS1 is significantly overexpressed in ovarian carcinoma tissue compared with adjacent non-cancerous sample. The luciferase reporter gene assay reveals the relationship between LOXL1-AS1 and miR-18b-5p, miR-18b-5p and its target gene, Vacuolar ATPase Assembly Factor VMA21 (VMA21). Transfection of LOXL1-AS1 siRNA or miR-18b-5p mimics inhibits the growth and aggressive phenotypes of SKOV3 and OVCAR3 cell. Furthermore, miR-18b-5p suppresses ovarian carcinoma cell proliferation and metastasis by targeting VMA21 and LOXL1-AS1 regulates ovarian carcinoma cell growth and metastasis through sponging miR-18b-5p. These findings suggest that lncRNA LOXL1-AS1 promotes ovarian cancer cell growth, migratory and invasiveness via modulating miR-18b-5p/VMA21 axis.

LncRNA LOXL1-AS1 promotes endometrial cancer progression by sponging miR-28-5p to upregulate RAP1B expression

BACKGROUND

Increasing lncRNAs are found to be involved in the biological process of multiple cancer types. Herein, we aimed to reveal the role of LOXL1-AS1 in endometrial cancer (EC) progression.

METHODS

Tumor and corresponding normal tissues were obtained from EC patients. Si-LOXL1-AS1 and miR-28-5p inhibitor were transfected to downregulate the expressions of LOXL1-AS1 and miR-28-5p, while miR-28-5p mimics were used to upregulate the miR-28-5p expression. CCK-8 and colony assays were applied to estimate the cell proliferation. Flow cytometry was performed to measure the cell apoptosis. Wound healing and transwell assays were conducted to assess the cell migration and invasion abilities. Informatics analysis was used to explore the relationship among LOXL1-AS1, miR-28-5p and RAP1B.

RESULTS

LOXL1-AS1 was found markedly up-regulated in EC tissues and cell lines. LOXL1-AS1 knockdown displayed evident suppression in cell proliferation, migration and invasion, as well as promotion in cell apoptosis. Moreover, the LOXL1-AS1 induced regulatory effects on EC cells were partially reversed by miR-28-5p inhibitor. Mechanistically, LOXL1-AS1 competitively bond to miR-28-5p, resulting in upregulation of RAP1B. Additionally, in vivo study confirmed the findings discovered in vitro.

CONCLUSIONS

In summary, LOXL1-AS1 exerted oncogenic roles in EC progression by sponging miR-28-5p and thereby upregulating RAP1B. This finding might provide potential targets for EC therapy.

lncRNA JPX/miR-33a-5p/Twist1 axis regulates tumorigenesis and metastasis of lung cancer by activating Wnt/β-catenin signaling

Background

MicroRNAs (miRNAs) and Twist1-induced epithelial-mesenchymal transition (EMT) in cancer cell dissemination are well established, but the involvement of long noncoding RNAs (lncRNAs) in Twist1-mediated signaling remains largely unknown.

Methods

RT-qPCR and western blotting were conducted to detect the expression levels of lncRNA JPX and Twist1 in lung cancer cell lines and tissues. The impact of JPX on Twist1 expression, cell growth, invasion, apoptosis, and in vivo tumor growth were investigated in lung cancer cells by western blotting, rescue experiments, colony formation assay, flow cytometry, and xenograft animal experiment.

Results

We observed that lncRNA JPX was upregulated in lung cancer metastatic tissues and was closely correlated with tumor size and an advanced stage. Functionally, JPX promoted lung cancer cell proliferation in vitro and facilitated lung tumor growth in vivo. Additionally, JPX upregulated Twist1 by competitively sponging miR-33a-5p and subsequently induced EMT and lung cancer cell invasion. Interestingly, JPX and Twist1 were coordinately upregulated in lung cancer tissues and cells. Mechanically, the JPX/miR-33a-5p/Twist1 axis participated in EMT progression by activating Wnt/β-catenin signaling.

Conclusions

These findings suggest that lncRNA JPX, a mediator of Twist1 signaling, could predispose lung cancer cells to metastasis and may serve as a potential target for targeted therapy.

Long Non-coding RNA LOXL1-AS1 Drives Breast Cancer Invasion and Metastasis by Antagonizing miR-708-5p Expression and Activity

LOXL1-AS1, a recently characterized long non-coding RNA (lncRNA), has been reported to modulate tumor progression in several types of cancer. However, the expression and role of LOXL1-AS1 in breast cancer remain unclear. In this study, we sought to identify novel lncRNA regulators engaged in breast cancer metastasis. To this end, we examined 42 cancer-related lncRNAs between MCF7 (with low metastatic potential) and MDA-MB-231 (with high metastatic potential) cells. These lncRNAs have been found to affect the invasiveness of several cancer types, but they are still undefined in breast cancer. Among the 42 candidates, LOXL1-AS1 is significantly increased in MDA-MB-231 cells relative to MCF7 cells. We also show that LOXL1-AS1 is upregulated in breast cancer tissues and cells compared to noncancerous counterparts. Increased LOXL1-AS1 expression is correlated with tumor stage and lymph node metastasis in breast cancer patients. Biologically, overexpression of LOXL1-AS1 enhances and knockdown of LOXL1-AS1 suppresses breast cancer cell migration and invasion. In vivo studies demonstrate that depletion of LOXL1-AS1 inhibits breast cancer metastasis. Mechanistically, LOXL1-AS1 sponges miR-708-5p to increase nuclear factor κB (NF-κB) activity. LOXL1-AS1 can also interact with EZH2 protein to enhance EZH2-mediated transcriptional repression of miR-708-5p. Rescue experiments indicate that co-expression of miR-708-5p attenuates LOXL1-AS1-induced invasiveness in breast cancer. In addition, there is a negative correlation between LOXL1-AS1 and miR-708-5p expression in breast cancer specimens. Overall, LOXL1-AS1 upregulation facilitates breast cancer invasion and metastasis by blocking miR-708-5p expression and activity. LOXL1-AS1 serves as a potential therapeutic target for breast cancer treatment.

LncRNA LOXL1-AS1 facilitates the tumorigenesis and stemness of gastric carcinoma via regulation of miR-708-5p/USF1 pathway

Objectives

As one of the most life‐threatening malignancies, gastric cancer is the third contributor of cancer mortalities globally. Increasing studies have proven the regulatory roles of lncRNAs in the development of diverse malignant tumours. But little is known about its function and molecular mechanism in gastric carcinoma.

Materials and methods

RT‐qPCR was performed to measure the expression pattern of LOXL1‐AS1 in gastric cancer. To ascertain its definite role, CCK‐8, EdU, Western blot, transwell and sphere formation assays were adopted. RNA pull‐down, RIP, ChIP and luciferase reporter assays were carried out to investigate the molecular mechanism of LOXL1‐AS1 in gastric carcinoma.

Results

LOXL1‐AS1 was highly expressed in tissues and cells of gastric cancer. The upregulation of LOXL1‐AS1 predicted poor prognosis in gastric carcinoma. Our findings demonstrated that LOXL1‐AS1 accelerated the deterioration of gastric cancer by inducing cell proliferation, migration, EMT and stemness. Moreover, the expression of USF1 in gastric cancer was higher than in normal control and LOXL1‐AS1 negatively modulated USF1. Functionally, LOXL1‐AS1 acted as a ceRNA to upregulate USF1 via sponging miR‐708‐5p. Besides, we confirmed USF1 promoted the transcription of stemness marker SOX2. Rescue experiments testified the stimulative role of LOXL1‐AS1/miR‐708‐5p/USF1 pathway in gastric cancer progression. It was also validated that LOXL1‐AS1 facilitated cell growth of gastric carcinoma in vivo.

Conclusions

Our study unravelled that LOXL1‐AS1/miR‐708‐5p/USF1 pathway contributed to the development of gastric cancer.