Long non-coding RNA LOXL1-AS1: a potential biomarker and therapeutic target in human malignant tumors

Long non-coding RNAs (lncRNAs) are transcripts that contain more than 200 nucleotides. Despite their inability to code proteins, multiple studies have identified their important role in human cancer through different mechanisms. LncRNA lysyl oxidase like 1 antisense RNA 1 (LOXL1-AS1), a newly discovered lncRNA located on human chromosome 15q24.1, has recently been shown to be involved in the occurrence and progression of various malignancies, such as colorectal cancer, gastric cancer, hepatocellular carcinoma, prostate cancer, non-small cell lung cancer, ovarian cancer, cervical cancer, breast cancer, glioma, thymic carcinoma, pancreatic carcinoma. LOXL1-AS1 acts as competitive endogenous RNA (ceRNA) and via sponging various miRNAs, including miR-374b-5p, miR-21, miR-423-5p, miR-589-5p, miR-28-5p, miR-324-3p, miR-708-5p, miR-143-3p, miR-18b-5p, miR-761, miR-525-5p, miR-541-3p, miR-let-7a-5p, miR-3128, miR-3614-5p, miR-377-3p and miR-1224-5p to promote tumor cell proliferation, invasion, migration, apoptosis, cell cycle, and epithelial-mesenchymal transformation (EMT). In addition, LOXL1-AS1 is involved in the regulation of P13K/AKT and MAPK signaling pathways. This article reviews the current understanding of the biological function and clinical significance of LOXL1-AS1 in human cancers. These findings suggest that LOXL1-AS1 may be both a reliable biomarker and a potential therapeutic target for cancers.

LOXL1-AS1 contributes to metastasis in sonic-hedgehog medulloblastoma by promoting cancer stem-like phenotypes

BACKGROUND

Medulloblastomas (MBs) are one of the most common malignant brain tumor types in children. MB prognosis, despite improvement in recent years, still depends on clinical and biological risk factors. Metastasis is the leading cause of MB-related deaths, which highlights an unmet need for risk stratification and targeted therapy to improve clinical outcomes. Among the four molecular subgroups, sonic-hedgehog (SHH)-MB harbors clinical and genetic heterogeneity with a subset of high-risk cases. Recently, long non-coding (lnc)RNAs were implied to contribute to cancer malignant progression, but their role in MB remains unclear. This study aimed to identify pro-malignant lncRNAs that have prognostic and therapeutic significance in SHH-MB.

METHODS

The Daoy SHH-MB cell line was engineered for ectopic expression of MYCN, a genetic signature of SHH-MB. MYCN-associated lncRNA genes were identified using RNA-sequencing data and were validated in SHH-MB cell lines, MB tissue samples, and patient cohort datasets. SHH-MB cells with genetic manipulation of the candidate lncRNA were evaluated for metastatic phenotypes in vitro, including cell migration, invasion, sphere formation, and expressions of stemness markers. An orthotopic xenograft mouse model was used to evaluate metastasis occurrence and survival. Finally, bioinformatic screening and in vitro assays were performed to explore downstream mechanisms.

RESULTS

Elevated lncRNA LOXL1-AS1 expression was identified in MYCN-expressing Daoy cells and MYCN-amplified SHH-MB tumors, and was significantly associated with lower survival in SHH-MB patients. Functionally, LOXL1-AS1 promoted SHH-MB cell migration and cancer stemness in vitro. In mice, MYCN-expressing Daoy cells exhibited a high metastatic rate and adverse effects on survival, both of which were suppressed under LOLX1-AS1 perturbation. Integrative bioinformatic analyses revealed associations of LOXL1-AS1 with processes of cancer stemness, cell differentiation, and the epithelial-mesenchymal transition. LOXL1-AS1 positively regulated the expression of transforming growth factor (TGF)-β2. Knockdown of TGF-β2 in SHH-MB cells significantly abrogated their LOXL1-AS1-mediated prometastatic functions.

CONCLUSIONS

This study proved the functional significance of LOXL1-AS1 in SHH-MB metastasis by its promotion of TGF-β2-mediated cancer stem-like phenotypes, providing both prognostic and therapeutic potentials for targeting SHH-MB metastasis.

Up-regulation of long non-coding RNA LOXL1-AS1 functions as an oncogene in cervical squamous cell carcinoma by sponging miR-21

LncRNA LOXL1-AS1 has been reported to be upregulated in several types of cancer and plays oncogenic roles. We analysed TCGA dataset and observed the downregulation of LOXL1-AS1 in cervical squamous cell carcinoma (CSCC). We therefore analysed the roles of LOXL1-AS1 in CSCC. We observed that LOXL1-AS1 was downregulated in CSCC. LOXL1-AS1 was predicted to interact with miR-21, while overexpression experiments showed that LOXL1-AS1 and miR-21 had no significant effects on the expression of each other. However, LOXL1-AS1 overexpression led to the upregulation of RHOB, a direct target of miR-21. Cell invasion and migration analysis showed decreased invasion and migration rates of CSCC cells after LOXL1-AS1 and RHOB overexpression. MiR-21 played an opposite role at reduced the effects of LOXL1-AS1 and RHOB overexpression. Therefore, LOXL1-AS1 may promote CSCC cell invasion and migration by sponging miR-21 to upregulate RHOB.

Application of lncRNA-miRNA-mRNA ceRNA network analysis in the treatment of androgenic alopecia

BACKGROUND

Long noncoding RNAs (lncRNAs) can be used as competitive endogenous RNAs (ceRNAs) to bind to microRNAs (miRNAs) to regulate gene expression. Previous studies have demonstrated that ceRNAs play an important role in the development of tumors. However, it is not clear whether the lncRNA-miRNA-mRNA ceRNA network plays a role in androgenic alopecia (AGA).

METHODS

The hair follicles of three AGA patients and three healthy individuals were collected for high-throughput whole transcriptome sequencing to screen for differentially expressed lncRNAs. Differentially expressed lncRNA target genes were subjected to databases to predict miRNA-mRNA and lncRNA-miRNA relationship pairs, and a ceRNA network was constructed using Cytoscape software. Relative expression was verified by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR).

RESULTS

84 lncRNAs were significantly differentially expressed between the hair follicles of AGA patients and those of healthy individuals; 30 were upregulated, and 54 were downregulated. The top 10 upregulated lncRNAs were ENST00000501520, ENST00000448179, ENST00000318291, ENST00000568280, ENST00000561121, ENST00000376609, ENST00000602414, ENST00000573866, ENST00000513358, and ENST00000564194. The top 10 downregulated lncRNAs were ENST00000566804, ENST00000561973, ENST00000587680, ENST00000569927, ENST00000340444, ENST00000424345, ENST00000589787, NR_024344, NR_073026, and NR_110001. The qRT-PCR validation results and receiver-operating characteristic curve analysis indicated that one upregulated lncRNA, LOXL1-AS1 (ENST00000564194), had the most significant clinical diagnostic potential. After further analysis, it was concluded that LOXL1-AS1 could be used as a sponge to target hsa-miR-5193, thereby regulating TP53 expression.

CONCLUSION

The ceRNA network-regulating AGA was constructed through high-throughput sequencing. Our study also identified a key lncRNA that is possibly related to the AGA pathological process.

Long Non-coding RNA LOXL1-AS1 Facilitates Colorectal Cancer Progression via Regulating miR-1224-5p/miR-761/HK2 Axis

Colorectal cancer (CRC) is one of the most common cancers worldwide. Long non-coding RNAs (lncRNAs) play crucial roles in the development of malignant tumors. The present study aimed to explore the function and potential mechanism of lncRNA LOXL1 antisense RNA 1 (LOXL1-AS1) in CRC. The abundance of LOXL1-AS1, miR-1224-5p, miR-761, and hexokinase 2 (HK2) was detected by quantitative real-time PCR or western blot assay. Cell proliferation was assessed by Cell Counting Kit-8 and colony formation assays. Cell apoptosis, invasion, and migration were examined by flow cytometry, transwell assay, and wound healing assay. Glycolysis was evaluated by detecting glucose consumption, lactate production, and ATP/ADP ratios. Xenograft assay was used for in vivo tumor growth analysis. LOXL1-AS1 and HK2 levels were increased, while miR-1224-5p and miR-761 levels were reduced in CRC tissues and cells. Knockdown of LOXL1-AS1 suppressed CRC cell proliferation, invasion, migration, and glycolysis, and induced cell apoptosis. Silencing of LOXL1-AS1 blocked tumor growth in vivo. Moreover, LOXL1-AS1 accelerated CRC cell progression by absorbing miR-1224-5p/miR-761. Besides, miR-1224-5p and miR-761 inhibited CRC cell progression via targeting HK2. LOXL1-AS1 contributed to CRC progression via modulating miR-1224-5p/miR-761/HK2 pathway.

The LOXL1 antisense RNA 1 (LOXL1-AS1)/microRNA-423-5p (miR-423-5p)/ectodermal-neural cortex 1 (ENC1) axis promotes cervical cancer through the mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway

As the fourth commonest malignancy among females worldwide, cervical cancer (CC) poses a huge challenge to human health. The pivotal regulatory roles of lncRNAs in cancers have been highlighted. LOXL1 antisense RNA 1 (LOXL1-AS1) has been reported to play a key role in cervical squamous cell carcinoma and other various cancers. Thus, we investigated the roles and mechanisms of lncRNA LOXL1-AS1 in CC. The in vivo experiments demonstrated that LOXL1-AS1 downregulation inhibited tumor growth and metastasis and proliferation of CC cells. The results of RT-qPCR demonstrated that LOXL1-AS1 and ectodermal-neural cortex 1 (ENC1) expression levels were upregulated in CC cells and tissues, while microRNA-423-5p (miR-423-5p) level was downregulated. As subcellular fractionation assays, RNA pull down assays and luciferase reporter assays revealed, LOXL1-AS1 bound to miR-423-5p and miR-423-5p targeted ENC1. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, wound healing and colony formation assays demonstrated that miR-423-5p upregulation and LOXL1-AS1 downregulation inhibited CC cell proliferation and migration, while ENC1 upregulation attenuated the inhibitory effects of miR-423-5p upregulation on the malignant phenotypes of CC cells. Western blotting was conducted to measure protein levels and the results showed that ENC1 knockdown inhibited the activation of ERK/MEK pathway. In summary, the LOXL1-AS1/miR-423-5p/ENC1 axis accelerates CC development through the MEK/ERK pathway.

LncRNA LOXL1-AS1 Facilitates the Oncogenic Character in Cervical Cancer by the miR-526b-5p /LYPLA1 Axis

Increasing reports demonstrate that long noncoding RNAs participate in the regulation of numerous malignancies, cervical cancer included. Although lncRNA LOXL1 antisense RNA 1 has been commonly accepted to be an oncogene in many cancers. Here, the role of LOXL1-AS1 in CC still need to be explored. In this study, LOXL1-AS1 was found elevated in CC tissues and cells. LOXL1-AS1 depletion restrained CC cell proliferation, migration, invasion, and angiogenesis in vivo. Furthermore, we found that LOXL1-AS1 upregulated Lysophospholipase 1 expression via sequestering miR-526b-5p. Rescue assays revealed that overexpression of LYPLA1 reversed the LOXL1-AS1 silencing-induced inhibitory effects on the malignant phenotypes of CC cells. To conclude, this study showed that LOXL1-AS1 facilitates cellular process in CC via functioning as a miR-526b-5p sponge.

LncRNA LOXL1-AS1 inhibits proliferation of PDLSCs and downregulates IL-1β in periodontitis patients

BACKGROUND

The carcinogenic role of lncRNA LOXL1-AS1 in thoracic aortic aneurysm has been confirmed, but its role in the pathogenesis of periodontitis remains unclear. Our preliminary deep sequencing data revealed LOXL1-AS1 downregulation in periodontitis and its inverse correlation with IL-1β, a critical inflammatory mediator in periodontitis. This study was therefore performed to investigate the potential interaction between LOXL1-AS1 and IL-1β in periodontitis.

METHODS

The study included 30 periodontitis patients (18 males and 12 females at the age of 34 to 44 years, with a mean of 39.3 ± 2.1 years) and 30 healthy controls (18 males and 12 females at the age of 33 to 44 years with a mean of 39.2 ± 2.0 years). The effects of LOXL1-AS1 overexpression on IL-1β were evaluated by RT-qPCR and Western blot. CCK-8 assay was used to analyze cell proliferation.

RESULTS

LOXL1-AS1 was downregulated in periodontitis-affected periodontal ligament stem cells (PDLSCs) compared with healthy PDLSCs, while IL-1β was upregulated in periodontitis-affected PDLSCs and was inversely correlated with LOXL1-AS1. LOXL1-AS1 overexpression mediated IL-1β downregulation in PDLSCs. IL-1β treatment did not affect LOXL1-AS1 expression. Moreover, LOXL1-AS1 overexpression inhibited the proliferation of periodontitis-affected PDLSCs. LOXL1-AS1 overexpression and IL-1β knockdown increased Bax/Bcl-2 ratio and caspase-3 level.

CONCLUSION

This study is the first to report LOXL1-AS1 downregulation in periodontitis. Moreover, LOXL1-AS1 might inhibit the proliferation of periodontitis-affected PDLSCs and downregulate IL-1β to improve periodontitis.

Study on the mechanism of LOXL1-AS1/miR-3614-5p/YY1 signal axis in the malignant phenotype regulation of hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors with high mortality worldwide. Accumulating researches have indicated that long non‑coding RNAs (lncRNAs) are involved in varies human cancers, including HCC. Nevertheless, the specific molecular mechanism of lncRNA lysyl oxidase like 1 antisense RNA 1 (LOXL1-AS1) in HCC is still unclear.

Methods

LOXL1-AS1 expression was tested via qRT-PCR in HCC cells. Functional and mechanism assays were respectively done to evaluate the biological functions of HCC cells and the potential interaction of LOXL1-AS1 and other factors.

Results

We discovered that LOXL1-AS1 was high expressed in HCC cells. Inhibition of LOXL1-AS1 repressed cell proliferation, migration and invasion, but enhanced cell apoptosis in HCC. Further, miR-3614-5p was proven to be sponged by LOXL1-AS1. Additionally, Yin Yang 1 (YY1) was proven as the target gene of miR-3614-5p, and YY1 depletion could repress HCC cell malignant behaviors. YY1 could also transcriptionally activate LOXL1-AS1 expression. In rescue assays, we confirmed that overexpression of YY1 or miR-3614-5p inhibition could reverse the suppressive effects of LOXL1-AS1 silence on the malignant behaviors of HCC cells.

Conclusion

In short, LOXL1-AS1/miR-3614-5p/YY1 forms a positive loop in modulating HCC cell malignant behaviors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13062-021-00312-8.

Long non-conding RNA LOXL1-AS1 sponges miR-589-5p to up-regulate CBX5 expression in renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) is a common malignant tumor that seriously endangers people's health. In recent years, long non-coding RNAs (lncRNAs) have been discovered to play vital roles in diverse cancers, including RCC. LncRNA lysyl oxidase like 1 antisense RNA 1 (LOXL1-AS1) has been found to exert carcinogenic functions in several cancers, but its role and mechanism in RCC have not been investigated.

METHODS

qRT-PCR was utilized for testing RNA expression and Western blot for protein expression in RCC tissues or cells. Then, we assessed cell function by conducting a series of functional experiments, such as 5-ethynyl-2'-deoxyuridine staining, colony formation, flow cytometry, JC-1, Western blot and transwell migration experiments. Following, RNA immunoprecipitation, pull down and luciferase reporter experiments were carried out to explore the regulatory mechanisms of LOXL1-AS1 in RCC.

RESULTS

LOXL1-AS1 was highly expressed in RCC tissues and cells. Moreover, knockdown of LOXL1-AS1 hampered RCC cell proliferation and migration. Importantly, miR-589-5p that was lowly expressed and worked as a tumor-inhibitor in RCC was found to bind with LOXL1-AS1. Furthermore, chromobox 5 (CBX5) targeted by miR-589-5p could expedite cell proliferation and migration in RCC. Finally, overexpressed CBX5 or inhibited miR-589-5p reversed the repressive impacts of silenced LOXL1-AS1 on RCC malignant phenotypes.

CONCLUSIONS

LncRNA LOXL1-AS1 sequestered miR-589-5p to augment CBX5 expression in RCC cells, opening a new way for potential development in RCC treatment.

LncRNA LOXL1-AS1 promotes esophageal squamous cell carcinoma progression by targeting DESC1

Recently, ample evidence indicated that numerous aberrantly expressed long non-coding RNAs (lncRNAs) participated in the development of multiple malignancies. However, the expression and function of lncRNA LOXL1-AS1 in mediating esophageal squamous cell carcinoma (ESCC) carcinogenesis remains largely elusive. Here we validated that LOXL1-AS1 was significantly upregulated in ESCC tissues compared with the corresponding adjacent non-neoplastic tissues, and LOXL1-AS1 expression was positively correlated with ESCC patients' lymph node metastasis. Besides, LOXL1-AS1 knockdown impaired ESCC cells proliferation, migration and invasion capabilities in vitro. Furthermore, inhibiting LOXL1-AS1 in ESCC cells increased the percentage of cells at the G1 phase, accompanied by reducing in S phase in contrast to scramble control, and silencing of LOXL1-AS1 evoked ESCC cell apoptosis. From high throughput RNA sequencing (RNA-seq) analysis, we identified that differentially expressed in squamous cell carcinoma 1 (DESC1) was a critical downstream target of LOXL1-AS1. Taken together, we demonstrated the function and mechanism of LOXL1-AS1 in contributing ESCC progression for the first time, and indicated LOXL1-AS1 may be a novel therapeutic biomarker of ESCC.

Targeted-regulating of miR-515-5p by LncRNA LOXL1-AS1 on the proliferation and migration of trophoblast cells

OBJECTIVE

This study aims to elucidate the molecular mechanism of LOXL1-AS1 in proliferation and migration of trophoblast cells.

METHODS

We have used specific small interfering RNAs (si-RNA) and microRNA (mi-RNA) to knock down the target gene or m-RNA. In this regard we used following siRNAs: si-NC, si-LOXL1-AS1, pcDNA-NC, pcDNA-LOXL1-AS1, miR-NC, miR-515-5p. These si-RNA and miRNA were transfected into JeG-3 cells. Real-time quantitative PCR (RT-qPCR) was used to detect the expressions of LOXL1-AS1 and miR-515-5p. Western blot was used to detect Cyclin D1, matrix metalloproteinase 2 (MMP2), matrix metalloproteinases 9 (MMP9), phosphorylated p65 (p-p65), profilin of phosphorylated nuclear transcription factor κB (p-IκBα). MTT assay was used to detect cell survival rate, and the luciferase assay was used to detected the targeting relationship of LOXL1-AS1 and miR-515-5p.

RESULTS

Our results showed that human placental trophoblast cells had higher level of LOXL1-AS1 in comparison to human choriocarcinoma cells, however, human placental trophoblast cells had lower level of miR-515-5p. In addition, the expression of CyclinD1, MMP2, MMP9 were significantly decreased in JeG-3 cell lines. We observed lower cell survival rate and lower cell migration number in JeG-3 cell lines. Our results demonstrated that LOXL1-AS1 could target miR-515-5p, and subsequently reverse the inhibitory effect of LOXL1-AS1 on proliferation and migration in JEG-3 cells. Also, lower expressions of p-p65 and p-IкBα in JeG-3 cells showed that miR-515-5p could reversed the inhibitory effect of LOXL1-AS1 on NF-κB signaling pathway.

CONCLUSIONS

The low expression of LOXL1-AS1 inhibits the proliferation and migration of human choriocarcinoma cells, which might be related to miR-515-5p and NF-κB signaling pathways.

LncRNA LOXL1-AS1 controls osteogenic and adipocytic differentiation of bone marrow mesenchymal stem cells in postmenopausal osteoporosis through regulating the miR-196a-5p/Hmga2 axis

INTRODUCTION

Exploring molecular mechanisms of human bone marrow mesenchymal stem cells (hBMMSCs) differentiation, a crucial step for bone formation, is a new direction for treating postmenopausal osteoporosis. LncRNAs are involved in lots of biological processes including hBMMSCs differentiation. The present study aimed to explore the effect of LOXL1-AS1 on hBMMSCs differentiation.

MATERIALS AND METHODS

We examined the expression levels of LOXL1-AS1, miR-196a-5p and Hmga2 in peripheral blood from postmenopausal osteoporosis patients by RT-qPCR, and detected their changes during the osteogenic differentiation of hBMMSCs by RT-qPCR. RT-qPCR and western blot measured the level of biomarkers of bone formation and osteogenic differentiation (osteopontin, OPN; Alkaline phosphatase, ALP; Runt-related transcription factor-2, Runx-2). The effects of LOXL1-AS1 on the osteogenic and adipocytic differentiation of hBMMSCs were, respectively, determined by ALP, ARS staining assays and oil red O staining assay.

RESULTS

The abnormal high expression of LOXL1-AS1 was found in patients. LOXL1-AS1 expression showed a gradual decrease during the osteogenic differentiation of hBMMSCs. However, LOXL1-AS1 overexpression inhibited the hBMMSCs osteogenic differentiation but promoted adipocytic differentiation. Furthermore, LOXL1-AS1 was identified to be a sponge of miR-196a-5p and Hmga2 as a target gene of miR-196a-5p. Besides, LOXL1-AS1 sponged miR-196a-5p to mediate Hmga2 expression, which played contrary effects on regulating osteogenic and adipocytic differentiation of hBMMSCs. Moreover, LOXL1-AS1/miR-196a-5p/Hmga2 axis regulated hBMMSCs differentiation through controlling C/EBPβ-mediated PPARγ expression.

CONCLUSION

These findings facilitate understanding the molecular mechanism of hBMMSCs differentiation and bring up a novel sight for postmenopausal osteoporosis therapy.

LOXL1-AS1 contributes to the proliferation and migration of laryngocarcinoma cells through miR-589-5p/TRAF6 axis

Background

LOXL1-AS1 is a long non-coding RNA (lncRNA) that plays crucial roles in various cancers. However, the functional role of LOXL1-AS1 in laryngocarcinoma remains unclear. Thus we planned to probe into the function and underlying mechanism of LOXL1-AS1 in laryngocarcinoma.

Methods

Gene expression was evaluated in laryngocarcinoma cells using RT-qPCR. The ability of cell proliferation and migration was assessed by CCK8, colony formation, wound healing and transwell assays. The interaction among LOXL1-AS1, miR-589-5p and TRAF6 was detected by Ago2-RIP, RNA pull down and luciferase reporter assays.

Results

LOXL1-AS1 was overexpressed in laryngocarcinoma cells. Silencing of LOXL1-AS1 suppressed cell proliferation, migration and EMT in laryngocarcinoma. Moreover, miR-589-5p, the downstream of LOXL1-AS1, directly targeted TRAF6 in laryngocarcinoma. Importantly, LOXL1-AS1 augmented TRAF6 expression in laryngocarcinoma cells by sequestering miR-589-5p. Besides, miR-589-5p worked as a tumor-inhibitor while TRAF6 functioned as a tumor-facilitator in laryngocarcinoma. Of note, rescue experiments both in vitro and in vivo validated that LOXL1-AS1 aggravated the malignancy in laryngocarcinoma by targeting miR-589-5p/TRAF6 pathway.

Conclusions

LOXL1-AS1 promotes the proliferation and migration of laryngocarcinoma cells through absorbing miR-589-5p to upregulate TRAF6 expression.

Long Non-Coding RNA LOXL1-AS1 Enhances Colorectal Cancer Proliferation, Migration and Invasion Through miR-708-5p/CD44-EGFR Axis

Introduction

Colorectal cancer (CRC), the third most common cancer worldwide, involves a physiological and pathological long non-coding RNA (lncRNA) paradigm shift. It has been reported that the lncRNA LOXL1-AS1 affects tumor development for many kinds of cancers, but its functions and mechanisms in CRC remain unknown.

Methods

Expression levels of LOXL1-AS1 and miR-708-5p within CRC tissues and cell lines were measured using qRT-PCR. The performance of gain-of-function and loss-of-function assays was aimed at examining the effects of LOXL1-AS1 and miR-708-5p; colony formation and cell viability assays were carried out to measure cell multiplication; and Transwell migration and wound-healing assays were carried out for the measurement of cell migration and invasion. Luciferase reporter assay was used to verify the interactions between LOXL1-AS1 and miR-708-5p and between miR-708-5p and the CD44-EGFR signaling pathway. Finally, expression of CD44 and EGFR proteins was measured by Western blot and immunofluorescence assays.

Results

In this study, we reveal that the regulation of lncRNA LOXL1-AS1 occurs within CRC based on the correlation with poor clinical outcomes. LOXL1-AS1 knockdown along with miR-708-5p overpresentation in CRC cell lines inhibited cell multiplication, migration, and invasion. The inhibiting effect of LOXL1-AS1 knockdown on CRC was reversed by upregulating the CD44-EGFR signal pathway. From the perspective of mechanism, LOXL1-AS1 imposes sponging upon miR-708-5p and thereby promotes the CD44-EGFR signal pathway in CRC cells.

Discussion

This study demonstrated that lncRNA LOXL1-AS1 enhances multiplication, migration, invasion, and progression of CRC by sponging miR-708-5p to regulate the CD44-EGFR signal pathway.

LncRNA LOXL1-AS1 is transcriptionally activated by JUND and contributes to osteoarthritis progression via targeting the miR-423-5p/KDM5C axis

AIMS

This study focused on investigating the potential role of long non-coding RNA (lncRNA) lysyl oxidase like 1 antisense RNA 1 (LOXL1-AS1) in the progression of osteoarthritis (OA).

MATERIALS AND METHODS

qRT-PCR assay was applied to detect gene expression, while western blot was performed to measure levels of apoptosis-related proteins. CCK-8, colony formation and TUNEL assays were conducted to explore the functional role of LOXL1-AS1 in OA. ChIP assay was utilized to assess the affinity between JunD proto-oncogene, AP-1 transcription factor subunit (JUND) and LOXL1-AS1 promoter. Mechanism experiments were implemented to investigate the underlying molecular mechanism of LOXL1-AS1.

KEY FINDINGS

LOXL1-AS1 was up-regulated in OA cartilage tissues. Silencing LOXL1-AS1 hampered proliferation and inflammation, yet promoting apoptosis in chondrocytes. LOXL1-AS1 was transcriptionally activated by JUND1. LOXL1-AS1 sequestered miR-423-5p and abolished miR-423-5p-mediated repression on lysine demethylase 5C (KDM5C), thus promoted the development of OA.

SIGNIFICANCE

LncRNA LOXL1-AS1 is transcriptionally activated by JUND and facilitates the proliferation and inflammation of chondrocytes via elevating miR-423-5p-mediated KDM5C in OA, which may provide potential therapeutic target for OA.

LOXL1-AS1 Contributes to Non-Small Cell Lung Cancer Progression by Regulating miR-3128/RHOXF2 Axis

Purpose

The purpose of this study was to investigate the molecular mechanism of LncRNA LOXL1-AS1 in non-small cell lung cancer (NSCLC).

Methods

Lung cancer cell lines (H1299, A549, H520 and H596) and human normal lung epithelial cell line (BEAS-2B) were used in this study. Gene expression was measured by qRT-PCR (quantitative real-time PCR). The bioinformatics databases (miRDB and TargetScan7) were used to predict target genes. Luciferase assay and pull-down assay were processed for verifying the binding sites. CCK8 assay was used for detecting proliferation, and transwell assay was undertaken for migration and invasion.

Results

LncRNA LOXL1-AS1 was higher expressed in lung cancer tissues and cells. Moreover, LOXL1-AS1 expression was upregulated in tumor tissues with advanced stages and metastasis. After knocking down LOXL1-AS1, proliferation, invasion and migration of H1299 and A549 cells were inhibited. Interestingly, miR-3128 was negatively regulated by LncRNA LOXL1-AS1, which inhibited the expression of RHOXF2. Rescue assay also confirmed that miR-3128 inhibitor and oeRHOXF2 could rescue the effect of down-regulated LOXL1-AS1 on proliferation, invasion and migration progression.

Conclusion

LOXL1-AS1 promotes the progression of NSCLC by regulating miR-3128/RHOXF2 axis, which might be a new potential target for the diagnosis and treatment of NSCLC.

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.

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.

LOXL1-AS1 Drives The Progression Of Gastric Cancer Via Regulating miR-142-5p/PIK3CA Axis

Background

Gastric cancer (GC) is a deadly disease, and its incidence is especially high in East Asia including China. Recently, some long non-coding RNA (lncRNAs) have been identified as oncogenes or tumor suppressors. This study aimed to determine the function and mechanism of lncRNA LOXL1-AS1 on the progression of GC.

Methods

RT-PCR was done to measure the expression levels of LOXL1-AS1 and miR-142-5p in GC tissues. The association between pathological indexes and LOXL1-AS1 expression was also analyzed. Human GC cell lines AGS and BGC823 were used as cell models. CCK-8 and colony formation assays were conducted to assess the effect of LOXL1-AS1 on the proliferation of GC cell lines. Transwell assay was conducted to determine the influence of LOXL1-AS1 on cell migration and invasion. Furthermore, luciferase reporter assay was carried out to confirm the relationship of miR-142-5p with LOXL1-AS1. Additionally, Western blot was done to detect the regulatory function of LOXL1-AS1 on PIK3CA, a target of miR-142-5p. In vivo experiment was also performed to validate the roles and mechanism of LOXL1-AS1 on the growth and metastasis of GC cells.

Results

LOXL1-AS1 expression in GC samples was significantly increased, which was correlated with unfavorable pathological indexes. Highly expressed LOXL1-AS1 was closely linked to shorter overall survival time and post-progression survival time of the patients. LOXL1-AS1 markedly modulated the malignant phenotypes of GC cells. Additionally, overexpressed LOXL1-AS1 notably reduced the expression of miR-142-5p, but enhanced the expression level of PIK3CA. In vivo experiments further validated that knockdown of LOXL1-AS1 inhibited the growth and metastasis of GC cells via regulating miR-142-5p and PIK3CA.

Conclusion

LOXL1-AS1 was a sponge of tumor suppressor miR-142-5p in GC, enhanced the expression of PIK3CA indirectly and functioned as an oncogenic lncRNA.

LncRNA LOXL1-AS1 regulates the tumorigenesis and development of lung adenocarcinoma through sponging miR-423-5p and targeting MYBL2

Lung adenocarcinoma (LUAD) is the most common form of malignant tumor and closely correlated with high risk of death worldwide. Accumulating researches have manifested that long noncoding RNAs (lncRNAs) are deeply involved in the progression of multiple cancers. LncRNA LOXL1 antisense RNA 1 (LOXL1‐AS1) was identified as an oncogene in several cancers, nonetheless, its biological effect and regulatory mechanism have not been explained in LUAD. Our present study suggested that LOXL1‐AS1 expression was considerably increased in LUAD tissues and cells. Moreover, LOXL1‐AS1 deficiency notably hampered cell proliferation and migration as well as dramatically facilitated cell apoptosis. Through molecular mechanism assays, LOXL1‐AS1 was identified as a cytoplasmic RNA and acted as a sponge of miR‐423‐5p. Furthermore, MYBL2 was targeted and negatively modified by miR‐423‐5p. Rescue experiments revealed that MYBL2 knockdown could counteract miR‐423‐5p repression‐mediated enhancement on the progression of LOXL1‐AS1 downregulated LUAD cells. More importantly, MYBL2 was discovered to interact with LOXL1‐AS1 promoter, indicating a positive feedback loop of LOXL1‐AS1/miR‐423‐5p/MYBL2 in LUAD. These findings manifested the carcinogenic role of LOXL1‐AS1 and LOXL1‐AS1/miR‐423‐5p/MYBL2 feedback loop in LUAD, which could be helpful to explore effective therapeutic strategy for LUAD patients.

LncRNA LOXL1-AS1/miR-28-5p/SEMA7A axis facilitates pancreatic cancer progression

Pancreatic cancer (PC), one of the most aggressive and lethal human malignancies, is associated with a deplorable prognosis despite progressive therapeutic strategies. Emerging evidence manifests that miR-28-5p is involved in several cancers, and its descending expression is associated with poor prognosis. Nevertheless, the function of miR-28-5p in PC remains unclear. Thus, the underlying regulatory mechanism of miR-28-5p in PC is urgent to be clarified. In the present study, we first recognized miR-28-5p was downregulated in PC, and miR-28-5p overexpression inhibited cell proliferation and migration in PC. Then miR-28-5p was verified to act as a molecular sponge of LOXL1-AS1. Therefore, the function of LOXL1-AS1 was further explored in PC, presenting that LOXL1-AS1 suppression inhibited cell proliferation and migration. What is more, SEMA7A was found to be a target gene for miR-28-5p and was upregulated in PC. In addition, LOXL1-AS1 could positively regulate SEMA7A expression while miR-28-5p could negatively regulate SEMA7A expression. According to rescue experiments, SEMA7A overexpression partially neutralized LOXL1-AS1 silence-mediated inhibitory function on progression in PC. Taken together, all the data demonstrated that LOXL1-AS1/miR-28-5p/SEMA7A axis facilitated pancreatic cancer progression, which may be regarded as an innovative therapeutic target for PC treatment. SIGNIFICANCE OF THE STUDY: Our findings constitute the first report to delineate that lncRNA LOXL1-AS1/miR-28-5p/SEMA7A axis facilitates PC progression. According to our experimental results, we found the expression of miR-28-5p was downregulated in PC cells and miR-28-5p overexpression inhibited cell proliferation and migration in PC. LOXL1-AS1 could sponge miR-28-5p and then upregulate the expression of SEMA7A. Thus, LOXL1-AS1/miR-28-5p/SEMA7A axis facilitated PC progression. This initially proposed point might provide a novel molecular target for PC treatment.

LncRNA LOXL1-AS1 promotes invasion and proliferation of non-small-cell lung cancer through targeting miR-324-3p

LncRNAs are played crucial roles in athogenesis of NSCLC. LOXL1-AS1 involved in development of several tumors. So far, there is no study about expression and function pattern of the LOXL1-AS1 in NSCLC. In this reference, we firstly proved that LOXL1-AS1 was overexpressed in NSCLC cell lines (H23, A549, H1299 and SPC-A1) compared to 16HBE cell. The expression of LOXL1-AS1 was overexpressed in NSCLC specimens than adjacent control specimens. We found that 29 of 40 cases showed higher LOXL1-AS1 expression in NSCLC samples as compared to adjacent control specimens. Ectopic expression of LOXL1-AS1 promoted H1299 cell and H23 cell proliferation. LOXL1-AS1 overexpression promoted ki-67 and cyclin D1 expression in the NSCLC cell. Overexpression of LOXL1-AS1 promoted cell invasion and induced N-cadherin and Vimentin expression and suppressed E-cadherin expression in the NSCLC cell. LOXL1-AS1 acts as one sponge for miR-324-3p in NSCLC cell. Moreover, the expression of miR-324-3p was lower in NSCLC specimens than adjacent control specimens. We found that 24 of 40 cases showed lower miR-324-3p expression in NSCLC samples as compared to adjacent control specimens. Further correlation assay indicated a negative association between miR-324-3p and LOXL1-AS1 expression. miR-324-3p restoration attenuates the function of LOXL1-AS1 overexpression on NSCLC cell. These results indicated that LOXL1-AS1 enhanced NSCLC cell proliferation and invasion via sponging miR-324-3p in NSCLC cell.

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.

LOXL1-AS1 predicts poor prognosis and promotes cell proliferation, migration, and invasion in osteosarcoma

lncRNA LOXL1 antisense RNA 1 (lncRNA LOXL1-AS1) was recently found to function as oncogenic lncRNA in glioblastoma, prostate cancer, and medulloblastoma. The role of LOXL1-AS1 in osteosarcoma was still unknown. In our study, we found LOXL1-AS1 expression levels were higher in osteosarcoma tissues and cell lines than normal bone tissues and normal osteoblast cell line, respectively. Moreover, high-expression of LOXL1-AS1 was correlated with Enneking stage, tumor size, distant metastasis, histological grade, and overall survival time in osteosarcoma patients. Furthermore, LOXL1-AS1 overexpression acted as an independent poor predictor for overall survival in osteosarcoma patients. The loss-of-function studies showed knockdown of LOXL1-AS1 dramatically inhibited osteosarcoma cell proliferation, migration, and invasion through suppressing PI3K-AKT pathway. In conclusion, LOXL1-AS1 predicts clinical progression and poor prognosis in osteosarcoma patients and functions as oncogenic lncRNA to regulate cell proliferation, cell cycle, migration, and invasion.

Long non-coding RNA LOXL1-AS1 acts as a ceRNA for miR-324-3p to contribute to cholangiocarcinoma progression via modulation of ATP-binding cassette transporter A1

Accumulating evidence has appreciated long non-coding RNAs (lncRNAs) as novel prognostic markers and therapeutic targets in malignant carcinomas. Here, we aim to investigate the value of a novel cancer-related lncRNA, LOXL1-AS1, in cholangiocarcinoma (CCA). LOXL1-AS1 was found overexpressed in CCA tissues screened by high-throughput sequencing technology. Upregulation of LOXL1-AS1 was identified by TCGA database and qRT-PCR analysis. Additionally, upregulation of LOXL1-AS1 was associated with lymph node invasion, advanced TNM stages and unfavorable prognosis. Loss-of-function and gain-of-function experiments were conducted and validated that LOXL1-AS1 could facilitate cell proliferation, migration and invasion and attenuate cell apoptosis. Moreover, luciferase reporter and rescue assays indicated that LOXL1-AS1 functioned as a ceRNA to elevate ATP-binding cassette transporter A1 (ABCA1) level by sponging miR-324-3p and exhibited the malignant phenotypes of CCA cells, thereby playing an oncogenic role in CCA. Taken together, this study reveals that LOXL1-AS1 might act as a potential biomarker and therapeutic target for CCA clinical application.