Genome-wide screening for differentially methylated long noncoding RNAs identifies LIFR-AS1 as an epigenetically regulated lncRNA that inhibits the progression of colorectal cancer.

BACKGROUND: Aberrant DNA methylation is an epigenetic marker that has been linked to the pathogenesis of colorectal cancer (CRC). Long noncoding RNAs (lncRNAs) have been increasingly identified to be associated with tumorigenic processes of CRC. Identifying epigenetically dysregulated lncRNAs and characterizing their effects during carcinogenesis are focuses of cancer research. METHODS: Differentially methylated loci and expressed lncRNAs were identified by integrating DNA methylome and transcriptome analyses using The Cancer Genome Atlas database. Bisulfite sequencing PCR (BSP) was performed to analyze LIFR-AS1 promoter methylation status. The functional roles of LIFR-AS1 in CRC were determined by in vitro and in vivo experiments. RESULTS: We identified a novel hypermethylated lncRNA, LIFR-AS1, that was downregulated and associated with tumorigenesis, metastasis, and poor prognosis in CRC. High methylation burden of LIFR-AS1 indicated a poor survival of CRC patients. Promoter hypermethylation of LIFR-AS1 in tumor tissues was confirmed by BSP. Functional assays revealed that LIFR-AS1 could competitively bind to hsa-miR-29b-3p, and repressed colon cancer cell proliferation, colony formation and invasion. LIFR-AS1 also inhibited tumor growth in a mouse xenograft model of CRC. CONCLUSIONS: Our results showed that the identified DNA methylation-dysregulated lncRNAs may be potential biomarkers and highlighted a role for LIFR-AS1 as a tumor suppressor in CRC.

LncRNA LIFR-AS1 overexpression suppressed the progression of serous ovarian carcinoma.

BACKGROUND: Serous ovarian carcinoma (SOC) is a common malignant tumor in female reproductive system. Long noncoding RNA (lncRNA) LIFR-AS1 is a tumor suppressor gene in colorectal cancer, but its effect and underlying mechanism in SOC are still unclear. Therefore, this study focuses on unveiling the regulatory mechanism of LIFR-AS1 in SOC. METHODS: The relationship between LIFR-AS1 expression and prognosis of SOC patients was analyzed by TCGA database and Starbase, and then, the LIFR-AS1 expression in SOC tissues and cells was detected by quantitative real-time PCR (qRT-PCR) and in situ hybridization (ISH). Besides, the relationship between LIFR-AS1 and clinical characteristics was analyzed. Also, the effects of LIFR-AS1 on the biological behaviors of SOC cells were measured by Cell Counting Kit-8, colony formation, and wound-healing and Transwell assays, respectively. Western blot and qRT-PCR were employed to determine the protein expressions of genes related to proliferation (PCNA), apoptosis (cleaved caspase-3), epithelial-mesenchymal transition (E-cadherin, N-cadherin, and Snail). RESULTS: LIFR-AS1 was lowly expressed in SOC, which was correlated with the poor prognosis of SOC patients. Low expression of LIFR-AS1 in SOC was associated with the tumor size, clinical stage, lymph node metastasis, and distant metastasis. LIFR-AS1 overexpression promoted the expressions of cleaved caspase-3 and E-cadherin while suppressing the malignant behaviors (proliferation, migration, and invasion) of SOC cells, the expressions of PCNA, N-cadherin, and Snail. Besides, silencing LIFR-AS1 exerted the effects opposite to overexpressed LIFR-AS1. CONCLUSION: LIFR-AS1 overexpression inhibits biological behaviors of SOC cells, which may be a new therapeutic method.

The Pleiotropic role, functions and targeted therapies of LIF/LIFR axis in cancer: Old spectacles with new insights.

The dysregulation of leukemia inhibitory factor (LIF) and its cognate receptor (LIFR) has been associated with multiple cancer initiation, progression, and metastasis. LIF plays a significant tumor-promoting role in cancer, while LIFR functions as a tumor promoter and suppressor. Epithelial and stromal cells secrete LIF via autocrine and paracrine signaling mechanism(s) that bind with LIFR and subsequently with co-receptor glycoprotein 130 (gp130) to activate JAK/STAT1/3, PI3K/AKT, mTORC1/p70s6K, Hippo/YAP, and MAPK signaling pathways. Clinically, activating the LIF/LIFR axis is associated with poor survival and anti-cancer therapy resistance. This review article provides an overview of the structure and ligands of LIFR, LIF/LIFR signaling in developmental biology, stem cells, cancer stem cells, genetics and epigenetics of LIFR, LIFR regulation by long non-coding RNAs and miRNAs, and LIF/LIFR signaling in cancers. Finally, neutralizing antibodies and small molecule inhibitors preferentially blocking LIF interaction with LIFR and antagonists against LIFR under pre-clinical and early-phase pre-clinical trials were discussed.

Long non-coding RNA LIFR-AS1 suppressed the proliferation, angiogenesis, migration and invasion of papillary thyroid cancer cells via the miR-31-5p/SIDT2 axis.

Long non-coding RNA LIFR-AS1 is low-expressed in many cancers, but its functions in papillary thyroid carcinoma (PTC) were not defined and require further study. The relationship between LIFR-AS1 expression and clinicopathological characteristics of patients with PTC was statistically analyzed. The downregulation of LIFR-AS1 in PTC tissues and cell lines was predicted by bioinformatics analysis and verified by qRT-PCR. After overexpressing or silencing LIFR-AS1, the regulatory role of LIFR-AS1 in PTC was examined by performing MTT, colony formation, wound healing, Transwell, ELISA, tube formation and xenograft tumor experiment. MiR-31-5p and SID1 transmembrane family member 2 (SIDT2) expressions in PTC tissues or cell lines were detected by qRT-PCR, Western blot, or in situ hybridization. The relationship between miR-31-5p and LIFR-AS1/SIDT2 was predicted by LncBase, TargetScan or Pearson correlation test and then verified by Dual-Luciferase Reporter assay, RNA pull-down assay and qRT-PCR. The regulatory effect of LIFR-AS1/miR-31-5p/SIDT2 axis on the biological behaviors of PTC cells was confirmed by functional experiments and rescue experiments mentioned above. The tumor size and lymphatic metastasis were correlated with LIFR-AS1 overexpression. Overexpressed LIFR-AS1 suppressed tumorigenesis in vivo. LIFR-AS1 and SIDT2 expressions were suppressed in PTC tissues, while that of miR-31-5p was elevated in PTC tissues. LIFR-AS1 was negatively correlated with miR-31-5p. LIFR-AS1 sponged miR-31-5p to upregulate SIDT2, thereby inhibiting the viability, proliferation, migration, invasion, and the secretion of vascular endothelial growth factor (VEGF) of PTC cells and angiogenesis of human umbilical vein endothelial cells (HUVECs). This paper demonstrates that LIFR-AS1/miR-31-5p/SIDT2 axis modulated the development of PTC.

M6A-mediated up-regulation of LncRNA LIFR-AS1 enhances the progression of pancreatic cancer via miRNA-150-5p/ VEGFA/Akt signaling.

N6-methyladenosine (m6A) modification, the most abundant internal methylation of eukaryotic RNA transcripts, is critically implicated in RNA processing. There is extensive evidence indicating that long non-coding RNAs (lncRNAs) serve as key regulators of oncogenesis and tumor progression in humans. Through prior study has assessed that LIFR-AS1 plays a key role in various kinds of malignant tumors. However, the exact role of m6A induced LIFR-AS1 in pancreatic cancer (PC) and its potential molecular mechanisms remain largely unknown. In this study, we determined that PC cell lines and tumors exhibit increased LIFR-AS1 expression that correlates with larger tumor size, lymph node metastasis, and more advanced TNM stage. Functionally, loss-of-function studies indicated that LIFR-AS1 knockdown decreased the proliferation, migration, and invasion of PC cells in vitro. Mechanistically, we found that METTL3 induced m6A hyper-methylation on the 3' UTR of LIFR-AS1 to enhance its mRNA stability and LIFR-AS1 could directly interact with miR-150-5p, thereby indirectly up-regulating VEGFA expressions within cells. Through rescue experiments, we were able to confirm that the unfavorable impact of LIFR-AS1 knockdown on VEGFA /PI3K/Akt Signaling could be reversed via the inhibition of miR-150-5p expression. Together, these findings indicate that a noval m6A-LIFR-AS1 axis promotes PC progression at least in part via regulation of the miR-150-5p/VEGFA axis, indicating that this regulatory axis may be a viable clinical target for the treatment of PC.

Long non-coding RNA LIFR-AS1 regulates the proliferation, migration and invasion of human thyroid cancer cells.

The long non-coding RNA (lncRNA) LIFR-AS1 has been shown to be involved in the development of several human cancers. This study was designed to determine the expression profile and role of lncRNA-LIFR-AS1 in human thyroid cancer. The results showed significant (p < 0.05) upregulation of LncRNA-LIFR-AS1 in thyroid cancer tissues and cells. However, silencing of LncRNA-LIFR-AS1 inhibited the viability and proliferation of human thyroid cancer cells inducing G2/M cell cycle arrest. The G2/M phase cells increased from 8.56% in negative control (NC) to around 35.03% in si-LIFR-AS1. This was also found to be concomitant with the downregulation of cyclin B1 and CDK1 expressions. The thyroid cancer cells exhibited remarkably lower invasion and migration under transcriptional knockdown of lncRNA-LIFR-AS1 which was also associated with downregulation of MMP-2 and MMP-9 expression. Importantly, transcriptional silencing of lncRNA-LIFR-AS1 inhibited thyroid cancer tumorigenesis, in vivo. Collectively, the results suggest the tumor-promoting role of lncRNA-LIFR-AS1 in thyroid cancer and highlight its potential as therapeutic target.

Macrophages-derived exosomal lncRNA LIFR-AS1 promotes osteosarcoma cell progression via miR-29a/NFIA axis.

BACKGROUND: Osteosarcoma (OS) is the most common primary malignant bone tumor in young people. Tumor-associated macrophages (TAMs) have been reported to play an important role in the development of osteosarcoma. However, the detailed molecular mechanisms remain largely unknown and need to be elucidated. Recently, exosomes have been reported as the crucial mediator between tumor cells and the tumor microenvironment. And a lot of lncRNAs have been reported to act as either oncogenes or tumor suppressors in osteosarcoma. In this research, we aim to explore the role of macrophages-derived exosomal lncRNA in osteosarcoma development and further elucidated the potential molecular mechanisms involved. METHODS: TAMs were differentiated from human mononuclear cells THP-1, and a high-throughput microarray assay was used to analyze the dysregulated lncRNAs and miRNAs in osteosarcoma cells co-cultured with macrophages-derived exosomes. Western blot, qRT-PCR assays, and Dual-luciferase reporter assay were used to verify the interaction among LIFR-AS1, miR-29a, and NFIA. Cck-8, EdU, colony formation assay, wound-healing, and transwell assay were performed to explore the characterize the proliferation and metastasis ability of OS cells. And qPCR, Western blots, immunohistochemistry, and cell immunofluorescence were used to detect the expression of relative genes or proteins. RESULTS: In this study, we found that THP-1-induced macrophage-derived exosomes could facilitate osteosarcoma cell progression both in vitro and in vivo. Then, the results of the high-throughput microarray assay showed that LIFR-AS1 was highly expressed and miR-29a was lowly expressed. Furthermore, LIFR-AS1 was identified as a miR-29a sponge, and NFIA was validated as a direct target of miR-29a. Functional assays demonstrated that knockdown of exosomal LIFR-AS1 could attenuate the promotion effects of macrophages-derived exosomes on osteosarcoma cell progression and miR-29a inhibition could reserve the effect of LIFR-AS1-knockdown exosomes. Correspondingly, NFIA-knockdown could partially reverse the tumor inhibition effect of miR-29a on osteosarcoma cells. CONCLUSIONS: Taken together, macrophages-derived exosomal lncRNA LIFR-AS1 can promote osteosarcoma cell proliferation, invasion, and restrain cell apoptosis via miR-29a/NFIA axis, which can act as a potential novel therapeutic target for osteosarcoma therapy.

LncRNA LIFR-AS1 promotes proliferation and invasion of gastric cancer cell via miR-29a-3p/COL1A2 axis.

BACKGROUND: LncRNA was known to be closely associated with the progression of human tumors. The role of lncRNA LIFR-AS1 in the pathogenesis and progression of gastric tumor is still unclear. The aim of this study was to investigate the function of LIFR-AS1 and the underlying mechanism in the pathogenesis and progression of gastric cancer. METHODS: QRT-PCR was used to evaluate the expression of LIFR-AS1, miR-29a-3p and COL1A2 in gastric tumor tissues and cells. Western blotting was used to evaluate the protein expression of COL1A2 in gastric tumor cells. CCK-8 assay, transwell assay and flow cytometry were used to evaluate the roles of LIFR-AS1, miR-29a-3p and COL1A2 in cell proliferation, invasion, migration and apoptosis. The relationship among LIFR-AS1, miR-29a-3p and COL1A2 was assessed by bioinformatics analyses and luciferase reporter assay. RESULTS: The expression levels of LIFR-AS1 were significantly increased in gastric tumor tissues and cells, while the expression levels of miR-29a-3p were decreased. The expression of miR-29a-3p was negatively correlated with the expression of LIFR-AS1 in gastric cancer tumor tissues. Knocking down of LIFR-AS1 inhibited proliferation, invasion and migration of gastric tumor cells, and induced apoptosis of gastric tumor cells. Bioinformatics analyses and integrated experiments revealed that LIFR-AS1 elevated the expression of COL1A2 through sponging miR-29a-3p, which further resulted in the progression of gastric tumor. CONCLUSION: LIFR-AS1 plays an important role as a competing endogenous RNA in gastric tumor pathogenesis and may be a potential target for the diagnosis and treatment of gastric tumor.

Long noncoding RNA LIFR-AS1 suppresses proliferation, migration and invasion and promotes apoptosis through modulating miR-4262/NF-κB pathway in glioma.

AIM: This study aimed to explore the role of lncRNA leukemia inhibitory factor receptor antisense RNA 1 (LIFR-AS1) on glioma and its underlying molecular mechanism. METHODS: The expression of LIFR-AS1 and miR-4262 was detected by quantitative real-time polymerase chain reaction (qRT-RCR) in both glioma tissues and cell lines. Colony formation assay, 5-ethynyl-20-deoxyuridine (EdU) assay, flow cytometry and transwell assay were respectively conducted to detect cell clones, proliferation, apoptosis, migration and invasion. The effect of LIFR-AS1 on the chemoresistance to temozolomide (TMZ) of glioma cells was also analyzed. In addition, dual-luciferase reporter gene assay was performed to evaluate the luciferase activity. The expressions of nuclear factor-κB (NF-κB) p65, p-NF-κB p65 and inhibitor of κBα (IκBα) in glioma cells were measured by western blot. RESULTS: LIFR-AS1 was lowly expressed and miR-4262 was highly expressed in glioma tissues and cell lines. LIFR-AS1 overexpression inhibited the proliferation, migration and invasion and promoted apoptosis of glioma cells. LIFR-AS1 overexpression also reduced the chemoresistance to TMZ of glioma cells. Moreover, LIFR-AS1 overexpression suppressed the activation of NF-κB signaling pathway in glioma cells. miR-4262 was the target gene of LIFR-AS1. We also found that miR-4262 abrogated the functions of LIFR-AS1 on cell proliferation, apoptosis, migration and invasion of glioma cells in the NF-κB pathway. CONCLUSION: LIFR-AS1 could suppress the proliferation, migration and invasion and promote the apoptosis through modulating miR-4262/NF-κB pathway in glioma.

LIFR-AS1 modulates Sufu to inhibit cell proliferation and migration by miR-197-3p in breast cancer.

Numerous evidence has recently demonstrated that long non-coding RNAs (lncRNAs) play vital roles in the oncogenesis and development of a wide range of human neoplasms. Leukemia inhibitory factor receptor antisense RNA 1 (LIFR-AS1), a novel cancer-related lncRNA, has been reported to be under-expressed in breast cancer and associated with poor prognosis. However, the exact role of LIFR-AS1 in breast cancer remains largely unclear. The present study aimed to investigate the biological role of LIFR-AS1 in breast cancer and clarify the potential molecular mechanisms. In the present study, we found that LIFR-AS1 was significantly down-regulated in both tissues and cell lines. Furthermore, over-expression of LIFR-AS1 inhibited breast cancer cell proliferation, colony formation, migration and invasion, whereas knockdown of LIFR-AS1 promoted breast cancer cell proliferation, colony formation, migration and invasion. Moreover, LIFR-AS1 was observed to up-regulate suppressor of fused gene (Sufu) expression by competitively binding to miR-197-3p in breast cancer cells. Notably, miR-197-3p inhibitor reversed the promoting effects of LIFR-AS1 knockdown on breast cancer cell proliferation, colony formation, migration and invasion. Additionally, LIFR-AS1 knockdown promoted tumor growth in vivo To sum up, our results imply the tumor-suppressing role of LIFR-AS1 in breast cancer.

Functional role of a long non-coding RNA LIFR-AS1/miR-29a/TNFAIP3 axis in colorectal cancer resistance to pohotodynamic therapy.

Colorectal Cancer (CRC) is one of the most common digestive system malignant tumors. Recently, PDT has been used as a first-line treatment for colon cancer; however, limited curative effect was obtained due to resistance of CRC to PDT. During the past decades, accumulating CRC-related long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and mRNAs have been reported to exert diverse functions through various biological processes; their dysregulation might trigger and/or promote the pathological changes. Herein, we performed microarrays analysis to identify dysregulated lncRNAs, miRNAs and mRNAs in PDT-treated HCT116 cells to figure out the lncRNA-miRNA interactions related to the resistance of CRC to PDT treatment, and the downstream mRNA target, as well as the molecular mechanism. We found a total of 1096 lncRNAs dysregulated in PDT-treated CRC HCT116 cells; among them, LIFR-AS1 negatively interacted with miR-29a, one of the dysregulated miRNAs in PDT-treated CRC cells, to affect the resistance of CRC to PDT. LIFR-AS1 knockdown attenuated, whereas miR-29a inhibition enhanced the cellular effect of PDT on HCT116 cell proliferation and apoptosis. Furthermore, among the dysregulated mRNAs, TNFAIP3 was confirmed to be a direct target of miR-29a and exerted a similar effect to LIFR-AS1 on the cellular effects of PDT. In summary, LIFR-AS1 serves as a competitive endogenous RNA (ceRNA) for miR-29a to inhibit its expression and up-regulate downstream target TNFAIP3 expression, finally modulating the resistance of CRC to PDT. We provide an experimental basis for this lncRNA/miRNA/mRNA network being a promising target in CRC resistance to PDT treatment.