The m6A methyltransferase METTL3 promotes hypoxic pulmonary arterial hypertension via targeting PTEN

Abstract Background N6-methyladenosine (m6A) is the most prevalent internal RNA modification in mammal mRNAs. Accumulating evidence has indicated the crucial role of m6A modification in cardiovascular diseases including cardiac hypertrophy, heart failure, ischemic heart disease, vascular calcification, restenosis, and aortic aneurysm. However, the role of m6A methylation in the occurrence and development of hypoxic pulmonary hypertension (HPH) remains largely unknown. Purpose The present study aims to explore the role of key transferase METTL3, in the development of HPH. Methods Hypoxic rat models and pulmonary artery smooth muscle cells (PASMCs) and were used to research the METTL3-mediated m6A in HPH in vivo and in vitro. CCK-8, EdU, PCNA, transwell and TUNEL assay were performed to evaluate the proliferation, migration and apoptosis rates of PASMCs. m6A RNA Methylation Quantification Kit and m6A-qPCR were utilized to measure the total m6A level and m6A-PTEN mRNA expression. RNA immunoprecipitation and RNA pull down were used to detect the interaction between METTL3 and PTEN mRNA. The half-life of mRNA was detected through actinomycin D assay. Results Both METTL3 mRNA and protein were found abnormally upregulated in pulmonary arteries of HPH rats and hypoxia induced PASMCs. Furthermore, downregulation of METTL3 attenuated PASMCs proliferation and migration exposed to hypoxia. In addition, m6A binding protein YTHDF2 was found significantly increased in HPH group in vivo and in vitro. Mechanistically, YTHDF2 recognized METTL3 mediated m6A-PTEN mRNA and promoted the degradation of PTEN. Decreased PTEN led to over-proliferation of PASMCs through activation of PI3K/Akt signaling pathway. Conclusion METTL3/YTHDF2/PTEN axis exerts a significant role in hypoxia induced PASMCs proliferation, providing a novel therapeutic target for HPH. FUNDunding Acknowledgement Type of funding sources: Foundation. Main funding source(s): National Natural Science Foundation of China Figure 1

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The long noncoding RNA KTN1-AS1 promotes bladder cancer tumorigenesis via KTN1 cis-activation and the consequent initiation of Rho GTPase-mediated signaling

Clinical Science ◽

10.1042/cs20200908 ◽

2021 ◽

Vol 135 (3) ◽

pp. 555-574

Author(s):

Xueying Hu ◽

Liang Xiang ◽

Dong He ◽

Rongrong Zhu ◽

Jianing Fang ◽

...

Keyword(s):

Bladder Cancer ◽

Noncoding Rna ◽

Rho Gtpase ◽

Invasion And Migration ◽

Rna Immunoprecipitation ◽

And Migration ◽

Epigenetic Modulation

Abstract Background: Accumulating evidence support the hypothesis that long noncoding RNAs (lncRNAs) are involved in several physiological and pathological conditions, including cancer. Here, we investigated the potential role of lncRNAs in bladder cancer. Methods: We first looked at available datasets retrieved from the TCGA database and discovered that the lncRNA KTN 1 antisense RNA 1 (KTN1-AS1) was significantly up-regulated in several cancer types including bladder cancer, but was decreased in some other tumors. Therefore, we focused our attention on KTN1-AS1. Using both in vitro and in vivo systems that allowed the modulation of KTN1-AS1 and expression of other relevant proteins, we investigated in-depth the role of KTN1-AS1 in bladder cancer (and the mechanism behind). We further investigated the potential KTN1-AS1-interacting proteins using RNA immunoprecipitation, and explored the KTN1-AS1-related epigenetic landscape (with a particular emphasis on acetylation) using chromatin immunoprecipitation (ChIP) assays. Results: KTN1-AS1 silencing inhibited the proliferation, invasion, and migration of bladder cancer cells, while KTN1-AS1 overexpression had the obvious opposite effects. Mechanistically, KTN1-AS1 promoted the recruitment of EP300, a histone acetyltransferase that enriched acetylation of histone H3 at lysine 27 (H3K27Ac) in the KTN1 promoter region. This epigenetic modulation contributed to the up-regulation of KTN1, which affected bladder cancer growth and progression via the regulation of Rho GTPase (RAC1, RHOA, and CDC42)-mediated signaling. Conclusion: Overall, our data support the idea that the lncRNA KTN1-AS1 promotes bladder cancer tumorigenesis via modulation of the KTN1/Rho GTPase axis and is a promising new therapeutic target for the treatment of bladder cancer.

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Knockout of Ajuba Attenuates the Growth and Migration of Hepatocellular Carcinoma Cells

Cytogenetic and Genome Research ◽

10.1159/000512264 ◽

2020 ◽

Vol 160 (11-12) ◽

pp. 650-658

Author(s):

Yichen Le ◽

Yi He ◽

Meirong Bai ◽

Ying Wang ◽

Jiaxue Wu ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Cell Growth ◽

Cancer Progression ◽

Normal Liver ◽

Cell Growth And Migration ◽

And Migration ◽

Hcc Cells

Ajuba has been found to be mutated or aberrantly regulated in several human cancers and plays important roles in cancer progression via different signaling pathways. However, little is known about the role of Ajuba in hepatocellular carcinoma (HCC). Here, we found an upregulation of Ajuba expression in HCC tissues compared with normal liver tissues, while a poor prognosis was observed in HCC patients with high Ajuba expression. Knockout of Ajuba in HCC cells inhibited cell growth in vitro and in vivo, suppressed cell migration, and enhanced the cell apoptosis under stress. Moreover, re-expression of Ajuba in Ajuba-deficient cells could restore the phenotype of Ajuba-deficient cells. In conclusion, these results indicate that Ajuba is upregulated in HCC and promotes cell growth and migration of HCC cells, suggesting that Ajuba could possibly be a new target for HCC diagnosis and treatment.

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Progression and Differentiation of Alveolar Rhabdomyosarcoma Is Regulated by PAX7 Transcription Factor—Significance of Tumor Subclones

Cells ◽

10.3390/cells10081870 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1870

Author(s):

Klaudia Skrzypek ◽

Grażyna Adamek ◽

Marta Kot ◽

Bogna Badyra ◽

Marcin Majka

Keyword(s):

Transcription Factor ◽

Cell Lines ◽

Migration Activity ◽

Id Proteins ◽

Rh30 Cell ◽

Str Profile ◽

And Migration

Rhabdomyosarcoma (RMS), is the most frequent soft tissue tumor in children that originates from disturbances in differentiation process. Mechanisms leading to the development of RMS are still poorly understood. Therefore, by analysis of two RMS RH30 cell line subclones, one subclone PAX7 negative, while the second one PAX7 positive, and comparison with other RMS cell lines we aimed at identifying new mechanisms crucial for RMS progression. RH30 subclones were characterized by the same STR profile, but different morphology, rate of proliferation, migration activity and chemotactic abilities in vitro, as well as differences in tumor morphology and growth in vivo. Our analysis indicated a different level of expression of adhesion molecules (e.g., from VLA and ICAM families), myogenic microRNAs, such as miR-206 and transcription factors, such as MYOD, MYOG, SIX1, and ID. Silencing of PAX7 transcription factor with siRNA confirmed the crucial role of PAX7 transcription factor in proliferation, differentiation and migration of RMS cells. To conclude, our results suggest that tumor cell lines with the same STR profile can produce subclones that differ in many features and indicate crucial roles of PAX7 and ID proteins in the development of RMS.

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Dual Effects ofβ3Integrin Subunit Expression on Human Pancreatic Cancer Models

Analytical Cellular Pathology ◽

10.1155/2010/917013 ◽

2010 ◽

Vol 33 (5-6) ◽

pp. 191-205 ◽

Cited By ~ 1

Author(s):

S. Marchán ◽

S. Pérez-Torras ◽

A. Vidal ◽

J. Adan ◽

F. Mitjans ◽

...

Keyword(s):

Pancreatic Cancer ◽

Rho Gtpases ◽

Cell Attachment ◽

Human Pancreatic Cancer ◽

Cell Growth And Migration ◽

Subunit Expression ◽

And Migration

Background: Pancreatic cancer, the fifth leading cause of adult cancer death in Western countries, lacks early detection, and displays significant dissemination ability. Accumulating evidence shows that integrin-mediated cell attachment to the extracellular matrix induces phenotypes and signaling pathways that regulate tumor cell growth and migration.Methods: In view of these findings, we examined the role ofβ3in pancreatic cancer by generating two stableβ3-expressing pancreatic human cell lines and characterizing their behavior in vitro and in vivo.Results: Transduction ofβ3selectively augmented the functional membraneαvβ3integrin levels, as evident from the enhanced adhesion and migration abilities related to active Rho GTPases. No effects on in vitro anchorage-dependent growth, but higher anoikis were detected inβ3-overexpressing cells. Moreover, tumors expressingβ3displayed reduced growth. Interestingly, treatment of mice with anαv-blocking antibody inhibited the growth ofβ3-expressing tumors to a higher extent.Conclusion: Our results collectively support the hypothesis thatαvβ3integrin has dual actions depending on the cell environment, and provide additional evidence on the role of integrins in pancreatic cancer, which should eventually aid in improving prediction of the effects of therapies addressed to modulate integrin activities in these tumors.

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METTL3 promotes the initiation and metastasis of ovarian cancer by inhibiting CCNG2 expression via promoting the maturation of pri-microRNA-1246

Cell Death Discovery ◽

10.1038/s41420-021-00600-2 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Xuehan Bi ◽

Xiao Lv ◽

Dajiang Liu ◽

Hongtao Guo ◽

Guang Yao ◽

...

Keyword(s):

Ovarian Cancer ◽

Molecular Mechanisms ◽

High Expression ◽

Ovarian Cancer Cells ◽

Inadequate Knowledge ◽

And Migration ◽

Cancer Tissues

AbstractOvarian cancer is a common gynecological malignant tumor with a high mortality rate and poor prognosis. There is inadequate knowledge of the molecular mechanisms underlying ovarian cancer. We examined the expression of methyltransferase-like 3 (METTL3) in tumor specimens using RT-qPCR, immunohistochemistry, and Western blot analysis, and tested the methylation of METTL3 by MSP. Levels of METTL3, miR-1246, pri-miR-1246 and CCNG2 were then analyzed and their effects on cell biological processes were also investigated, using in vivo assay to validate the in vitro findings. METTL3 showed hypomethylation and high expression in ovarian cancer tissues and cells. Hypomethylation of METTL3 was pronounced in ovarian cancer samples, which was negatively associated with patient survival. Decreased METTL3 inhibited the proliferation and migration of ovarian cancer cells and promoted apoptosis, while METTL3 overexpression exerted opposite effects. Mechanistically, METTL3 aggravated ovarian cancer by targeting miR-1246, while miR-1246 targeted and inhibited CCNG2 expression. High expression of METTL3 downregulated CCNG2, promoted the metabolism and growth of transplanted tumors in nude mice, and inhibited apoptosis. The current study highlights the promoting role of METTL3 in the development of ovarian cancer, and presents new targets for its treatment.

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miR-495-3p Depresses Cell Proliferation and Migration By Down-Regulating HMGB1 in Colorectal Cancer

10.21203/rs.3.rs-663678/v1 ◽

2021 ◽

Author(s):

Zhang Jieling ◽

Li Kai ◽

Zheng Huifen ◽

Zhu Yiping

Keyword(s):

Colorectal Cancer ◽

Cell Proliferation ◽

Luciferase Reporter ◽

Luciferase Reporter Gene ◽

Gene Assay ◽

And Migration ◽

Cancer Tissues

Abstract Background: MicroRNAs play an important role in the genesis and progression of tumors, including colorectal cancer (CRC), which has a high morbidity and mortality rate. In this research, the role of miR-495-3p and HMGB1 in CRC was investigated.Methods: We performed qRT-PCR to detect the expression of miR-495-3p in colorectal cancer tissues and cell lines. Functional experiments such as CCK-8 assay, EDU assay, Transwell assay and apoptosis assay were conducted to explore the effects of miR-495-3p on the proliferation, migration and apoptosis of CRC cells in vitro. Then, the use of database prediction, dual-luciferase reporter gene assay and functional experiments verified the role of miR-495-3p target gene HMGB1 in CRC. Finally, rescue experiments was performed to investigate whether overexpression of HMGB1 could reverse the inhibitory effect of miR-495-3p on CRC cell proliferation in vivo and in vitro.Results: miR-495-3p was down-regulated in colorectal cancer tissues and cell lines, and could inhibit the proliferation and migration of colorectal cancer cells, and promote cell apoptosis. The database prediction and dual-luciferase reporter gene assay showed that HMGB1 was the downstream target gene of miR-495-3p. We finally demonstrated that miR-495-3p inhibited CRC cell proliferation by targeting HMGB1 in vitro and in vivo.Conclusion: Our research shows that miR-495-3p inhibits the progression of colorectal cancer by down-regulating the expression of HMGB1, which indicates that miR-495-3p may become a potential therapeutic target for colorectal cancer.

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lncRNA H19 binds VGF and promotes pNEN progression via PI3K/AKT/CREB signaling

Endocrine Related Cancer ◽

10.1530/erc-18-0552 ◽

2019 ◽

Vol 26 (7) ◽

pp. 643-658 ◽

Cited By ~ 6

Author(s):

Meng Ji ◽

Yanli Yao ◽

Anan Liu ◽

Ligang Shi ◽

Danlei Chen ◽

...

Keyword(s):

Migration And Invasion ◽

Neuroendocrine Neoplasms ◽

Endocrine Tumors ◽

Rna Seq ◽

Rna Immunoprecipitation ◽

Poor Differentiation ◽

Tumor Growth And Metastasis

Pancreatic neuroendocrine neoplasms (pNENs) are endocrine tumors arising in pancreas and is the most common neuroendocrine tumors. Mounting evidence indicates lncRNA H19 could be a determinant of tumor progression. However, the expression and mechanism of H19 and the relevant genes mediated by H19 in pNENs remain undefined. Microarray analysis was conducted to identify the differentially expressed lncRNAs in pNENs. H19 expression was analyzed in 39 paired pNEN tissues by qPCR. The biological role of H19 was determined by functional experiments. RNA pulldown, mass spectroscopy and RNA immunoprecipitation were performed to confirm the interaction between H19 and VGF. RNA-seq assays were performed after knockdown H19 or VGF. H19 was significantly upregulated in pNEN tissues with malignant behaviors, and the upregulation predicted poor prognosis in pNENs. In vitro and in vivo data showed that H19 overexpression promoted tumor growth and metastasis, whereas H19 knockdown led to the opposite phenotypes. H19 interacted with VGF, which was significantly upregulated in pNENs, and higher VGF expression was markedly related to poor differentiation and advanced stage. Furthermore, VGF was downregulated when H19 was knocked down, and VGF promoted cell proliferation, migration and invasion. Mechanistic investigations revealed that H19 activated PI3K/AKT/CREB signaling and promoted pNEN progression by interacting with VGF. These findings indicate that H19 is a promising prognostic factor in pNENs with malignant behaviors and functions as an oncogene via the VGF-mediated PI3K/AKT/CREB pathway. In addition, our study implies that VGF may also serve as a candidate prognostic biomarker and therapeutic target in pNENs.

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Mitogen Kinase Kinase (MKK7) controls cytokine production in vitro and in vivo in mice

10.1101/2021.06.25.449967 ◽

2021 ◽

Author(s):

Amada D. Caliz ◽

Hyung-Jin Yoo ◽

Anastassiia Vertii ◽

Cathy Tournier ◽

Roger J. Davis ◽

...

Keyword(s):

Cytokine Production ◽

Cell Types ◽

Minor Role ◽

Cellular Processes ◽

Mitogen Activated Protein ◽

And Migration ◽

Jnk Activation

Mitogen kinase kinase 4 (MKK4) and Mitogen kinase kinase 7 (MKK7) are members of the MAP2K family which can activate downstream mitogen-activated protein kinases (MAPKs). MKK4 has been implicated in the activation of both, c-Jun N-terminal Kinase (JNK) and p38 MAPK, whereas MKK7 only activates JNK in response to different stimuli. The stimuli as well as cell type determine the choice of MAP2K member that mediates the response. In a variety of cell types, the MKK7 contributes to the activation of downstream MAPKs, JNK, which is known to regulate essential cellular processes, such as cell death, differentiation, stress response, and cytokine secretion. Previous studies have implicated the role of MKK7 in stress signaling pathways and cytokine production. However, little is known about the degree to which MKK7 and MKK4 contributes to innate immune response in macrophages as well as during inflammation in vivo. To address this question and elucidate the role of MKK7 and MKK4 in macrophage and in vivo, we developed MKK7- and MKK4-deficient mouse models with tamoxifen-inducible Rosa26 CreERT. This study reports that MKK7 is required for JNK activation both in vitro and in vivo. Additionally, we demonstrated that MKK7 in macrophages is necessary for LPS induced cytokine production and migration which appears to be a major contributor to the inflammatory response in vivo. Whereas MKK4 plays a significant but minor role in cytokine production in vivo.

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lncRNA OXCT1-AS1 Promotes Metastasis in Non-Small-Cell Lung Cancer by Stabilizing LEF1, In Vitro and In Vivo

BioMed Research International ◽

10.1155/2021/4959381 ◽

2021 ◽

Vol 2021 ◽

pp. 1-15

Author(s):

Binru Li ◽

Libo Zhu ◽

Linlin Li ◽

Rui Ma

Keyword(s):

Lung Cancer ◽

Small Cell Lung Cancer ◽

Cell Lines ◽

Small Cell ◽

Small Cell Lung ◽

Invasion And Migration ◽

And Migration

Long noncoding RNAs (lncRNAs) play nonnegligible roles in the metastasis of non-small-cell lung cancer (NSCLC). This study is aimed at investigating the biological role of lncRNA OXCT1-AS1 in NSCLC metastasis and the underlying regulatory mechanisms. The expression profiles of lncRNA OXCT1-AS1 in different NSCLC cell lines were examined. Then, the biological function of lncRNA OXCT1-AS1 in NSCLC metastasis was explored by loss-of-function assays in vitro and in vivo. Further, the protective effect of lncRNA OXCT1-AS1 on lymphoid enhancer factor 1 (LEF1) was examined using RNA pull-down and RNA immunoprecipitation assays. Additionally, the role of LEF1 in NSCLC metastasis was investigated. Results indicated that lncRNA OXCT1-AS1 expression was significantly increased in NSCLC cell lines. Functional analysis revealed that knockdown of lncRNA OXCT1-AS1 impaired invasion and migration in vitro. Additionally, the ability of lncRNA OXCT1-AS1 to promote NSCLC metastasis was also confirmed in vivo. Mechanistically, through direct interaction, lncRNA OXCT1-AS1 maintained LEF1 stability by blocking NARF-mediated ubiquitination. Furthermore, LEF1 knockdown impaired invasion and migration of NSCLC in vitro and in vivo. Collectively, these data highlight the ability of lncRNA OXCT1-AS1 to promote NSCLC metastasis by stabilizing LEF1 and suggest that lncRNA OXCT1-AS1 represents a novel therapeutic target in NSCLC.

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The Association of Aberrant Expression of FGF1 and mTOR-S6K1 in Colorectal Cancer

Frontiers in Oncology ◽

10.3389/fonc.2021.706838 ◽

2021 ◽

Vol 11 ◽

Author(s):

Tinghui Duan ◽

Diyuan Zhou ◽

Yizhou Yao ◽

Xinyu Shao

Keyword(s):

Colorectal Cancer ◽

Malignant Neoplasms ◽

Aberrant Expression ◽

Protein Levels ◽

And Migration ◽

High Level ◽

Proliferation And Migration

Colorectal cancer (CRC) is one of the most frequent malignant neoplasms worldwide, and the effect of treatments is limited. Fibroblast growth factor 1 (FGF1) has been involved in a wide variety of several malignant diseases and takes part in the tumorigenesis of CRC. However, the function and mechanism of FGF1 in CRC remains elusive. In this study, the results indicated that FGF1 is elevated in CRC tissues and linked with poor prognosis (P < 0.001). In subgroup analysis of FGF1 in CRC, regardless of any clinic-factors except gender, high level FGF1 expression was associated with markedly shorter survival (P < 0.05). In addition, the expression of p-S6K1 and FGF1 was not associated in normal tissue (P = 0.781), but their expression was closely related in tumor tissue (P = 0.010). The oncogenic role of FGF1 was determined using in vitro and in vivo functional assays. FGF1 depletion inhibited the proliferation and migration of CRC cells in vitro and vivo. FGF1 was also significantly correlated with mTOR-S6K1 pathway on the gene and protein levels (P < 0.05). In conclusion, FGF1 acts as a tumor activator in CRC, and against FGF1 may provide a new visual field on treating CRC, especially for mTORC1-targeted resistant patients.

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