Down-regulation of LATS2 in non-small cell lung cancer promoted the growth and motility of cancer cells

Non-coding RNAs and angiogenesis in cardiovascular diseases: a comprehensive review

Non-coding RNAs (ncRNAs) have key roles in the etiology of many illnesses, including heart failure, myocardial infarction, stroke, and in physiological processes like angiogenesis. In transcriptional regulatory circuits that control heart growth, signaling, and stress response, as well as remodeling in cardiac disease, ncRNAs have become important players. Studies on ncRNAs and cardiovascular disease have made great progress recently. Here, we go through the functions of non-coding RNAs (ncRNAs) like circular RNAs (circRNAs), and microRNAs (miRNAs) as well as long non-coding RNAs (lncRNAs) in modulating cardiovascular disorders.

The circRNA-miRNA/RBP regulatory network in myocardial infarction

Myocardial infarction (MI) is a serious heart disease that causes high mortality rate worldwide. Noncoding RNAs are widely involved in the pathogenesis of MI. Circular RNAs (circRNAs) are recently validated to be crucial modulators of MI. CircRNAs are circularized RNAs with covalently closed loops, which make them stable under various conditions. CircRNAs can function by different mechanisms, such as serving as sponges of microRNAs (miRNAs) and RNA-binding proteins (RBPs), regulating mRNA transcription, and encoding peptides. Among these mechanisms, sponging miRNAs/RBPs is the main pathway. In this paper, we systematically review the current knowledge on the properties and action modes of circRNAs, elaborate on the roles of the circRNA-miRNA/RBP network in MI, and explore the value of circRNAs in MI diagnosis and clinical therapies. CircRNAs are widely involved in MI. CircRNAs have many advantages, such as stability, specificity, and wide distribution, which imply that circRNAs have a great potential to act as biomarkers for MI diagnosis and prognosis.

Hippo in Gastric Cancer: From Signalling to Therapy

The Hippo pathway is one of the most important ones in mammals. Its key functions in cell proliferation, tissue growth, repair, and homeostasis make it the most crucial one to be controlled. Many means have been deployed for its regulation, since this pathway is not only composed of core regulatory components, but it also communicates with and regulates various other pathways, making this signalisation even more complex. Its role in cancer has been studied more and more over the past few years, and it presents YAP/TAZ as the major oncogenic actors. In this review, we relate how vital this pathway is for different organs, and how regulatory mechanisms have been bypassed to lead to cancerous states. Most studies present an upregulation status of YAP/TAZ, and urge the need to target them. A focus is made here on gastric carcinogenesis, its main dysregulations, and the major strategies adopted and tested to counteract Hippo pathway disbalance in this disease. Hippo pathway targeting can be achieved by various means, which are described in this review. Many studies have tested different potential molecules, which are detailed hereby. Though not all tested in gastric cancer, they could represent a real interest.

Targeting lncRNAs in programmed cell death as a therapeutic strategy for non-small cell lung cancer

Lung cancer is a leading cause of cancer-related mortality worldwide, with non-small cell lung cancer (NSCLC) being the most common histological type. Owing to the limited therapeutic efficacy and side effects of currently available therapies for NSCLC, it is necessary to identify novel therapeutic targets for NSCLC. Long non-coding RNAs (lncRNAs) are non-protein-coding RNAs with a transcript length of more than 200 nucleotides, which play a vital role in the tumorigenesis and progression of multiple cancers, including NSCLC. Induction of programmed cell death (PCD) is the main mechanism leading to tumour cell death in most cancer treatments. Recent studies have demonstrated that lncRNAs are closely correlated with PCD including apoptosis, pyroptosis, autophagy and ferroptosis, which can regulate PCD and relevant death pathways to affect NSCLC progression and the efficacy of clinical therapy. Therefore, in this review, we focused on the function of lncRNAs in PCD of NSCLC and summarized the therapeutic role of targeting lncRNAs in PCD for NSCLC treatment, aiming to provide new sights into the underlying pathogenic mechanisms and propose a potential new strategy for NSCLC therapy so as to improve therapeutic outcomes with the ultimate goal to benefit the patients.

Downregulation of circFASTKD1 ameliorates myocardial infarction by promoting angiogenesis

Circular RNAs (circRNAs), a novel class of endogenous long non-coding RNAs, have attracted considerable attention due to their closed continuous loop structure and potential clinical value. In this study, we investigated the function of circFASTKD1 in vascular endothelial cells. CircFASTKD1 bound directly to miR-106a and relieved its inhibition of Large Tumor Suppressor Kinases 1 and 2, thereby suppressing the Yes-Associated Protein signaling pathway. Under both normal and hypoxic conditions, the ectopic expression of circFASTKD1 reduced the viability, migration, mobility and tube formation of vascular endothelial cells, whereas the downregulation of circFASTKD1 induced angiogenesis by promoting these processes. Moreover, downregulation of circFASTKD1 in mice improved cardiac function and repair after myocardial infarction. These findings indicate that circFASTKD1 is a potent inhibitor of angiogenesis after myocardial infarction and that silencing circFASTKD1 exerts therapeutic effects during hypoxia by stimulating angiogenesis in vitro and in vivo.

Regulation of Hippo signaling pathway in cancer: A MicroRNA perspective

Recent studies have suggested that Hippo signaling is not only involved in controlling organ size in Drosophila but can also regulate cell proliferation, tissue homeostasis, differentiation, apoptosis and regeneration. Any dysregulation of Hippo signaling, especially the hyper activation of its downstream effectors YAP/TAZ, can lead to uncontrolled cell proliferation and malignant transformation. In majority of cancers, expression of YAP/TAZ is extremely high and this increased expression of YAP/TAZ has been shown to be an independent predictor of prognosis and indicator of increased cell proliferation, metastasis and poor survival. In this review, we have summarized the most recent findings about the cross talk of Hippo signaling pathway with other signaling pathways and its regulation by different miRNAs in various cancer types. Recent evidence has suggested that Hippo pathway is also involved in mediating the resistance of different cancer cells to chemotherapeutic drugs and in a few cancer types, this is brought about by regulating miRNAs. Therefore, the delineation of the underlying mechanisms regulating the chemotherapeutic resistance might help in developing better treatment options. This review has attempted to provide an overview of different drugs/options which can be utilized to target oncogenic YAP/TAZ proteins for therapeutic interventions.

The novel long non-coding RNA LATS2-AS1-001 inhibits gastric cancer progression by regulating the LATS2/YAP1 signaling pathway via binding to EZH2

Background

To explore the expression pattern and role of the novel long non-coding RNA LATS2 antisense transcript 1 (LATS2-AS1-001) in gastric cancer (GC).

Methods

qRT-PCR was applied to evaluate LATS2-AS1-001 expression and correlation with LATS2 in GC. In vitro experiments were performed to investigate the role of LATS2-AS1-001 in GC cells. RNA immunoprecipitation (RIP) was performed to assess the interaction between EZH2 and LATS2-AS1-001. LATS2/YAP1 signaling pathway proteins were detected by immunoblot. Oncomine and KMPLOT data analysis was conducted to assess the prognostic value of YAP1 in GC.

Results

Decreased expression levels of LATS2-AS1-001 and LATS2 were confirmed in 357 GC tissues compared with the normal mucosa. A strong positive correlation between LATS2-AS1-001 and LATS mRNA expression was found in Pearson Correlation analysis (r = 0.719, P < 0.001). Furthermore, ROC curve analysis revealed areas under the curves for LATS2-AS1-001 and LATS2 of 0.7274 and 0.6865, respectively (P < 0.001), which indicated that LATS2-AS1-001 and LATS could be used as diagnostic indicators in GC. Moreover, ectopic expression of LATS2-AS1-001 decreased cell viability, induced G0/G1 phase arrest, and inhibited cell migration and invasion in GC cells. Mechanistically, overexpressing LATS2-AS1-001 upregulated LATS2 and induced YAP1 phosphorylation via binding to EZH2. Oncomine and KMPLOT database analysis demonstrated YAP1 was highly expressed in human GC samples, and high YAP1 expression predicted poor patient prognosis in GC.

Conclusion

This study revealed that lncRNA LATS2-AS1-001 might serve as a potential diagnostic index in GC and act as a suppressor of GC progression.

The Hippo Kinase LATS2 Controls Helicobacter pylori-Induced Epithelial-Mesenchymal Transition and Intestinal Metaplasia in Gastric Mucosa

BACKGROUND & AIMS

Gastric carcinoma is related mostly to CagA+-Helicobacter pylori infection, which disrupts the gastric mucosa turnover and elicits an epithelial-mesenchymal transition (EMT) and preneoplastic transdifferentiation. The tumor suppressor Hippo pathway controls stem cell homeostasis; its core, constituted by the large tumor suppressor 2 (LATS2) kinase and its substrate Yes-associated protein 1 (YAP1), was investigated in this context.

METHODS

Hippo, EMT, and intestinal metaplasia marker expression were investigated by transcriptomic and immunostaining analyses in human gastric AGS and MKN74 and nongastric immortalized RPE1 and HMLE epithelial cell lines challenged by H pylori, and on gastric tissues of infected patients and mice. LATS2 and YAP1 were silenced using small interfering RNAs. A transcriptional enhanced associated domain (TEAD) reporter assay was used. Cell proliferation and invasion were evaluated.

RESULTS

LATS2 and YAP1 appear co-overexpressed in the infected mucosa, especially in gastritis and intestinal metaplasia. H pylori via CagA stimulates LATS2 and YAP1 in a coordinated biphasic pattern, characterized by an early transient YAP1 nuclear accumulation and stimulated YAP1/TEAD transcription, followed by nuclear LATS2 up-regulation leading to YAP1 phosphorylation and targeting for degradation. LATS2 and YAP1 reciprocally positively regulate each other's expression. Loss-of-function experiments showed that LATS2 restricts H pylori-induced EMT marker expression, invasion, and intestinal metaplasia, supporting a role of LATS2 in maintaining the epithelial phenotype of gastric cells and constraining H pylori-induced preneoplastic changes.

CONCLUSIONS

H pylori infection engages a number of signaling cascades that alienate mucosa homeostasis, including the Hippo LATS2/YAP1/TEAD pathway. In the host-pathogen conflict, which generates an inflammatory environment and perturbations of the epithelial turnover and differentiation, Hippo signaling appears as a protective pathway, limiting the loss of gastric epithelial cell identity that precedes gastric carcinoma development.

Large tumor suppressor 2, LATS2, activates JNK in a kinase-independent mechanism through ASK1

Apoptosis signal-regulating kinase 1 (ASK1) is an important mediator of the cell stress response pathways. Because of its central role in regulating cell death, the activity of ASK1 is tightly regulated by protein-protein interactions and post-translational modifications. Deregulation of ASK1 activity has been linked to human diseases, such as neurological disorders and cancer. Here we describe the identification and characterization of large tumor suppressor 2 (LATS2) as a novel binding partner for ASK1. LATS2 is a core kinase in the Hippo signaling pathway and is commonly downregulated in cancer. We found that LATS2 interacts with ASK1 and increases ASK1-mediated signaling to promote apoptosis and activate the JNK mitogen-activated protein kinase (MAPK). This change in MAPK signaling is dependent on the catalytic activity of ASK1 but does not require LATS2 kinase activity. This work identifies a novel role for LATS2 as a positive regulator of the ASK1-MKK-JNK signaling pathway and establishes a kinase-independent function of LATS2 that may be part of the intricate regulatory system for cellular response to diverse stress signals.

YAP and TAZ in Lung Cancer: Oncogenic Role and Clinical Targeting

Lung cancer is the leading cause of cancer death in the world and there is no current treatment able to efficiently treat the disease as the tumor is often diagnosed at an advanced stage. Moreover, cancer cells are often resistant or acquire resistance to the treatment. Further knowledge of the mechanisms driving lung tumorigenesis, aggressiveness, metastasization, and resistance to treatments could provide new tools for detecting the disease at an earlier stage and for a better response to therapy. In this scenario, Yes Associated Protein (YAP) and Trascriptional Coactivator with PDZ-binding motif (TAZ), the final effectors of the Hippo signaling transduction pathway, are emerging as promising therapeutic targets. Here, we will discuss the most recent advances made in YAP and TAZ biology in lung cancer and, more importantly, on the newly discovered mechanisms of YAP and TAZ inhibition in lung cancer as well as their clinical implications.

Long non-coding RNA PVT1 as a novel candidate for targeted therapy in hematologic malignancies

Cancerous cells show resistance to various forms of therapy, so applying up to the minute targeted therapy is crucial. For this purpose, long non-coding RNA PVT1 as shown by recent studies is an important oncogene that interacts with vital cellular signaling pathways and different proteins such as c-Myc, NOP2 and LATS2. Due to the enormous role of long non-coding RNAs in development of leukemias, we aimed to show the role of PVT1 knock-down on fate of different hematologic cell lines. owing to this matter, various experiments such as Real-time PCR, cell cycle analysis and apoptosis assay were performed. Meanwhile, proliferation rate by CFSE, protein expression of c-Myc and hTERT by western blot and flow cytometry analysis were investigated. Our results demonstrated that PVT1 knock-down results in c-Myc degradation, proliferation down-regulation, induction of apoptosis and G0/G1 arrest. Simultaneously, for the first time, we posited the relation between this oncogene with hTERT that reduced after PVT1 knock-down. Considering these results, long non-coding RNA PVT1 may be a potential option for targeted therapy in hematologic malignancies.

The pseudogene DUXAP10 promotes an aggressive phenotype through binding with LSD1 and repressing LATS2 and RRAD in non small cell lung cancer

Pseudogenes have been considered as non-functional transcriptional relics of human genomic for long time. However, recent studies revealed that they play a plethora of roles in diverse physiological and pathological processes, especially in cancer, and many pseudogenes are transcribed into long noncoding RNAs and emerging as a novel class of lncRNAs. However, the biological roles and underlying mechanism of pseudogenes in the pathogenesis of non small cell lung cancer are still incompletely elucidated. This study identifies a putative oncogenic pseudogene DUXAP10 in NSCLC, which is located in 14q11.2 and 2398 nt in length. Firstly, we found that DUXAP10 was significantly up-regulated in 93 human NSCLC tissues and cell lines, and increased DUXAP10 was associated with patients poorer prognosis and short survival time. Furthermore, the loss and gain of functional studies including growth curves, migration, invasion assays and in vivo studies verify the oncogenic roles of DUXAP10 in NSCLC. Finally, the mechanistic experiments indicate that DUXAP10 could interact with Histone demethylase Lysine specific demethylase1 (LSD1) and repress tumor suppressors Large tumor suppressor 2 (LATS2) and Ras-related associated with diabetes (RRAD) transcription in NSCLC cells. Taken together, these findings demonstrate DUXAP10 exerts the oncogenic roles through binding with LSD1 and epigenetic silencing LATS2 and RRAD expression. Our investigation reveals the novel roles of pseudogene in NSCLC, which may serve as new target for NSCLC diagnosis and therapy.

The LATS1 and LATS2 tumor suppressors: beyond the Hippo pathway

Proper cellular functionality and homeostasis are maintained by the convergent integration of various signaling cascades, which enable cells to respond to internal and external changes. The Dbf2-related kinases LATS1 and LATS2 (LATS) have emerged as central regulators of cell fate, by modulating the functions of numerous oncogenic or tumor suppressive effectors, including the canonical Hippo effectors YAP/TAZ, the Aurora mitotic kinase family, estrogen signaling and the tumor suppressive transcription factor p53. While the basic functions of the LATS kinase module are strongly conserved over evolution, the genomic duplication event leading to the emergence of two closely related kinases in higher organisms has increased the complexity of this signaling network. Here, we review the LATS1 and LATS2 intrinsic features as well as their reported cellular activities, emphasizing unique characteristics of each kinase. While differential activities between the two paralogous kinases have been reported, many converge to similar pathways and outcomes. Interestingly, the regulatory networks controlling the mRNA expression pattern of LATS1 and LATS2 differ strongly, and may contribute to the differences in protein binding partners of each kinase and in the subcellular locations in which each kinase exerts its functions.

microRNA-605 promotes cell proliferation, migration and invasion in non-small cell lung cancer by directly targeting LATS2

Lung cancer is the most common cause of cancer- associated mortality for men and women worldwide. An increasing number of studies have reported that the abnormal expression of microRNAs contributes to the pathogenesis of the majority of human cancer types, including non-small cell lung cancer (NSCLC). The present study aimed to measure microRNA-650 (miR-650) expression in NSCLC and evaluate its function in NSCLC cells. Reverse transcription-quantitative polymerase chain reaction was used to determine miR-650 expression in NSCLC tissue samples and cell lines. Assays for cell proliferation, migration and invasion were performed to investigate the roles of miR-650 on NSCLC progression. Furthermore, the mechanisms underlying the effects of miR-650 on NSCLC cell growth and metastasis were determined. In the current study, miR-650 was demonstrated to be highly expressed in NSCLC tissue samples and cell lines. Inhibition of expression of miR-650 suppressed NSCLC cell proliferation, migration and invasion in vitro. Additionally, large tumor suppressor kinase 2 (LATS2) was identified as a direct target gene of miR-650 in NSCLC. LATS2 was revealed to be significantly downregulated in NSCLC tissues and was negatively correlated with miR-650 expression. Notably, LATS2 re-expression decreased NSCLC cell proliferation, migration and invasion; similar to the effects induced by miR-650 underexpression. In conclusion, the results of the current study suggest that miR-650 may serve as an oncogene by direct targeting LATS2 in NSCLC formation and progression.

The clinical significance and biological function of large tumour suppressor 2 in hepatocellular carcinoma

OBJECTIVES

Present evidence has suggested that large tumour suppressor 2 (LATS2) is abnormally expressed in most human cancer. However, the clinical and prognostic value in hepatocellular carcinoma (HCC) is still unknown.

MATERIALS AND METHODS

Large tumour suppressor 2 mRNA and protein expression levels in HCC tissues and cell lines were detected by qRT-PCR, immunohistochemistry or Western blot. The correlation between LATS2 expression and clinicopathological factors was analysed through immunohistochemistry. The function of LATS2 on HCC cell growth and mobility was explored through MTT, colony formation, Transwell migration and invasion assays. The molecular mechanism of LATS2 was screened and confirmed by qRT-PCR and Western blot.

RESULTS AND CONCLUSION

In this study, LATS2 mRNA and protein expressions were decreased in HCC tissues and cell lines compared with normal hepatic tissues and hepatic cell line. Low LATS2 expression was oppositely corrected with tumour stage, vascular invasion and metastasis. The univariate and multivariate analyses suggested that low LATS2 expression was an independent poor prognostic factor for HCC patients. The in vitro experiments showed that LATS2 regulated HCC cells migration and invasion, but had no effect on HCC cells proliferation. Meanwhile, LATS2 modulated metastasis-associated genes expression including E-cadherin, vimentin, snail, slug, MMP2 and MMP9. In conclusion, LATS2 is a prognostic biomarker and a tumour metastasis suppressor in HCC.

Long Noncoding RNA PVT1 Promotes Non-Small Cell Lung Cancer Cell Proliferation through Epigenetically Regulating LATS2 Expression

Long noncoding RNAs (lncRNA) are a novel class of transcripts with no protein coding capacity, but with diverse functions in cancer cell proliferation, apoptosis, and metastasis. The lncRNA PVT1 is 1,716 nt in length and located in the chr8q24.21 region, which also contains the myelocytomatosis (MYC) oncogene. Previous studies demonstrated that MYC promotes PVT1 expression in primary human cancers. However, the expression pattern and potential biologic function of PVT1 in non-small cell lung cancer (NSCLC) is still unclear. Here, we found that PVT1 was upregulated in 105 human NSCLC tissues compared with normal samples. High expression of PVT1 was associated with a higher tumor-node-metastasis stage and tumor size, as well as poorer overall survival. Functional analysis revealed that knockdown of PVT1 inhibited NSCLC cell proliferation and induced apoptosis both in vitro and in vivo RNA immunoprecipitation and chromatin immunoprecipitation assays demonstrated that PVT1 recruits EZH2 to the large tumor suppressor kinase 2 (LATS2) promoter and represses LATS2 transcription. Furthermore, ectopic expression of LATS2 increased apoptosis and repressed lung adenocarcinoma cell proliferation by regulating the Mdm2-p53 pathway. Taken together, our findings indicated that PVT1/EZH2/LATS2 interactions might serve as new target for lung adenocarcinoma diagnosis and therapy. Mol Cancer Ther; 15(5); 1082-94. ©2016 AACR.

miR-25 promotes glioblastoma cell proliferation and invasion by directly targeting NEFL

Glioblastoma multiforme (GBM) is the most malignant and common brain tumor; it is aggressive growth pattern means that GBM patients face a poor prognosis even when receiving the best available treatment modalities. In recent years, an increasing number of reports suggest that the discovery of microRNAs (miRNAs) might provide a novel therapeutic target for human cancers, including GBM. One miRNA in particular, microRNA-25 (miR-25), is overexpressed in several cancers, wherein accumulating evidence indicates that it functions as an oncogene. However, the function of miR-25 in GBM has not been totally elucidated. In this study, we demonstrated that miR-25 was significantly up-regulated in astrocytoma tissues and glioblastoma cell lines. In vitro studies further demonstrated that overexpressed miR-25 was able to promote, while its antisense oligos inhibited cell proliferation and invasion in U251 cells. Moreover, we identified neurofilament light polypeptide (NEFL) as a novel target molecule of miR-25. Also of note was the fact that NEFL was down-regulated with increased levels of miR-25 expression in human astrocytoma clinical specimens. In addition, via the mTOR signaling pathway, NEFL-siRNA could significantly attenuate the inhibitory effects of knockdown miR-25 on the proliferation and invasion of U251 cells. Overall, our results showed an important role for miR-25 in regulating NEFL expression in GBM, and suggest that miR-25 could be a potential target for GBM treatment.

LATS2 inhibits the activity of NF-κ B signaling by disrupting the interaction between TAK1 and IKKβ

NF-κB signaling plays very important role in the tumorigenesis of nonsmall cell lung cancer (NSCLC). However, the molecular mechanisms for the dysregulation of NF-κB signaling in NSCLC have not been fully understood. In the previous reports, we have showed that large tumor suppressor gene 2 (LATS2) inhibited NF-κB signaling in NSCLC cells, whereas the details for the mechanism remain unknown. Here, we reported that LATS2 is a suppressor of tumor necrosis factor (TNF-α)-induced NF-κB signaling by inhibiting the interaction between TAK1 and IKKβ. Overexpression of LATS2 largely blocked TNF-α-induced NF-κB activation and IκBα degradation, whereas knockdown of LATS2 showed the opposing results. Mechanistically, we identified that LATS2 interacted with IKKβ and blocked the interaction between IKKβ and TAK1. Our results indicate that LATS2 functions as a pivotal negative regulator in TNF-α-induced activation of NF-κB via disrupting the interaction of TAK1 with IKKβ.

miR-107 and miR-25 simultaneously target LATS2 and regulate proliferation and invasion of gastric adenocarcinoma (GAC) cells

Although a series of oncogenes and tumor suppressors were identified in the pathological development of gastric adenocarcinoma (GAC), the underlying molecule mechanism were still not fully understood. The current study explored the expression profile of miR-107 and miR-25 in GAC patients and their downstream regulative network. qRT-PCR analysis was performed to quantify the expression of these two miRNAs in serum samples from both patients and healthy controls. Dual luciferase assay was conducted to verify their putative bindings with LATS2. MTT assay, cell cycle assay and transwell assay were performed to explore how miR-107 and miR-25 regulate proliferation and invasion of gastric cancer cells. Findings of this study demonstrated that total miR-107 or miR-25 expression might be overexpressed in gastric cancer patients and they can simultaneously and synchronically regulate LATS2 expression, thereby affecting gastric cancer cell growth and invasion. Therefore, the miR-25/miR-107-LATS2 axis might play an important role in proliferation and invasion of the gastric cancer cells.