Inhibitory Effect of MiR-449b on Cancer Cell Growth and Invasion through LGR4 in Non-Small-Cell Lung Carcinoma

Prediction of lung adenocarcinoma prognosis and diagnosis with a novel model anchored in circadian clock-related genes

Lung adenocarcinoma is the most common primary lung cancer seen in the world, and identifying genetic markers is essential for predicting the prognosis of lung adenocarcinoma and improving treatment outcomes. It is well known that alterations in circadian rhythms are associated with a higher risk of cancer. Moreover, circadian rhythms play a regulatory role in the human body. Therefore, studying the changes in circadian rhythms in cancer patients is crucial for optimizing treatment. The gene expression data and clinical data were sourced from TCGA database, and we identified the circadian clock-related genes. We used the obtained TCGA-LUAD data set to build the model, and the other 647 lung adenocarcinoma patients' data were collected from two GEO data sets for external verification. A risk score model for circadian clock-related genes was constructed, based on the identification of 8 genetically significant genes. Based on ROC analyses, the risk model demonstrated a high level of accuracy in predicting the overall survival times of lung adenocarcinoma patients in training folds, as well as external data sets. This study has successfully constructed a risk model for lung adenocarcinoma prognosis, utilizing circadian rhythm as its foundation. This model demonstrates a dependable capacity to forecast the outcome of the disease, which can further guide the relevant mechanism of lung adenocarcinoma and combine behavioral therapy with treatment to optimize treatment decision-making.

Rspo2-LGR4 exacerbates hepatocellular carcinoma progression via activation of Wnt/β-catenin signaling pathway

BACKGROUND

The leucine-rich repeat-containing G-protein-coupled receptor 4 (LGR4) plays an important role in stem cell differentiation, organ development and cancer. Whether LGR4 affects the progression of hepatocellular carcinoma (HCC) remains unknown. This study aimed to reveal the role of LGR4 in HCC.

METHODS

Clinical samples of HCC were collected to assess the expression of LGR4 and its correlation with patients' clinical characteristics. The expression level of LGR4 in HCC cells was altered by pharmacological and genetic methods, and the role of LGR4 in HCC progression was analyzed by in vivo and in vitro assays. HCC was induced by diethylnitrosamine (DEN) and carbon tetrachloride (CCl4) in wild-type and LGR4 deficient mice, the effect of LGR4 on HCC was examined by histopathological evaluation and biochemical assays.

RESULTS

LGR4 expression was up-regulated in HCC samples, and its expression level was positively correlated with tumor size, microvascular invasion (MVI), TNM stage and pathological differentiation grade of HCC patients. In the mouse HCC model induced by DEN+CCl4, knockdown of LGR4 effectively inhibited the progression of HCC. Silencing of LGR4 inhibited the proliferation, migration, invasion, stem cell-like properties and Warburg effect of HCC cells. These phenotypes were promoted by R-spondin2 (Rspo2), an endogenous ligand for LGR4. Rspo2 markedly increased the nuclear translocation of β-catenin, whereas IWR-1, an inhibitor of Wnt/β-catenin signaling, reversed its effect. Deficiency of LGR4 significantly reduced the nuclear translocation of β-catenin and the expression of its downstream target genes cyclinD1 and c-Myc.

CONCLUSIONS

LGR4 promotes HCC progression via Wnt/β-catenin signaling pathway.

MiR-24-3p Attenuates Doxorubicin-induced Cardiotoxicity via the Nrf2 Pathway in Mice

OBJECTIVE

The nuclear factor erythroid 2 (NFE2)-related factor 2 (Nrf2) is associated with doxorubicin (DOX)-induced cardiac injury. It has been reported that microRNA-24-3p (miR-24-3p) may regulate the Keapl by mRNA degradation, whereas Keapl can suppress the activation of Nrf2. However, the role of miR-24-3p in DOX-related cardiotoxicity remains unclear.

METHODS

The mice receiving DOX were used as cardiac injury model. In this study, an adenoassociated virus 9 system was used to deliver miR-24-3p or miR-scramble to mice hearts. The echocardiographic and hemodynamic analyses were used to evaluate the effects of miR-24-3p on cardiac function under DOX stimulation. ELISA and RT-PCR were used to detect protein or mRNA expressions associated with cardiac injury, inflammation response, apoptosis and oxidative stress. Western Blot were used for quantitative analysis of the roles of miR-24-3p in regulating Nrf2 expression. H9C2 cells used to verify the role of miR-24-3p in vitro.

RESULTS

We found that miR-24-3p mRNA was significantly decreased in DOX-treated mice and cardiomyocytes. Overexpression of miR-24-3p blocked cardiac injury caused by DOX injection, as reflected by the reduction in the levels of cardiac troponin I, creatinine kinase isoenzyme MB and the N-terminal pro brain natriuretic peptide. Furthermore, miR-24-3p reduced oxidative stress and cell loss without affecting the inflammation response. As expected, we found that Nrf2 was upregulated by miR-24-3p supplementation, and that the protective efforts of miR-24-3p supplementation were abolished when Nrf2 was silenced.

CONCLUSION

The results from this study suggest that miR-24-3p protects cardiomyocytes against DOX-induced heart injury via activation of the Nrf2 pathway. miR-24-3p supplementation may be a novel strategy to counteract the cardiac side effects of DOX treatment.

Emerging Roles for LGR4 in Organ Development, Energy Metabolism and Carcinogenesis

The leucine-rich repeats containing G protein-coupled receptor 4 (LGR4) belonging to G protein-coupled receptors (GPCRs) family, had various regulatory roles at multiple cellular types and numerous targeting sites, and aberrant LGR4 signaling played crucial roles in diseases and carcinogenesis. On the basis of these facts, LGR4 may become an appealing therapeutic target for the treatment of diseases and tumors. However, a comprehensive investigation of its functions and applications was still lacking. Hence, this paper provided an overview of the molecular characteristics and signaling mechanisms of LGR4, its involvement in multiple organ development and participation in the modulation of immunology related diseases, metabolic diseases, and oxidative stress damage along with cancer progression. Given that GPCRs accounted for almost a third of current clinical drug targets, the in-depth understanding of the sophisticated connections of LGR4 and its ligands would not only enrich their regulatory networks, but also shed new light on designing novel molecular targeted drugs and small molecule blockers for revolutionizing the treatment of various diseases and tumors.

The Role of LGR4 (GPR48) in Normal and Cancer Processes

Leucine-rich repeats containing G protein-coupled receptor 4 (LGR4) is a receptor that belongs to the superfamily of G protein-coupled receptors that can be activated by R-spondins (RSPOs), Norrin, circLGR4, and the ligand of the receptor activator of nuclear factor kappa-B (RANKL) ligands to regulate signaling pathways in normal and pathological processes. LGR4 is widely expressed in different tissues where it has multiple functions such as tissue development and maintenance. LGR4 mainly acts through the Wnt/β-catenin pathway to regulate proliferation, survival, and differentiation. In cancer, LGR4 participates in tumor progression, invasion, and metastasis. Furthermore, recent evidence reveals that LGR4 is essential for the regulation of the cancer stem cell population by controlling self-renewal and regulating stem cell properties. This review summarizes the function of LGR4 and its ligands in normal and malignant processes.

Long non-coding RNA GAS5 aggravates myocardial depression in mice with sepsis via the microRNA-449b/HMGB1 axis and the NF-κB signaling pathway

Sepsis is a common cause of deaths of patients in intensive care unit. The study aims to figure out the role of long non-coding RNA (lncRNA) GAS5 in the myocardial depression in mice with sepsis. Cecal ligation and puncture (CLP) was applied to induce sepsis in mice, and then the heart function, myocardium structure, and the inflammatory response were evaluated. Differentially expressed lncRNAs in mice with sepsis were identified. Then gain- and loss-of-functions of GAS5 were performed in mice to evaluate its role in mouse myocardial depression. The lncRNA-associated microRNA (miRNA)-mRNA network was figured out via an integrative prediction and detection. Myocardial injury was observed by overexpression of high-mobility group box 1 (HMGB1) in septic mice with knockdown of GAS5 expression. Activity of NF-κB signaling was evaluated, and NF-κB inhibition was induced in mice with sepsis and overexpression of GAS5. Collectively, CLP resulted in myocardial depression and injury, and increased inflammation in mice. GAS5 was highly expressed in septic mice. GAS5 inhibition reduced myocardial depression, myocardial injury and inflammation responses in septic mice. GAS5 was identified to bind with miR-449b and to elevate HMGB1 expression, thus activating the NF-κB signaling. HMGB1 overexpression or NF-κB inactivation reduced the GAS5-induced myocardial depression and inflammation in septic mice. Our study suggested that GAS5 might promote sepsis-induced myocardial depression via the miR-449b/HMGB1 axis and the following NF-κB activation.

LGR4 overexpression is associated with clinical parameters and poor prognosis of serous ovarian cancer

OBJECTIVE

LGR4 expression in serous ovarian cancer paraffin-embedded tissues and fresh tissues were investigated, and its expression associated with clinicopathological parameters and prognosis in serous ovarian cancer was explored.

METHODS

From Dec, 2009 to Jan, 2020, 122 paraffin-embedded serous ovarian cancer patients and 41 paired paratumor tissues who were both diagnosed and operated at the memorial hospital of Sun Yat-sen University and Integrated Hospital of Traditional Chinese Medicine, Southern Medical University were selected in this research, respectively, and all of these tissues were performed by immunohistochemistry (IHC) with a polyclonal antibody for LGR4. Meanwhile, from Aug, 2013 to Mar, 2019, 15 cases of serous ovarian cancer fresh tissues and 15 cases of paratumor fresh tissues who were operated at Integrated Hospital of Traditional Chinese Medicine, Southern Medical University were performed with Quantitative Real-time PCR to detect the mRNA expression of LGR4, respectively.

RESULTS

LGR4 expression was much higher both in paraffin-embedded and fresh cancer tissues than that in paratumor tissues, respectively, and its expression was associated with recurrence free survival and overall survival in serous ovarian cancer patients. Moreover, in a multivariate model LGR4 was an indeed independent predictor of poor survival in serous ovarian cancer patients.

CONCLUSION

LGR4 is upregulated in serous ovarian cancer, and LGR4 is an indeed useful independent prognostic predictor in serous ovarian cancer, and it may provide important clinical value of serous ovarian cancer.

The Combined Detection of Immune Genes for Predicting the Prognosis of Patients With Non-Small Cell Lung Cancer

Lung cancer is one of the leading causes of cancer-related death. In recent years, there has been an increasing interest in the fields of tumor and immunity. This study focused on the possible prognostic value of immune genes in non-small cell lung cancer patients. We used The Cancer Genome Atlas (TCGA) to download gene expression data and clinical information of lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). The immune gene list was downloaded from the Immport database. We then constructed immune gene prognostic models on the basis of Cox regression analysis. We further evaluated the clinical significance of the models via survival analysis, receiver operating characteristic (ROC) curves, and independent prognostic factor analysis. Moreover, we analyzed the associations of prognostic models with both mutation burdens and neoantigens. Using the Gene Expression Omnibus (GEO) and Kaplan-Meier plotter databases, we evaluated the validity of the prognostic models. The prognostic model of LUAD included 13 immune genes, and the prognostic model of LUSC contained 10 immune genes. High-risk patients based on prognostic models had a lower 5-year survival rate than did low-risk patients. The ROC curve analysis demonstrated the prediction accuracy of the prognostic models, as the area under the curve (AUC) was 0.742, 0.707, and 0.711 for LUAD, and 0.668, 0.703, and 0.668 for LUSC, when the predicted survival times were 1, 3, and 5 years, respectively. The mutation burden analysis showed that mutation level was associated with the risk score in patients with LUAD. The analysis based on GEO and Kaplan-Meier plotter demonstrated the prognostic validity of the models. Therefore, immune gene-related models of LUAD and LUSC can predict prognosis. Further study of these genes may enable us to better distinguish between LUAD and LUSC and lead to improvement in immunotherapy for lung cancer.

LncRNA NEAT1/microRNA-129-5p/SOCS2 axis regulates liver fibrosis in alcoholic steatohepatitis

Background

Long non-coding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) has been reported to play an essential role in non-alcoholic fatty liver disease. However, the role of NEAT1 in regulation of alcoholic steatohepatitis (ASH) remains largely unknown. This study aims to explore the role of NEAT1 in ASH by mediating microRNA-129-5p (miR-129-5p) targeting suppressor of cytokine signaling 2 (SOCS2).

Methods

NEAT1, miR-129-5p and SOCS2 expression in serum of ASH patients were assessed. In the in vitro cellular experiment, we transfected siRNAs, oligonucleotides or plasmids into ethanol-induced AML-12 mouse hepatocytes to alter NEAT1 and miR-129-5p expression, and inflammatory factors and lipid content were determined. In the in vivo animal experiment, we injected lentiviruses carrying siRNAs, oligonucleotides or plasmids onto ASH mice (ASH induced by feeding mice a Lieber-DeCarli ethanol diet) to alter NEAT1 and miR-129-5p expression through the tail vein. Serum liver function, blood lipids and inflammatory factors were detected; liver histopathology, liver cell apoptosis, and fibrosis were observed. The relationship between NEAT1 and miR-129-5p, or between miR-129-5p and SOCS2 was verified.

Results

MiR-129-5p was reduced while NEAT1 and SOCS2 were elevated in ASH. Inhibited NEAT1 or elevated miR-129-5p suppressed the elevated lipid metabolism and restrained inflammation reaction in ethanol-stimulated AML-12 cells. The promoted miR-129-5p and inhibited NEAT1 could improve the liver function and repress blood lipid, inflammation reaction, hepatocyte apoptosis and liver fibrosis in ethanol-induced ASH mice. Furthermore, NEAT1 could negatively regulate miR-129-5p to target SOCS2.

Conclusion

We have found that the inhibited NEAT1 could suppress liver fibrosis in ASH mice by promoting miR-129-5p and restraining SOCS2, thereby decelerating the development of ASH.

Aberrant expression of miR-4728 in patients with non-small cell lung cancer and its regulatory effects on tumor progression in tumor cells

Non-small cell lung cancer (NSCLC) is a common malignant tumor with poor prognosis and an increasing number of cases. MicroRNA (miR)-4728 is related with the progression of various types of cancer, and is dysregulated in NSCLC, which indicates that miR-4728 may serve as a biomarker for NSCLC. The present study aimed to investigate the clinical significance of miR-4728 in NSCLC diagnosis and prognosis, and to explore the biological function of miR-4728 in NSCLC progression. Serum and tissue samples were collected from 122 patients with NSCLC. By conducting reverse transcription-quantitative PCR, the Cell Counting Kit-8 assay and Transwell assays, the expression of miR-4728 and its effect on NSCLC cell proliferation, migration and invasion were investigated. The diagnostic value of miR-4728 was evaluated by plotting a receiver operating characteristic curve, and Kaplan-Meier and Cox regression analyses were conducted to assess the prognostic value of miR-4728. miR-4728 was significantly downregulated in NSCLC serum and tissue samples compared with healthy controls, with a relatively high diagnostic accuracy and ability to predict poor overall survival time in patients with NSCLC. By conducting gain- and loss-of-function experiments, the results indicated that miR-4728 knockdown significantly promoted NSCLC cell proliferation, migration and invasion compared with the inhibitor negative control (NC) group. By contrast, miR-4728 overexpression displayed the opposite effect on NSCLC cell proliferation, migration and invasion. The present study indicated that miR-4728 was downregulated in NSCLC and may serve as a candidate diagnostic and prognostic biomarker. NSCLC cell proliferation, migration and invasion were inhibited by miR-4728 overexpression compared with the mimic NC group, which suggested that miR-4728 may serve as a therapeutic target for NSCLC.

Long intergenic non-protein coding RNA 00475 silencing acts as a tumor suppressor in glioma under hypoxic condition by impairing microRNA-449b-5p-dependent AGAP2 up-regulation

Objective

Long non-coding RNAs have been demonstrated to be involved in the progression of a variety of cancers, including glioma. Through microarray analyses, long intergenic non-protein coding RNA 00475 (LINC00475) was identified in the glioma development. However, its potential role remains incompletely understood. This study aimed to elucidate the effect of LINC00475 on the development of glioma under hypoxic conditions.

Methods

Glioma cells underwent hypoxic treatment and were collected. The functional role of LINC00475 and AGAP2 in glioma was determined using ectopic expression, depletion, and reporter assay experiments. Then, the expression of LINC00475, microRNA (miR)-449b-5p, AGAP2, FAK, and HIF-1α was determined. In addition, cell migration and invasion were examined. Finally, a tumor xenograft was carried out in nude mice to explore the role of LINC00475 on oxidation in vivo.

Results

LINC00475 was identified to be overexpressed in hypoxic glioma samples, which was further observed to bind to and down-regulate miR-449b-5p, and negatively targeted AGAP2. Moreover, we also revealed a positive correlation between LINC00475 and AGAP2 expression in glioma. In addition, silencing of LINC00475 decreased the extent of FAK phosphorylation and reduced the expression of HIF-1α and AGAP2. It was also observed that LINC00475 silencing suppressed glioma cell proliferation, migration, and invasion, and promoted cell apoptosis. Moreover, oxidation of nude mice was promoted by LINC00475 silencing.

Conclusion

Taken together, LINC00475 silencing exerted an inhibitory effect on glioma under hypoxic conditions by down-regulating AGAP2 via up-regulation of miR-449b-5p.

The Interplay of MicroRNA-34a, LGR4, EMT-Associated Factors, and MMP2 in Regulating Uveal Melanoma Cells

Purpose

MicroRNA-34a (miR-34a) has been implicated in many biological processes. It is downregulated in uveal melanoma, and introduction of miR-34a inhibits the proliferation and migration of uveal melanoma cells. Leucine-rich repeat-containing G protein-coupled receptor 4 (LGR4) is a novel target of miR-34a identified first in retinal pigment epithelial cells. In this study, we sought to evaluate the interaction of miR-34a and LGR4 in uveal melanoma and its downstream mechanisms.

Methods

The expression of LGR4, epithelial-mesenchymal transition (EMT)-associated factors, and matrix metalloproteinase 2 (MMP2) in uveal melanoma cells was assessed by immunoblotting and immunofluorescence analysis. MicroRNA-34a mimic molecules, LGR4 small interfering RNA (siRNA), or MMP2-specific siRNA were transiently transfected into uveal melanoma cells. In vitro scratch and Transwell assays were used to evaluate the migratory and invasive potential of the resultant uveal melanoma cells.

Results

LGR4 is upregulated in uveal melanoma cells. Introduction of miR-34a significantly decreased the expression level of LGR4. Transfection with miR-34a or knockdown of LGR4 attenuated the aggressiveness of uveal melanoma cells. In addition, there was a decrease in the expression of mesenchymal markers N-cadherin, vimentin, and Snail following miR-34a introduction or knockdown of LGR4. Finally, MMP2 was found to be a downstream effector for miR-34a and LGR4 that regulates the migration and invasion of uveal melanoma cells.

Conclusions

MicroRNA-34a negatively controls LGR4, thereby inhibiting the migration and invasion of uveal melanoma cells. Ultimately, both miR-34a and LGR4 impact the aggressiveness of uveal melanoma with alterations in the markers of the EMT. MMP2 is a downstream effector that influences the metastasis seen with uveal melanoma cells.

MicroRNA-449b-5p suppresses cell proliferation, migration and invasion by targeting TPD52 in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is an important type of head and neck malignant cancer with geographical distribution. MicroRNA-449b-5p (miR-449b-5p) is related to the development of various cancers, while its function in NPC remains unknown. The present study aimed to investigate the role and target gene of miR-449b-5p in NPC. Expressions of miR-449b-5p in NPC cell lines and clinical tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was determined by MTT and colony formation assays. Migration and invasion abilities after different treatment were evaluated by wound healing and Transwell assays, respectively. Dual-luciferase reporter assay was performed to explore the relationship between miR-449b-5p and tumour protein D52 (TPD52). TPD52 expression was determined by qRT-PCR and western blot assay. miR-449b-5p was significantly downregulated in NPC cell lines and clinical tissues than the matched control. Overexpression of miR-449b-5p inhibited proliferation, migration and invasion of NPC cells. Dual-luciferase reporter assay indicated that miR-449b-5p directly targeted TPD52. Furthermore, shRNA-mediated downregulation of TPD52 rectified the promotion of cell migration and invasion by miR-449b-5p inhibition. In conclusion, the present study suggests that miR-449b-5p, as a novel tumour-suppressive miRNA against NPC, inhibits proliferation, migration and invasion of NPC cells via inhibiting TPD52 expression.

miR‑802 inhibits the aggressive behaviors of non‑small cell lung cancer cells by directly targeting FGFR1

Emerging reports have revealed that several microRNAs (miRNAs) are abnormally expressed in non‑small cell lung cancer (NSCLC). miRNAs have been identified as oncogenes or tumor suppressors, and regulate various biological processes including oncogenesis and development. miR‑802 is dysregulated in multiple types of human cancer, and exerts tumor‑suppressive or promoting roles. However, the expression levels and functional roles of miR‑802 in NSCLC remain largely unknown. In the present study, miR‑802 expression was demonstrated to be decreased in NSCLC tissues and cell lines. A low miR‑802 expression was significantly correlated with the tumor stage, lymph node metastasis and brain metastasis in NSCLC patients. Restoring miR‑802 expression inhibited NSCLC cell proliferation and colony formation, induced cell apoptosis, decreased cell migration and invasion in vitro, and hindered in vivo tumor growth. Mechanistically, fibroblast growth factor receptor 1 (FGFR1) was confirmed as the target gene of miR‑802 in NSCLC cells. In addition, FGFR1 silencing mimicked the tumor‑suppressing roles of miR‑802 upregulation in NSCLC cells. Furthermore, rescue experiments revealed that FGFR1 reintroduction rescued the miR‑802‑induced inhibition of the malignant phenotypes in NSCLC cells. Notably, miR‑802 was able to deactivate the phosphoinositide 3‑kinase (PI3K)/AKT serine/threonine kinase (Akt)/mammalian target of rapamycin (mTOR) pathway in NSCLC cells in vitro and in vivo. Overall, these results demonstrated that miR‑802 could downregulate FGFR1 expression, thereby deactivating the PI3K/Akt/mTOR pathway and inhibiting the malignant development of NSCLC. Thus, miR‑802 may be a therapeutic candidate for patients with NSCLC.