MiR-98 Promotes Apoptosis of Glioma Cells via Suppressing IKBKE/NF-κB Pathway

MAPK signaling pathway-based glioma subtypes, machine-learning risk model, and key hub proteins identification

An early diagnosis and precise prognosis are critical for the treatment of glioma. The mitogen‑activated protein kinase (MAPK) signaling pathway potentially affects glioma, but the exploration of the clinical values of the pathway remains lacking. We accessed data from TCGA, GTEx, CGGA, etc. Up-regulated MAPK signaling pathway genes in glioma were identified and used to cluster the glioma subtypes using consensus clustering. The subtype differences in survival, cancer stemness, and the immune microenvironment were analyzed. A prognostic model was trained with the identified genes using the LASSO method and was validated with three external cohorts. The correlations between the risk model and cancer-associated signatures in cancer were analyzed. Key hub genes of the gene set were identified by hub gene analysis and survival analysis. 47% of the MAPK signaling pathway genes were overexpressed in glioma. Subtypes based on these genes were distinguished in survival, cancer stemness, and the immune microenvironment. A risk model was calculated with high confidence in the prediction of overall survival and was correlated with multiple cancer-associated signatures. 12 hub genes were identified and 8 of them were associated with survival. The MAPK signaling pathway was overexpressed in glioma with prognostic value.

LIN28B and Let-7 in Diffuse Midline Glioma: A Review

Diffuse midline glioma (DMG) is the most lethal of all childhood cancers. DMGs are driven by histone-tail-mutation-mediated epigenetic dysregulation and partner mutations in genes controlling proliferation and migration. One result of this epigenetic and genetic landscape is the overexpression of LIN28B RNA binding protein. In other systems, LIN28B has been shown to prevent let-7 microRNA biogenesis; however, let-7, when available, faithfully suppresses tumorigenic pathways and induces cellular maturation by preventing the translation of numerous oncogenes. Here, we review the current literature on LIN28A/B and the let-7 family and describe their role in gliomagenesis. Future research is then recommended, with a focus on the mechanisms of LIN28B overexpression and localization in DMG.

miRNA-451 regulates the NF-κB signaling pathway by targeting IKKβ to inhibit glioma cell growth

Glioblastoma multiforme (GBM) is associated with a poor prognosis, and effective treatments are lacking. Our previous studies have shown that miRNA-451 is closely related to the development and progression of glioma. miRNA-451 is a tumor suppressor whose expression is negatively correlated with the WHO grades of gliomas, but its specific mechanism is still unclear. Research shows that NF-κB is highly expressed in early malignant glioma, and thus, the NF-κB signaling pathway has become an important target for the treatment of malignant glioma. Activation of IKK is a critical step in the activation of the classical NF-κB pathway. By performing a bioinformatics analysis, we found that IKKβ is a potential direct target of miRNA-451 in glioma. In this study, we transfected lentivirus expressing miRNA-451 to test the effect of miRNA-451 overexpression on malignant glioma cell lines and confirmed that IKKβ is a target gene of miRNA-451 by luciferase assay. By targeting IKKβ, MTT, cell invasion and wound-healing assays showed that cell proliferation, cell invasion and migration were significantly suppressed in the LV-miRNA-451 group. Western blotting results showed that the expression levels of IKKβ, p-p65, MMP-2, MMP-9, Cyclin D1, p16 and PCNA were significantly decreased in the LV-miRNA-451 group. In vivo, miRNA-451 significantly decreased glioma cell growth, and the survival of BALB/c-A nude mice was significantly prolonged. Immunohistochemistry showed that p-p65, Cyclin D1 and Ki67 expression was significantly reduced in the LV-miRNA-451 group. Taken together, these results suggest that miRNA-451 could regulate the NF-κB signaling pathway by targeting IKKβ, which inhibits glioma cell growth in vitro and in vivo. Therefore, this study may provide novel insight into miRNA-451-targeted therapy for glioma.

Aberrant expression profile of miR-32, miR-98 and miR-374 in chronic lymphocytic leukemia

INTRODUCTION

Leukemia is a malignant and progressive disease of hematopoiesis. The disease arises due to abnormal proliferation and development of white blood cells and their precursors in the blood and bone marrow. Chronic lymphoblastic leukemia (CLL) is a subtype of blood cancers, with the origin of B lymphocytes and the involvement of bone marrow, blood and lymph nodes. MicroRNAs (miRNAs) are small non-coding RNAs with pivotal roles in cellular and molecular processes related to different malignancies, including CLL. In this way, we aimed to evaluate the expression of miR-32-5p, miR-98-5p, and miR-374b-5p in CLL patients. We also investigated the signaling pathways regulated by the studied miRs and also frequently disturbed miRs in CLL.

METHODS

Blood samples were collected from 32 CLL patients from Kermanshah province, Iran and 34 age and sex-matched healthy individuals. RNA was extracted from PBMCs and then was subjected to cDNA synthesis. Using specifically designed primers and Real-Time PCR method the expression of miRNAs was detected and was statistically analyzed. Using mirPath v.3, systematic pathway enrichment analysis was performed for the three studied miRNAs here along with the frequently disturbed miRNAs in CLL.

RESULTS

The experiments indicated a significant reduction in the expression of all three miRs (p-value<0.0001) in CLL patients compared with healthy individuals. ROC analysis suggested that the three studied miRs can serve as potential biomarkers for early diagnosis of CLL. The in silico analysis suggested proteoglycans in cancer as a pathway regulated by the studied miRs and frequently dysregulated miRs in CLL.

CONCLUSION

The observed reduction in expression of miR-32-5p, miR-98-5p, and miR-374b-5p in treatment naïve CLL patients here might be suggestive of their modulatory protective role in CLL progression. Moreover, the candidate peripheral miRNAs could potentially serve as diagnostic biomarkers which warrant further investigation in a larger sample size.

MicroRNA-4500 Inhibits Migration, Invasion, and Angiogenesis of Breast Cancer Cells via RRM2-Dependent MAPK Signaling Pathway

With the consideration of the dynamic role of microRNAs (miRNAs) in breast cancer, miRNAs may serve as therapeutic targets, helping to prevent development of therapy resistance, maintain stable disease, and prohibit metastatic spread. We identified the differentially expressed breast cancer-related gene ribonucleotide reductase subunit M2 (RRM2) as the study focus through microarray expression profiles. Next, the upstream regulatory microRNA (miR)-4500 of RRM2 was predicted using bioinformatics website analysis, and their binding was verified by a dual luciferase reporter gene assay. The regulatory effects of miR-4500 on breast cancer cell proliferation, apoptosis, migration, invasion, and capillary-like tube formation of endothelial cells were assessed by gain- and loss-of-function experiments. The experimental data revealed that miR-4500 was downregulated, whereas RRM2 was upregulated in breast cancer cells. Mechanistic analysis revealed that miR-4500 downregulated the RRM2 expression to inactivate the mitogen-activated protein kinase (MAPK) signaling pathway. Furthermore, miR-4500 exerted anti-tumor effects by targeting RRM2 through suppression of the MAPK signaling pathway in vitro, evidenced by attenuated cancer cell migration and invasion and capillary-like tube formation of endothelial cells. The in vivo experiments further corroborated in vitro results. Collectively, overexpressed miR-4500 could downregulate RRM2 and inhibit activation of the MAPK signaling pathway, thus attenuating breast cancer cell proliferation, invasion, migration, and angiogenesis and promoting breast cancer cell apoptosis.

Silencing lncRNA FOXD2-AS1 inhibits proliferation, migration, invasion and drug resistance of drug-resistant glioma cells and promotes their apoptosis via microRNA-98-5p/CPEB4 axis

OBJECTIVE

This study was conducted to elucidate the long non-coding RNA FOXD2-AS1 (lncRNA FOXD2-AS1) expression in glioma and its mechanism on the biological features of glioma cells and the drug resistance of temozolomide (TMZ).

RESULTS

Highly expressed FOXD2-AS1 was found in glioma. There was more powerful chemotherapeutic resistance of TMZ resistant cell lines than that of the parent cell lines. Silence of FOXD2-AS1 suppressed proliferation and drug resistance and promoted apoptosis of drug-resistant glioma cells. Overexpressed FOXD2-AS1 presented an opposite trend. FOXD2-AS1 could be used as a competing endogenous RNA to adsorb miR-98-5p, thereby up-regulating CPEB4.

CONCLUSION

Our study suggests that down-regulated FOXD2-AS1 repressed invasion, proliferation, migration and drug resistance of drug-resistant glioma cells while stimulating their apoptosis via increasing miR-98-5p and inhibiting CPEB4 expression.

METHODS

FOXD2-AS1, microRNA-98-5p (miR-98-5p) and cytoplasmic polyadenylation element binding (CPEB4) expression in glioma tissues were tested. Expression of E-cadherin, N-cadherin and Vimentin in glioma cells were explored. A series of assays were conducted to detect the function of FOXD2-AS1 in migration, proliferation, apoptosis, and invasion of glioma cells. Changes in drug-resistance of cells under TMZ treatment were examined, and tumor formation in nude mice was performed to test the changes of drug resistance in vivo.

MicroRNA-98 targets HMGA2 to inhibit the development of retinoblastoma through mediating Wnt/β-catenin pathway

BACKGROUND

Recently, the incidence and mortality of retinoblastoma (RB) have gradually increased. Many studies support the pivotal role of microRNAs (miRNAs) in the pathogenesis of RB. Alternation of microRNA-98 (miR-98) expression has been detected in several cancers, excluding RB. This study was designed to assess the regulatory mechanisms of miR-98 in human RB.

METHODS

RT-qPCR and Western blot analysis were used to detect miR-98 and HMGA2 expression. The effects of miR-98 were explored using the CCK-8 and Transwell assays. Dual-luciferase reporter assay was performed to confirm the relationship between miR-98 and HMGA2.

RESULTS

In RB, downregulation of miR-98 was identified. Upregulation of miR-98 inhibited proliferation, invasion and migration of RB cells. Further, HMGA2 was confirmed as a direct target gene of miR-98. And knockdown of HMGA2 suppressed the progression of RB. Moreover, upregulation of HMGA2 reversed the suppressive effects in the development of RB. In addition, miR-98 also showed suppressive effect on EMT and Wnt/β-catenin pathway.

CONCLUSION

MiR-98 targets HMGA2 to act as a tumor suppressor in RB by mediating Wnt/β-catenin pathway.

microRNA-98 protects sepsis mice from cardiac dysfunction, liver and lung injury by negatively regulating HMGA2 through inhibiting NF-κB signaling pathway

Recently, MicroRNA-98 (miR-98) works as a biomarker in some diseases, such as lung cancer, Schizophrenia, and breast cancer, but there still lack of studies on the function of miR-98 during sepsis. Thus, our study is conducted to figure out the function of miR-98 for the regulation of cardiac dysfunction, liver and lung injury in sepsis mice. Cecum ligation and puncture was used to establish the sepsis mice model. Next, miR-Con and agomiR-98 were injected into the tail vein of mice 48 h after modeling. Then, expression of miR-98, HMGA2, NF-κB, inflammatory factors, apoptosis-related proteins in myocardial, liver and lung tissues of septic mice were determined. Moreover, other indices that were associated with cardiac dysfunction, liver and lung injury in septic mice were detected. Finally, bioinformatics analysis and luciferase activity assay were utilized to validate the binding site between miR-98 and HMGA2. miR-98 was poorly expressed, while HMGA2, NF-κB pathway-related proteins were highly expressed in myocardial, liver, and lung tissues of mice with sepsis. Upregulated miR-98 inhibited HMGA2, NF-κB, TNF-α, IL-6, Bcl-2 and increased IL-10, Cleaved caspase-3 and Bax expression in myocardial, liver, and lung tissues of septic mice. Upregulation of miR-98 decreased LVEDP, CTn-I, BNP, ALT, AST, TBIL, LDH, and PaCO₂ while increased +dp/dt max, -dp/dt max, pH and PaO₂ in sepsis mice. miR-98 was a direct target gene of HMGA2. Our study provides evidence that miR-98 protects sepsis mice from cardiac dysfunction, liver and lung injury by negatively mediating HMGA2 via the inhibition of the NF-κB signaling pathway.

Overexpression of microRNA-98 inhibits cell proliferation and promotes cell apoptosis via claudin-1 in human colorectal carcinoma

Colorectal carcinoma (CRC) is a major cause of cancer-related deaths worldwide, and investigations on novel targets are imperative. MiR-98 has been reported to act as a tumor suppressor in several cancers. To evaluate miR-98 as a novel anticancer molecule for CRC, examinations to validate whether miR-98 conferred an inhibiting effect on proliferation, migration, and invasion were performed. The microarray-based gene expression profiling involving CRC was used to identify the differentially expressed genes. The potential relationship between miR-98 and CLDN1 was analyzed by cell experimentation. Then, the CRC cells were transfected with miR-98 mimic or miR-98 inhibitor to investigate the potential effect of miR-98 overexpression and depletion on CRC cell proliferation, migration, invasion, and apoptosis. The expressions of CLDN1, Bcl-2 associated protein x (Bax), runt-related transcription factor 3 (RUNX3), B-cell lymphoma 2 (Bcl-2), C-myc, and proliferating cell nuclear antigen (PCNA) were determined. The downregulated miR-98 along with an upregulated CLDN1 was observed in CRC, in which miR-98 could target to regulate CLDN1. The overexpression of miR-98 or silencing of CLDN1 was shown to increase the expression of Bax and RUNX3 along with promoted cell apoptosis and arrested cells in G1 phase, while decreasing the expression of CLDN1, Bcl-2, C-myc, and PCNA with suppressed proliferation, migration, and invasion. Collectively, the current study supports the notion that miR-98 plays an inhibitory role in human CRC cell proliferation, migration, and invasion and act as a contributor for cell apoptosis by downregulating CLDN1. The current study highlights a potential future strategy to help prevent the development of CRC.

MCCK1 enhances the anticancer effect of temozolomide in attenuating the invasion, migration and epithelial-mesenchymal transition of glioblastoma cells in vitro and in vivo

Chemotherapy with temozolomide (TMZ) is the traditional treatment for glioblastoma (GBM). Nevertheless, majority of GBM patients have recurrence from resistance to the chemotherapy. Herein, we examined combinational effects of MCCK1 (a specific and effective IKKε inhibitor) with TMZ in GBM U251MG and U‐87MG cell lines as well as U251MG xenograft models to overcome the therapeutic limitation of chemotherapy for GBM. Although MCCK1 alone showed inhibitory effects on in vitro proliferation, migration, invasion, and EMT of U251MG and U‐87MG cells, combination of MCCK1 and TMZ showed enhanced inhibitory effects. In the U251MG GBM xenograft models, MCCK1 showed synergistic therapeutic effects in combination with TMZ to reduce tumor volumes significantly. These data indicated that MCCK1 could be a candidate sensitizer to potentiate therapeutic effects of conventional cytotoxic treatment for GBM.