MicroRNA-623 Inhibits Epithelial-Mesenchymal Transition to Attenuate Glioma Proliferation by Targeting TRIM44

MiR-623 links lncRNA RP11-89 and cyclin D1 to regulate the proliferation of glioblastoma cells

PURPOSE

The tumorigenesis of bladder cancer has been proven to be related to the increased expression of lncRNA RP11-89, the participation of which in glioblastoma (GBM) is unknown. We predicted that RP11-89 could be targeted by miR-623, which targets cyclin D1. We then analyzed the role of RP11-89 in GBM.

MATERIALS AND METHODS

Samples of both GBM and paired non-tumor tissue were obtained from 58 GBM patients to analyze the expression of RP11-89 and miR-623 through RT-qPCR. The direct binding of miR-623 to RP11-89 was analyzed with RNA-RNA pull down. The role of RP11-89 and miR-623 in regulating each other's expression was analyzed with overexpression assay. The role of RP11-89 and miR-623 in regulating the expression of cyclin D1 and GBM cell proliferation was analyzed by Western blot and BrdU assay, respectively.

RESULTS

RP11-89 was expressed in high amounts in GBM, while miR-623 was expressed in low amounts in GBM. RP11-89 and miR-623 were not closely correlated, while miR-623 directly bound to RP11-89. RP11-89 and miR-623 showed no direct role in each other's expression. RP11-89 suppressed the role of miR-623 in downregulating cyclin D1 and GBM cell proliferation.

CONCLUSIONS

Therefore, miR-623 may link lncRNA RP11-89 and cyclin D1 to regulate the proliferation of GBM cells.

Intricate confrontation: Research progress and application potential of TRIM family proteins in tumor immune escape

BACKGROUND

Tripartite motif (TRIM) family proteins have more than 80 members and are widely found in various eukaryotic cells. Most TRIM family proteins participate in the ubiquitin-proteasome degradation system as E3-ubiquitin ligases; therefore, they play pivotal regulatory roles in the occurrence and development of tumors, including tumor immune escape. Due to the diversity of functional domains of TRIM family proteins, they can extensively participate in multiple signaling pathways of tumor immune escape through different substrates. In current research and clinical contexts, immune escape has become an urgent problem. The extensive participation of TRIM family proteins in curing tumors or preventing postoperative recurrence and metastasis makes them promising targets.

AIM OF REVIEW

The aim of the review is to make up for the gap in the current research on TRIM family proteins and tumor immune escape and propose future development directions according to the current progress and problems.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This up-to-date review summarizes the characteristics and biological functions of TRIM family proteins, discusses the mechanisms of TRIM family proteins involved in tumor immune escape, and highlights the specific mechanism from the level of structure-function-molecule-pathway-phenotype, including mechanisms at the level of protein domains and functions, at the level of molecules and signaling pathways, and at the level of cells and microenvironments. We also discuss the application potential of TRIM family proteins in tumor immunotherapy, such as possible treatment strategies for combination targeting TRIM family protein drugs and checkpoint inhibitors for improving cancer treatment.

TRIM44 aggravates cardiac fibrosis after myocardial infarction via TAK1 stabilization

Myocardial infarction (MI) is one of the most dangerous cardiovascular events. Cardiac fibrosis is a common pathological feature of remodeling after injury that is related to adverse clinical results with no effective treatment. Previous studies have confirmed that TRIM44, an E3 ligase, can promote the proliferation and migration of various tumor cells. However, the role of TRIM44 in cardiac fibrosis remains unknown. Models of TGF-β1 stimulation and MI-induced fibrosis were established to investigate the role and potential underlying mechanism of TRIM44 in cardiac fibrosis. The results showed that cardiac fibrosis was significantly inhibited after TRIM44 knockdown in a mouse model of MI, while it was enhanced when TRIM44 was overexpressed. Furthermore, in vitro studies showed that fibrosis markers were significantly reduced in cardiac fibroblasts (CFs) with TRIM44 knockdown, whereas TRIM44 overexpression promoted the expression of fibrosis markers. Mechanistically, TRIM44 maintains TAK1 stability by inhibiting the degradation of k48-linked polyubiquitination-mediated ubiquitination, thereby increasing phosphorylated TAK1 expression in the fibrotic environment and activating MAPKs to promote fibrosis. Pharmacological inhibition of TAK1 phosphorylation reversed the fibrogenic effects of TRIM44 overexpression. Combined, these results suggest that TRIM44 is a potential therapeutic target for cardiac fibrosis.

miR-623 Targets Metalloproteinase-1 and Attenuates Extravasation of Brain Metastatic Triple-Negative Breast Cancer Cells

Background

Most breast cancer-related deaths result from metastasis. Understanding the molecular basis of metastasis is needed for the development of effective targeted and preventive strategies. Matrix metalloproteinase-1 (MMP1) plays an important role in brain metastasis (BM) of triple-negative breast cancer (TNBC) by promoting extravasation of cancer cells across the brain endothelium (BE). MMP1 expression is controlled by endogenous microRNAs. Preliminary bioinformatics analysis has revealed that miR-623, known to target the 3ʹUTR of MMP1, is significantly downregulated in brain metastatic tumors compared to primary BC tumors. However, the involvement of miR-623 in MMP1 upregulation in breast cancer brain metastatic cells (BCBMC) remains unexplored. Here, we investigated the role of miR-623 in MMP1 regulation and its impact on the extravasation of TNBC cells through the BE in vitro.

Materials and Methods

A loss-and-gain of function method was employed to address the effect of miR-623 modulation on MMP1 expression. MMP1 regulation by miR-623 was investigated by real-time PCR, western blot, luciferase and transwell migration assays using an in vitro human BE model.

Results

Our results confirmed that brain metastatic TNBC cells express lower levels of miR-623 compared with cells having low propensity to spread toward the brain. miR-623 binds to the 3′-untranslated region of MMP1 transcript and downregulates its expression. Restoring miR-623 expression significantly decreased MMP1 expression, preserved the endothelial barrier integrity, and attenuated transmigration of BCBMC through the BE.

Conclusion

Our study elucidates, for the first time, the crucial role of miR-623 as MMP1 direct regulator in BCBMC and sheds light on miR-623 as a novel therapeutic target that can be exploited to predict and prevent brain metastasis in TNBC. Importantly, the presents study helps in unraveling a brain metastasis-specific microRNA signature in TNBC that can be used as a guide to personalized metastasis prediction and preventive approach with better therapeutic outcome.

Non-coding RNAs and glioblastoma: Insight into their roles in metastasis

Glioma, also known as glioblastoma multiforme (GBM), is the most prevalent and most lethal primary brain tumor in adults. Gliomas are highly invasive tumors with the highest death rate among all primary brain malignancies. Metastasis occurs as the tumor cells spread from the site of origin to another site in the brain. Metastasis is a multifactorial process, which depends on alterations in metabolism, genetic mutations, and the cancer microenvironment. During recent years, the scientific study of non-coding RNAs (ncRNAs) has led to new insight into the molecular mechanisms involved in glioma. Many studies have reported that ncRNAs play major roles in many biological procedures connected with the development and progression of glioma. Long ncRNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) are all types of ncRNAs, which are commonly dysregulated in GBM. Dysregulation of ncRNAs can facilitate the invasion and metastasis of glioma. The present review highlights some ncRNAs that have been associated with metastasis in GBM. miRNAs, circRNAs, and lncRNAs are discussed in detail with respect to their relevant signaling pathways involved in metastasis.

MicroRNA Interrelated Epithelial Mesenchymal Transition (EMT) in Glioblastoma

MicroRNAs (miRNA) are small non-coding RNAs that are 20–23 nucleotides in length, functioning as regulators of oncogenes or tumor suppressor genes. They are molecular modulators that regulate gene expression by suppressing gene translation through gene silencing/degradation, or by promoting translation of messenger RNA (mRNA) into proteins. Circulating miRNAs have attracted attention as possible prognostic markers of cancer, which could aid in the early detection of the disease. Epithelial to mesenchymal transition (EMT) has been implicated in tumorigenic processes, primarily by promoting tumor invasiveness and metastatic activity; this is a process that could be manipulated to halt or prevent brain metastasis. Studies show that miRNAs influence the function of EMT in glioblastomas. Thus, miRNA-related EMT can be exploited as a potential therapeutic target in glioblastomas. This review points out the interrelation between miRNA and EMT signatures, and how they can be used as reliable molecular signatures for diagnostic purposes or targeted therapy in glioblastomas.

Identification of a novel circular RNA circZNF652/miR-486-5p/SERPINE1 signaling cascade that regulates cancer aggressiveness in glioblastoma (GBM)

Circular RNAs (circRNAs) are closely associated with cancer development in glioblastoma (GBM), and this study aims to explore the molecular mechanisms of a novel circular RNA circZNF652 in regulating GBM aggressiveness. The present study found that CircZNF652 and SERPINE1 were upregulated, while miR-486-5p was downregulated in GBM tissues and cell lines, and GBM patients with high expression of CircZNF652 and SERPINE1, and patients with low expression of miR-486-5p tended to have a worse prognosis. Further results validated that both silencing of circZNF652 and miR-486-5p overexpression suppressed cell growth, migration, invasion, epithelial–mesenchymal transition (EMT) and tumorigenesis in GBM cells in vitro and in vivo. Next, the underlying mechanisms were investigated, and we found that circZNF652 sponged miR-486-5p to upregulate SERPINE1 in GBM cells. Also, we validated that knock-down of circZNF652 regulated the miR-486-5p/SERPINE1 axis to reverse the malignant phenotypes in GBM cells. Interestingly, we noticed that GBM cells derived exosomes were characterized by high-expressed CircZNF652. Collectively, we concluded that targeting the circular RNA circZNF652/miR-486-5p/SERPINE1 axis was a novel and effective strategy to suppress cancer progression in GBM.

circ_0030018 promotes glioma proliferation and metastasis

Background

Circular RNA (circRNA) plays an essential role in tumor progression, including glioma. circ_0030018 is a newly discovered circRNA that is highly expressed in glioma. However, its role and mechanism in glioma need to be further elucidated.

Methods

The expression of circ_0030018, microRNA (miR)-194-5p, and tripartite motif containing 44 (TRIM44) was examined using quantitative real-time PCR. Cell proliferation, migration, invasion, and apoptosis were determined using MTT assay, colony formation assay, transwell assay, and flow cytometry. Moreover, dual-luciferase reporter assay and RNA pull-down assay were used to verify the interactions among circ_0030018, miR-194-5p, and TRIM44. The protein expression of TRIM44 was assessed by western blot analysis. Animal experiments were conducted to explore the role of circ_0030018 in glioma tumor growth in vivo.

Results

circ_0030018 was overexpressed in glioma tissues and cells, and its silencing could inhibit glioma cell proliferation, migration, invasion, and accelerate apoptosis. miR-194-5p could be sponged by circ_0030018, and its overexpression could hinder the progression of glioma cells. Further experiments revealed that miR-194-5p inhibitor reversed the negative regulation of circ_0030018 knockdown on glioma cell progression. In addition, TRIM44 was a target of miR-194-5p, and its downregulation could repress glioma cell progression. Overexpressed TRIM44 reversed the inhibition effect of miR-194-5p on glioma cell progression. Animal experiments suggested that circ_0030018 knockdown could reduce glioma tumor growth through regulating miR-194-5p and TRIM44.

Conclusion

Our 8data showed that circ_0030018 enhanced glioma progression by sponging miR-194-5p to regulate TRIM44, indicating that circ_0030018 might be a potential treatment target for glioma.