MicroRNA-138 Increases Chemo-Sensitivity of Glioblastoma through Downregulation of Survivin

Simultaneous Targeting of Tumor Cells and Tumor-Associated Macrophages To Reprogram Glioblastoma Using Trypsinized Extracellular Vesicles Carrying Tumor Suppressive MicroRNA

Glioblastoma (GBM) remains difficult to treat due to poor drug delivery across the blood-brain barrier and an immunosuppressive tumor microenvironment (TME). Tumor-suppressive microRNAs (miRNAs) offer a promising strategy to reprogram both tumor cells and the TME, but inefficient delivery systems limit their clinical application. We previously reported that tumor-suppressive miR-138 regresses tumor growth in preclinical GBM models. Here, we demonstrate that trypsin digestion of extracellular vesicles (EVs) enhances labeling efficiency with folate (FA), enhancing selective targeting of folate receptor (FR)-positive GBM cells and enabling simultaneous targeting of tumor-associated macrophages (TAMs). FA-labeled trypsinized EVs (tEVs) loaded with miR-138 inhibit tumor growth, depolarize TAMs, and enhance antitumor immunity. This study represents the first preclinical attempt to modulate tumor cells and innate immunity via miRNA-loaded tEVs, offering a novel and more effective therapeutic approach to GBM treatment.

Unraveling the noncoding RNA landscape in glioblastoma: from pathogenesis to precision therapeutics

Glioblastoma (GBM) is an aggressive type IV brain tumor that originates from astrocytes and has a poor prognosis. Despite intensive research, survival rates have not significantly improved. Noncoding RNAs (ncRNAs) are emerging as critical regulators of carcinogenesis, progression, and increased treatment resistance in GBM cells. They influence angiogenesis, migration, epithelial-to-mesenchymal transition, and invasion in GBM cells. ncRNAs, such as long ncRNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), are commonly dysregulated in GBM. miRNAs, such as miR-21, miR-133a, and miR-27a-3p, are oncogenes that increase cell proliferation, metastasis, and migration by targeting TGFBR1 and BTG2. In contrast, lncRNAs, such as HOXD-AS2 and LINC00511, are oncogenes that increase the migration, invasion, and proliferation of cells. CircRNAs, such as circ0001730, circENTPD7, and circFOXO3, are oncogenes responsible for cell growth, angiogenesis, and viability. Developing novel therapeutic strategies targeting ncRNAs, cell migration, and angiogenesis is a promising approach for GBM. By targeting these dysregulated ncRNAs, we can potentially restore a healthy balance in gene expression and influence disease progression. ncRNAs abound within GBM, demonstrating significant roles in governing the growth and behavior of these tumors. They may also be useful as biomarkers or targets for therapy. The use of morpholino oligonucleotides (MOs) suppressing the oncogene expression of HOTAIR, BCYRN1, and cyrano, antisense oligonucleotides (ASOs) suppressing the expression of ncRNAs such as MALAT1 and miR-10b, locked nucleic acids (LNAs) suppressing miR-21, and peptide nucleic acids (PNAs) suppressing the expression of miR-155 inhibited the PI3K pathway, tumor growth, angiogenesis, proliferation, migration, and invasion. Targeting oncogenic ncRNAs with RNA-interfering strategies such as MOs, ASOs, LNAs, CRISPR-Cas9 gene editing, and PNA approaches may represent a promising therapeutic strategy for GBM. This review emphasizes the critical role of ncRNAs in GBM pathogenesis, as well as the potential for new therapeutic strategies targeting these pathways to improve the prognosis and quality of life for GBM patients.

Circ_0071589 contributes to growth, angiogenesis, and metastasis of colorectal cancer through regulating miR-296-5p/EN2 axis

To explore the function and regulation mechanism of circ_0071589 in colorectal cancer (CRC). The expression levels of circ_0071589, microRNA-296-5p (miR-296-5p), and Engrailed-2 (EN2) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Western blot was performed to check the protein levels of EN2 and apoptosis-related proteins. Cell colony formation and 5-Ethynyl-29-deoxyuridine (EdU) assay were used to exhibit cell proliferation. Cell apoptosis was shown by flow cytometry. Tube formation assay manifested the angiogenesis ability of CRC cells. Transwell assay demonstrated cell migration and invasion. The interaction between miR-296-5p and circ_0071589 or EN2 was identified by dual-luciferase reporter assay. The effect of circ_0071589 on tumor formation was demonstrated by in vivo tumor formation experiments. Immunohistochemical (IHC) assay was used to detect the positive cell rate of Ki67 in tumor tissue. Circ_0071589 was upregulated in CRC tissue and cells. Circ_0071589 knockdown repressed CRC cells proliferation, angiogenesis, migration, invasion, and promoted cell apoptosis. MiR-296-5p was downregulated in CRC tissue and cells. And miR-296-5p inhibitor could reverse the malignant phenotypes and angiogenesis inhibition of CRC cells caused by circ_0071589 knockdown. Additionally, miR-296-5p decreased CRC cell colony formation, EdU-positive cells, angiogenesis, and increased cell apoptosis through reducing the expression level of EN2. Finally, circ_0071589 silencing inhibited tumor formation in vivo. Circ_0071589 upregulated EN2 expression through sponging miR-296-5p, thereby promoting the malignant phenotype and angiogenesis of CRC cells, which provided a new target for the treatment of CRC.

MiR-138-5p improves the chemosensitivity of MDA-MB-231 breast cancer cell line to paclitaxel

BACKGROUND

Chemotherapy is a predominant strategy for breast cancer (BC) treatment and paclitaxel (PTX) has been known as a conventional chemotherapeutic drug. However, insensitivity of BC cells to PTX limits the anti-tumor effects of this agent. MicroRNAs are closely related to BC which are suggested as therapeutic factors in the combination therapy of BC. We examined the possible efficacy of miR-138-5p restoration in combination with PTX to impove BC treatment.

METHODS

The human breast cancer cell line MDA-MB-231 was transfected with miR-138-5p mimics and treated with PTX, in a combined or separate manner. The MTT assay was accomplished to determine inhibitory doses of PTX. Annexin V/PI assay and DAPI staining were applied to evaluate apoptosis. Flow cytometry was applied to determine cells arrested in different phases of the cell-cycle. Expression levels of molecular factors involved in cell migration, proliferation, apoptosis, and cell cycle were determined via western blotting and qRT-PCR.

RESULTS

MiR-138-5p combined with PTX suppressed cell migration via modulating MMP2, E-cadherin, and vimentin and sustained colony formation and proliferation by downregulation of the PI3K/AKT pathway. qRT-PCR showed that miR-138-5p increases BC chemosensitivity to PTX by regulating the apoptosis factors, including Bcl-2, Bax, Caspase 3, and Caspase 9. Moreover, miR-138-5p restoration and paclitaxel therapy combined arrest the cells in the sub-G1 and G1 phases of cell cycle by regulating p21, CCND1, and CDK4.

CONCLUSIONS

Restored miR-138-5p intensified the chemosensitivity of MDA-MB-231 cell line to PTX, and the combination of miR-138-5p with PTX might represent a novel approach in BC treatment.

Systematic characterization and biological functions of non-coding RNAs in glioblastoma

Glioblastoma multiforme (GBM) is the most malignant and aggressive type of glioma. Non-coding RNAs (ncRNAs) are RNAs that do not encode proteins but widely exist in eukaryotic cells. The common characteristics of these RNAs are that they can all be transcribed from the genome without being translated into proteins, thus performing biological functions, particularly microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs. Studies have found that ncRNAs are associated with the occurrence and development of GBM, and there is a complex regulatory network among ncRNAs, which can regulate cell proliferation, migration, apoptosis and differentiation, thus provide a basis for the development of highly specific diagnostic tools and therapeutic strategies in the future. The present review aimed to comprehensively describe the biogenesis, general features and functions of regulatory ncRNAs in GBM, and to interpret the potential biological functions of these ncRNAs in GBM as well as their impact on clinical diagnosis, treatment and prognosis and discusses the potential mechanisms of these RNA subtypes leading to cancer in order to contribute to the better design of personalized GBM therapies in the future.