Background: Molecular-targeted therapy plays an important role in the combined treatment of breast cancer. Long noncoding RNA (LncRNA) plays a significant role in regulating breast cancer progression. The present study is to reveal the potential roles and molecular mechanism that the secretory carrier-associated membrane protein 1-transcript variant 2 (SCAMP1-TV2) has in breast. Methods: Cell Counting Kit-8 (CCK-8), RNA Immunoprecipitation (RIP), and RNA pull-down assays were employed to determine the interactions between SCAMP1-TV2 and Pumilio RNA binding family member 2 (PUM2). The luciferase reporter assays and chromatin immunoprecipitation (ChIP) assays were used to get to know the effect of human insulinoma-associated 1 (INSM1) directly on the SAM and SH3 domain containing 1 (SASH1) promoter. Results: Silenced SCAMP1-TV2 inhibited the proliferation, migration, and invasion of breast cancer cells, and promoted cell apoptosis. Meanwhile, SCAMP1-TV2 downregulation decreased its binding to PUM2 and increased the binding of PUM2 to INSM1 messenger RNA (mRNA), thus promoting the degradation of INSM1 mRNA. Silencing INSM1 decreased its inhibitory effect on SASH1 transcription and inhibited the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway. The xenograft tumor growth in a nude mice was significantly inhibited by the silencing of SCAMP1-TV2 in combination with the overexpression of PUM2. Conclusions: SCAMP1-TV2/PUM2/INSM1 pathway plays an important role in regulating the biological behavior of breast cancer cells.

The obstacle in delivering therapeutics to glioblastoma (GBM) is tumor-induced angiogenesis which leads to the formation of abnormal vessels and a dysfunctional blood-tumor barrier. Here, we elucidated the effect of endothelial-monocyte activating polypeptide II (EMAP II) on the GBM-induced angiogenesis as well as its potential mechanisms. Our results proved that EMAP II inhibited the viability, mitochondrial membrane potential, migration and tube formation of GBM-induced endothelial cells (GECs) by inducing cell autophagy, demonstrated by cell viability assay, JC-1 staining assay, transwell assay and tube formation assay, respectively. Cell autophagy was induced by EMAP II through the observation of autophagic vacuoles formation and the up-regulation of microtubule-associated protein-1 light chain-3 (LC3)-II and p62/SQSTM1 expression, demonstrated by transmission electron microscopy analysis, immunofluorescence assay and Western blot assay. The activity of PI3K/AKT/mTOR signal pathway could be inhibited by the EMAP II treatment. Furthermore, unfolded protein response (UPR)-related proteins (GRP78, eIF2α, and CHOP) were up-regulated by EMAP II, which suggest that GECs exposed to EMAP II experienced endoplasmic reticulum stress. Further, mechanistic investigations found that EMAP II reduced the miR-96 expression which could directly target the 3'-UTR of these UPR-related proteins, and over-expression of miR-96 inhibited LC3 and p62/SQSTM1 expression by down-regulating these UPR-related proteins in GECs. Moreover, the combination of EMAP II with miR-96 inhibitor showed the inhibitory effect on the viability, migration, and in vitro tube formation of GECs, which are critical for angiogenesis. Taken together, we have demonstrated the fact that EMAP II resulted in the decreased GBM-induced angiogenesis by inducing autophagy, which might contribute to establishing potential strategies for human GBM treatment.

The existence of blood-tumor barrier (BTB) severely restricts the efficient delivery of antitumor drugs to cranial glioma tissues. Various strategies have been explored to increase BTB permeability. RNA-binding proteins and circular RNAs have recently emerged as potential regulators of endothelial cells functions. In this study, RNA-binding protein KH RNA-binding domain containing, signal transduction associated 3 (KHDRBS3) and circular RNA DENND4C (cDENND4C) were enriched in GECs. KHDRBS3 bound to cDENND4C and increased its stability. The knockdown of cDENND4C increased the permeability of BTB via downregulating the expressions of tight junction-related proteins. The miR-577 was lower expressed in GECs. The overexpressed miR-577 increased the permeability of BTB by reducing the tight junction-related protein expressions, and vice versa. Furthermore, cDENND4C acted as a molecular sponge of miR-577, which bound to miR-577 and inhibited its negative regulation of target genes ZO-1, occludin and claudin-1 to regulate BTB permeability. Single or combined treatment of KHDRBS3, cDENND4C, and miR-577 effectively promoted antitumor drug doxorubicin (DOX) across BTB to induce apoptosis of glioma cells. Collectively, the present study indicated that KHDRBS3 could regulate BTB permeability through the cDENND4C/miR-577 axis, which enhanced doxorubicin delivery across BTB. These findings may provide a novel strategy for chemotherapy of brain tumors.

Recent studies indicate circular RNAs are related to dysregulation of vascular endothelial cell function, yet the underlying mechanisms have remained elusive. Here, we characterized the functional role of circular RNA USP1 (circ-USP1) in the regulation of the blood-tumour barrier (BTB) permeability and the potential mechanisms. In the current study, the circ-USP1 expressing level was up-regulated in glioma cerebral microvascular endothelial cells (GECs) of the BTB model in vitro. Knockdown of circ-USP1 disrupted the barrier integrity, increased its permeability as well as reduced tight junction-related protein claudin-5, occludin and ZO-1 expressions in GECs. Bioinformatic prediction and luciferase assay indicated that circ-USP1 bound to miR-194-5p and suppressed its activity. MiR-194-5p contributed to circ-USP1 knockdown-induced increase of BTB permeability via targeting and down-regulating transcription factor FLI1. Furthermore, FLI1 regulated the expressions of claudin-5, occludin and ZO-1 in GECs through binding to their promoter regions. Single or combined treatment of circ-USP1 and miR-194-5p effectively promoted anti-tumour drug doxorubicin across BTB to induce apoptosis of glioma cells. Overall, this present study identified the crucial regulation of circ-USP1 on BTB permeability via miR-194-5p/FLI1 axis-mediated regulation of tight junction proteins, which might facilitate the development of therapeutics against human gliomas.

This study was performed to determine whether EMAP II increases the permeability of the blood-tumor barrier (BTB) by affecting the expression of miR-330-3p as well as its possible mechanisms. We determined the over-expression of miR-330-3p in glioma microvascular endothelial cells (GECs) by Real-time PCR. Endothelial monocyte-activating polypeptide-II (EMAP-II) significantly decreased the expression of miR-330-3p in GECs. Pre-miR-330-3p markedly decreased the permeability of BTB and increased the expression of tight junction (TJ) related proteins ZO-1, occludin and claudin-5, however, anti-miR-330-3p had the opposite effects. Anti-miR-330-3p could enhance the effect of EMAP-II on increasing the permeability of BTB, however, pre-miR-330-3p partly reversed the effect of EMAP-II on that. Similarly, anti-miR-330-3p improved the effects of EMAP-II on increasing the expression levels of PKC-α and p-PKC-α in GECs and pre-miR-330-3p partly reversed the effects. MiR-330-3p could target bind to the 3'UTR of PKC-α. The results of in vivo experiments were similar to those of in vitro experiments. These suggested that EMAP-II could increase the permeability of BTB through inhibiting miR-330-3p which target negative regulation of PKC-α. Pre-miR-330-3p and PKC-α inhibitor decreased the BTB permeability and up-regulated the expression levels of ZO-1, occludin and claudin-5 while anti-miR-330-3p and PKC-α activator brought the reverse effects. Compared with EMAP-II, anti-miR-330-3p and PKC-α activator alone, the combination of the three combinations significantly increased the BTB permeability. EMAP-II combined with anti-miR-330-3p and PKCα activator could enhance the DOX's effects on inhibiting the cell viabilities and increasing the apoptosis of U87 glioma cells. Our studies suggest that low-dose EMAP-II up-regulates the expression of PKC-α and increases the activity of PKC-α by inhibiting the expression of miR-330-3p, reduces the expression of ZO-1, occludin and claudin-5, and thereby increasing the permeability of BTB. The results can provide a new strategy for the comprehensive treatment of glioma.

Glioma is primary brain tumour with a poor prognosis. Metabolic reprogramming is a hallmark of glioma, and is critical in the development of antiglioma agents and glioma therapy. Cuproptosis is a novel form of cell death mediated by protein lipidation and highly associated with mitochondrial metabolism. However, the clinical impact of cuproptosis-related genes (CRGs) in glioma remains largely unknown. The purpose of this study is to create a new CRGs signature that can be used to predict survival and immunotherapy in glioma patients. LASSO regression analysis was applied to establish prognostic gene signatures. Furthermore, a CRGs signature-based nomogram was developed and demonstrated good predictive potential. We also analyzed the relationship of CRGs and immune infiltration and the correlation with the pathological grade of glioma. Finally, we explored the miRNA that may regulate cuproptosis-related gene FDX1. We found that miR-606 was markedly downregulated in GBM, overexpression of miR-606 can significantly inhibit aerobic glycolysis and proliferation of GBM cells. FDX1 was upregulated in GBM, knockdown of FDX1 significantly inhibit aerobic glycolysis and proliferation of GBM cells. And luciferase assay was used to verified that miR-606 binds to and regulates FDX1 mRNA. These results provide a basis for further exploring the biological mechanisms of cuproptosis. This study may provide new potential therapeutic perspectives for patients with glioma.

The blood-tumor barrier (BTB) contributes to poor therapeutic efficacy by limiting drug uptake; therefore, elevating BTB permeability is essential for glioma treatment. Here, we prepared astrocyte microvascular endothelial cells (ECs) and glioma microvascular ECs (GECs) as in vitro blood-brain barrier (BBB) and BTB models. Upregulation of METTL3 and IGF2BP3 in GECs increased the stability of CPEB2 mRNA through its m6A methylation. CPEB2 bound to and increased SRSF5 mRNA stability, which promoted the ETS1 exon inclusion. P51-ETS1 promoted the expression of ZO-1, occludin, and claudin-5 transcriptionally, thus regulating BTB permeability. Subsequent in vivo knockdown of these molecules in glioblastoma xenograft mice elevated BTB permeability, promoted doxorubicin penetration, and improved glioma-specific chemotherapeutic effects. These results provide a theoretical and experimental basis for epigenetic regulation of the BTB, as well as insight into comprehensive glioma treatment.

Vasculogenic mimicry (VM) is an endothelium-independent tumor microcirculation that provides adequate blood supply for tumor growth. The presence of VM greatly hinders the treatment of glioblastoma (GBM) with anti-angiogenic drugs. Therefore, targeting VM formation may be a feasible therapeutic strategy for GBM. The research aimed to evaluate the roles of BUD13, CDK12, MBNL1 in regulating VM formation of GBM. BUD13 and CDK12 were upregulated and MBNL1 was downregulated in GBM tissues and cells. Knockdown of BUD13, CDK12, or overexpression of MBNL1 inhibited GBM VM formation. METTL3 enhanced the stability of BUD13 mRNA and upregulated its expression through m6A methylation. BUD13 enhanced the stability of CDK12 mRNA and upregulated its expression. CDK12 phosphorylated MBNL1, thereby regulating VM formation of GBM. The simultaneous knockdown of BUD13, CDK12, and overexpression of MBNL1 reduced the volume of subcutaneously transplanted tumors in nude mice and prolonged the survival period. Thus, the BUD13/CDK12/MBNL1 axis plays a crucial role in regulating VM formation of GBM and provides a potential target for GBM therapy.

Studies have found that RNA-binding proteins (RBPs) are dysfunctional and play a significant regulatory role in the development of glioma. Based on The Cancer Genome Atlas database and the previous studies, we selected heterogeneous nuclear ribonucleoprotein (HNRNPD) as the research candidate and sought its downstream targeted genes. In the present study, HNRNPD, linc00707, and specific protein 2 (SP2) were highly expressed, while zinc fingers and homeboxes 2 (ZHX2) and miR-651-3p were remarkedly downregulated in glioma tissues and cells. HNRNPD, linc00707, and SP2 knockdown or ZHX2 and miR-651-3p overexpression suppressed glioma cells proliferation, migration, and invasion and vasculogenic mimicry (VM) formation. Knockdown of HNRNPD increased the stability of ZHX2 mRNA. ZHX2 bound to the promoter region of linc00707 and negatively regulate its expression. Linc00707 could bind with miR-651-3p, while miR-651-3p bound to the 3' untranslated region (3'UTR) of SP2 mRNA to negatively regulate its expression. The transcription factor SP2 directly bound to the promoter regions of the VM formation-related proteins MMP2, MMP9, and VE-cadherin, playing a role in promoting transcription in order to regulate the VM formation ability of glioma cells.

The blood-brain barrier (BBB) strongly restricts the entry of anti-glioma drugs into tumor tissues and thus decreases chemotherapy efficacy. Malignant gliomas are highly invasive tumours that use the perivascular space for invasion and co-opt existing vessels as satellite tumor form. Because regulation of the effect of noncoding RNA on BBB function is attracting growing attention, we investigated the effects of noncoding RNA on the permeability of glioma conditioned normal BBB and the mechanism involved using PIWI-associated RNA piR-DQ590027 as a starting point.

Aberrant expression of long noncoding RNAs has recently been reported in tumorigenesis and plays a pivotal role in regulating malignant behavior of cancers. In this study, we confirmed that the long noncoding RNAs human histocompatibility leukocyte antigen (HLA) complex P5 (HCP5) was up-regulated in glioma tissues as well as in U87 and U251 cells. Knockdown of HCP5 inhibited the malignant biological behavior of glioma cells by reducing proliferation, migration and invasion, and inducing apoptosis. HCP5 regulated the malignant behavior of glioma cells by binding to microRNA-139, which functions as a tumor suppressor. Moreover, knockdown of HCP5 down-regulated Runt-related transcription factor 1, a direct and functional downstream target of microRNA-139 that is involved in microRNA-139-mediated tumor-suppressive effects in glioma cells. Runt-related transcription factor 1 increased promoter activities and upregulated expression of the oncogenic gene astrocyte elevated gene-1 (AEG-1). Runt-related transcription factor 1 also increased the promoter activities and expression of HCP5, which showed a positive feedback loop in regulating the malignant behavior of glioma cells. In conclusion, this study demonstrated that the HCP5-microRNA-139- Runt-related transcription factor 1 feedback loop plays a pivotal role in regulating the malignant behavior of glioma cells, which may provide a potential therapeutic strategy for treating glioma.

The existence of the blood-tumor barrier (BTB) severely hinders the transport of anti-tumor drugs to brain tumor tissues. Selectively opening BTB is of great significance to improve the chemotherapy effect of glioma. Pseudogenes have been recognized as important regulators in various biologic processes. In this study, we identified that ribosomal protein L32 pseudogene 3 (RPL32P3) was highly expressed in glioma-exposed endothelial cells (GECs). Knockdown of RPL32P3 decreased the expression of tight junction-related proteins (TJPs) and increased BTB permeability. Subsequent analysis of the underlying mechanism indicated that RPL32P3 recruited lysine methyltransferase 2 A (KMT2A) to the Y-box binding protein 2 (YBX2) promoter region and mediated H3K4me3 to promote YBX2 transcription. Highly expressed YBX2 bound and stabilized hepatocyte nuclear factor 4 gamma (HNF4G) mRNA. Highly expressed HNF4G directly bound to the promoters of TJPs ZO-1, occludin and claudin-5 to promote their transcriptional activities and regulated BTB permeability. The simultaneous knockdown of RPL32P3, YBX2, and HNF4G combined with doxorubicin (DOX) increased the apoptosis of glioma cells. In conclusion, the current study indicated that RPL32P3 knockdown increased BTB permeability through the YBX2/HNF4G pathway. These findings may provide new targets for the comprehensive treatment of glioma.

Glioma, a common malignant tumour of the human central nervous system, has poor prognosis and limited treatment options. Dissecting the biological mechanisms underlying glioma pathogenesis can facilitate the development of better therapies. Here, we investigated the endogenous expression of BTB and CNC homolog 2 (BACH2), fused in sarcoma (FUS), TSLNC8 and microRNA (miR)-10b-5p in glioma cells and tissues. We studied the interaction between BACH2 and FUS and its contribution to glioma progression. We demonstrated that the interaction between BACH2 and FUS promoted glioma progression via transcriptional inhibition of TSLNC8. Overexpression of TSLNC8 restrained glioma progression by suppressing miR-10b-5p. Binding of TSLNC8 to miR-10b-5p attenuated the suppression of WWC family member 3 (WWC3) by miR-10b-5p and activated the Hippo signalling pathway. Growth of subcutaneous xenografts could be inhibited by knockdown of BACH2 or FUS, by overexpressing TSLNC8 or a combination of the three, also leading to a prolonged survival in nude mice. Our results indicate that the BACH2 and FUS/TSLNC8/miR-10b-5p/WWC3 axis is responsible for glioma development and could serve as a potential target for the development of new glioma therapies.

Accumulating evidence has highlighted the potential role of long non-coding RNAs (lncRNAs) in the biological behaviors of glioblastoma stem cells (GSCs). Here, we elucidated the function and possible molecular mechanisms of the effect of lncRNA-SOX2OT on the biological behaviors of GSCs.

Warburg effect is a hallmark of cancer cells, wherein glycolysis is preferred over oxidative phosphorylation even in aerobic conditions. Reprogramming of glycometabolism is especially crucial for malignancy in glioma. RNA-binding proteins and long noncoding RNAs are important for aerobic glycolysis during malignant transformation. Thus, we determined the expression and function of RNA-binding protein Lin28A, long noncoding RNA SNHG14, and transcription factor IRF6 in human glioma cells to elucidate the mechanism(s) underlying their role in glycolysis. Quantitative real-time polymerase chain reaction and western blotting showed that Lin28A and SNHG14 were overexpressed and IRF6 was downregulated in glioma. Depleting Lin28A from cells decreased the stability and expression of SNHG14. Furthermore, depleting SNHG14 reduced IRF6 mRNA degradation by targeting its 3' untranslated region and inhibiting STAU1-mediated degradation, thereby increasing the expression of IRF6. PKM2 is an important enzyme in aerobic glycolysis, and GLUT1 is the primary transporter that facilitates glucose uptake. IRF6 inhibited the transcription of PKM2 and GLUT1, thereby impairing glycolysis and cell proliferation and inducing apoptosis in glioma. Notably, depleting Lin28A and SNHG14 and overexpressing IRF6 reduced the growth of xenograft tumors in vivo and prolonged the survival of nude mice. Taken together, our data revealed that the Lin28A/SNHG14/IRF6 axis is crucial for reprogramming glucose metabolism and stimulating tumorigenesis in glioma cells. Thus, targeting this axis might help in the development of a novel therapeutic strategy for glioma metabolism.

Upstream ORF (uORF) is a translational initiation element located in the 5'UTR of eukaryotic mRNAs. Studies have found that uORFs play an important regulatory role in many diseases. Based on The Cancer Genome Atlas database, the results of our experiments and previous research evidence, we investigated transcription factor AP-4 (TFAP4) and its uORF, LIM and SH3 protein 1 (LASP1), long noncoding RNA 00520 (LINC00520), and microRNA (miR)-520f-3p as candidates involved in glioma malignancy, which is a poorly understood process. Both TFAP4-66aa-uORF and miR-520f-3p were downregulated, and TFAP4, LASP1, and LINC00520 were highly expressed in glioma tissues and cells. TFAP4-66aa-uORF or miR-520f-3p overexpression or TFAP4, LASP1, or LINC00520 knockdown inhibited glioma cell proliferation, migration, and invasion, but promoted apoptosis. TFAP4-66aa-uORF inhibited the translation of TFAP4 by binding to the TFAP4 mRNA. MicroRNA-520f-3p inhibited TFAP4 expression by binding to its 3'UTR. However, LINC00520 could promote the expression of TFAP4 by competitively binding to miR-520f-3p. In addition, TFAP4 transcriptionally activated LASP1 and LINC00520 expression by binding to their promoter regions, forming a positive feedback loop of TFAP4/LINC00520/miR-520f-3p. Our findings together indicated that TFAP4-66aa-uORF inhibited the TFAP4/LINC00520/miR-520f-3p feedback loop by directly inhibiting TFAP4 expression, subsequently leading to inhibition of glioma malignancy. This provides a basis for developing new therapeutic approaches for glioma treatment.

Angiogenesis plays a critical role in the progression of glioma. Previous studies have indicated that RNA-binding proteins (RBPs) interact with RNAs and participate in the regulation of the malignant behaviors of tumors. As a type of endogenous non-coding RNAs, circular RNAs (circRNAs) are abnormally expressed in various cancers and are involved in diverse tumorigeneses including angiogenesis.

Glioma is the most common primary malignancy in the brain, and vasculogenic mimicry (VM) is one of the blood supply methods. Here we investigated the possibility that lncRNAs regulate the stability of transcription factors through the SMD pathway, which affects proliferation, migration, invasion, and the ability to form VMs in glioma. Expression of PABPC5, HCG15, and ZNF331 was detected by real-time qPCR or western blot in glioma. Cell Counting Kit-8, Transwell assays, and in vitro VM tube formation were used to investigate PABPC5, HCG15, and ZNF331 function in cell proliferation, migration, invasion, and VM, respectively. ChIP assays were used to ascertain the interaction betweenZNF331 and LAMC2 or PABPC5. PABPC5 and HCG15 were highly expressed in glioma cells. ZNF331 was lowly expressed. PABPC5 bound HCG15 to increase its stability. Knockdown HCG15 reduced the degradation of ZNF331 mRNA by the SMD pathway. ZNF331 inhibited transcription through binding to the promoter region of LAMC2 and PABPC5 and inhibited the ability to form VMs in glioma cells. The PABPC5/HCG15/ZNF331 feedback loop plays an important role in regulating VM formation in glioma and provides new targets for glioma treatment.

Angiogenesis plays an important role in the progress of glioma. RNA-binding proteins (RBPs) and circular RNAs (circRNAs), dysregulated in various tumors, have been verified to mediate diverse biological behaviors including angiogenesis.

Preliminary studies have shown that endothelial-monocyte-activating polypeptide-II (EMAP-II) induces autophagy and inhibits the viability of glioma cells via an unknown molecular mechanism. This study explored the possible mechanisms associated with EMAP-II-induced autophagy in glioma cells by regulation of the expression of microRNA-20a (miR-20a). EMAP-II effectively inhibited the viability, migration and invasion of human U-87 and U-251 glioma cells. EMAP-II also up-regulated the expression level of autophagy biomarker microtubule-associated protein one light chain 3 (LC3)-II/I, autophagy related gene ATG7 and ATG5, but down-regulated autophagy substrate P62/SQSTM1 protein expression. The expression levels of miR-20a decreased significantly after U-87 and U-251 cells were treated with EMAP-II. MiR-20a overexpression partly reversed the EMAP-II-induced up-regulation of LC3-II/I and down-regulation of P62/SQSTM1. MiR-20a had a negative regulatory effect on the expression of the proteins ATG7 and ATG5; which were also targets of miR-20a, as detected by a dual-luciferase reporter assay. In addition, both EMAP-II and miR-20a inhibition significantly reduced the viability, migration and invasion of U-87 and U-251 cells, and their combination showed a synergistic effect. Furthermore, nude mice carrying silencing-expressed miR-20a combined with EMAP-II treatment produced the smallest tumors and the highest survival. In summary, low-dose EMAP-II increased expression levels of ATG5 and ATG7 via down-regulation of the expression of miR-20a. This activated the autophagy pathway, thereby significantly inhibiting the viability, migration and invasion of U-87 and U-251 glioma cells. The combined treatment of EMAP-II with a miR-20a inhibitor showed a synergistic effect against glioma.