Loss of SH3GL2 promotes the migration and invasion behaviours of glioblastoma cells through activating the STAT3/MMP2 signalling

The role and application of small extracellular vesicles in glioma

Small extracellular vesicles (sEVs) are cell-derived, nanometer-sized particles enclosed by a lipid bilayer. All kinds of biological molecules, including proteins, DNA fragments, RNA, lipids, and metabolites, can be selectively loaded into sEVs and transmitted to recipient cells that are near and distant. Growing shreds of evidence show the significant biological function and the clinical significance of sEVs in cancers. Numerous recent studies have validated that sEVs play an important role in tumor progression and can be utilized to diagnose, stage, grading, and monitor early tumors. In addition, sEVs have also served as drug delivery nanocarriers and cancer vaccines. Although it is still infancy, the field of basic and translational research based on sEVs has grown rapidly. In this review, we summarize the latest research on sEVs in gliomas, including their role in the malignant biological function of gliomas, and the potential of sEVs in non-invasive diagnostic and therapeutic approaches, i.e., as nanocarriers for drug or gene delivery and cancer vaccines.

Clinicopathological characteristics of pheochromocytoma/paraganglioma and screening of prognostic markers

BACKGROUND

Malignant pheochromocytoma/paraganglioma (PCPG) is lethal and difficult to diagnose before metastasis. This study is aiming to characterize the PCPG and explore novel prognostic markers.

METHODS

Clinical data of patients with pathologically confirmed invasive and noninvasive PCPG were collected and analyzed. Then, the differentially expressed genes (DEGs) and HUB genes were identified by R package "limma" in GSE67066-GPL570. Afterward, the prognostic markers were screened out using R packages of "survival" and "survminer" based on the TCGA data.

RESULTS

The 34 invasive PCPGs were characterized by irregular contour and unclear boundary on CT and capsule/extracapsule tissue invasion on pathology compared with the 42 noninvasive PCPGs. Then, 29 upregulated and 30 downregulated DEGs were identified in malignant PCPG compared with benign, which were mainly enriched in the terms of calcium ion binding, neuron cell-cell adhesion, axon, regulation of hormone levels, and regulation of secretion by cell. Of which, nine DEGs were furtherly selected as the HUB genes. Finally, CNTN4 and SH3GL2 were found to be highly expressed in malignant PCPGs and negatively correlated with progression-free interval.

CONCLUSIONS

Malignant PCPGs tend to be aggressive in imaging and pathology. The high expression of CNTN4 and SH3GL2 in PCPGs may indicate a poor prognosis.

Exposure to real-ambient particulate matter induced vascular hypertrophy through activation of PDGFRβ

BACKGROUND

Vascular toxicity induced by particulate matter (PM) exposure exacerbates the onset and development of cardiovascular diseases; however, its detailed mechanism remains unclear. Platelet-derived growth factor receptor β (PDGFRβ) acts as a mitogen for vascular smooth muscle cells (VSMCs) and is therefore essential for normal vasoformation. However, the potential effects of PDGFRβ on VSMCs in PM-induced vascular toxicity have not yet been elucidated.

METHODS

To reveal the potential roles of PDGFRβ signalling in vascular toxicity, individually ventilated cage (IVC)-based real-ambient PM exposure system mouse models and PDGFRβ overexpression mouse models were established in vivo, along with in vitro VSMCs models.

RESULTS

Vascular hypertrophy was observed following PM-induced PDGFRβ activation in C57/B6 mice, and the regulation of hypertrophy-related genes led to vascular wall thickening. Enhanced PDGFRβ expression in VSMCs aggravated PM-induced smooth muscle hypertrophy, which was attenuated by inhibiting the PDGFRβ and janus kinase 2 /signal transducer and activator of transcription 3 (JAK2/STAT3) pathways.

CONCLUSION

Our study identified the PDGFRβ gene as a potential biomarker of PM-induced vascular toxicity. PDGFRβ induced hypertrophic effects through the activation of the JAK2/STAT3 pathway, which may be a biological target for the vascular toxic effects caused by PM exposure.

Cellular and molecular features related to exceptional therapy response and extreme long-term survival in glioblastoma

Glioblastoma Multiforme (GBM) remains the most common malignant primary brain tumor with a dismal prognosis that rarely exceeds beyond 2 years despite extensive therapy, which consists of maximal safe surgical resection, radiotherapy, and/or chemotherapy. Recently, it has become clear that GBM is not one homogeneous entity and that both intra-and intertumoral heterogeneity contributes significantly to differences in tumoral behavior which may consequently be responsible for differences in survival. Strikingly and in spite of its dismal prognosis, small fractions of GBM patients seem to display extremely long survival, defined as surviving over 10 years after diagnosis, compared to the large majority of patients. Although the underlying mechanisms for this peculiarity remain largely unknown, emerging data suggest that still poorly characterized both cellular and molecular factors of the tumor microenvironment and their interplay probably play an important role. We hereby give an extensive overview of what is yet known about these cellular and molecular features shaping extreme long survival in GBM.

Structuring and validating a prognostic model for low-grade gliomas based on the genes for plasma membrane tension

Background

Recent studies indicate that cell mechanics are associated with malignancy through its impact on cell migration and adhesion. Gliomas are the most common primary malignant brain tumors. Low-grade gliomas (LGGs) include diffuse LGGs (WHO grade II) and intermediate-grade gliomas (WHO grade III). Few studies have focused on membrane tension in LGGs. Herein, we assessed the prognostic value of plasma membrane tension-related genes (MTRGs) in LGGs.

Methods

We selected plasma MTRGs identified in previous studies for analysis. Based on LGG RNA sequencing (RNA-seq) data in The Cancer Genome Atlas, a prognostic signature containing four genes was constructed via log-rank testing, LASSO regression and stepwise multivariate Cox regression and was validated with other datasets. Additionally, functional annotation, pathway enrichment and immune and molecular characteristics of the prognostic model defined subgroups were analyzed. Thereafter, a predictive nomogram that integrated baseline characteristics was constructed to determine the 3, 5, and 10-year overall survival (OS) of patients with LGG. Differentially expressed genes were confirmed via quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC).

Results

Our MTRG prognostic signature was based on ARFIP2, PICK1, SH3GL2, and SRGAP3 expression levels. The high-risk group was more positively associated with apoptosis and cell adhesion pathways and exhibited a low IDH1 mutation rate, high TP53 mutation rate and a low 1p19q co-deletion rate. The high-risk group also exhibited incremental infiltration of immune cells, more forceful immune activities and high expression of immune checkpoints as well as benefited less from immune therapy compared with the low-risk group. Our prognostic model had better forecasting ability than other scoring systems. We found that the nomogram was a better tool for predicting outcomes for patients with LGG. Finally, qRT-PCR confirmed that SH3GL2 and SRGAP3 expression levels in glioma tissues were significantly lower than those in normal brain tissues. The results of IHC analysis confirmed that SH3GL2 protein expression was higher in patients with longer survival.

Conclusion

Our plasma membrane tension-related gene prognostic signature is a prospective tool that can differentiate between prognosis, gene mutation landscape, immune microenvironment, immune infiltration and immunotherapeutic efficacy in LGG.

Exosome-based strategies for diagnosis and therapy of glioma cancer

Glioblastoma belongs to the most aggressive type of cancer with a low survival rate that is characterized by the ability in forming a highly immunosuppressive tumor microenvironment. Intercellular communication are created via exosomes in the tumor microenvironment through the transport of various biomolecules. They are primarily involved in tumor growth, differentiation, metastasis, and chemotherapy or radiation resistance. Recently several studies have highlighted the critical role of tumor-derived exosomes against immune cells. According to the structural and functional properties, exosomes could be essential instruments to gain a better molecular mechanism for tumor understanding. Additionally, they are qualified as diagnostic/prognostic markers and therapeutic tools for specific targeting of invasive tumor cells such as glioblastomas. Due to the strong dependency of exosome features on the original cells and their developmental status, it is essential to review their critical modulating molecules, clinical relevance to glioma, and associated signaling pathways. This review is a non-clinical study, as the possible role of exosomes and exosomal microRNAs in glioma cancer are reported. In addition, their content to overcome cancer resistance and their potential as diagnostic biomarkers are analyzed.

Triphlorethol-A attenuates U251 human glioma cancer cell proliferation and ameliorates apoptosis through JAK2/STAT3 and p38 MAPK/ERK signaling pathways

Glioma is the foremost recurrent type of brain tumor in humans; in particular, glioblastoma (GBM) is the main form of brain tumor (GBM) that is highly proliferative and impervious to apoptosis. Triphlorethol-A (TA), a phlorotannin isolated from Ecklonia cava, exhibited cytoprotective, antioxidant, and anticancer properties. However, the exact molecular action of TA in the U251 human GBM cells remains unknown. This may be the first report on the antiproliferative and apoptotic mechanisms of TA on GBM. The cytotoxicity, intracellular reactive oxygen species (ROS), matrix metalloproteinase (MMP), and cell apoptosis activity of TA have been evaluated by the MTT assay and by DCFH-DA, Rh-123, AO/EB, and western blot analysis. The results obtained showed that TA abridged the viability of U251 cells, while MMP increased apoptosis by increasing the ROS levels in a time-dependent manner. The results showed that a reduction in U251 cell proliferation was associated with the regulation of JAK2/STAT3 and p38 MAPK/ERK signaling pathways. TA was found to suppress pJAK, pSTAT3, p38 MAPK, and pERK phosphorylation, thereby causing Bax/Bcl-2 imbalance, activating the caspase cascade and cytochrome c, and inducing apoptosis. Our findings showed that the suppression of JAK2/STAT3 and p38 MAPK/ERK signaling by TA results in cell growth arrest and stimulation of apoptosis in GBM cells. These studies justify the protective remedy of TA against GBM.

CTR9-mediated JAK2/STAT3 pathway promotes the proliferation, migration, and invasion of human glioma cells

Background

CTR9 (Cln three requiring 9) has been reported to be implicated in protein modification and oncogenesis of several human cancers. However, the protein expression and mechanism of CTR9 in glioma progression remain unclear.

Methods

We analyzed mRNA expression of CTR9 and CTR9‐related survival curves in the public database. Then, we detected CTR9 expression in glioma tissues and constructed U251 and U87 cells with stable silencing or overexpression of CTR9. Cell function tests and Western blot were conducted to explore the effects of CTR9 on glioma proliferation, invasion and migration, and the specific mechanism. All the date was presented as means ± SEM. Two‐sample t test and one‐way analysis of variance (ANOVA) were used to identify whether there was a significant difference between each group of data.

Results

We found that CTR9 was overexpressed in glioma and inversely associated with glioma patient survival. The results manifested that knockdown of CTR9 suppressed the proliferation, migration, and invasion of glioma cells, while overexpression facilitated them. The underlying molecular mechanism may involve the regulation of JAK2/STAT3 pathway by CTR9.

Conclusion

Our present study indicates that CTR9 is highly expressed in glioma and related to glioma grading and prognosis. CTR9 regulates malignant behaviors of glioma cells by activating JAK2/STAT3 pathway. Therefore, CTR9 may be a promising biomarker for the targeted therapy and prognosis evaluation of glioma.

ANP32A promotes the proliferation, migration and invasion of hepatocellular carcinoma by modulating the HMGA1/STAT3 pathway

Acidic leucine-rich nuclear phosphoprotein-32A (ANP32A) has been reported to play an essential role in the development and progression of various human cancers. However, its expression pattern and possible mechanism in human hepatocellular carcinoma (HCC) remain to be elucidated. In this study, we used western blot and immunohistochemical staining to detect protein expression. The effects of ANP32A on the proliferation, migration and invasion of HCC cells were examined using 5-ethynyl-20-deoxyuridine (EdU), colony formation, CCK-8, and transwell assays. RT-qPCR was performed to detect mRNA expression. The interaction between ANP32A and the high mobility group A1 (HMGA1) mRNA was assessed using RNA immunoprecipitation (RIP). The tumorigenicity of ANP32A was assessed by establishing a xenograft tumor model in Balb/c nude mice. We found that the ANP32A protein was expressed at high levels in patients with HCC, which was associated with a poor prognosis. Functional experiments revealed that the silencing of ANP32A inhibited the proliferation, migration, and invasion of HCC cells, whereas overexpression of ANP32A promoted these processes. Further investigations indicated that ANP32A bound the HMGA1 mRNA and maintained its stability to promote the expression of HMGA1, thereby increasing the expression and activation of STAT3. Finally, a xenograft tumor model of Balb/c nude mice confirmed the tumorigenicity of ANP32A. This study found that ANP32A is up-regulated in patients with HCC and may accelerate the proliferation, migration and invasion of HCC cells by modulating the HMGA1/STAT3 pathway.

TSG101 Promotes the Proliferation, Migration, and Invasion of Human Glioma Cells by Regulating the AKT/GSK3β/β-Catenin and RhoC/Cofilin Pathways

The tumor susceptibility gene 101 (TSG101) has been reported to play important roles in the development and progression of several human cancers, such as pancreatic cancer, prostate cancer, and hepatocellular carcinoma. However, its potential roles and underlined mechanisms in human glioma are still needed to be further clarified. This study was designed to assess the expression of TSG101 in glioma patients and its effects on glioma cell proliferation, migration, and invasion. Publicly available data revealed that TSG101 mRNA was significantly upregulated in glioma tissues, and high levels of TSG101 were associated with poor prognosis in glioma patients. Western blot and immunohistochemistry experiments further showed that the expression level of TSG101 protein was significantly upregulated in glioma patients, especially in the patients with high-grade glioma. The functional studies showed that knockdown of TSG101 suppressed the proliferation, migration, and invasion of glioma cells, while overexpression of TSG101 facilitated them. Mechanistic studies indicated that the proliferation, migration, and invasion induced by TSG101 in human glioma were related to AKT/GSK3β/β-catenin and RhoC/Cofilin signaling pathways. In conclusion, the above results suggest that the expression of TSG101 is elevated in glioma patients, which accelerates the proliferation, migration, and invasion of glioma cells by regulating the AKT/GSK3β/β-catenin and RhoC/Cofilin pathways.

Proteasomal degradation of polycomb-group protein CBX6 confers MMP-2 expression essential for mesothelioma invasion

The aggressive invasiveness of malignant mesothelioma limits cancer therapy, however, the molecular mechanisms underlying the invasiveness remain largely unknown. Here we found that the matrix metalloproteinase-2 (MMP-2) was required for the invasion of mesothelioma cells in the collagen matrix and the gene expression of MMP-2 was correlated with the invasive phenotype. The MMP-2 gene expression was regulated by DNA and histone methylation around the transcription start site, implicating the involvement of the polycomb repressive complex (PRC). Knockdown of PRC component chromobox 6 (CBX6) promoted MMP-2 expression and invasion of mesothelioma cells. Transcriptome analysis suggested that CBX6 regulates sets of genes involved in cancer cell migration and metastasis. In invasive but not non-invasive cells, CBX6 was constantly unstable owing to ubiquitination and protein degradation. In human tissues, CBX6 localized in the nuclei of normal mesothelium and benign mesothelioma, but the nuclear staining of CBX6 was lost in malignant mesothelioma. These results suggest involvement of proteasomal degradation of CBX6 in mesothelioma progression.

Role of exosomes in malignant glioma: microRNAs and proteins in pathogenesis and diagnosis

Malignant gliomas are the most common and deadly type of central nervous system tumors. Despite some advances in treatment, the mean survival time remains only about 1.25 years. Even after surgery, radiotherapy and chemotherapy, gliomas still have a poor prognosis. Exosomes are the most common type of extracellular vesicles with a size range of 30 to 100 nm, and can act as carriers of proteins, RNAs, and other bioactive molecules. Exosomes play a key role in tumorigenesis and resistance to chemotherapy or radiation. Recent evidence has shown that exosomal microRNAs (miRNAs) can be detected in the extracellular microenvironment, and can also be transferred from cell to cell via exosome secretion and uptake. Therefore, many recent studies have focused on exosomal miRNAs as important cellular regulators in various physiological and pathological conditions. A variety of exosomal miRNAs have been implicated in the initiation and progression of gliomas, by activating and/or inhibiting different signaling pathways. Exosomal miRNAs could be used as therapeutic agents to modulate different biological processes in gliomas. Exosomal miRNAs derived from mesenchymal stem cells could also be used for glioma treatment. The present review summarizes the exosomal miRNAs that have been implicated in the pathogenesis, diagnosis and treatment of gliomas. Moreover, exosomal proteins could also be involved in glioma pathogenesis. Exosomal miRNAs and proteins could also serve as non-invasive biomarkers for prognosis and disease monitoring. Video Abstract.

Identification of hub genes and small-molecule compounds in medulloblastoma by integrated bioinformatic analyses

Background

Medulloblastoma (MB) is the most common intracranial malignant tumor in children. The genes and pathways involved in the pathogenesis of MB are relatively unknown. We aimed to identify potential biomarkers and small-molecule drugs for MB.

Methods

Gene expression profile data sets were obtained from the Gene Expression Omnibus (GEO) database and the differentially expressed genes (DEGs) were identified using the Limma package in R. Functional annotation, and cell signaling pathway analysis of DEGs was carried out using DAVID and Kobas. A protein-protein interaction network was generated using STRING. Potential small-molecule drugs were identified using CMap.

Result

We identified 104 DEGs (29 upregulated; 75 downregulated). Gene ontology analysis showed enrichment in the mitotic cell cycle, cell cycle, spindle, and DNA binding. Cell signaling pathway analysis identified cell cycle, HIF-1 signaling pathway, and phospholipase D signaling pathway as key pathways. SYN1, CNTN2, FAIM2, MT3, and SH3GL2 were the prominent hub genes and their expression level were verified by RT-qPCR. Vorinostat, resveratrol, trichostatin A, pyrvinium, and prochlorperazine were identified as potential drugs for MB. The five hub genes may be targets for diagnosis and treatment of MB, and the small-molecule compounds are promising drugs for effective treatment of MB.

Conclusion

In this study we obtained five hub genes of MB, SYN1, CNTN2, FAIM2, MT3, and SH3GL2 were confirmed as hub genes. Meanwhile, Vorinostat, resveratrol, trichostatin A, pyrvinium, and prochlorperazine were identified as potential drugs for MB.

TAB3 upregulates PIM1 expression by directly activating the TAK1-STAT3 complex to promote colorectal cancer growth

Transforming growth factor-β-activated kinase 1 (TAK1)-binding protein 3 (TAB3) and the proviral integration site for Moloney murine leukaemia virus 1 (PIM1) are implicated in cancer development. In this study, we investigated the relationship between TAB3 and PIM1 in colorectal cancer (CRC) and determined the potential role and molecular mechanism of TAB3 in PIM1-mediated CRC growth. We found that TAB3 and PIM1 expression levels were positively correlated in CRC tissues. The knockdown of TAB3 significantly decreased PIM1 expression and inhibited CRC proliferation in vitro and in vivo. The upregulation of PIM1 rescued the decreased cell proliferation induced by TAB3 knockdown, whereas PIM1 knockdown decreased TAB3-enhanced CRC proliferation. Additionally, TAB3 regulates PIM1 expression through the STAT3 signalling pathway and confirmed a positive correlation between TAB3 and phosphorylated-STAT3 expression in CRC tissues. Patients with high expression of TAB3 and phosphorylated-STAT3 had the worst prognosis. Mechanistically, TAB3 regulates PIM1 expression by promoting STAT3 phosphorylation and activation through the formation of the TAB3-TAK1-STAT3 complex. Overall, a novel CRC regulatory circuit involving the TAB3-TAK1-STAT3 complex and PIM1 was identified, the dysfunction of which may contribute to CRC tumorigenesis.

YY1 inhibits the migration and invasion of pancreatic ductal adenocarcinoma by downregulating the FER/STAT3/MMP2 signaling pathway

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis and a high mortality rate. The transcription factor YY1 acts as an inhibitor of many types of tumors. We found that YY1 knockdown promoted the invasion and migration of PANC-1 and BxPC-3 cells; FER knockdown partially restored the promotion of pancreatic cancer caused by YY1 knockdown. In vivo experiments yielded the same results. According to luciferase reporter gene, electrophoretic mobility shift (EMSA) and chromatin immunoprecipitation (ChIP) assays, YY1 directly binds to the FER promoter region. Moreover, higher level FER expression results in a worse TNM stage and prognosis for patients with PDAC. Furthermore, by downregulating FER, YY1 inhibits the formation of the STAT3-MMP2 complex, thereby suppressing expression of MMP2 and ultimately inhibiting the migration and invasion of pancreatic cancer. Our study demonstrates that the YY1/FER/STAT3/MMP2 axis is associated with the progression of pancreatic cancer and may provide a new therapeutic target for the treatment of pancreatic cancer.

Determination of genetic aberrations and novel transcripts involved in the pathogenesis of oligodendroglioma using array comparative genomic hybridization and next generation sequencing

The aim of the present study was to determine the genetic aberrations and novel transcripts, particularly the fusion transcripts, involved in the pathogenesis of low-grade and anaplastic oligodendroglioma. In the present study, tissue samples were obtained from patients with oligodendroglioma and additionally from archived tissue samples from the Brain Tumor Tissue Bank of the Brain Tumor Foundation of Canada. Six samples were obtained, three of which were low-grade oligodendroglioma and the other three anaplastic oligodendroglioma. DNA and RNA were extracted from each tissue sample. The resulting genomic DNA was then hybridized using the Agilent CytoSure 4×180K oligonucleotide array. Human reference DNA and samples were labeled using Cy3 cytidine 5′-triphosphate (CTP) and Cy5 CTP, respectively, while human Cot-1 DNA was used to reduce non-specific binding. Microarray-based comparative genomic hybridization data was then analyzed for genetic aberrations using the Agilent Cytosure Interpret software v3.4.2. The total RNA isolated from each sample was mixed with oligo dT magnetic beads to enrich for poly(A) mRNA. cDNAs were then synthesized and subjected to end-repair, poly(A) addition and connected using sequencing adapters using the Illumina TruSeq RNA Sample Preparation kit. The fragments were then purified and selected as templates for polymerase chain reaction amplification. The final library was constructed with fragments between 350–450 base pairs and sequenced using deep transcriptome sequencing on an Illumina HiSeq 2500 sequencer. The array comparative genomic hybridization revealed numerous amplifications and deletions on several chromosomes in all samples. However, the most interesting result was from the next generation sequencing, where one anaplastic oligodendroglioma sample was demonstrated to have five novel fusion genes that may potentially serve a critical role in tumor pathogenesis and progression.

Identification of key microRNAs and their targets in exosomes of pancreatic cancer using bioinformatics analysis

Pancreatic cancer (PC) is one of the most lethal tumors, due to late diagnosis and limited surgical strategies. It has been reported that serum exosomal microRNAs (S-Exo-miRNAs) play a pivotal role as signaling molecules and serve as noninvasive diagnosis methods for PC. The combination of S-Exo-miRNAs with the corresponding target also plays an important role in the tumor microenvironment.Here we investigated S-Exo-miRNAs involved in PC. The gene expression profile was downloaded from the Gene Expression Omnibus (GEO) database. The analysis was carried out using GEO2R. The targets of differentially expressed serum exosomal miRNAs (DE-S-Exo-miRNAs) were predicted by 4 bioinformatic algorithms (miRanda, miRDB, miRWalk, and Targetscan). Further analysis with gene ontology (GO) and Kyoto Encyclopedia of Genomes pathway (KEGG) enrichment analyses were performed with Cytoscape software version 3.4.0. Subsequently, the interaction regulatory network of target genes was performed with the Search Tool for the Retrieval of Interacting Genes (STRING) database (http://www.string-db.org/) and visualized using Cytoscape software.We downloaded the gene expression profile GSE50632, which was based on an Agilent microarray GPL17660 platform containing 4 eligible samples. In total 467 DE-S-Exo-miRNAs were obtained, including 7 overexpressed miRNAs (1.50%), and 460 remaining underexpressed miRNAs (98.50%). The databases miRWalk, miRDB, miRanda, and TargetScan were used to predict their potential targets, which were subsequently submitted to Cytoscape software version 3.4.0 (www.cytoscape.org). Next the functional and pathway enrichment analysis were used for the KEGG pathway and GO categories analysis. The enrichment analysis identified the genes involved in such processes as developmental and negative regulation of multicellular organismal processes, regulation of anatomical structure morphogenesis, regulation of cell death, apoptotic processes and mitogen-activated protein kinase (MAPK) signaling pathway, transforming growth factor - beta (TGF -β) signaling pathway, cyclic adenosine monophosphate (cAMP) signaling pathway, and the phosphatidylinositol-3 kinases/Akt (PI3K-Akt) signaling pathway. Subsequently according to the protein-protein interaction (PPI) network, the top 10 genes were obtained. The enrichment analyses of the genes involved in a significant module revealed that these genes were related to the TGF-β signaling pathway. After reviewing the literature, we identified the apoptosis genes, and their corresponding miRNAs that have a relationship with apoptosis of the tumor.This analysis provides a comprehensive understanding of the roles of S-Exo-miRNAs and the related targets in the development of PC. Additionally, the present study provides promising candidate targets for early diagnosis and therapeutic intervention. However, these predictions require further experimental validation in future studies.

Exosomes of glioma cells deliver miR-148a to promote proliferation and metastasis of glioblastoma via targeting CADM1

Exosomes are now considered to be involved in mediating cell-to-cell communication to promote or inhibit tumor progression. However, the role and molecular mechanism of exosomes in promoting glioblastoma (GBM) metastasis remains elusive. Here, we found that circulating exosomal miR-148a levels were significantly higher in serum from GBM patients compared with serum from healthy volunteers. In T98G cells, inhibition of miR-148a suppressed cell proliferation and metastasis. In addition, we identified Cell adhesion molecule 1 (CADM1) as a target gene of miR-148a using luciferase reporter assay. Both protein and mRNA levels of CADM1 were decreased in tissues from GBM patients. There was a strong negative correlation between exosomal miR-148a and CADM1 mRNA levels in samples of patients. Moreover, miR-148a antagonist increased p-STAT3 protein level to activate STAT3 pathway. In conclusion, our findings indicated that miR-148a delivered by exosomes may promote cancer cell proliferation and metastasis via targeting CADM1 to activate STAT3 pathway, suggesting a predictor and therapeutic target role of exosomal miR-148a in GBM patients.

Knockdown of RWD domain containing 3 inhibits the malignant phenotypes of glioblastoma cells via inhibition of phosphoinositide 3-kinase/protein kinase B signaling

Glioblastoma is the most common and malignant primary brain tumor. RWD domain containing 3 (RWDD3) has been previously reported to serve a promoting role in pituitary tumors. However, the exact role of RWDD3 in glioblastoma remains unclear. Therefore, the present study aimed to investigate the expression levels of RWDD3 in human glioblastoma tissues and cell lines, as well as to examine the regulatory mechanism of RWDD3 underlying glioblastoma growth and metastasis. The results revealed that RWDD3 was significantly upregulated in glioblastoma tissues compared with normal brain tissues, while high expression of RWDD3 was associated with a shorter survival time of glioblastoma patients. The expression levels of RWDD3 were also higher in the glioblastoma cell lines compared with the normal human astrocyte cell line. Subsequent to knockdown of RWDD3, the proliferation of glioblastoma U87 and U251 cells was significantly decreased, possibly due to the cell cycle arrest at G1 phase, as well as the increased cell apoptosis. Furthermore, downregulation of RWDD3 also suppressed U87 and U251 cell invasion by inhibiting the expression levels of matrix metalloproteinase 2 (MMP2) and MMP9. Molecular mechanism investigation demonstrated that knockdown of RWDD3 significantly downregulated the activity of the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) signaling pathway. Activation of PI3K/AKT signaling prevented the suppressive effects of RWDD3 downregulation on glioblastoma cell proliferation and migration, concurrent with increased protein levels of MMP2 and MMP9. In conclusion, the current study demonstrated for the first time that inhibition of RWDD3 expression inhibited glioblastoma progression, at least partly, via suppressing the PI3K/AKT signaling activity, and thus RWDD3 may be a novel potential therapeutic target for glioblastoma.

PHAP1 promotes glioma cell proliferation by regulating the Akt/p27/stathmin pathway

PHAP1 (Putative HLA‐DR‐associated protein 1), also termed acidic leucine‐rich nuclear phosphoprotein 32A (ANP32A), Phosphoprotein 32 (pp32) or protein phosphatase 2A inhibitor (I1PP2A), is a multifunctional protein aberrantly expressed in multiple types of human cancers. However, its expression pattern and clinical relevance in human glioma remain unknown. In this study, Western blotting and immunohistochemistry analysis demonstrated PHAP1 protein was highly expressed in glioma patients, especially in those with high‐grade disease. Publicly available data also revealed high levels of PHAP1 were associated with poor prognosis in glioma patients. The functional studies showed that knock‐down of PHAP1 suppressed the proliferation of glioma cells, while overexpression of PHAP1 facilitated it. The iTRAQ proteomic analysis suggested that stathmin might be a potential downstream target of PHAP1. Consistently, PHAP1 knock‐down significantly decreased the expression of stathmin, while overexpression of PHAP1 increased it. Also, the upstream negative regulator, p27, expression levels increased upon PHAP1 knock‐down and decreased when PHAP1 was overexpressed. As a result, the phosphorylated Akt (S473), an upstream regulator of p27, expression levels decreased upon silencing of PHAP1, but elevated after PHAP1 overexpression. Importantly, we demonstrate the p27 down‐regulation, stathmin up‐regulation and cell proliferation acceleration induced by PHAP1 overexpression were dependent on Akt activation. In conclusion, the above results suggest that PHAP1 expression is elevated in glioma patients, which may accelerate the proliferation of glioma cells by regulating the Akt/p27/stathmin pathway.

Src is the primary target of aripiprazole, an atypical antipsychotic drug, in its anti-tumor action

Aripiprazole (ARP) is an atypical anti-psychotic drug widely used to treat schizophrenia and bipolar disorder. The pharmacological effects of ARP on cancer cells are still poorly understood. In this study, anti-cancer effects of ARP on various malignant tumor cells and its molecular mechanism were further carefully examined by using cell proliferation assay, xenograft mouse model, immunoblotting analysis, migration assay, luciferase reporter gene assay, kinase assay, and overexpression strategy. Treatment with ARP induced cytotoxicity in U251 glioma cells, MKN-1 gastric adenosquamous carcinoma cells, and CT26 colon carcinoma cells. ARP suppressed cell proliferation of LN428, MDA-MB-231, and HEK293 cells. Pro-apoptotic factors active caspase-3, -8, and -9, as well as p53, were upregulated, whereas the protein and mRNA levels of anti-apoptotic factor B-cell lymphoma 2 (Bcl-2) decreased. In agreement with the in vitro results, ARP compound also significantly suppressed the growth of tumor masses formed by injecting CT26 colon cancer cells into mice. ARP treatment also effectively decreased the migratory ability of U251 glioma cells by downregulating metalloproteinase-9. Levels of phosphorylated Src, phosphorylated phosphatidylinositide 3-kinase (PI3K), and phosphorylated signal transducer and activator of transcription 3 (STAT3) were significantly decreased following ARP treatment. ARP compound reduced the kinase activity of Src. Our studies suggest that Src may be an important target molecule linked to the antitumor effects of ARP.