SH3GL2 is frequently deleted in non-small cell lung cancer and downregulates tumor growth by modulating EGFR signaling

Molecular mechanism of SH3GL3 recombinant protein and attenuates the acute lung inflammation in Klebsiella pneumonia rats by mollugin treatment by regulating STAT3/ROS signaling pathway

In recent years, pulmonary infection caused by Klebsiella pneumoniae has been increasing in clinical practice, becoming one of the important pathogens threatening human health. Morukin, as a commonly used antibiotic, has a certain effect in the treatment of bacterial pneumonia, but the acute pulmonary inflammation caused by Morukin has also brought serious side effects to patients. Therefore, the aim of this study was to explore the molecular mechanism of SH3GL3 recombinant protein and investigate its effect on reducing acute pulmonary inflammation in the treatment of Klebsiella pneumoniae infection by modulating the STAT3/ROS signaling pathway. In this study, recombinant SH3GL3 protein was prepared by genetic engineering technology to establish an animal model of Klebsiella pneumoniae infection. The effect of recombinant SH3GL3 protein on acute pulmonary inflammation was evaluated by observing the pathological changes of lung tissue, inflammatory cell infiltration and expression levels of inflammatory factors in each group. Western blot, immunohistochemistry and other techniques were used to detect the expression and activity of STAT3 and ROS signaling pathway related proteins, in order to reveal the molecular mechanism of SH3GL3 recombinant protein in alleviating inflammation. In the SH3GL3 recombinant protein intervention group, the pathological changes of lung tissue were significantly reduced, the number of inflammatory cells was reduced, and the expression level of inflammatory factors was decreased. Further molecular mechanism studies have shown that SH3GL3 recombinant protein can significantly inhibit the phosphorylation and activation of STAT3 and reduce the production of ROS, thus inhibiting the activation of STAT3/ROS signaling pathway and alleviating pulmonary inflammation. The recombinant protein SH3GL3 effectively alleviates acute pulmonary inflammation in the treatment of Klebsiella pneumoniae infection with morukin by regulating the STAT3/ROS signaling pathway.

A network-based analysis to identify a piRNA-target signature related to colorectal cancer prognosis: in silico and in vitro study

PURPOSE

Patients with colorectal cancer (CRC) are diagnosed in advanced stages and have worse overall survival. Also, this cancer incidence is rising in many countries. The aim of this study is to find piwi-interacting RNAs (piRNA) predicting the prognosis of patients with colorectal cancer, using bioinformatics and evaluating these results through RT-qPCR method.

METHODS

The target genes of piRNAs were predicted using miRDB and TargetRank databases. Protein-protein interaction (PPI) networks were constructed by STRING and were analyzed with Cytoscape software and the MCODE tool used for module construction. Expression levels of final selected piRNAs in 18 pairs of CRC tissue and adjacent normal tissue were measured by quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR).

RESULTS

Twenty CRC-related piRNAs and 980 target genes were included in this study. After PPI analysis 19 hub genes were identified. Then, the prognostic value of these hub genes was assessed via Kaplan-Meier survival analyses. This survival analysis indicated that the expression of six genes was significantly associated with overall survival of patients with CRC. These genes are targets of hsa-piR-487, hsa-piR-28944 and piR-hsa-8401. Also, the pathway analysis revealed the potential signal pathways of these piRNAs targets involved in CRC. RT-qPCR showed that hsa-piR-487 and hsa-piR-28944 expression significantly were down-regulated in CRC tumor tissues compared with the adjacent normal tissues (P < 0.05, P < 0.01).

CONCLUSION

It seems that hsa-piR-487 and hsa-piR-28944 can be considered as a potential biomarker for the diagnosis of CRC. However, it is still necessary to conduct studies with a higher statistical population and measure them in the serum of patients to confirm these results.

SH3GL2 and MMP17 as lung adenocarcinoma biomarkers: a machine-learning based approach

Objective

Using bioinformatics machine learning methods, our research aims to identify the potential key genes associated with Lung adenocarcinoma (LUAD).

Methods

We obtained two gene expression profiling microarrays (GSE68571 and GSE74706) from the public Gene Expression Omnibus (GEO) database at the National Centre for Biotechnology Information (NCBI). The purpose was to identify Differentially Expressed Genes (DEGs) between the lung adenocarcinoma group and the healthy control group. The limma R package in R was utilized for this analysis. For the differential gene diagnosis of lung adenocarcinoma, we employed the least absolute shrinkage and selection operator (LASSO) regression and SVM-RFE screening crossover. To evaluate the performance, ROC curves were plotted. We performed immuno-infiltration analysis using CIBERSORT. Finally, we validated the key genes through qRT-PCR and Western-blot verification, then downregulated MMP17 gene expression, upregulated SH3GL2 gene expression, and performed CCK8 experiments.

Results

A total of 32 Differentially Expressed Genes (DEGs) were identified. Two diagnostic marker genes, SH3GL2 and MMP17, were selected by employing LASSO and SVM-RFE machine learning methods. In Lung adenocarcinoma cells, the expression of MMP17 was observed to be elevated compared to normal lung epithelial cells in the control group (P < 0.05). In contrast, a down-regulation of SH3GL2 was found in Lung adenocarcinoma cells (P < 0.05). Finally, we downregulated MMP17 and upregulated SH3GL2 gene expression, then the CCK8 showed that the proliferation of both lung cancer cells was inhibited.

Conclusion

SH3GL2 and MMP17 are expected to be potential biomarkers for Lung adenocarcinoma.

Study on Potential Differentially Expressed Genes in Idiopathic Pulmonary Fibrosis by Bioinformatics and Next-Generation Sequencing Data Analysis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease with reduced quality of life and earlier mortality, but its pathogenesis and key genes are still unclear. In this investigation, bioinformatics was used to deeply analyze the pathogenesis of IPF and related key genes, so as to investigate the potential molecular pathogenesis of IPF and provide guidance for clinical treatment. Next-generation sequencing dataset GSE213001 was obtained from Gene Expression Omnibus (GEO), and the differentially expressed genes (DEGs) were identified between IPF and normal control group. The DEGs between IPF and normal control group were screened with the DESeq2 package of R language. The Gene Ontology (GO) and REACTOME pathway enrichment analyses of the DEGs were performed. Using the g:Profiler, the function and pathway enrichment analyses of DEGs were performed. Then, a protein-protein interaction (PPI) network was constructed via the Integrated Interactions Database (IID) database. Cytoscape with Network Analyzer was used to identify the hub genes. miRNet and NetworkAnalyst databaseswereused to construct the targeted microRNAs (miRNAs), transcription factors (TFs), and small drug molecules. Finally, receiver operating characteristic (ROC) curve analysis was used to validate the hub genes. A total of 958 DEGs were screened out in this study, including 479 up regulated genes and 479 down regulated genes. Most of the DEGs were significantly enriched in response to stimulus, GPCR ligand binding, microtubule-based process, and defective GALNT3 causes HFTC. In combination with the results of the PPI network, miRNA-hub gene regulatory network and TF-hub gene regulatory network, hub genes including LRRK2, BMI1, EBP, MNDA, KBTBD7, KRT15, OTX1, TEKT4, SPAG8, and EFHC2 were selected. Cyclothiazide and rotigotinethe are predicted small drug molecules for IPF treatment. Our findings will contribute to identification of potential biomarkers and novel strategies for the treatment of IPF, and provide a novel strategy for clinical therapy.

SH3GL3 acts as a novel tumor suppressor in glioblastoma tumorigenesis by inhibiting STAT3 signaling

Glioblastoma (GBM) is the most severe malignant tumors of the central nervous system. Glioblastoma stem cells (GSCs) are considered to account for tumor initiation, therapeutic resistance, and tumor relapse. Yet the underlying mechanisms of GSC stemness maintenance remain largely unknown. Abnormal activation of STAT3 signaling is required for GBM tumorigenesis and GSC self-renewal. In this study, we provide evidence that SH3GL3 was weakly expressed in GBM and its high expression correlated with a favorable prognosis for GBM patients. Ectopic of SH3GL3 expression considerably inhibits GBM cell malignant behaviors, including GBM cell proliferation, migration as well as GSCs self-renewal ability. Mechanistically, we first found that SH3GL3 interacts with STAT3, which thereby inhibiting STAT3 nuclear localization. Overexpression of constitutively activated (STAT3-C) restored the growth, migration and self-renewal ability impaired by overexpression of SH3GL3. Together, our work shed insight on a critical regulatory mechanism mediated by SH3GL3 to decrease the stem cell-like property and tumorigenic potential.

SH3GL3 functions as a potent tumor suppressor in lung cancer in a SH3 domain dependent manner

Lung cancer is one of the most common and aggressive cancer and a leading cause of cancer related deaths worldwide. Few studies have prospectively examined the functions of SH3GL3 in cancer progression, however, the biological functions of SH3GL3 in lung cancer initiation and progression remains largely unknown. Here, we show that both mRNA and protein levels of SH3GL3 are weakly expressed in lung cancer tissues and cell lines and its expression negatively correlates with the survival of lung cancer patients. Overexpression of SH3GL3 dramatically inhibits lung cancer cells malignancy behaviors, including proliferation and migration. Additionally, SH3GL3 curbs cell cycle at G0/G1 phase and induces cellular apoptosis of lung cancer cells and inhibits lung cancer stem cell self-renewal dependents on its SH3 domain. Moreover, we report for the first time that SH3GL3 inhibits lung cancer progression partially through p21 and up-regulates p21 in transcriptional level. Collectively, our work suggests that SH3GL3 acts as a potent tumor suppressor in lung cancer progression and have a potential to serve as diagnostic and prognostic biomarker of lung cancer.

Cancer Testis Antigen Promotes Triple Negative Breast Cancer Metastasis and is Traceable in the Circulating Extracellular Vesicles

Triple negative breast cancer (TNBC) has poor survival, exhibits rapid metastases, lacks targeted therapies and reliable prognostic markers. Here, we examined metastasis promoting role of cancer testis antigen SPANXB1 in TNBC and its utility as a therapeutic target and prognostic biomarker. Expression pattern of SPANXB1 was determined using matched primary cancer, lymph node metastatic tissues and circulating small extracellular vesicles (sEVs). cDNA microarray analysis of TNBC cells stably integrated with a metastasis suppressor SH3GL2 identified SPANXB1 as a potential target gene. TNBC cells overexpressing SH3GL2 exhibited decreased levels of both SPANXB1 mRNA and protein. Silencing of SPANXB1 reduced migration, invasion and reactive oxygen species production of TNBC cells. SPANXB1 depletion augmented SH3GL2 expression and decreased RAC-1, FAK, A-Actinin and Vinculin expression. Phenotypic and molecular changes were reversed upon SPANXB1 re-expression. SPANXB1 overexpressing breast cancer cells with an enhanced SPANXB1:SH3GL2 ratio achieved pulmonary metastasis within 5 weeks, whereas controls cells failed to do so. Altered expression of SPANXB1 was detected in the sEVs of SPANXB1 transduced cells. Exclusive expression of SPANXB1 was traceable in circulating sEVs, which was associated with TNBC progression. SPANXB1 represents a novel and ideal therapeutic target for blocking TNBC metastases due to its unique expression pattern and may function as an EV based prognostic marker to improve TNBC survival. Uniquely restricted expression of SPANXB1 in TNBCs, makes it an ideal candidate for targeted therapeutics and prognostication.

Identification of differentially expressed genes between primary lung cancer and lymph node metastasis via bioinformatic analysis

Lung cancer (LC), with its high morbidity and mortality rates, is one of the most widespread and malignant neoplasms. Mediastinal lymph node metastasis (MLNM) severely affects postoperative survival of patients with LC. Additionally, the molecular mechanisms of LC with MLNM (MM LC) remain not well understood. To identify the key biomarkers in its carcinogenesis and development, the datasets GSE23822 and GSE13213 were obtained from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) were identified, and the Database for Annotation, Visualization and Integrated Discovery was used to perform functional annotations of DEGs. Search Tool for the Retrieval of Interacting Genes and Cytoscape were utilized to obtain the protein-protein interaction (PPI) network, and to analyze the most significant module. Subsequently, a Kaplan-Meier plotter was used to analyze overall survival (OS). Additionally, one co-expression network of the hub genes was obtained from cBioPortal. A total of 308 DEGs were identified in the two microarray datasets, which were mainly enriched during cellular processes, including the Gene Ontology terms ‘cell’, ‘catalytic activity’, ‘molecular function regulator’, ‘signal transducer activity’ and ‘binding’. The PPI network was composed of 315 edges and 167 nodes. Its significant module had 11 hub genes, and high expression of actin β, MYC, arginine vasopressin, vesicle associated membrane protein 2 and integrin subunit β1, and low expression of NOTCH1, synaptojanin 2 and intersectin 2 were significantly associated with poor OS. In summary, hub genes and DEGs presented in the present study may help identify underlying targets for diagnostic and therapeutic methods for MM LC.

Quantitative proteomics reveals reduction of endocytic machinery components in gliomas

Background

Gliomas are the most frequent and aggressive malignancies of the central nervous system. Decades of molecular analyses have demonstrated that gliomas accumulate genetic alterations that culminate in enhanced activity of receptor tyrosine kinases and downstream mediators. While the genetic alterations, like gene amplification or loss, have been well characterized, little information exists about changes in the proteome of gliomas of different grades.

Methods

We performed unbiased quantitative proteomics of human glioma biopsies by mass spectrometry followed by bioinformatic analysis.

Findings

Various pathways were found to be up- or downregulated. In particular, endocytosis as pathway was affected by a vast and concomitant reduction of multiple machinery components involved in initiation, formation, and scission of endocytic carriers. Both clathrin-dependent and -independent endocytosis were changed, since not only clathrin, AP-2 adaptins, and endophilins were downregulated, but also dynamin that is shared by both pathways. The reduction of endocytic machinery components caused increased receptor cell surface levels, a prominent phenotype of defective endocytosis. Analysis of additional biopsies revealed that depletion of endocytic machinery components was a common trait of various glioma grades and subclasses.

Interpretation

We propose that impaired endocytosis creates a selective advantage in glioma tumor progression due to prolonged receptor tyrosine kinase signaling from the cell surface.

Fund

This work was supported by Grants 316030-164105 (to P. Jenö), 31003A-162643 (to M. Spiess) and PP00P3-176974 (to G. Hutter) from the Swiss National Science Foundation. Further funding was received by the Department of Surgery from the University Hospital Basel.

Decreased expression of USP9X is associated with poor prognosis in Chinese pancreatic ductal adenocarcinoma patients

The present study aimed to investigate the expression level of ubiquitin specific peptidase 9X (USP9X) and its clinical significance in Chinese patients with pancreatic ductal adenocarcinoma (PDAC). The mRNA expression levels of USP9X in 30 paired PDAC tissue samples were examined by reverse transcription-quantitative polymerase chain reaction. The protein expression of USP9X was analyzed by immunohistochemistry (IHC) in a tissue microarray containing 205 PDAC specimens. All analyses were performed by SPSS 20.0 and GraphPad Prism 5.0 software. The USP9X mRNA level was significantly decreased in 18/30 (60.0%) PDAC tissue samples compared with matched surrounding non-tumor tissue samples. The results of IHC revealed that decreased expression of USP9X was inversely associated with liver metastasis (P=0.032). Kaplan-Meier survival curves indicated that patients with high expression of USP9X presented a longer clinical overall survival time (P<0.001). Univariate and multivariate COX regression analysis revealed that USP9X protein expression level was a significant, and independent prognostic factor for the overall survival rate of patients with PDAC. The results of the present study indicate that USP9X may serve as a candidate tumor suppressor and prognostic biomarker in PDAC.

Identification of genes and critical control proteins associated with inflammatory breast cancer using network controllability

One of the most aggressive forms of breast cancer is inflammatory breast cancer (IBC), whose lack of tumour mass also makes a prompt diagnosis difficult. Moreover, genomic differences between common breast cancers and IBC have not been completely assessed, thus substantially limiting the identification of biomarkers unique to IBC. Here, we developed a novel statistical analysis of gene expression profiles corresponding to microdissected IBC, non-IBC (nIBC) and normal samples that enabled us to identify a set of genes significantly associated with a specific disease state. Second, by using advanced methods based on controllability network theory, we identified a set of critical control proteins that uniquely and structurally control the entire proteome. By mapping high change variance genes in protein interaction networks, we found that a large statistically significant fraction of genes whose variance changed significantly between normal and IBC and nIBC disease states were among the set of critical control proteins. Moreover, this analysis identified the overlapping genes with the highest statistical significance; these genes may assist in developing future biomarkers and determining drug targets to disrupt the molecular pathways driving carcinogenesis in IBC.

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

SH3GL2 (Src homology 3 (SH3) domain GRB2‐like 2) is mainly expressed in the central nervous system and regarded as a tumour suppressor in human glioma. However, the molecular mechanism of the SH3GL2 protein involved in malignant behaviours of human glioma has not been elucidated. In this study, we tried to investigate the role of SH3GL2 in glioma cell migration and invasion and explore its underlined molecular mechanism. Firstly, we discovered that the protein level of SH3GL2 was widely decreased in the human glioma patients, especially in high‐grade glioma tissues. Then, we determined the role of SH3GL2 in migration and invasion of glioma cells upon SH3GL2 knocking down and overexpressing. It was showed that knocking down of SH3GL2 promoted the migration and invasion of glioma cells, whereas overexpression of SH3GL2 inhibited them. Further study on molecular mechanism disclosed that silencing of SH3GL2 obviously activated the STAT3 (signal transducer and activator of transcription 3) signalling thereby promoting the expression and secretion of MMP2. On the contrary, overexpression of SH3GL2 had opposite effect. Taken together, the above results suggest that SH3GL2 suppresses migration and invasion behaviours of glioma cells through negatively regulating STAT3/MMP2 signalling and that loss of SH3GL2 may intensify the STAT3/MMP2 signalling thereby contributing to the migration and invasion of glioma cells.

Integrated Analysis of DNA Methylation and mRNA Expression Profiles Data to Identify Key Genes in Lung Adenocarcinoma

Introduction. Lung adenocarcinoma (LAC) is the most frequent type of lung cancer and has a high metastatic rate at an early stage. This study is aimed at identifying LAC-associated genes. Materials and Methods. GSE62950 downloaded from Gene Expression Omnibus included a DNA methylation dataset and an mRNA expression profiles dataset, both of which included 28 LAC tissue samples and 28 adjacent normal tissue samples. The differentially expressed genes (DEGs) were screened by Limma package in R, and their functions were predicted by enrichment analysis using TargetMine online tool. Then, protein-protein interaction (PPI) network was constructed using STRING and Cytoscape. Finally, LAC-associated methylation sites were identified by CpGassoc package in R and mapped to the DEGs to obtain LAC-associated DEGs. Results. Total 913 DEGs were identified in LAC tissues. In the PPI networks, MAD2L1, AURKB, CCNB2, CDC20, and WNT3A had higher degrees, and the first four genes might be involved in LAC through interaction. Total 8856 LAC-associated methylation sites were identified and mapped to the DEGs. And there were 29 LAC-associated methylation sites located in 27 DEGs (e.g., SH3GL2, BAI3, CDH13, JAM2, MT1A, LHX6, and IGFBP3). Conclusions. These key genes might play a role in pathogenesis of LAC.

Uncovering Driver DNA Methylation Events in Nonsmoking Early Stage Lung Adenocarcinoma

As smoking rates decrease, proportionally more cases with lung adenocarcinoma occur in never-smokers, while aberrant DNA methylation has been suggested to contribute to the tumorigenesis of lung adenocarcinoma. It is extremely difficult to distinguish which genes play key roles in tumorigenic processes via DNA methylation-mediated gene silencing from a large number of differentially methylated genes. By integrating gene expression and DNA methylation data, a pipeline combined with the differential network analysis is designed to uncover driver methylation genes and responsive modules, which demonstrate distinctive expressions and network topology in tumors with aberrant DNA methylation. Totally, 135 genes are recognized as candidate driver genes in early stage lung adenocarcinoma and top ranked 30 genes are recognized as driver methylation genes. Functional annotation and the differential network analysis indicate the roles of identified driver genes in tumorigenesis, while literature study reveals significant correlations of the top 30 genes with early stage lung adenocarcinoma in never-smokers. The analysis pipeline can also be employed in identification of driver epigenetic events for other cancers characterized by matched gene expression data and DNA methylation data.

Targeting HER (ERBB) signaling in head and neck cancer: An essential update

HNC (head and neck cancer) remains the 6th most common carcinoma worldwide. The suboptimal survival and toxicities observed with conventional approaches warrant exploration of novel therapeutic strategies such as targeted therapies. Although targeting EGFR (epidermal growth factor receptor) with cetuximab demonstrated clinical promise, HER (human epidermal growth factor receptor) or ERBB (erythroblastic leukemia viral oncogene homolog) targeted therapy in HNC has overall been suboptimal to date in clinical settings. Overcoming the resistance as well as identifying new strategies therefore remains a significant challenge. In this review, we will discuss the emerging roles of HER members besides EGFR. A comprehensive "three-dimensional" view of HER signaling pathway from the importance of EGFR nuclear translocation to our maturing concept of receptors' "spatial regulation", as well as the interdependence and interaction among different HER members will also be addressed to complete an essential update of HER signaling in HNC.

SNP rs1049430 in the 3'-UTR of SH3GL2 regulates its expression: Clinical and prognostic implications in head and neck squamous cell carcinoma

Single nucleotide polymorphisms (SNPs) in the 3'-UTR region are emerging cis-regulatory factors associated with the occurrences of several human diseases. SH3GL2, which is located at chromosome 9p21-22, is associated with hyperplastic/mildly dysplastic lesions of the head and neck and has a long 3'-UTR with multiple SNPs. The aim of the present study was to determine the susceptible allele(s) in the 3'-UTR SNPs of SH3GL2 in head and neck squamous cell carcinoma (HNSCC). First, we screened the genotypes of all SNPs located in the 3'-UTR of SH3GL2 in 110 controls and 147 cases in Indian populations by sequencing. A SNP (rs1049430:>G/T) that showed only heterozygosity was further confirmed by genotyping with an Illumina GoldenGate platform in 530 controls and 764 cases. Genotype-specific survival analysis of the HNSCC patients was performed. In addition, genotype-specific mRNA stability, isoform expression and protein expression were analyzed. SNP rs1049430 was not associated with disease occurrence, but it was associated with poor patient outcome. The G allele was associated with decreased SH3GL2 mRNA stability, differential splicing and low protein expression. Thus, our data demonstrate that the presence of the susceptible G allele in SNP rs1049430 is associated with the inactivation of SH3GL2 and could be used as a prognostic marker of HNSCC.

Endophilin-1 regulates blood-brain barrier permeability via EGFR-JNK signaling pathway

Endophilin-1 (Endo1), a multifunctional protein, is essential for synaptic vesicle endocytosis. However, the role and mechanism of endophilin-1 in blood-brain barrier (BBB) function are still unclear. This study was performed to determine whether endophilin-1 regulated BBB permeability via the EGFR-JNK signaling pathway. In the present study, we found that endophilin-1 over-expression in human cerebral microvascular endothelial cell (hCMEC/D3) increased BBB permeability and meanwhile reduced the expression levels of epidermal growth factor receptor (EGFR), phosphorylated c-Jun N-terminal kinase (p-JNK). While endophilin-1 knockdown led to the contrary results. After JNK inhibitor SP600125 was administered to the endophilin-1 silenced hCMEC/D3 cells, the transendothelial electrical resistance (TEER) value was decreased and the permeability coefficient values to 4kDa and 40kDa FITC-dextran were increased. Results observed by Transmission electron microscopy (TEM) showed that tight junctions (TJs) were opened. Moreover, immunofluorescence and Western blot assays revealed the discontinuous distribution of TJ-associated proteins ZO-1, occludin on cell-cell boundaries and a significant decrease in protein expressing levels. Therefore, these results indicated that endophilin-1 positively regulated BBB permeability via the EGFR-JNK signaling pathway in hCMEC/D3 cells, which would provide an experimental basis for further research on endophilin-1 mediated the opening of BBB.

Context-dependent function of the deubiquitinating enzyme USP9X in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and deadly malignancies. Recently, the deubiquitinating protease USP9X has been shown to behave as an oncogene in a number of neoplasms, including those of breast, brain, colon, esophagus and lung, as well as KRAS wild-type PDAC. However, other studies suggest that USP9X may function as a tumor-suppressor in a murine PDAC model when USP9X expression is depleted during early pancreatic development. To address the conflicting findings surrounding the role of USP9X in PDAC, we examined the effects of knocking down USP9X in five human PDAC cell lines (BxPC3, Capan1, CD18, Hs766T, and S2-013). We demonstrate that knocking down USP9X in each of the PDAC cell lines reduces their anchorage-dependent growth. Using an inducible shRNA system to knock down USP9X in both BxPC3 and Capan1 cells, we also determined that USP9X is necessary for the anchorage-independent growth. In addition, knockdown of USP9X alters the cell cycle profile of BxPC3 cells and increases their invasive capacity. Finally, we show that an inhibitor of deubiquitinating proteases, WP1130, induces significant cytotoxicity in each of the five PDAC cell lines tested. Overall, our work and the work of others indicate that the function and role of USP9X is highly context-dependent. Although USP9X may function as a tumor-suppressor during the establishment of PDAC, data presented here argue that USP9X promotes cell growth in advanced PDAC cells when PDAC is typically diagnosed. Hence, USP9X may be a promising therapeutic target for the treatment of advanced PDAC.

MiR-330-mediated regulation of SH3GL2 expression enhances malignant behaviors of glioblastoma stem cells by activating ERK and PI3K/AKT signaling pathways

MicroRNAs are currently considered as an active and rapidly evolving area for the treatment of tumors. In this study, we elucidated the biological significance of miR-330 in glioblastoma stem cells (GSCs) as well as the possible molecular mechanisms. SH3GL2 is mainly distributed in the central nervous system and considered to be a tumor suppressor in many tumors. In the present study, we identified miR-330 as a potential regulator of SH3GL2 and we found that it was to be inversely correlated with SH3GL2 expression in GSCs which were isolated from U87 cell lines. The expression of miR-330 enhanced cellular proliferation, promoted cell migration and invasion, and dampened cell apoptosis. When the GSCs were co-transfected with the plasmid containing short hairpin RNA directed against human SH3GL2 gene and miR-330 mimic, we found that miR-330 promoted the malignant behavior of GSCs by down-regulating the expression of SH3GL2. Meanwhile, the ERK and PI3K/AKT signaling pathways were significantly activated, leading to the decreased expression of apoptotic protein and increased expression of anti-apoptotic protein. Furthermore, in orthotopic mouse xenografts, the mice given stable over-expressed SH3GL2 cells co-transfected with miR-330 knockdown plasmid had the smallest tumor sizes and longest survival. In conclusion, these results suggested that miR-330 negatively regulated the expression of SH3GL2 in GSCs, which promoted the oncogenic progression of GSCs through activating ERK and PI3K/AKT signaling pathways. The elucidation of these mechanisms will provide potential therapeutic approaches for human glioblastoma.

Loss of Sh3gl2/endophilin A1 is a common event in urothelial carcinoma that promotes malignant behavior

Urothelial carcinoma (UC) causes substantial morbidity and mortality worldwide. However, the molecular mechanisms underlying urothelial cancer development and tumor progression are still largely unknown. Using informatics analysis, we identified Sh3gl2 (endophilin A1) as a bladder urothelium-enriched transcript. The gene encoding Sh3gl2 is located on chromosome 9p, a region frequently altered in UC. Sh3gl2 is known to regulate endocytosis of receptor tyrosine kinases implicated in oncogenesis, such as the epidermal growth factor receptor (EGFR) and c-Met. However, its role in UC pathogenesis is unknown. Informatics analysis of expression profiles as well as immunohistochemical staining of tissue microarrays revealed Sh3gl2 expression to be decreased in UC specimens compared to nontumor tissues. Loss of Sh3gl2 was associated with increasing tumor grade and with muscle invasion, which is a reliable predictor of metastatic disease and cancer-derived mortality. Sh3gl2 expression was undetectable in 19 of 20 human UC cell lines but preserved in the low-grade cell line RT4. Stable silencing of Sh3gl2 in RT4 cells by RNA interference 1) enhanced proliferation and colony formation in vitro, 2) inhibited EGF-induced EGFR internalization and increased EGFR activation, 3) stimulated phosphorylation of Src family kinases and STAT3, and 4) promoted growth of RT4 xenografts in subrenal capsule tissue recombination experiments. Conversely, forced re-expression of Sh3gl2 in T24 cells and silenced RT4 clones attenuated oncogenic behaviors, including growth and migration. Together, these findings identify loss of Sh3gl2 as a frequent event in UC development that promotes disease progression.

Overexpression of EGFR in head and neck squamous cell carcinoma is associated with inactivation of SH3GL2 and CDC25A genes

The aim of this study is to understand the mechanism of EGFR overexpression in head and neck squamous cell carcinoma (HNSCC). For this reason, expression/mutation of EGFR were analyzed in 30 dysplastic head and neck lesions and 148 HNSCC samples of Indian patients along with 3 HNSCC cell lines. In addition, deletion/methylation/mutation/expression of SH3GL2 (associated with EGFR degradation) and CDC25A (associated with dephosphorylation of EGFR) were analyzed in the same set of samples. Our study revealed high frequency of EGFR overexpression (66–84%), low frequency of gene amplification (10–32.5%) and absence of functional mutation in the dysplastic lesions and HNSCC samples. No correlation was found between protein overexpression and mRNA expression/gene amplification status of EGFR. On the other hand, frequent alterations (deletion/methylation) of SH3GL2 (63–77%) and CDC25A (37–64%) were seen in the dysplastic and HNSCC samples. Two novel single nucleotide polymorphism (SNPs) were found in the promoter region of SH3GL2. Reduced expression of these genes showed concordance with their alterations. Overexpression of EGFR and p-EGFR were significantly associated with reduced expression and alterations of SH3GL2 and CDC25A respectively. In-vitro demethylation experiment by 5-aza-2′-deoxycytidine (5-aza-dC) showed upregulation of SH3GL2 and CDC25A and downregulation of EGFR expression in Hep2 cell line. Poor patient outcome was predicted in the cases with alterations of SH3GL2 and CDC25A in presence of human papilloma virus (HPV) infection. Also, low SH3GL2 and high EGFR expression was a predictor of poor patient survival. Thus, our data suggests that overexpression of EGFR due to its reduced degradation and dephosphorylation is needed for development of HNSCC.