KDM4B protects against obesity and metabolic dysfunction.

Although significant progress has been made in understanding epigenetic regulation of in vitro adipogenesis, the physiological functions of epigenetic regulators in metabolism and their roles in obesity remain largely elusive. Here, we report that KDM4B (lysine demethylase 4B) in adipose tissues plays a critical role in energy balance, oxidation, lipolysis, and thermogenesis. Loss of KDM4B in mice resulted in obesity associated with reduced energy expenditure and impaired adaptive thermogenesis. Obesity in KDM4B-deficient mice was accompanied by hyperlipidemia, insulin resistance, and pathological changes in the liver and pancreas. Adipocyte-specific deletion of Kdm4b revealed that the adipose tissues were the main sites for KDM4B antiobesity effects. KDM4B directly controlled the expression of multiple metabolic genes, including Ppargc1a and Ppara Collectively, our studies identify KDM4B as an essential epigenetic factor for the regulation of metabolic health and maintaining normal body weight in mice. KDM4B may provide a therapeutic target for treatment of obesity.

The epigenetic modifier PBRM1 restricts the basal activity of the innate immune system by repressing retinoic acid-inducible gene-I-like receptor signalling and is a potential prognostic biomarker for colon cancer.

It has long been known that patients suffering from inflammatory bowel disease (IBD) have an increased risk of developing colorectal cancer (CRC). The innate immune system of host cells provides a first-line defence against pathogenic infection, whereas an uncontrolled inflammatory response under homeostatic conditions usually leads to pathological consequences, as exemplified by the chronic inflammation of IBD. The key molecules and pathways keeping innate immunity in check are still poorly defined. Here, we report that the chromatin remodeller polybromo-1 (PBRM1) is a repressor of innate immune signalling mediated by retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs). Knockdown of PBRM1 in colon cancer cells increased the expression of two receptor genes (RIG-I and MDA5) and upregulated interferon (IFN)-related and inflammation-related gene signatures. The innate immune signal stimulated by a double-stranded RNA viral mimic was exaggerated by PBRM1 suppression. PBRM1 cooperated with polycomb protein EZH2 to directly bind the cis-regulatory elements of RIG-I and MDA5, thereby suppressing their transcription. Moreover, upregulation of RIG-I and MDA5 is required for IFN response activation induced by PBRM1 silencing. TRIM25, a protein stimulated by the RLR pathway and IFN production, physically interacted with PBRM1 and induced PBRM1 protein destabilization by promoting its ubiquitination. These findings reveal a PBRM1-RLR regulatory circuit that can keep innate immune activity at a minimal level in resting cells, and also ensure a robust inflammatory response in the case of pathogen invasion. PBRM1 was found to be downregulated in primary tissues from patients with CRC or IBD, and its expression correlated negatively with that of RLR genes and interferon-stimulated genes in CRC samples. Lower PBRM1 expression was associated with advanced pathological grade and poorer survival of CRC patients, indicating that PBRM1 could serve as a potential prognostic biomarker for CRC. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Gene expression profile analysis of U251 glioma cells with shRNA-mediated SOX9 knockdown.

PURPOSE: In glioma, the sex-determining region Y-box 9 gene (SOX9) is overexpressed and its downregulation leads to inhibition of cell proliferation, invasion and increased cell apoptosis. To further evaluate the molecular and signal pathways associated with the function of SOX9 and SOX9 target genes, a global gene expression profile of the established SOX9-knockdown U251 cells was investigated. METHODS: The molecular function and biological pathways of differentially expressed genes (DEGs) were identified by gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The interactome networks of DEGs were constructed using the STRING online tool. The genes were further validated by RT-qPCR. RESULTS: GO analysis revealed that a set of 194 DEGs was shared in both the SOX9 KD-1 and SOX9 KD-2 U251 cells. GO analysis and KEGG pathway analysis showed that the DEGs were associated with biological processes involving cellular responses to hypoxia, osteoblast differentiation and angiogenesis, and special biological pathways, such as a TGF-beta signaling pathway and a HIF-1 signaling pathway. In addition, computational network of novel identified potential target genes linked to SOX9, including TGFB2, VEGFA, EGLN3 (PHD3), CA9 and HIF-1a. All of these genes were downregulated in the SOX9 knockdown U251 cells. CONCLUSIONS: SOX9 may be a key regulator impacting the glioma cellular processes by influencing the cellular response to hypoxia and HIF-1 signaling pathway. TGFB2, VEGFA, EGLN3 (PHD3), CA9, and HIF-1a may be the target genes of SOX9.

Zinc-finger protein 545 is a novel tumour suppressor that acts by inhibiting ribosomal RNA transcription in gastric cancer.

OBJECTIVE: Zinc-finger protein 545 (ZNF545) is a member of the family of Krüppel-associated box-containing zinc-finger proteins. The aim of this study was to clarify its biological function as a tumour suppressor in gastric cancer. DESIGN: The biological function of ZNF545 was determined by cell growth and apoptosis assays. The ZNF545 target signal pathway was identified by promoter luciferase assay, northern blot, run-on transcription assay, chromatin immunoprecipitation and coimmunoprecipitation assays. The clinical application of ZNF545 was assessed in primary gastric cancers. RESULTS: ZNF545 was silenced or reduced in 16 out of 18 gastric cancer cell lines by promoter hypermethylation. Restoration of ZNF545 expression in gastric cancer cell lines suppressed cell proliferation and induced apoptosis. These effects of ZNF545 were attributed to inhibition of ribosomal RNA (rRNA) transcription. Inhibition of rRNA transcription by ZNF545 was further revealed to be associated with direct ribosomal DNA (rDNA) promoter binding, recruitment of the corepressor, heterochromatin protein 1ß, and reduction of trimethylated histone H3 at the Lys4 residue at the rDNA locus. ZNF545 methylation was detected in 51.9% (41/79) of gastric cancer tissues, 27.0% (20/74) of adjacent non-tumour gastric tissues (p=0.001), but none of 20 normal controls. Multivariate analysis revealed that patients with ZNF545 methylation had a significant decrease in overall survival. Kaplan-Meier survival curves showed that ZNF545 methylation was significantly associated with shortened survival in patients with stage I-II gastric cancer. CONCLUSIONS: ZNF545 acts as a functional tumour suppressor in gastric cancer by inhibiting rRNA transcription. Its methylation at early stages of gastric carcinogenesis is an independent prognostic factor.

FEZF2, a novel 3p14 tumor suppressor gene, represses oncogene EZH2 and MDM2 expression and is frequently methylated in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus-associated tumor prevalent in southern China and southeast Asia, with the 3p14-p12 locus reported as a critical tumor suppressor gene (TSG) region during its pathogenesis. We identified a novel 3p14.2 TSG, FEZF2 (FEZ family zinc finger 2), for NPC. FEZF2 is readily expressed in normal tissues including upper respiratory epithelium, testis, brain and ovary tissues, as well as in immortalized nasopharyngeal epithelial cell line NP69, but it is completely silenced in NPC cell lines due to CpG methylation of its promoter, although no homozygous deletion of FEZF2 was detected. 5-Aza-2'-deoxycytidine treatment restored FEZF2 expression in NPC cell lines along with its promoter demethylation. FEZF2 was frequently downregulated in NPC tumors, with promoter methylation detected in 75.5% of tumors, but only in 7.1% of normal nasopharyngeal tissues. Restored FEZF2 expression suppressed NPC cell clonogenicity through inducing G2/M cell cycle arrest and apoptosis and also inhibited NPC cell migration and stemness. FEZF2 acted as a histone deacetylase-associated repressor downregulating multiple oncogenes including EZH2 and MDM2, through direct binding to their promoters. Concomitantly, overexpression of EZH2 was frequently detected in NPC tumors. Thus, we have identified FEZF2 as a novel 3p14.2 TSG frequently inactivated by promoter methylation in NPC, which functions as a repressor downregulating multiple oncogene expression.

Down-regulation of tyrosine aminotransferase at a frequently deleted region 16q22 contributes to the pathogenesis of hepatocellular carcinoma.

UNLABELLED: Loss of 16q is one of the most frequent alterations in many malignancies including hepatocellular carcinomas (HCC), suggesting the existence of a tumor suppressor gene (TSG) within the frequently deleted region. In this report we describe the identification and characterization of one candidate TSG, tyrosine aminotransferase gene (TAT), at 16q22.1. Loss of one TAT allele was detected in 27/50 (54%) of primary HCCs by quantitative real-time polymerase chain reaction. In addition, homo-deletion of TAT alleles was detected in two cases. Down-regulation of TAT was detected in 28/50 (56%) of HCCs, which was significantly associated with the loss of TAT allele and hypermethylation of TAT 5' CpG island (CGI) region (P < 0.001). Functional studies found that TAT has a strong tumor suppressive ability. Introduction of the TAT gene into HCC cell lines could effectively inhibit colony formation in soft agar, foci formation, and tumor formation in nude mice. Further study found that the tumor suppressive mechanism of TAT was associated with its proapoptotic role in a mitochondrial-dependent manner by promoting cytochrome-c release and activating caspase-9 and PARP. CONCLUSION: Taken together, our findings suggest that TAT plays an important suppressive role in the development and progression of HCC.

[Application of deep convolutional neural networks in the diagnosis of laryngeal squamous cell carcinoma based on narrow band imaging endoscopy].

Objective: To explore the possibility of using artificial intelligence (AI) technology based on convolutional neural network (CNN) to assist the clinical diagnosis of laryngeal squamous cell carcinoma (LSCC) through deep learning algorithm. Methods: A deep CNN was developed and applied in narrow band imaging (NBI) endoscopy of 4 799 patients with laryngeal lesions, including 3 168 males and 1 631 females, aged from 21 to 87 years, from 2015 to 2017 in Beijing Tongren Hospital, Capital Medical University. A simple randomization method was used to select the laryngeal NBI images of 2 427 patients (1 388 benign lesions and 1 039 LSCC lesions) for the training and correction the CNN model. The remaining laryngeal NBI images of 2 372 patients (including 1 276 benign lesions and 1 096 LSCC lesions) were used as validation data set to compare performance between CNN and otolaryngologists. SPSS 21.0 software was used for Chi-square test to calculate the accuracy, sensitivity and specificity of AI and otolaryngologists. The area under the curve (AUC) of receiver operating curve (ROC) was used to evaluate the diagnostic ability of the algorithm for NBI images. Results: The accuracy, sensitivity and specificity for NBI predictions were respectively 90.91% (AUC=0.96), 90.12% and 91.53%, which were equivalent to those for otolaryngologists' predictions (accuracy, sensitivity and specificity were (91.93±3.20)%, (91.33±3.25)% and (93.02±2.59)%, t values were 0.64, 0.75 and 1.17, and P values were 0.32, 0.28 and 0.21, respectively). The diagnostic efficiency of CNN was significantly higher than that of otolaryngologists (0.01 vs. 5.50, t =9.15, P<0.001). Conclusion: AI based on deep CNN is effective for using in the laryngeal NBI image diagnosis, showing a good application prospect in the diagnosis of LSCC.

A deep convolutional neural network-based method for laryngeal squamous cell carcinoma diagnosis.

BACKGROUND: Laryngeal squamous cell carcinoma (LSCC) is one of the most common tumors of the respiratory tract. Currently, the diagnosis of LSCC is mainly based on a laryngoscopy analysis and pathological findings. Deep-learning algorithms have been shown to provide accurate clinical diagnoses. METHODS: We developed a deep convolutional neural network (CNN) model, and evaluated its application to narrow-band imaging (NBI) endoscopy and pathological diagnoses of LSCC at several hospitals. A total of 4,591 patients' laryngeal NBI scans (1,927 benign and 2,664 LSCC) were used to test and validate the model. Additionally, 3,458 pathological images (752 benign and 2,706 LSCC) of 1,228 patients' hematoxylin and eosin staining slides (318 benign and 910 LSCC) were used for the pathological diagnosis training and validation. The images were randomly divided into training, validation and testing images at the ratio of 70:15:15. An independent test cohort of LSCC NBI scans and pathological images from other institutions were also used. RESULTS: In the NBI group, the areas under the curve of the validation, test, and independent test data sets were 0.966, 0.964, and 0.873, respectively, and those of the pathology group were 0.994, 0.981, and 0.982, respectively. Our method was highly accurate at diagnosing LSCC. CONCLUSIONS: In this study, the CNN model performed well in the NBI and pathological diagnosis of LSCC. More accurate and faster diagnoses could be achieved with the assistance of this algorithm.

Loss of KDM4B exacerbates bone-fat imbalance and mesenchymal stromal cell exhaustion in skeletal aging.

Skeletal aging is a complex process, characterized by a decrease in bone formation, an increase in marrow fat, and stem cell exhaustion. Loss of H3K9me3, a heterochromatin mark, has been proposed to be associated with aging. Here, we report that loss of KDM4B in mesenchymal stromal cells (MSCs) exacerbated skeletal aging and osteoporosis by reducing bone formation and increasing marrow adiposity via increasing H3K9me3. KDM4B epigenetically coordinated ß-catenin/Smad1-mediated transcription by removing repressive H3K9me3. Importantly, KDM4B ablation impaired MSC self-renewal and promoted MSC exhaustion by inducing senescence-associated heterochromatin foci formation, providing a mechanistic explanation for stem cell exhaustion with aging. Moreover, while KDM4B was required for parathyroid hormone-mediated bone anabolism, KDM4B depletion accelerated bone loss and marrow adiposity induced by a high-fat diet. Our results suggest that the epigenetic rejuvenation and reversing bone-fat imbalance might be new strategies for preventing and treating skeletal aging and osteoporosis by activating KDM4B in MSCs.

CDCA2 Inhibits Apoptosis and Promotes Cell Proliferation in Prostate Cancer and Is Directly Regulated by HIF-1α Pathway.

Prostate cancer (PCa) is a major serious malignant tumor and is commonly diagnosed in older men. Identification of novel cancer-related genes in PCa is important for understanding its tumorigenesis mechanism and developing new therapies against PCa. Here, we used RNA sequencing to identify the specific genes, which are upregulated in PCa cell lines and tissues. The cell division cycle associated protein (CDCA) family, which plays a critical role in cell division and proliferation, is upregulated in the PCa cell lines of our RNA-Sequencing data. Moreover, we found that CDCA2 is overexpressed, and its protein level positively correlates with its histological grade, clinical stage, and Gleason Score. CDCA2 was further found to be upregulated and correlated with poor prognosis and patient survival in multiple cancer types in The Cancer Genome Atlas (TCGA) dataset. The functional study suggests that inhibition of CDCA2 will lead to apoptosis and lower proliferation in vitro. Silencing of CDCA2 also repressed tumor growth in vivo. Loss of CDCA2 affects several oncogenic pathways, including MAPK signaling. In addition, we further demonstrated that CDCA2 was induced in hypoxia and directly regulated by the HIF-1α/Smad3 complex. Thus, our data indicate that CDCA2 could act as an oncogene and is regulated by hypoxia and the HIF-1αpathway. CDCA2 may be a useful prognostic biomarker and potential therapeutic target for PCa.

CADM2 inhibits human glioma proliferation, migration and invasion.

Malignant glioma is one of the most common malignant tumors in the brain parenchyma with a poor prognosis. Cell adhesion molecules (CADMs) immunoglobulin super family is involved in the maintenance of cell adhesion, polarity and tumor suppression. However, the role and mechanisms of CADM2 in human glioma have yet to be elucidated. Therefore, the present study evaluated the expression level of CADM2 and demonstrated that CADM2 was markedly downregulated in human glioma tissues compared with normal brain tissue and glioma cell lines, and the CADM2 expression level was significantly decreased in high­grade glioma tissues. Overexpression of CADM2 inhibited the proliferation of glioma cell proliferation in vitro and in vivo. CADM2 also inhibited the migration and invasion of U87 and U251 cells. Furthermore, overexpression of CADM2 induced a significant decrease in the expression of G1/S transition key regulators, cyclin D1, cyclin E, cyclin­dependent kinase (CDK)2 and CDK4. Additionally, CADM2 expression was associated with alterations in epithelial­mesenchymal transition (EMT) markers, including E­cadherin and ß­catenin. Taken together, the results of the present study demonstrated that CADM2 inhibits glioma tumorigenesis by regulating the cell cycle and the EMT process, suggesting that CADM2 may be a novel potential therapeutic target in human glioma.

Author Correction: KDM3 epigenetically controls tumorigenic potentials of human colorectal cancer stem cells through Wnt/ß-catenin signalling.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A response prediction model for taxane, cisplatin, and 5-fluorouracil chemotherapy in hypopharyngeal carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. The five-year survival rate of HNSCC has not improved even with major technological advancements in surgery and chemotherapy. Currently, docetaxel, cisplatin, and 5-fluoruracil (TPF) treatment has been the most popular chemotherapy method for HNSCC; but only a small percentage of HNSCC patients exhibit a good response to TPF treatment. Unfortunately, at present, no reasonably effective prediction model exists to assist clinicians with patient treatment. For this reason, patients have no other alternative but to risk neoadjuvant chemotherapy in order to determine their response to TPF. In this study, we analyzed the gene expression profile in TPF-sensitive and non-sensitive patient samples. We identified a gene expression signature between these two groups. We further chose 10 genes and trained a support vector machine (SVM) model. This model has 88.3% sensitivity and 88.9% specificity to predict the response to TPF treatment in our patients. In addition, four more TPF responsive and four more TPF non-sensitive patient samples were used for further validation. This SVM model has been proven to achieve approximately 75.0% sensitivity and 100% specificity to predict TPF response in new patients. This suggests that our 10-genes SVM prediction model has the potential to assist clinicians to personalize treatment for HNSCC patients.

Clinical significance of Iroquois Homeobox Gene - IRX1 in human glioma.

The present study aimed to investigate the location, expression and clinical significance of Iroquois homeobox gene (IRX1) in human glioma. The expression of IRX1 gene in glioma cell lines (U87, U373, LN229 and T98G) and normal brain tissue was detected via reverse transcription-polymerase chain reaction. The IRX1 protein in fresh glioma specimens, with the adjacent normal brain tissue, was quantified through western blotting. The archived glioma only specimens from the present hospital and glioma specimens with adjacent normal brain tissue, from Alenabio biotechnology, were subjected to immunohistochemistry and tissue microarray analysis, respectively. The Kaplan-Meier method was employed to assess the correlation between the IRX1 level and the overall survival time of the patients. IRX1 gene was demonstrated to be expressed at varying levels in U373, LN229 and T98G cells, however not in U87 cells and normal brain tissue. Western blotting revealed increased IRX1 expression in glioma tissue compared with adjacent normal brain tissue. Furthermore, a direct correlation was observed between the IRX1 expression and the clinical glioma grade, with a significant difference in the gene expression between high grade and low grade glioma (P<0.05). Notably, IRX1 was identified to be localized to the cytoplasm in the adjacent normal brain and World Health Organization grade I glioma, whereas was identified to be present in the nucleus in higher grade glioma. In addition to being established as a significant prognostic variable, IRX1 expression was positively correlated with the overall survival of glioma patients. IRX1 gene may therefore exhibit an oncogenic role in glioma condition, and thus may be of clinical importance as a future therapeutic target.

Association between SOX9 and CA9 in glioma, and its effects on chemosensitivity to TMZ.

Temozolomide (TMZ) is a standard chemotherapeutic drug used in the treatment of glioblastoma multiforme (GBM); however, resistance to this drug is common. SRY-Box 9 (SOX9) expression is associated with a poor prognosis of patients with GBM and with resistance to TMZ. Therefore, the aim of this study was to examine the effects of SOX9 inhibition on the sensitivity of glioma cells to TMZ treatment. We knocked down the expression of SOX9 (SOX9KD) via lentiviral infection in two glioblastoma (U87 and U251) cell lines, and the cells were then subjected to gene microarray, Gene Ontology and KEGG analysis pathway, all of which revealed a close association between SOX9 and the carbonic anhydrase 9 (CA9) gene. The TMZ-mediated apoptosis of glioma cells was significantly increased in the cells in the SOX9KD group. The potential underlying mechanism involved the downregulation of SOX9 and CA9 expression, which in turn decreased Akt phosphorylation, downregulated BCL­2 expression, and upregulated BAX expression, as assessed by western blot analysis and RT-qPCR. The effects were found to be substantially enhanced in the cells in the SOX9KD group treated with TMZ. Subsequently, considering the association between SOX9 and CA9, the effects of CA9 inhibition, using a CA9 inhibitor (U­104), on the chemosensitivity of glioma cells to TMZ were assessed. The results revealed that the use of U­104 + TMZ effectively induced glioma cell death, compared to treatment with TMZ alone. The underlying mechanisms were similar to those observed with the silencing of SOX9 in the TMZ-treated glioma cells. On the whole, the findings of this study establish the SOX9/CA9-mediated oncogenic pathway in glioma, the inhibition of which enhances the sensitivity of glioma cells to TMZ treatment, and thus highlights the value of developing small molecules or antibodies against the SOX9/CA9 pathway, for combination therapy with TMZ, in the more efficient management of glioma.

SOX9-PDK1 axis is essential for glioma stem cell self-renewal and temozolomide resistance.

Glioblastoma multiforme (GBM) is the most common and aggressive brain tumor with limited therapeutic options. Glioma stem cell (GSC) is thought to be greatly responsible for glioma tumor progression and drug resistance. But the molecular mechanisms of GSC deriving recurrence and drug resistance are still unclear. SOX9 (sex-determining region Y (SRY)-box9 protein), a transcription factor expressed in most solid tumors, is reported as a key regulator involved in maintaining cancer hallmarks including the GSCs state. Previously, we have observed that silencing of SOX9 suppressed glioma cells proliferation both in vitro and in vivo. Here, we found that SOX9 was essential for GSC self-renewal. Silencing of SOX9 down-regulated a broad range of stem cell markers and inhibited glioma cell colony and sphere formation. We identified pyruvate dehydrogenase kinase 1 (PDK1) as a target gene of SOX9 using microarray analyses. PDK1 inactivation greatly inhibited glioma cell colony and sphere formation and sensitized glioma spheres to temozolomide (TMZ) toxicity. In addition, SOX9-shRNA and PDK1 inhibitor could greatly sensitize GSC to TMZ in vivo. Taken together, our data reveals that SOX9-PDK1 axis is a key regulator of GSC self-renewal and GSC temozolomide resistance. These findings may provide help for future human GBM therapy.

A novel read-through transcript JMJD7-PLA2G4B regulates head and neck squamous cell carcinoma cell proliferation and survival.

Recent findings on the existence of oncogenic fusion genes in a wide array of solid tumors, including head and neck squamous cell carcinoma (HNSCC), suggests that fusion genes have become attractive targets for cancer diagnosis and treatment. In this study, we showed for the first time that a read-through fusion gene JMJD7-PLA2G4B is presented in HNSCC, splicing neighboring jumonji domain containing 7 (JMJD7) and phospholipase A2, group IVB (PLA2G4B) genes together. Ablation of JMJD7-PLA2G4B significantly inhibited proliferation of HNSCC cells by promoting G1 cell cycle arrest and increased starvation-induced cell death compared to JMJD7-only knockdown HNSCC cells. Mechanistically, we found that JMJD7-PLA2G4B modulates phosphorylation of Protein Kinase B (AKT) to promote HNSCC cell survival. Moreover, JMJD7-PLA2G4B also regulated an E3 ligase S-phase kinase-associated protein 2 (SKP2) to control the cell cycle progression from G1 phase to S phase by inhibiting Cyclin-dependent kinase inhibitor 1 (p21) and 1B (p27) expression. Our study provides novel insights into the oncogenic control of JMJD7-PLA2G4B in HNSCC cell proliferation and survival, and suggests that JMJD7-PLA2G4B may serve as an important therapeutic target and prognostic marker for HNSCC development and progression.

OSR1 is a novel epigenetic silenced tumor suppressor regulating invasion and proliferation in renal cell carcinoma.

Renal cell carcinoma (RCC) is one of the most malignant tumors in human. Here, we found that odd-skipped related transcription factor 1 (OSR1) was downregulated in 769-P and 786-O cells due to promoter CpG methylation. OSR1 expression could be restored by pharmacological demethylation treatment in silenced cell lines. Knockdown of OSR1 in two normal expressed cell lines- A498 and ACHN promoted cell invasion and cellular proliferation. RNA-Sequencing analysis showed that expression profile of genes involved in multiple cancer-related pathways was changed when OSR1 was downregulated. By quantitative real-time PCR, we confirmed that depletion of OSR1 repressed the expression of several tumor suppresor genes involved in p53 pathway, such as p53, p21, p27, p57 and RB in A498 and ACHN. Moreover, knockdown of OSR1 suppressed the transcriptional activity of p53. Of note, OSR1 depletion also led to increased expression of a few oncogenic genes. We further evaluated the clinical significance of OSR1 in primary human RCC specimens by immunohistochemical staining and found that OSR1 expression was downregulated in primary RCC and negatively correlated with histological grade. Thus, our data indicate that OSR1 is a novel tumor suppressor gene in RCC. Downregulation of OSR1 might represent a potentially prognostic marker and therapeutic target for RCC.

MicroRNA-101 inhibits proliferation, migration and invasion of human glioblastoma by targeting SOX9.

Glioblastoma multiforme (GBM) is the most common primary malignant tumors originating in the brain parenchyma. At present, GBM patients have a poor prognosis despite the continuous progress in therapeutic technologies including surgery, radiotherapy, photodynamic therapy, and chemotherapy. Recent studies revealed that miR-101 was remarkably down-regulated in kinds of human cancers and was associated with aggressive tumor cell proliferation and stem cell self-renewal. Data also showed that miR-101 was down-regulated in primary glioma samples and cell lines, but the underlying molecular mechanism of the deregulation of miR-101 in glioma remained largely unknown. In this study, we found that miR-101 could inhibit the proliferation and invasion of glioma cells both in vitro and in vivo by directly targeting SOX9 [sex-determining region Y (SRY)-box9 protein]. Silencing of SOX9 exerted similar effects with miR-101 overexpression on glioma cells proliferation and invasion. Quantitative reverse transcription PCR and Western blotting analysis revealed a negative relationship between miR-101 and SOX9 in human glioma U251MG and U87MG cells, and the luciferase assay indicated that miR-101 altered SOX9 expression by directly targeting on 3'UTR. Taken together, our findings suggest that miR-101 regulates glioma proliferation, migration and invasion via directly down-regulating SOX9 both in vitro and in vivo, and miR-101 may be a potential therapeutic target for future glioma treatment.

Overexpression of a novel candidate oncogene KIF14 correlates with tumor progression and poor prognosis in prostate cancer.

Prostate cancer (PCa) is the second leading cause of death from cancer in men. The mechanism underlying tumorigenesis and development of PCa is largely unknown. Here, we identified Kinesin family member 14 (KIF14) as a novel candidate oncogene in PCa. We found that KIF14 was overexpressed in multiple PCa cell lines and primary PCa tissues. Knockdown of KIF14 in DU145 and PC3 prostate cancer cells suppressed cell proliferation, induced cell cycle arrest and apoptosis. Transcriptome analysis by RNA-sequencing demonstrated that KIF4 suppression led to transcriptional changes of genes involved in p53 and TGF-beta signaling pathway. In addition, upregulated expression of GADD45A, GADD45B, p21, PIDD and Shisa5, which contribute to growth arrest and apoptosis induction, and downregulated CCNB1 that promotes cell cycle progression were confirmed by quantitative real-time PCR after KIF4 knockdown. We further found that KIF14 protein level was positively correlated with T stage and Gleason Score. Patients with higher KIF14 expression had shorter overall survival time than those with lower KIF14 expression. Thus, our data indicate that KIF14 could act as a potential oncogene that contributes to tumor progression and poor prognosis in PCa, which may represent a novel and useful prognostic biomarker for PCa.