Wei-Qing Li

MicroRNA-21 targets LRRFIP1 and contributes to VM-26 resistance in glioblastoma multiforme.

MicroRNAs control a wide array of biological processes including cell differentiation, proliferation, and apoptosis whose dysregulation is a hallmark of cancer. MicroRNA-21 (miR-21) is overexpressed in many cancers including glioblastoma and contributes to tumor resistance to chemotherapy. We investigated whether miR-21 mediated chemoresistance to the chemotherapeutic agent VM-26 in glioblastoma cells and sought to identify the candidate target genes for miR-21 by gene expression profiling. Here we report that miR-21 was involved in mediating chemoresistance to VM-26 in glioblastoma cells. Suppression of miR-21 by specific antisense oligonucleotides in glioblastoma cell U373 MG led to enhanced cytotoxicities of VM-26 against U373 MG cells. We further identified and validated LRRFIP1, whose product is an inhibitor of NF-kappaB signaling, as a direct target gene of miR-21. Our findings suggest that miR-21 represents a promising target for therapeutic manipulation to increase the efficacy of chemotherapeutic agents in treating glioblastoma, a highly lethal type of cancer.

The rno‐miR‐34 family is upregulated and targets ACSL1 in dimethylnitrosamine‐induced hepatic fibrosis in rats

The mechanisms whereby hepatic fibrosis develops in chronic liver diseases remain incompletely defined. Here, we sought to examine whether microRNA (miRNA) became dysregulated in dimethylnitrosamine‐induced hepatic fibrosis in rats. Our microarray analysis revealed that the miR‐34 family was upregulated along with other miRNAs in liver fibrotic tissues. Six miRNAs, such as rno‐miR‐878, were downregulated. The findings were confirmed by RT‐PCR assays. Gene ontology analysis further showed that many of these dysregulated miRNAs were involved in lipid/fatty acid metabolism. The acyl‐CoA synthetase long‐chain family member 1 (ACSL1) gene contained specific binding sites for miR‐34a/miR‐34c. Additional enhanced green fluorescence protein reporter activity assays indicated that the miR‐34 family targeted ACSL1. Our RT‐PCR and immunoblotting assays further demonstrated that both the mRNA and protein levels of ACSL1 were markedly reduced in fibrotic liver tissues. Our findings suggest that miRNA becomes dysregulated during hepatic fibrosis, and that the miR‐34 family may be involved in the process by targeting ACSL1.

Carboxyl terminus of Hsp70-interacting protein (CHIP) contributes to human glioma oncogenesis

Malignant glioma is the most common adult primary brain tumor, and the mechanism of its oncogenesis is poorly understood. Growing evidence has shown that E3 ubiquitin ligases can promote tumorgenesis of glioma. CHIP is an E3 ubiquitin ligase that can induce ubiquitylation and degradation of many tumor‐related proteins, and it has been reported to act as an upstream regulator in breast cancer; however, its role in human gliomas has not been evaluated yet. In this study, the expression of CHIP in glioma tissues was studied using immunohistochemistry. CHIP expression in glioma cells was studied by real‐time RT‐PCR, western blot and double immunofluorescence staining. The role of CHIP in glioma oncogenesis was investigated by lentivirus‐mediated RNA interference (RNAi) and overexpression in vitro and in vivo. We showed CHIP expression in glioma samples was related to tumor grades, with stronger staining in high‐grade gliomas than in low‐grade gliomas. Knocking down of CHIP suppressed proliferation, colony formation of U251 and U87 glioma cells, while overexpression of CHIP resulted in enhanced proliferation and colony formation in vitro. In a nude mouse xenograft model, intratumoral injection of CHIP RNAi lentivirus significantly delayed tumor growth. In contrast, overexpression of CHIP resulted in enhanced tumor growth in vivo. After CHIP RNAi, both survivin mRNA and protein were decreased, while CHIP overexpression induced increased mRNA and protein levels of survivin. This is the first study demonstrating CHIP contributes to oncogenesis of glioma. (Cancer Sci 2011; 102: 959–966)

Up-regulation of USP2a and FASN in gliomas correlates strongly with glioma grade

Gliomas are the most common neoplasms in the central nervous system. The lack of efficacy of glioma therapies necessitates in-depth studies of glioma pathology, especially of the underlying molecular mechanisms that transform normal glial cells into tumor cells. Here we report that a deubiquitinating enzyme, ubiquitin-specific protease 2a (USP2a), and its substrate, fatty acid synthase (FASN), are over-expressed in glioma tissue. Using real-time quantitative polymerase chain reaction (PCR), Western blot and immunohistochemistry, we examined the expression and cellular distribution of USP2a and FASN in human glioma tissues. The expression patterns of USP2a and FASN correlated with the pathologic and clinical characteristics of the patients. Real-time PCR analysis showed that the expression levels of USP2a and its substrate FASN were higher in high-grade (World Health Organization [WHO] grades III and IV) glioma tissues than in low-grade (WHO grades I and II) glioma tissues. Western blot analysis indicated that the average optical densitometry ratio of USP2a and its substrate FASN in high-grade gliomas was higher than in low-grade gliomas. Moreover, statistical analysis of grade-classified glioma samples showed that the level of USP2a and FASN expression increased with the elevation of the WHO grade of glioma. USP2a protein expression was detected in the nucleus of glioma tissues and an increase in expression was significantly associated with the elevation of the WHO grade of glioma by immunohistochemistry. These findings expand our understanding of the molecular profiling of glioma and could shed light on new diagnostic criteria for gliomas.

Effect of Clazosentan in Patients with Aneurysmal Subarachnoid Hemorrhage: A Meta-Analysis of Randomized Controlled Trials

Background Cerebral vasospasm is the most important potentially treatable cause of mortality and morbidity following aneurysmal subarachnoid hemorrhage (aSAH). Clazosentan, a selective endothelinreceptor antagonist, has been suggested to help reduce the incidence of vasospasm in patients with aSAH. However, the results were controversial in previous trials. This meta-analysis attempts to assess the effect of clazosentan in patients with aSAH. Methodology/Principal Findings We systematically searched Pubmed, Embase, and the Cochrane Library from their inception until June, 2012. All randomized controlled trials (RCTs) related to the effect of clazosentan in aSAH were included. The primary outcomes included the incidence of angiographic vasospasm, new cerebral infarction (NCI), delayed ischemic neurological deficits (DIND), and vasospasm-related morbidity/mortality (M/M); the second outcomes included the occurrence of rescue therapy, all-cause-mortality, and poor outcome. 4 RCTs were included with a total of 2156 patients. The risk of angiographic vasospasm (relative risk [RR] = 0.58; 95% CI, 0.48 to 0.71), DIND (RR = 0.76; 95% CI, 0.62 to 0.92), and vasospasm-related M/M (RR = 0.80; 95% CI, 0.67 to 0.96) were statistically significantly reduced in the clazosentan group. Patients treated with clazosentan had a reduced occurrence of rescue therapy (RR = 0.62; 95% CI, 0.49 to 0.79). However, no statistically significant effects were observed in NCI (RR = 0.74; 95% CI, 0.52 to 1.04), mortality (RR = 1.03; 95% CI, 0.71 to 1.49), and poor outcome (RR = 1.12; 95% CI, 0.96 to 1.30). Conclusions/Significance Our pooling data supports that clazosentan is probably effective in preventing the occurrence of angiographic vasospasm, vasospasm-related DIND, vasospasm related M/M, and rescue therapy. However, no evidence lends significant supports to the benefits of clazosentan in decreasing the occurrence of NCI, mortality or improving the functional outcome.

Aggressive Angiomyxoma of the Vulva: Case Report and Literature Review

Aggressive angiomyxoma is a rare soft-tissue tumour, typically occurring in the female pelvis and carrying a high risk of local infiltration and relapse. Surgery remains the first line of treatment, however some adjuvant treatments, such as gonadotrophin-releasing hormone (GnRH) agonists, have been used for primary treatment and for treatment against tumour recurrence. We describe a case of vulvar aggressive angiomyxoma in a 31-year old woman who underwent surgical excision of the tumour. Diagnosis was made on the basis of histopathological examination and positive immunohistochemical staining with oestrogen and progesterone receptors. Postsurgery, a GnRH agonist (3.75 mg triptorelin) was injected intramuscularly every month for 3 months to prevent tumour recurrence and, to date, no relapse has been observed. Whether treatment is with surgery, hormone therapy or both, it is clear that aggressive angiomyxoma requires close, long-term follow-up to monitor for disease recurrence and that the individualization of each case is essential for adequate management.

Rosette-forming Glioneuronal Tumour of the Fourth Ventricle with Previous Intratumoural Haemorrhage: Case Report and Review of the Literature

The case is reported of a rosette-forming glioneuronal tumour of the fourth ventricle (RGTFV) in a 27-year-old male. Symptoms included headache, severe vomiting and clumsy walking that had progressively worsened over 14 days. Computed tomography and magnetic resonance imaging indicated a 3.0 × 2.5 × 2.0 cm solid-cystic mass in the fourth ventricle and obstructive hydrocephalus. The tumour showed evidence of previous intra-tumour haemorrhage, with heterogeneous enhancement after contrast administration. Complete excision of the lesion was performed. Signs of previous intra-tumoural haemorrhage were seen intra-operatively. The detailed clinical, radiological and pathological features in this patient are described and compared with existing literature on this type of tumour. Despite benign histological features and a reported favourable post-operative course, there is still limited clinical experience with this type of tumour, however intratumoural haemorrhage may result in morbidity and mortality. This report will help provide better characterization of this entity, improving the diagnosis and potentially reducing mortality in RGTFV.

Characterizing the role of PCDH9 in the regulation of glioma cell apoptosis and invasion.

PCDH9, a member of the protocadherin superfamily, is frequently lost in many different cancer types. This study aimed to detect PCDH9 expression in glioma tissues. This study also assessed the effects of PCDH9 expression in two different glioma cell lines. This was accomplished by manipulating PCDH9 expression in these glioma cell lines. The data showed that the expression of PCDH9 mRNA and protein was significantly decreased in gliomas compared to normal brain tissues. Lentivirus carrying PCDH9 cDNA restored PCDH9 expression in the U87 and U251 glioma cell lines. PCDH9 restoration in these cell lines reduced tumor cell viability, induced apoptosis, and caused G0/G1 cell cycle arrest. PCDH9 expression also suppressed the colony formation ability and invasion capacity of U87 and U251 cells. Molecularly, the restoration of PCDH9 expression upregulated Bax protein expression, but downregulated Bcl-2 and cyclin D1 expression. These data from the current study suggest that the loss of PCDH9 expression could contribute to glioma development and/or progression. Further studies will evaluate PCDH9 expression as a biomarker for the early detection of gliomas and as a prognostic indicator for this cancer type.

High bone sialoprotein (BSP) expression correlates with increased tumor grade and predicts a poorer prognosis of high-grade glioma patients.

Objectives To investigate the expression and prognostic value of bone sialoprotein (BSP) in glioma patients. Methods We determined the expression of BSP using real-time RT-PCR and immunohistochemistry in tissue microarrays containing 15 normal brain and 270 glioma samples. Cumulative survival was calculated by the Kaplan-Meier method and analyzed by the log-rank test. Univariate and multivariate analyses were performed by the stepwise forward Cox regression model. Results Both BSP mRNA and protein levels were significantly elevated in high-grade glioma tissues compared with those of normal brain and low-grade glioma tissues, and BSP expression positively correlated with tumor grade (P<0.001). Univariate and multivariate analysis showed high BSP expression was an independent prognostic factor for a shorter progression-free survival (PFS) and overall survival (OS) in both grade III and grade IV glioma patients [hazard ratio (HR) = 2.549 and 3.154 for grade III glioma, and HR = 1.637 and 1.574 for grade IV glioma, respectively]. Patients with low BSP expression had a significantly longer median OS and PFS than those with high BSP expression. Small extent of resection and lineage of astrocyte served as independent risk factors of both shorter PFS and OS in grade III glioma patients; GBM patients without O6-methylguanine (O6-meG) DNA methyltransferase (MGMT) methylation and Karnofsky performance score (KPS) less than 70 points were related to poor prognosis. Lack of radiotherapy related to shorter OS but not affect PFS in both grade III and grade IV glioma patients. Conclusion High BSP expression occurs in a significant subset of high-grade glioma patients and predicts a poorer outcome. The study identifies a potentially useful molecular marker for the categorization and targeted therapy of gliomas.

High cytoplasmic FOXO1 and pFOXO1 expression in astrocytomas are associated with worse surgical outcome.

FOXO1 is at a convergence point of receptor tyrosine kinase (RTK) signaling, which is one of the three core pathways implicated in glioblastoma. It was recently shown that FOXO1 can effectively induce glioma cell death and inhibit tumor growth through cell cycle arrest and apoptosis. We therefore evaluated FOXO1 and pFOXO1 protein expression in 181 primary astrocytoma samples and 16 normal brain samples. Astrocytoma samples expressed higher cytoplasmic FOXO1 and pFOXO1 than normal brain samples. Nuclear pFOXO1 level was significantly higher than nuclear FOXO1 in astrocytomas. High cytoplasmic FOXO1 expression was associated with older onset age (P = 0.001) and higher WHO grade (P = 0.001). The trend was also observed between cytoplasmic pFOXO1 expression and WHO grade although not significant. Univariate survival analysis showed that both high cytoplasmic FOXO1 and pFOXO1 expression indicated a significantly shorter median overall survival and progression-free survival. Multivariate survival analysis revealed cytoplasmic FOXO1 expression, cytoplasmic pFOXO1 expression, WHO grade, gender, extent of resection and radiotherapy to be independent prognostic factors for overall survival and progression-free survival. Thus, our data suggested that cytoplasmic FOXO1 and pFOXO1 expression may serve as valuable prognostic variables in astrocytomas and may have significant implications for the development and application of targeted therapy.