Dual Role of WISP1 in maintaining glioma stem cells and tumor-supportive macrophages in glioblastoma.

The interplay between glioma stem cells (GSCs) and the tumor microenvironment plays crucial roles in promoting malignant growth of glioblastoma (GBM), the most lethal brain tumor. However, the molecular mechanisms underlying this crosstalk are incompletely understood. Here, we show that GSCs secrete the Wnt-induced signaling protein 1 (WISP1) to facilitate a pro-tumor microenvironment by promoting the survival of both GSCs and tumor-associated macrophages (TAMs). WISP1 is preferentially expressed and secreted by GSCs. Silencing WISP1 markedly disrupts GSC maintenance, reduces tumor-supportive TAMs (M2), and potently inhibits GBM growth. WISP1 signals through Integrin α6ß1-Akt to maintain GSCs by an autocrine mechanism and M2 TAMs through a paracrine manner. Importantly, inhibition of Wnt/ß-catenin-WISP1 signaling by carnosic acid (CA) suppresses GBM tumor growth. Collectively, these data demonstrate that WISP1 plays critical roles in maintaining GSCs and tumor-supportive TAMs in GBM, indicating that targeting Wnt/ß-catenin-WISP1 signaling may effectively improve GBM treatment and the patient survival.

Thioridazine Enhances P62-Mediated Autophagy and Apoptosis Through Wnt/ß-Catenin Signaling Pathway in Glioma Cells.

Thioridazine (THD) is a common phenothiazine antipsychotic drug reported to suppress growth in several types of cancer cells. We previously showed that THD acts as an antiglioblastoma and anticancer stem-like cell agent. However, the signaling pathway underlying autophagy and apoptosis induction remains unclear. THD treatment significantly induced autophagy with upregulated AMPK activity and engendered cell death with increased sub-G1 in glioblastoma multiform (GBM) cell lines. Notably, through whole gene expression screening with THD treatment, frizzled (Fzd) proteins, a family of G-protein-coupled receptors, were found, suggesting the participation of Wnt/ß-catenin signaling. After THD treatment, Fzd-1 and GSK3ß-S9 phosphorylation (inactivated form) was reduced to promote ß-catenin degradation, which attenuated P62 inhibition. The autophagy marker LC3-II markedly increased when P62 was released from ß-catenin inhibition. Additionally, the P62-dependent caspase-8 activation that induced P53-independent apoptosis was confirmed by inhibiting T-cell factor/ß-catenin and autophagy flux. Moreover, treatment with THD combined with temozolomide (TMZ) engendered increased LC3-II expression and caspase-3 activity, indicating promising drug synergism. In conclusion, THD induces autophagy in GBM cells by not only upregulating AMPK activity, but also enhancing P62-mediated autophagy and apoptosis through Wnt/ß-catenin signaling. Therefore, THD is a potential alternative therapeutic agent for drug repositioning in GBM.

GSK3ß­mediated Ser156 phosphorylation modulates a BH3­like domain in BCL2L12 during TMZ­induced apoptosis and autophagy in glioma cells.

BH3 domains, classified initially as BCL2 homology domains, participate in both apoptosis and autophagy. Beclin­1 contains a BH3 domain, which is required for binding to antiapoptotic BCL2 homologs and BCL2­mediated inhibition of autophagy. BCL2­like 12 (BCL2L12) also harbors a BH3­like domain, which is 12 residues long and contains a LXXXAE/D motif. In a yeast two­hybrid system performed in the present study, BCL2L12 shared similar binding partnerships to antiapoptotic BCL2 homologs, such as Beclin­1. In addition, this BH3­like domain was involved in anti­apoptosis and drug­induced autophagy in glioma cell lines. Mutations in S156 and hydrophobic L213 to alanine counteracted the antiapoptotic properties of BCL2L12 and downregulated the activation of microtubule associated protein 1 light chain 3B (LC3B), autophagy­related (ATG)12­ATG5 conjugates and Beclin­1, compared with a BCL2L12 wild­type group. Molecular dynamics simulations revealed that phosphorylation at Ser156 of BCL2L12 (within α­6 and α­7 helices) influenced the BH3­like domain conformation (α­9 helix), indicating that glycogen synthase kinase (GSK) 3ß­mediated Ser156 phosphorylation modulated a BH3­like domain in BCL2L12. Altogether, the present findings indicated that BCL2L12 may participate in anti­apoptosis and autophagy via a BH3­like domain and GSK3ß­mediated phosphorylation at Ser156. Furthermore, blockade of temozolomide (TMZ)­induced autophagy by 3­methyladenine (3­MA) resulted in enhanced activation of apoptotic markers, as well as tumor suppresor protein p53 (p53) expression in U87MG cells. The present results suggested that p53 and O6­methylguanine DNA methyltransferase activation, and BCL2, BCL­extra large, Beclin­1 and BCL2L12 expression may be used as a detection panel to determine which patients can benefit from TMZ and ABT­737 combination treatment.

Arsenic trioxide disrupts glioma stem cells via promoting PML degradation to inhibit tumor growth.

Glioblastoma multiforme (GBM) is the most lethal brain tumor. Tumor relapse in GBM is inevitable despite maximal therapeutic interventions. Glioma stem cells (GSCs) have been found to be critical players in therapeutic resistance and tumor recurrence. Therapeutic drugs targeting GSCs may significantly improve GBM treatment. In this study, we demonstrated that arsenic trioxide (As2O3) effectively disrupted GSCs and inhibited tumor growth in the GSC-derived orthotopic xenografts by targeting the promyelocytic leukaemia (PML). As2O3 treatment induced rapid degradation of PML protein along with severe apoptosis in GSCs. Disruption of the endogenous PML recapitulated the inhibitory effects of As2O3 treatment on GSCs both in vitro and in orthotopic tumors. Importantly, As2O3 treatment dramatically reduced GSC population in the intracranial GBM xenografts and increased the survival of mice bearing the tumors. In addition, As2O3 treatment preferentially inhibited cell growth of GSCs but not matched non-stem tumor cells (NSTCs). Furthermore, As2O3 treatment or PML disruption potently diminished c-Myc protein levels through increased poly-ubiquitination and proteasome degradation of c-Myc. Our study indicated a potential implication of As2O3 in GBM treatment and highlighted the important role of PML/c-Myc axis in the maintenance of GSCs.

CDC20 maintains tumor initiating cells.

Glioblastoma is the most prevalent and lethal primary intrinsic brain tumor. Glioblastoma displays hierarchical arrangement with a population of self-renewing and tumorigenic glioma tumor initiating cells (TICs), or cancer stem cells. While non-neoplastic neural stem cells are generally quiescent, glioblastoma TICs are often proliferative with mitotic control offering a potential point of fragility. Here, we interrogate the role of cell-division cycle protein 20 (CDC20), an essential activator of anaphase-promoting complex (APC) E3 ubiquitination ligase, in the maintenance of TICs. By chromatin analysis and immunoblotting, CDC20 was preferentially expressed in TICs relative to matched non-TICs. Targeting CDC20 expression by RNA interference attenuated TIC proliferation, self-renewal and in vivo tumor growth. CDC20 disruption mediated its effects through induction of apoptosis and inhibition of cell cycle progression. CDC20 maintains TICs through degradation of p21CIP1/WAF1, a critical negative regulator of TICs. Inhibiting CDC20 stabilized p21CIP1/WAF1, resulting in repression of several genes critical to tumor growth and survival, including CDC25C, c-Myc and Survivin. Transcriptional control of CDC20 is mediated by FOXM1, a central transcription factor in TICs. These results suggest CDC20 is a critical regulator of TIC proliferation and survival, linking two key TIC nodes-FOXM1 and p21CIP1/WAF1-elucidating a potential point for therapeutic intervention.

Binding of HIV-1 gp120 to DC-SIGN promotes ASK-1-dependent activation-induced apoptosis of human dendritic cells.

During disease progression to AIDS, HIV-1 infected individuals become increasingly immunosuppressed and susceptible to opportunistic infections. It has also been demonstrated that multiple subsets of dendritic cells (DC), including DC-SIGN⁺ cells, become significantly depleted in the blood and lymphoid tissues of AIDS patients, which may contribute to the failure in initiating effective host immune responses. The mechanism for DC depletion, however, is unclear. It is also known that vast quantities of viral envelope protein gp120 are shed from maturing HIV-1 virions and form circulating immune complexes in the serum of HIV-1-infected individuals, but the pathological role of gp120 in HIV-1 pathogenesis remains elusive. Here we describe a previously unrecognized mechanism of DC death in chronic HIV-1 infection, in which ligation of DC-SIGN by gp120 sensitizes DC to undergo accelerated apoptosis in response to a variety of activation stimuli. The cultured monocyte-derived DC and also freshly-isolated DC-SIGN⁺ blood DC that were exposed to either cross-linked recombinant gp120 or immune-complex gp120 in HIV⁺ serum underwent considerable apoptosis after CD40 ligation or exposure to bacterial lipopolysaccharide (LPS) or pro-inflammatory cytokines such as TNFα and IL-1ß. Furthermore, circulating DC-SIGN⁺ DC that were isolated directly from HIV-1⁺ individuals had actually been pre-sensitized by serum gp120 for activation-induced exorbitant apoptosis. In all cases the DC apoptosis was substantially inhibited by DC-SIGN blockade. Finally, we showed that accelerated DC apoptosis was a direct consequence of excessive activation of the pro-apoptotic molecule ASK-1 and transfection of siRNA against ASK-1 significantly prevented the activation-induced excessive DC death. Our study discloses a previously unknown mechanism of immune modulation by envelope protein gp120, provides new insights into HIV immunopathogenesis, and suggests potential therapeutic approaches to prevent DC depletion in chronic HIV infection.

Anterior discectomies and interbody cage fusion without plate fixation for 5-level cervical degenerative disc disease: a 5-year follow-up.

Anterior discectomy and interbody fusion have been proven to be a safe and effective procedure for the treatment of cervical degenerative disc disease. Clinical results for 1- to 4-level interbody cage fusion without plate fixation are encouraging. Five-level cervical interbody cage fusion without plate fixation has not yet been previously reported. We report a 63-year-old female patient suffering from severe pain of the bilateral shoulders and left upper extremity with numbness and weakness of legs. Magnetic resonance imaging showed cervical degenerative disc herniation with cord compression between the levels of C2 and C7. Anterior cervical discectomy and interbody cage fusion without plate fixation were performed. Pain and neurological function improved dramatically after surgery. Asymptomatic subsidence of the cage occurred at the level of C6-7 two months postoperatively with no further progression of subsidence 5 years postoperatively. Good stability of the cages was seen on flexion and extension radiographs 5 years postoperatively. We report the first case with good long-term results of 5-level interbody cage fusion without plate fixation for anterior cervical degenerative disc surgery.

Functional outcome analysis: instrumented posterior lumbar interbody fusion for degenerative lumbar scoliosis.

PURPOSE: Although instrumented posterior lumbar interbody fusion (PLIF) has been becoming a popular and effective method for treating degenerative lumbar scoliosis, the clinical outcome is rarely reported. We retrospectively evaluated the clinical and radiographic outcomes in patients with degenerative lumbar scoliosis after instrumented PLIF. MATERIALS AND METHODS: A total of 58 patient's clinical characteristics had been reviewed retrospectively including clinical presentations, preoperative medical comorbidities, intraoperative status, and postoperative status. Oswestry disability index (ODI), visual analog scale (VAS), and patient satisfaction were evaluated before surgery and last follow-up period. The relationship between the difference of radiographic parameter and functional outcome was evaluated. RESULTS: Functional outcomes including ODI scores and VAS were significantly improved at the last visit. The ODI was 28.1 ± 8.0 before surgery and 12.2 ± 8.8 at the last visit. VAS was 7.4 ± 2.0 before surgery and 2.4 ± 2.0 at the last visit. Patient satisfaction was 72% at the last visit. ODI was significantly related to postoperative radiographic parameters including Cobb's angle (p < 0.001), L4 inclination (p = 0.011), coronal balance (p = 0.007), lateral vertebral translation (p < 0.001), Nash-Moe grade (p = 0.033), Nash-Moe degree (p = 0.025), and sagittal balance (p = 0.041) Using multiple regression analysis, ODI was significantly related to female gender, number of levels fixed, coronal balance, lateral vertebral translation, and Nash-Moe degree. The was no significant correlation between postoperative radiographic parameters and pain (VAS). Only lateral vertebral translation demonstrated a significant correlation in multiple regression analysis. CONCLUSIONS: Based on the VAS and ODI instrument, our studies demonstrated that instrumented PLIF for adult degenerative lumbar scoliosis can achieve a high rate of patient satisfaction and improvement in radiographic and clinical outcomes at a minimum of 2 years of follow-up.

Low-grade astrocytoma associated with abscess formation: case report and literature review.

A rare case of low-grade astrocytoma associated with abscess formation occurred in a 52-year-old man presenting with Broca's aphasia. He underwent craniotomy and tumor removal under the impression of brain tumor with necrotic cystic change. Abscess accumulation within the intra-axial tumor was found intraoperatively. Literature related to brain abscess with brain tumor is reviewed, with an emphasis on abscesses with astrocytoma. We discuss the common brain tumors that are associated with abscess, pathogens that coexist with brain tumor, and the pathogeneses of coexisting brain abscess and tumor. It is very important to know how to differentiate between and diagnose a brain abscess and tumor, or brain abscess with tumor, preoperatively from clinical presentation and through the use of computed tomography, conventional magnetic resonance imaging, diffusion-weighted imaging or magnetic resonance spectroscopy.

Thrombocytosis: a paraneoplastic syndrome in patients with hepatocellular carcinoma.

AIM: Hepatocellular carcinoma (HCC) patients manifest a variety of paraneoplastic syndromes. Thrombocytosis was reported in children with hepatoblastoma. The aims of this study were to evaluate the prevalence and clinical significance of thrombocytosis in HCC patients and its relationships with serum thrombopoietin (TPO). METHODS: We retrospectively reviewed clinical, biochemical and image data of 1,154 HCC patients. In addition, we measured platelet count and serum TPO in HCC patients with and without thrombocytosis, in patients with cirrhosis, chronic hepatitis and healthy subjects in a cross-sectional study. RESULTS: Thirty-one (2.7%) of 1,154 HCC patients had thrombocytosis (platelet count > or = 400 K/mm3). HCC patients with thrombocytosis were significantly younger, had a higher serum alpha-fetoprotein, higher rate of main portal vein thrombosis, larger tumor volume, shorter survival, and were less likely to receive therapy than HCC patients without thrombocytosis. Multivariate logistic regression analyses showed that tumor volumes > or = 30% and serum alpha-fetoprotein > or = 140,000 ng/mL could significantly predict thrombocytosis. HCC patients with thrombocytosis had a significantly higher mean serum TPO than those without, as well as patients with cirrhosis, chronic hepatitis and healthy subjects. Platelet count and serum TPO dropped significantly after tumor resection in HCC patients with thrombocytosis and re-elevated after tumor recurred. Furthermore, the expression of TPO mRNA was found to be more in tumor tissues than in non-tumor tissues of liver in an HCC patient with thrombocytosis. CONCLUSION: Thrombocytosis is a paraneoplastic syndrome of HCC patients due to the overproduction of TPO by HCC. It is frequently associated with a large tumor volume and high serum alpha-fetoprotein.