[Retracted] α3ß1 integrin promotes radiation-induced migration of meningioma cells.

Following the publication of the above paper, we were contacted by the University of Illinois at Chicago, to request the retraction of the above article. Following a formal institutional investigation, the investigation panel concluded that the images in question had falsifying elements. Regarding the above study, the specific allegations that were investigated were that of falsifying elements of Fig. 2A, right panel, row 3, columns 2, 3 and 4 and Fig. 4D, left panel, row 5, columns 1, 2 and 3; Fig. 4A, row 1, columns 2, 3 and 4, and Fig. 4C, row 1, columns 5, 6 and 7; and Fig. 6C, row 1, column 3, and row 2, column 1.
Following a review of this paper conducted independently by the Editor of International Journal of Oncology, the Editor concurred with the conclusions of the investigation panel, and therefore the above paper has been retracted from the publication. We also tried to contact the authors, but did not receive a reply. The Editor apologizes to the readership for the inconvenience caused. [the original article was published in International Journal of Oncology 40: 1615-1624, 2012; DOI: 10.3892/ijo.2011.987].

Transient Vestibulopathy in Wallenberg's Syndrome: Pathologic Analysis.

OBJECTIVE: To report an unusual lateral medullary stroke (LMS) associated with transient unidirectional horizontal, nystagmus, and decreased horizontal vestibulo-ocular reflex (h-VOR) gain that mimicked a peripheral vestibulopathy. MRI suggested involvement of caudal medial vestibular nucleus (MVN); however, the rapid resolution of the nystagmus and improved h-VOR gain favored transient ischemia without infarction. Decreased h-VOR gain is expected with peripheral vestibular lesions within the labyrinth or superior vestibular nerve; less frequently lateral pontine strokes involving the vestibular root entry, the vestibular fascicle, or neurons within the MVN may be responsible. The h-VOR is typically normal in LMS. METHODS: Clinicopathologic examination of a 61-year-old man with an acute vestibular syndrome (AVS) and left LMS who died 3 weeks after the stroke. Postmortem brainstem analysis was performed. RESULTS: The stroke involved the lateral medulla and pontomedullary junction, near the MVN, sparing the cerebellum and pons. To explain transient vestibular findings there are two possible hypotheses; the first would be that the MVN survived the ischemic process and would be histologically intact, and the second that vestibular afferents in the horizontal semicircular canal were ischemic and recovered after the ischemic process. Neuropathological examination showed a left LMS whose extent matched that seen by imaging. Non-ocular motor signs correlated well with structures affected by the infarction. Neurons and glia within nearby MVN were spared, as predicted by the rapid normalization of the ocular motor signs. Although unlikely, the possibility of transient intralabyrinthine arteriolar ischemia cannot be excluded. Additionally, truncal lateropulsion was due to combined lateral vestibulospinal tract and lateral reticular nucleus infarction. CONCLUSION: LMS may rarely be associated with an AVS that either represents or mimics a peripheral vestibulopathy. To our knowledge, this is the first neuropathologic examination of the brainstem of an LMS associated with transient vestibular findings occurring in the context of an anterior/posterior (AICA/PICA) cerebellar arterial variant stroke.

Correction: Intermittent Hypoxia Effect on Osteoclastogenesis Stimulated by Neuroblastoma Cells.

[This corrects the article DOI: 10.1371/journal.pone.0105555.].

Isolated CNS Hodgkin's lymphoma: implications for tissue diagnosis.

CNS involvement in the setting of lymphoid neoplasia is a clinical situation that requires specific diagnosis due to the disparate treatment regimens recommended for neoplasms of specific lymphoid cell types. Cerebrospinal fluid (CSF) sampling may provide sufficient information to determine the presence of abnormal lymphoid cells but may not be able to further specify the malignant cellular population. In cases where abnormal clinical or radiographic features are present, accurate tissue diagnosis is essential. In this report, we define a rare case of primary CNS intramedullary Hodgkin's lymphoma without leptomeningeal dissemination diagnosed via resectional biopsy of a conus medullaris lesion. The patient received post-resection radiation therapy and subsequently demonstrated radiographic and clinical improvement. Lymphoid neoplasia within the CNS comprises a diverse group with varying response and survival rates. Treatment hinges upon accurate diagnosis as chemotherapy varies widely among Hodgkin's and non-Hodgkin's lymphoma. While CSF sampling may yield a positive result with sufficiency to diagnose an abnormal lymphoid cell population, tissue is necessary for further defining cellular pathology. In this report, we define a rare case of primary CNS intramedullary Hodgkin's lymphoma without leptomeningeal dissemination via resectional biopsy of a conus medullaris lesion. In cases where abnormal enhancement is found in eloquent CNS regions and lymphoid neoplasia is suspected, management often entails either stereotactic biopsy or CSF sampling. While CSF analysis may differentiate malignancy at a low rate, tissue diagnosis via paraffin block immunohistochemistry is necessary to further classify malignancy as primary or peripheral, Hodgkin's or non-Hodgkin's lymphoma, or other such as metastatic leptomeningeal dissemination and glioma. Within the subtypes of lymphoid neoplasms, treatment regimens vastly differ and thus accurate tissue diagnosis is paramount. We therefore present a rare case of primary CNS intramedullary Hodgkin's lymphoma without leptomeningeal disease in the setting of immunocompromise diagnosed via open resectional biopsy of the conus medullaris.

Intermittent hypoxia effect on osteoclastogenesis stimulated by neuroblastoma cells.

BACKGROUND: Neuroblastoma is the most common extracranial pediatric solid tumor. Intermittent hypoxia, which is characterized by cyclic periods of hypoxia and reoxygenation, has been shown to positively modulate tumor development and thereby induce tumor growth, angiogenic processes, and metastasis. Bone is one of the target organs of metastasis in advanced neuroblastoma Neuroblastoma cells produce osteoclast-activating factors that increase bone resorption by the osteoclasts. The present study focuses on how intermittent hypoxia preconditioned SH-SY5Y neuroblastoma cells modulate osteoclastogenesis in RAW 264.7 cells compared with neuroblastoma cells grown at normoxic conditions. METHODS: We inhibited HIF-1α and HIF-2α in neuroblastoma SH-SY5Y cells by siRNA/shRNA approaches. Protein expression of HIF-1α, HIF-2α and MAPKs were investigated by western blotting. Expression of osteoclastogenic factors were determined by real-time RT-PCR. The influence of intermittent hypoxia and HIF-1α siRNA on migration of neuroblastoma cells and in vitro differentiation of RAW 264.7 cells were assessed. Intratibial injection was performed with SH-SY5Y stable luciferase-expressing cells and in vivo bioluminescence imaging was used in the analysis of tumor growth in bone. RESULTS: Upregulation of mRNAs of osteoclastogenic factors VEGF and RANKL was observed in intermittent hypoxia-exposed neuroblastoma cells. Conditioned medium from the intermittent hypoxia-exposed neuroblastoma cells was found to enhance osteoclastogenesis, up-regulate the mRNAs of osteoclast marker genes including TRAP, CaSR and cathepsin K and induce the activation of ERK, JNK, and p38 in RAW 264.7 cells. Intermittent hypoxia-exposed neuroblastoma cells showed an increased migratory pattern compared with the parental cells. A significant increase of tumor volume was found in animals that received the intermittent hypoxia-exposed cells intratibially compared with parental cells. CONCLUSIONS: Intermittent hypoxic exposure enhanced capabilities of neuroblastoma cells in induction of osteoclast differentiation in RAW 264.7 cells. Increased migration and intratibial tumor growth was observed in intermittent hypoxia-exposed neuroblastoma cells compared with parental cells.

Late adult-onset of X-linked myopathy with excessive autophagy.

INTRODUCTION: X-linked myopathy with excessive autophagy (XMEA) is characterized by autophagic vacuoles with sarcolemmal features. Mutations in VMA21 result in insufficient lysosome acidification, causing progressive proximal weakness with onset before age 20 years and loss of ambulation by middle age. METHODS: We describe a patient with onset of slowly progressive proximal weakness of the lower limbs after age 50, who maintains ambulation with the assistance of a cane at age 71. RESULTS: Muscle biopsy at age 66 showed complex muscle fiber splitting, internalized capillaries, and vacuolar changes characteristic of autophagic vacuolar myopathy. Vacuoles stained positive for sarcolemmal proteins, LAMP2, and complement C5b-9. Ultrastructural evaluation further revealed basal lamina reduplication and extensive autophagosome extrusion. Sanger sequencing identified a known pathologic splice site mutation in VMA21 (c.164-7T>G). CONCLUSIONS: This case expands the clinical phenotype of XMEA and suggests VMA21 sequencing be considered in evaluating men with LAMP2-positive autophagic vacuolar myopathy.

The heidenhain variant of Creutzfeldt-Jakob disease--a case series.

BACKGROUND: To study the neuro-ophthalmologic characteristics of patients with the visual variant of Creuztfeldt-Jakob disease (CJD) predominantly affecting the occipital and parietal lobes, known as the Heidenhain variant (HvCJD). The initial symptoms and findings may overlap with other posterior cerebral degenerative disorders. We reviewed our experience with HvCJD including clinical course and results of neuroimaging, electroencephalography (EEG), and cerebrospinal fluid (CSF) studies. Neuropathological postmortem findings were reviewed when available to confirm the clinical impression. METHODS: Retrospective study of HvCJD patients examined in the past 15 years at a single tertiary referral university hospital. Rapid rate of visual and neurological deterioration and abnormal diffusion-weighted imaging (DWI) were characteristic for HvCJD. RESULTS: Three patients displayed abnormalities in DWI, EEG, and CSF and had rapid clinical progression, leading to a clinical diagnosis of HvCJD. None underwent diagnostic cerebral biopsy. In 2 patients, the diagnosis of sporadic CJD was confirmed by postmortem neuropathologic, immunohistochemical, and genetic studies. CONCLUSIONS: The gold standard for establishing the diagnosis of HvCJD is based on the characteristic histopathologic findings and molecular confirmation. Concern with potential iatrogenic CJD, related to surgical instrumentation or operating room prion contamination, has limited the availability of confirmatory brain biopsy. Our case series illustrates how the combination of clinical neuroimaging and EEG studies and 14:3:3 protein and other neuronal protein marker levels can lead to the diagnosis of HvCJD. Immunohistochemical analysis and genetic testing at a specialized prion research center will assist in identifying the sporadic variant and genetic forms of CJD.

Temporal regulation of apoptotic and anti-apoptotic molecules after middle cerebral artery occlusion followed by reperfusion.

A tremendous effort has been expended to elucidate the role of apoptotic molecules in ischemia. However, many agents that target apoptosis, despite their proven efficacy in animal models, have failed to translate that efficacy and specificity in clinical settings. Therefore, comprehensive knowledge of apoptotic mechanisms involving key apoptotic regulatory molecules and the temporal expression profiles of various apoptotic molecules after cerebral ischemia may provide insight for the development of better therapeutic strategies aimed at cerebral ischemia. The present study investigates the extent of apoptosis and the regulation of apoptotic molecules both at mRNA and protein levels at various time points after focal cerebral ischemia in a rat model of middle cerebral artery occlusion. In this study, we performed various techniques, such as TTC (2,3,5-triphenyltetrazolium chloride), H&E (hematoxylin and eosin), and TUNEL (terminal deoxy nucleotidyl transferase-mediated nick-end labeling) staining, along with polymerase chain reaction (PCR) microarray, antibody microarray, reverse transcription (RT)-PCR, immunofluorescence, and immunoblot analyses. Our research provided a large list of pro-apoptotic and anti-apoptotic molecules and their temporal expression profiles both at the mRNA and protein levels. This information could be very useful for designing future stroke therapies and aid in targeting the right molecules at critical time to obtain maximum therapeutic benefit.

MMP-2 suppression abrogates irradiation-induced microtubule formation in endothelial cells by inhibiting αvß3-mediated SDF-1/CXCR4 signaling.

The majority of glioblastoma multiforme (GBM) tumors recur after radiation (IR) treatment due to increased angiogenesis and IR-induced signaling events in endothelial cells (ECs) that are involved in tumor neovascularization; however, these signaling events have yet to be well characterized. In the present study, we observed that IR (8 Gy) significantly elevated MMP-2 expression and gelatinolytic activity in 4910 and 5310 human GBM xenograft cells. In addition, ECs treated with tumor-conditioned media (CM) obtained from IR-treated 4910 and 5310 cells showed increased microtubule formation. In view of this finding, we investigated the possible anti-angiogenic effects of MMP-2 downregulation using siRNA (pM.si) in IR-treated cells. We also determined the effect of CM obtained from mock, pSV (scrambled vector) and pMMP-2.si on endothelial cell growth and vessel formation. pM.si-CM-treated ECs showed inhibited IR-CM-induced SDF-1, CXCR4, phospho-PI3K and phospho-AKT and αvß3 expression levels. In vitro angiogenesis assays also showed that the pM.si+IR decreased IR-induced vessel formation in ECs. Immunofluorescence and immunoprecipitation experiments indicated the abrogation of αvß3-SDF-1 interaction in pM.si-CM-treated ECs when compared to mock or pSV treatments. External supplementation of either rhMMP-2 or rhSDF-1 counteracted and noticeably reversed pM.si-inhibited SDF-1, CXCR4, phospho-PI3K and phospho-AKT expression levels and angiogenesis, thereby confirming the role of MMP-2 in the regulation of αvß3-mediated SDF-1/CXCR4 signaling. In addition to the in vitro results, the in vivo mouse dorsal air sac model also showed reduced angiogenesis after injection of pM.si alone or in combination with IR-treated xenograft cells. In contrast, injection of mock or pSV-treated cells resulted in robust formation of characteristic neovascularization. Collectively, our data demonstrate the role of MMP-2 in the regulation of SDF-1/CXCR4 signaling-mediated angiogenesis in ECs and show the anti-angiogenic efficacy of combining MMP-2 downregulation and IR when treating patients with GBM in the future.

Cathepsin B and uPAR regulate self-renewal of glioma-initiating cells through GLI-regulated Sox2 and Bmi1 expression.

Cancer-initiating cells comprise a heterogeneous population of undifferentiated cells with the capacity for self-renewal and high proliferative potential. We investigated the role of uPAR and cathepsin B in the maintenance of stem cell nature in glioma-initiating cells (GICs). Simultaneous knockdown of uPAR and cathepsin B significantly reduced the expression of CD133, Nestin, Sox2 and Bmi1 at the protein level and GLI1 and GLI2 at the messenger RNA level. Also, knockdown of uPAR and cathepsin B resulted in a reduction in the number of GICs as well as sphere size. These changes are mediated by Sox2 and Bmi1, downstream of hedgehog signaling. Addition of cyclopamine reduced the expression of Sox2 and Bmi1 along with GLI1 and GLI2 expression, induced differentiation and reduced subsphere formation of GICs thereby indicating that hedgehog signaling acts upstream of Sox2 and Bmi1. Further confirmation was obtained from increased luciferase expression under the control of a GLI-bound Sox2 and Bmi1 luciferase promoter. Simultaneous knockdown of uPAR and cathepsin B also reduced the expression of Nestin Sox2 and Bmi1 in vivo. Thus, our study highlights the importance of uPAR and cathepsin B in the regulation of malignant stem cell self-renewal through hedgehog components, Bmi1 and Sox2.

Blockade of SOX4 mediated DNA repair by SPARC enhances radioresponse in medulloblastoma.

SPARC is a matricellular glycoprotein and a putative radioresistance-reversal-gene. We therefore explored the possibility of SPARC expression on medulloblastoma radiosensitivity in vitro and in vivo. The combined treatment of the SPARC and irradiation resulted in increased cell death when compared to cells treated with irradiation alone in vitro and in vivo. SPARC expression prior to irradiation suppressed checkpoints-1,-2 and p53 phosphorylation and DNA repair gene XRCC1. We also demonstrate that SPARC expression suppressed irradiation induced SOX-4 mediated DNA repair. These results provide evidence of the anti-tumor effect of combining SPARC with irradiation as a new therapeutic strategy for the treatment of medulloblastoma.

SPARC overexpression inhibits cell proliferation in neuroblastoma and is partly mediated by tumor suppressor protein PTEN and AKT.

Secreted protein acidic and rich in cysteine (SPARC) is also known as BM-40 or Osteonectin, a multi-functional protein modulating cell-cell and cell-matrix interactions. In cancer, SPARC is not only linked with a highly aggressive phenotype, but it also acts as a tumor suppressor. In the present study, we sought to characterize the function of SPARC and its role in sensitizing neuroblastoma cells to radio-therapy. SPARC overexpression in neuroblastoma cells inhibited cell proliferation in vitro. Additionally, SPARC overexpression significantly suppressed the activity of AKT and this suppression was accompanied by an increase in the tumor suppressor protein PTEN both in vitro and in vivo. Restoration of neuroblastoma cell radio-sensitivity was achieved by overexpression of SPARC in neuroblastoma cells in vitro and in vivo. To confirm the role of the AKT in proliferation inhibited by SPARC overexpression, we transfected neuroblastoma cells with a plasmid vector carrying myr-AKT. Myr-AKT overexpression reversed SPARC-mediated PTEN and increased proliferation of neuroblastoma cells in vitro. PTEN overexpression in parallel with SPARC siRNA resulted in decreased AKT phosphorylation and proliferation in vitro. Taken together, these results establish SPARC as an effector of AKT-PTEN-mediated inhibition of proliferation in neuroblastoma in vitro and in vivo.

Cord blood stem cells inhibit epidermal growth factor receptor translocation to mitochondria in glioblastoma.

BACKGROUND: Overexpression of EGFR is one of the most frequently diagnosed genetic aberrations of glioblastoma multiforme (GBM). EGFR signaling is involved in diverse cellular functions and is dependent on the type of preferred receptor complexes. EGFR translocation to mitochondria has been reported recently in different cancer types. However, mechanistic aspects of EGFR translocation to mitochondria in GBM have not been evaluated to date. METHODOLOGY/PRINCIPLE FINDINGS: In the present study, we analyzed the expression of EGFR in GBM-patient derived specimens using immunohistochemistry, reverse-transcription based PCR and Western blotting techniques. In clinical samples, EGFR co-localizes with FAK in mitochondria. We evaluated this previous observation in standard glioma cell lines and in vivo mice xenografts. We further analyzed the effect of human umbilical cord blood stem cells (hUCBSC) on the inhibition of EGFR expression and EGFR signaling in glioma cells and xenografts. Treatment with hUCBSC inhibited the expression of EGFR and its co-localization with FAK in glioma cells. Also, hUCBSC inhibited the co-localization of activated forms of EGFR, FAK and c-Src in mitochondria of glioma cells and xenografts. In addition, hUCBSC also inhibited EGFR signaling proteins in glioma cells both in vitro and in vivo. CONCLUSIONS/SIGNIFICANCE: We have shown that hUCBSC treatments inhibit phosphorylation of EGFR, FAK and c-Src forms. Our findings associate EGFR expression and its localization to mitochondria with specific biological functions in GBM cells and provide relevant preclinical information that can be used for the development of effective hUCBSC-based therapies.

RETRACTED: MMP-9 induces CD44 cleavage and CD44 mediated cell migration in glioblastoma xenograft cells.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor in Chief. On behalf the University of Illinois at Chicago, the Associate Vice Chancellor and Research Integrity Officer requested retraction of the article because of the elements listed here that were deemed false: Figure 5B, bottom row, Columns 1, 2, 4 and 5, top panel; Figure 5B, Row 1, Columns 1 and 2, bottom panel; Figure 5B, Row 2, Columns 3 and 4 bottom panel. Based on these circumstances the Editor in Chief has therefore decided to retract the paper. The corresponding author has been non-responsive to approaches from the Publisher.

Integrin α9ß1-mediated cell migration in glioblastoma via SSAT and Kir4.2 potassium channel pathway.

The α9ß1 integrin accelerates cell migration through binding of the α9 cytoplasmic domain to SSAT, which catalyzes the catabolism of higher order polyamines, spermidine and spermine, to the lower order polyamine, putrescine. SSAT levels were downregulated at both the mRNA and protein levels by shRNA-mediated simultaneous knockdown of MMP-9 and uPAR/cathepsin B. In addition, we noted a prominent reduction in the expression of SSAT with MMP-9 and uPAR/cathepsin B knockdown in the tumor regions of 5310 injected nude mice brains. Further, SSAT knockdown in glioma xenograft cells significantly reduced their migration potential. Interestingly, MMP-9, uPAR and cathepsin B overexpression in these xenograft cells significantly elevated SSAT mRNA and protein levels. The migratory potential of MMP-9/uPAR/cathepsin B-overexpressed 4910 and 5310 cells was not affected by either glybenclamide (Kir 6.x inhibitor) or tertiapin-Q (Kir 1.1 and 3.x inhibitor) but instead was significantly inhibited by either barium or Kir4.2 siRNA treatments. Co-localization of α9 integrin with Kir4.2 was observed in both 4910 and 5310 xenograft cells. However, MMP-9 and uPAR/cathepsin B knockdown in these cells prominently reduced the co-localization of α9 with Kir4.2. Taken together, our results clearly demonstrate that α9ß1 integrin-mediated cell migration utilizes SSAT and the Kir4.2 potassium channel pathway, and inhibition of the migratory potential of these glioma xenograft cells by simultaneous knockdown of MMP-9 and uPAR/cathepsin B could be attributed to the reduced SSAT levels and co-localization of α9 integrin with Kir4.2 inward rectifier potassium channels.

SPARC expression induces cell cycle arrest via STAT3 signaling pathway in medulloblastoma cells.

Dynamic cell interaction with ECM components has profound influence in cancer progression. SPARC is a component of the ECM, impairs the proliferation of different cell types and modulates tumor cell aggressive features. We previously reported that SPARC expression significantly impairs medulloblastoma tumor growth in vivo. In this study, we demonstrate that expression of SPARC inhibits medulloblastoma cell proliferation. MTT assay indicated a dose-dependent reduction in tumor cell proliferation in adenoviral mediated expression of SPARC full length cDNA (Ad-DsRed-SP) in D425 and UW228 cells. Flow cytometric analysis showed that Ad-DsRed-SP-infected cells accumulate in the G2/M phase of cell cycle. Further, immunoblot and immunoprecipitation analyses revealed that SPARC induced G2/M cell cycle arrest was mediated through inhibition of the Cyclin-B-regulated signaling pathway involving p21 and Cdc2 expression. Additionally, expression of SPARC decreased STAT3 phosphorylation at Tyr-705; constitutively active STAT3 expression reversed SPARC induced G2/M arrest. Ad-DsRed-SP significantly inhibited the pre-established orthotopic tumor growth and tumor volume in nude-mice. Immunohistochemical analysis of tumor sections from mice treated with Ad-DsRed-SP showed decreased immunoreactivity for pSTAT3 and increased immunoreactivity for p21 compared to tumor section from mice treated with mock and Ad-DsRed. Taken together our studies further reveal that STAT3 plays a key role in SPARC induced G2/M arrest in medulloblastoma cells. These new findings provide a molecular basis for the mechanistic understanding of the effects of SPARC on medulloblastoma tumor cell proliferation.