http://hdl.handle.net/10027/7797 Wed, 19 Jun 2013 21:26:29 GMT 2013-06-19T21:26:29Z http://hdl.handle.net/10027/8607 Cord Blood Stem Cells Inhibit Epidermal Growth Factor Receptor Translocation to Mitochondria in Glioblastoma Dasari, Venkata Ramesh; Velpula, Kiran Kumar; Alapati, Kiranmai; Gujrati, Meena; Tsung, Andrew J. 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. © 2012 Dasari et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. doi:10.1371/journal.pone.0031884 Wed, 01 Feb 2012 06:00:00 GMT http://hdl.handle.net/10027/8607 2012-02-01T06:00:00Z http://hdl.handle.net/10027/8603 Ophthalmologic features of the common spinocerebellar ataxias Pula, John H; Gomez, Christopher M.; Kattah, Jorge C. Purpose of review: The spinocerebellar ataxias are a phenotypically and genetically diverse group of autosomal dominant disorders that cause pathological degeneration in the cerebellum, brainstem, and retina, resulting in a wide variety of ophthalmologic signs and symptoms. Recent findings: The genetic discrimination of the spinocerebellar ataxias has advanced dramatically over the past decade. The most common genetic (mutational) mechanism for the SCAs is an abnormal expansion to a stretch of glutamine amino acid residues (polyglutamine tract) encoded by any of several SCA-causing genes. Knowledge regarding the pathophysiology of polyglutamine-expansion-induced protein dysfunction is an area of intense investigation. Summary: The ophthalmologist may be the first to encounter a patient with spinocerebellar ataxia, and a review of the most common genetic subtypes of this disorder is helpful in diagnosis and management. Post print version of article may differ from published version. The definitive version of Pula, J. H., Gomez, C. M., & Kattah, J. C. 2010. Ophthalmologic features of the common spinocerebellar ataxias. Curr.Opin.Ophthalmol., 21(6): 447-453. is available through Lippincott, Williams & Wilkins at DOI: 10.1097/ICU.0b013e32833eaf71 Mon, 01 Nov 2010 05:00:00 GMT http://hdl.handle.net/10027/8603 2010-11-01T05:00:00Z http://hdl.handle.net/10027/8469 Ophthalmologic features of the common spinocerebellar ataxias Pula, John H; Gomez, Christopher M; Kattah, Jorge C Purpose of review: The spinocerebellar ataxias (SCAs) are a phenotypically and genetically diverse group of autosomal dominant disorders that cause pathological degeneration in the cerebellum, brainstem, and retina, resulting in a wide variety of ophthalmologic signs and symptoms. Recent findings: The genetic discrimination of the SCAs has advanced dramatically over the past decade. The most common genetic (mutational) mechanism for the SCAs is an abnormal expansion to a stretch of glutamine amino acid residues (polyglutamine tract) encoded by any of several SCA-causing genes. Knowledge regarding the pathophysiology of polyglutamine-expansion-induced protein dysfunction is an area of intense investigation. Summary: The ophthalmologist may be the first to encounter a patient with SCA, and a review of the most common genetic subtypes of this disorder is helpful in diagnosis and management. Post print version of article may differ from published version. The definitive version is available through Lippincott, Williams & Wilkins at DOI: 10.1097/ICU.0b013e32833eaf71 Mon, 01 Nov 2010 05:00:00 GMT http://hdl.handle.net/10027/8469 2010-11-01T05:00:00Z http://hdl.handle.net/10027/8366 Upregulation of PTEN in Glioma Cells by Cord Blood Mesenchymal Stem Cells Inhibits Migration via Downregulation of the PI3K/Akt Pathway Dasari, Venkata Ramesh; Kaur, Kiranpreet; Velpula, Kiran Kumar; Gujrati, Meena; Fassett, Daniel; Klopfenstein, Jeffrey D.; Dinh, Dzung H.; Rao, Jasti S. Background: PTEN (phosphatase and tensin homologue deleted on chromosome ten) is a tumor suppressor gene implicated in a wide variety of human cancers, including glioblastoma. PTEN is a major negative regulator of the PI3K/Akt signaling pathway. Most human gliomas show high levels of activated Akt, whereas less than half of these tumors carry PTEN mutations or homozygous deletions. The unique ability of mesenchymal stem cells to track down tumor cells makes them as potential therapeutic agents. Based on this capability, new therapeutic approaches have been developed using mesenchymal stem cells to cure glioblastoma. However, molecular mechanisms of interactions between glioma cells and stem cells are still unknown. Methodology/Principal Findings: In order to study the mechanisms by which migration of glioma cells can be inhibited by the upregulation of the PTEN gene, we studied two glioma cell lines (SNB19 and U251) and two glioma xenograft cell lines (4910 and 5310) alone and in co-culture with human umbilical cord blood-derived mesenchymal stem cells (hUCBSC). Cocultures of glioma cells showed increased expression of PTEN as evaluated by immunofluorescence and immunoblotting assays. Upregulation of PTEN gene is correlated with the downregulation of many genes including Akt, JUN, MAPK14, PDK2, PI3K, PTK2, RAS and RAF1 as revealed by cDNA microarray analysis. These results have been confirmed by reversetranscription based PCR analysis of PTEN and Akt genes. Upregulation of PTEN resulted in the inhibition of migration capability of glioma cells under in vitro conditions. Also, wound healing capability of glioma cells was significantly inhibited in co-culture with hUCBSC. Under in vivo conditions, intracranial tumor growth was inhibited by hUCBSC in nude mice. Further, hUCBSC upregulated PTEN and decreased the levels of XIAP and Akt, which are responsible for the inhibition of tumor growth in the mouse brain. Conclusions/Significance: Our studies indicated that upregulation of PTEN by hUCBSC in glioma cells and in the nude mice tumors downregulated Akt and PI3K signaling pathway molecules. This resulted in the inhibition of migration as well as wound healing property of the glioma cells. Taken together, our results suggest hUCBSC as a therapeutic agent in treating malignant gliomas. © 2010 Dasari et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The original version is available through the Public Library of Science at DOI: 10.1371/journal.pone.0010350. Mon, 26 Apr 2010 05:00:00 GMT http://hdl.handle.net/10027/8366 2010-04-26T05:00:00Z