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22 results on '"Witta, Samir E."'

4. Improvement of the neurological deficits in 6-hydroxydopamine-lesioned rats after transplantation with allogeneic simian virus 40 large tumor antigen gene-induced immortalized dopamine cells

Author

Clarkson, Edward D., Rosa, Francisco G. la, Edwards-Prasad, Judith, Weiland, David A., Witta, Samir E., Freed, Curt R., and Prasad, Kedar N.

Subjects
Dopamine -- Health aspects, Parkinson's disease -- Care and treatment, Neurons -- Physiological aspects, Science and technology
Abstract

The replacement of dopamine (DA) by DA neuron transplants in the treatment of advanced Parkinson disease (PD) is a rational approach. Because of limitations associated with fetal tissue transplants, a clone (1R[B.sub.3][AN.sub.27]) of simian virus 40 large tumor antigen (LTa) gene-induced immortalized DA neurons were used in this study. These allogeneic immortalized dopamine neurons, when grafted into striata of normal rats, did not divide, did not form tumors, did not produce LTa, did not extend neurites to host neurons, and were not rejected, for as long as 13 months after transplantation. Grafted cells when recultured in vitro resumed cell proliferation and LTa production, suggesting the presence of a LTa gene-inhibiting factor in the brain. The grafting of undifferentiated and differentiated 1R[B.sub.3][AN.sub.27] cells or differentiated murine neuroblastoma ([NBP.sub.2]) cells into striata of 6-hydroxydopamine-lesioned rats (an animal model of PD) caused a time-dependent improvement in neurological deficits (reduction in the methamphetamine-induced turning rate). At 3 months after transplantation, 100% of the animals receiving differentiated 1R[B.sub.3][AN.sub.27] cells, 63% of the animals receiving undifferentiated 1R[B.sub.3][AN.sub.27] cells, 56% of the animals receiving differentiated [NBP.sub.2] cells, and 0% of the sham-transplanted animals showed improvements in neurological deficits. At 6 months after transplantation, there was a progressive increase in spontaneous recovery in sham-transplanted animals. These results suggest that immortalized DA neurons should be further studied for their potential use in transplant therapy in advanced PD patients.

Published
1998

9. A phase Ib study of CUDC-101, a multitargeted inhibitor of EGFR, HER2, and HDAC, in patients with advanced head and neck, gastric, breast, liver, and non-small cell lung cancer.

Author

Fu, Siqing, primary, Nemunaitis, John J., additional, Bessudo, Alberto, additional, Bauman, Julie E., additional, Hamid, Omid, additional, Witta, Samir E., additional, Dy, Grace K., additional, Lai, Cheng, additional, Laliberte, Robert, additional, and Voi, Maurizio, additional

Published
2012
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10. Insulin-like Growth Factor Receptor 1 (IGF1R) Gene Copy Number Is Associated With Survival in Operable Non–Small-Cell Lung Cancer: A Comparison Between IGF1R Fluorescent In Situ Hybridization, Protein Expression, and mRNA Expression

Author

Dziadziuszko, Rafal, primary, Merrick, Daniel T., additional, Witta, Samir E., additional, Mendoza, Adelita D., additional, Szostakiewicz, Barbara, additional, Szymanowska, Amelia, additional, Rzyman, Witold, additional, Dziadziuszko, Katarzyna, additional, Jassem, Jacek, additional, Bunn, Paul A., additional, Varella-Garcia, Marileila, additional, and Hirsch, Fred R., additional

Published
2010
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15. Epidermal Growth Factor Receptor Messenger RNA Expression, Gene Dosage, and Gefitinib Sensitivity in Non–Small Cell Lung Cancer

Author

Dziadziuszko, Rafal, primary, Witta, Samir E., additional, Cappuzzo, Federico, additional, Park, Seongjin, additional, Tanaka, Koji, additional, Danenberg, Peter V., additional, Barón, Anna E., additional, Crino, Lucio, additional, Franklin, Wilbur A., additional, Bunn, Paul A., additional, Varella-Garcia, Marileila, additional, Danenberg, Kathleen D., additional, and Hirsch, Fred R., additional

Published
2006
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16. Restoring E-Cadherin Expression Increases Sensitivity to Epidermal Growth Factor Receptor Inhibitors in Lung Cancer Cell Lines

Author

Witta, Samir E., primary, Gemmill, Robert M., additional, Hirsch, Fred R., additional, Coldren, Christopher D., additional, Hedman, Karla, additional, Ravdel, Larisa, additional, Helfrich, Barbara, additional, Dziadziuszko, Rafal, additional, Chan, Daniel C., additional, Sugita, Michio, additional, Chan, Zeng, additional, Baron, Anna, additional, Franklin, Wilbur, additional, Drabkin, Harry A., additional, Girard, Luc, additional, Gazdar, Adi F., additional, Minna, John D., additional, and Bunn, Paul A., additional

Published
2006
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18. A Phase I and Pharmacokinetic Study of Exisulind and Docetaxel in Patients with Advanced Solid Tumors

Author

Witta, Samir E., primary, Gustafson, Daniel L., additional, Pierson, A. Scott, additional, Menter, Alexander, additional, Holden, Scott N., additional, Basche, Michele, additional, Persky, Martha, additional, O’Bryant, Cindy L., additional, Zeng, Chan, additional, Baron, Anna, additional, Long, Michael E., additional, Gibbs, Amy, additional, Kelly, Karen, additional, Bunn, Paul A., additional, Chan, Daniel C., additional, Pallansch, Patrick, additional, and Eckhardt, S. Gail, additional

Published
2004
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19. Somatic cell cloned transgenic bovine neurons for transplantation in parkinsonian rats

Author

Zawada, W. Michael, primary, Cibelli, Jose B., additional, Choi, Paul K., additional, Clarkson, Edward D., additional, Golueke, Paul J., additional, Witta, Samir E., additional, Bell, K. Pat, additional, Kane, Jeff, additional, de Leon, F. Abel Ponce, additional, Jerry, D. Joseph, additional, Robl, James M., additional, Freed, Curt R., additional, and Stice, Steven L., additional

Published
1998
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20. XlPOU 2, a noggin-inducible gene, has direct neuralizing activity

Author

Witta, Samir E., Agarwal, Veena R., and Sato, Sheryl M.

Abstract

XlPOU 2, a member of the class III POU domain family, is expressed initially in Spemann’s organizer, and later, in discrete regions of the developing nervous system in Xenopus laevis. XlPOU 2 may act downstream from initial neural induction events, since it is activated by the neural inducer, noggin. To determine if XlPOU 2 participates in the early events of neurogenesis, synthetic mRNA was microinjected into specific blastomeres of the 32-cell stage embryo. Misexpression of XlPOU 2 in the epidermis causes a direct switch in cell fate from an epidermal to a neuronal phenotype. In the absence of mesoderm induction, XlPOU 2 has the ability to induce a neuronal phenotype in uncommitted ectoderm. These data demonstrate the potential of XlPOU 2 to act as a master regulator of neurogenesis.

Published
1995
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21. XlPOU 2 is a potential regulator of Spemann’s Organizer

Author

Witta, Samir E. and Sato, Sheryl M.

Abstract

XlPOU 2, a member of the class III POU-domain family, is expressed initially at mid-blastula transition (MBT) and during gastrulation in the entire marginal zone mesoderm, including Spemann’s Organizer (the Organizer). To identify potential targets of XlPOU 2, the interaction of XlPOU 2 with other genes co-expressed in the Organizer was examined by microinjecting XlPOU 2’s mRNA into the lineage of cells that contributes to the Organizer, head mes-enchyme and prechordal plate. XlPOU 2 suppresses the expression of a number of dorsal mesoderm-specific genes, including gsc, Xlim-1, Xotx2, noggin and chordin, but not Xnot. As a consequence of the suppression of dorsal mesoderm gene expression, bone morphogenetic factor-4 (Bmp-4), a potent inducer of ventral mesoderm, is activated in the Organizer. Gsc is a potential target of XlPOU 2. XlPOU 2 is capable of binding a class III POU protein binding site (CATTAAT) that is located within the gsc promoter, in the activin-inducible (distal) element. Furthermore, XlPOU 2 suppresses the activation of the gsc promoter by activin signaling. At the neurula and tailbud stages, dorsoanterior structures are affected: embryos displayed micropthalmia and the loss of the first branchial arch, as detected by the expression of pax-6, Xotx2 and en-2. By examining events downstream from the Wnt and chordin pathways, we determined that XlPOU 2, when overexpressed, acts specifically in the Organizer, downstream from GSK-3β of the Wnt pathway and upstream from chordin. The interference in dorsalizing events caused by XlPOU 2 was rescued by chordin. Thus, in addition to its direct neuralizing ability, in a different context, XlPOU 2 has the potential to antagonize dorsalizing events in the Organizer.

Published
1997
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