Professor of Neurosurgery, Radiation Oncology, and Oncological Sciences
Neurobiology of Disease
Representative photo of luciferase-expressing intracranial tumors after injection of firefly D-Luciferin. Mouse #3 is the untreated control showing highest radiance compared to the mice #1 and #2 treated with an siRNA directed against HIF-1 demonstrating little or no expression of luciferase.
Neurosurgical Oncology. Hypoxia and angiogenesis in brain tumors, calcium channel antagonist mediated growth inhibition of brain tumors. Brain tumor biomarker discovery. Animal models of brain tumors and imaging pseudo progression
The laboratory research of Dr. Jensen involves determining how brain tumors develop new blood vessels and respond to hypoxic conditions. Most of the current research involves the role of Hypoxia Inducible Factor-1 in brain tumor angiogenesis and growth. Currently, inhibition of angiogenesis and growth after is being studied using small interering RNA (siRNA) technology in malignant glioma cells grown in vitro and in vivo. The aim of this project is to eventually target hypoxic regions within these tumors to stop angiogenesis and growth of human brain tumors.
A second interest is a continuation of a prior project using calcium channel antagonists for treatment of patients with brain tumors. These agents have been proposed to potentiate the effects of chemotherapeutic agents. Currently this is being tested in a mouse model. It is expected that this will eventually lead to use in clinical trials for patients with brain tumors refractory to other treatments.
Wang, X.L., Rongzuo, X., Wu, X., Gillespie, D., Jensen, R.L., and Lu, Z.R. (2009) Targeted systemic delivery of therapeutic siRNA with a multifunctional carrier controls tumor proliferation in mice. Mol Pharm, 6(3):738-746, epub March 18th, 2009, PMID 19296675.
Jensen, R.L. (2009) Brain tumor hypoxia: tumorigenesis, angiogenesis, imaging, pseudoprogression, and as a therapeutic target. J Neuro Oncology, 92:317-335.
Gillespie, D.L., Flynn, J.R., Ragel, B.T., Arce-Lareta, M., Kelly, D.A., Tripp, S.R., and Jensen, R.L. (2009) Silencing of HIF-alpha by RNA interference in human glioma cells in vitro and in vivo. Methods Mol Biol, 487:283-301.
Jensen, R.L., Shrieve, A.F., Samlowski, W., and Shrieve, D. (2008) Outcomes of patients with brain metastases from melanoma and renal cell carcinoma after primary stereotactic radiosurgery. Clinical Neurosurgery, 55:150-159.
Flynn, J.R., Wang, L., Gillespie, D.L., Ellsworth, G., Salzman, K.L., Kinney, A., and Jensen, R.L. (2008) A correlation of hypoxia response proteins, cellular proliferation, angiogenesis and tumor necrosis with survival in adults with glioblastoma multiforme. Cancer, 113(5):1032-1042, July 10th epub.
Ragel, B.T., Couldwell, W.R., McCutcheon, I., Wendlend, M., Whang, K., Gillespie, D.L., and Jensen, R.L. (2008) A comparison of cell lines involved in meningioma research. Surgical Neurology, 70(3):295-307.
Ragel, B.T., Elam, I., Mabey, D., Gillespie, D., Couldwell, W.T., and Jensen, R.L. (2008) A novel intracranial meningioma mouse model using luciferase expressing meningioma cells. J Neurosurgery 108:304-310.
Wang, X.L., Thanh, N., Gillepsie, D., Jensen, R., and Lu, Z.R. (2008) A novel multifunctional and reversibly polymerizable carrier for efficient siRNA delivery. Biomaterials, 29:15-22.
Ragel, B.T., Couldwell, W.T., Gillespie, D.L., and Jensen, R.L. (2007) Identification of hypoxia-induced genes in a malignant glioma cell line (U251) by cDNA microarrray analysis. Neurosurgical Review, 30:181-187, epub May 8.
Gillepsie, D., Whang, K., Ragel, B.T., Flynn, J.R., Kelly, D.A., and Jensen, R.L. (2007) Silencing of hypoxia inducible factor-1 by RNA interference attenuates human glioma growth in vivo. Clinical Cancer Research, 13(8):2441-2448.
Ragel, B.T., Jensen, R.L., Gillespie, D.L., Prescott, S.M., and Couldwell, W.T. (2006) Celecoxib inhibits meningioma tumor growth in a mouse xenograft model. Cancer, 109:588-597, Dec 19 epub.
Ragel, B., Gillespie, D., Kushnir, V., Polevaya, N., Kelly, D., and, Jensen, R.L. (2006) Calcium Channel Antagonists Augment Hydroxyurea- and RU486-Induced Inhibition of Meningioma Growth In Vivo and In In Vitro. Neurosurgery, 59:1109-1121.
Jensen, R.L., Ragel, B., Whang, K., and Gillepsie, D. (2006) Inhibition of hypoxiainducible factor-1a decreases vascular endothelial growth factor (VEGF) secretion and tumor growth in malignant gliomas. J Neurooncology, 78:233-247.
Ragel, B., and Jensen, R. (2004) Pathophysiology of Meningiomas. Seminars in Neurosurgery, 14:169-185.
Jensen, R. L., Gillespie, D., House, P., Layfield, L., and Shelton, C. (2004) Endolymphatic Sac Tumors In Patients With And Without Von Hippel Lindau Disease: The Role of VHL Genetic Mutation, VHL Protein and Hypoxia Inducible Factor-1± (HIF-1±) Expression. J Neurosurgery, 100:488-497.
Kan, P., Gottfried, O., Blumenthal, D., Townsend, J., and Jensen, R. (2004) Oligodendroglioma and Juvenile Pilocytic Astrocytoma Presenting as Synchronous Primary Brain Tumors: Case Report and Review of the Literature. J Neurosurgery, 100:700-705.
Ragel, B., and Jensen, R. L. (2003) New approaches for the treatment of refractory meningiomas. Cancer Control, 10:148-158.
Jensen, R. L., Soleau, S., Bhayani, M. K., and Christiansen, D. (2002) Hypoxia inducible factor 1a correlates with preoperative embolization of meningiomas. J. Neurosurgery, 97:658-667.
Jensen, R. L., and Wurster, R. D. (2001) Calcium channel antagonists inhibit growth of subcutaneous xenograft meningiomas in nude mice. Surgical Neurology, 55:275-283.
Jensen, R. L., Petr, M., and Wurster, R. D. (2000) Calcium channel antagonist effect on in vitro meningioma signal transduction pathways after growth factor stimulation. Neurosurgery, 46:692-703.
Jensen, R. L. (1998) Growth Factor Mediated Angiogenesis in the Malignant Progression of Glial Tumors. A Review. Surgical Neurology, 49:189-196.