Leomar Y. Ballester, MD, PhD
- Assistant Professor, Neuropathology, Department of Pathology & Laboratory Medicine
I am an Assistant Professor in the Department of Pathology and Laboratory Medicine at the University of Texas Health Science Center in Houston. As a neuropathologist, I am interested in the biology, diagnosis and treatment of brain tumors. As a molecular pathologist, I have the necessary skills to develop and implement clinical molecular diagnostic assays. My research interests involve the combination of histology and genomics to study the pathogenesis of brain tumors, identify clinically useful biomarkers, translate genomic discoveries into clinical diagnostic assays and develop targeted therapies.
Licenses and Certifications:
- Texas Medical License
- American Board of Pathology Certification in Anatomic Pathology
- American Board of Pathology Certification in Molecular Genetic Pathology
- American Board of Pathology Certification in Neuropathology to be taken on 09/18/2017
- B.S. in Biology
- University of Puerto Rico, Mayguez, PR
- Ph.D. in Genetics/Pharmacology
- Vanderbilt University, Nashville Tennessee
- Postdoctoral in Neuroscience
- UPR, San Juan, Puerto Rico, San Juan, PR
- M.D. in Medicine
- UPR School of Medicine, San Juan, Puerto Rico
- Residency in Anatomic Pathology
- NIH/NCI, Bethesda, MD
- Fellowship in Molecular Pathology
- Baylor College of Medicine, Houston, TX
- Fellowship in Neuropathology
- Houston Methodist Hospital/MD Anderson Cancer Center, Houston, TX
Areas of Interests
As a neuropathologist, I am interested in the biology, diagnosis and treatment of brain tumors. As a molecular pathologist, I have the necessary skills to develop and implement clinical molecular diagnostic assays.
My research interests involve the combination of histology and genomics to study the pathogenesis of brain tumors, identify clinically useful biomarkers, translate genomic discoveries into clinical diagnostic assays and develop targeted therapies.
Contributions to Science
Characterization of molecular mechanisms underlying abnormal ion channel activity in channelopathies. We characterized the mechanisms of abnormal ion channel activity as a result of ion channel mutations associated with cardiac and neuromuscular disease.
Chun T.U., Epstein M.T., Dick M 2nd, Andelfinger G., Ballester L.Y., Vanoye C.G., George A.L. Jr., Benson D.W. Polymorphic Ventricular Tachycardia and KCNJ2 Mutations. Heart Rhythm (2004) 1, 235–241. PMID: 15851159
Lundquist A.L., Turner C.L., Ballester L.Y., George A.L., Jr. Expression and Transcriptional Control of Human KCNE Genes. Genomics. 2006 Jan;87(1):119-28. PMID: 16303284.
Ballester, L.Y., Benson D.W., Wong B., Law I.H., Mathews K.D., Vanoye C.G., George A.L. Jr. Trafficking-competent and Trafficking-defective KCNJ2 Mutations Associated with Andersen Syndrome. Human Mutation, 2006 Apr;27(4):388. PMID: 16541386.
Ballester L.Y., Vanoye C.G., George A.L. Exaggerated Mg2+ inhibition of KCNJ2 as a Consequence of Reduced PIP2 Sensitivity in Andersen Syndrome. Channels, 2007 May;1(3):209-217. PMID: 18690034.
Mechanisms of regulation of nicotinic acetylcholine receptor activity in disease processes. We performed functional studies of nicotinic acetylcholine receptors and uncovered molecular mechanisms of activity modulation in the context of human disease.
Oyola-Cintrón J, Caballero-Rivera D, Ballester L, Baéz-Pagán CA, Martínez HL, Vélez-Arroyo KP, Quesada O, Lasalde-Dominicci JA. Lateral Diffusion, Function, and Expression of the Slow Channel Congenital Myasthenia Syndrome αC418W Nicotinic Receptor Mutation with Changes in Lipid Raft Components. J Biol Chem. 2015 Oct 30;290(44):26790-800. PMID: 26354438.
Ballester L.Y., Capo-Velez C.M., Garcia-Beltran W.F., Ramos F.M., Vazquez-Rosa E., Rios R., Mercado J.R., Melendez R.I., Lasalde-Dominicci J.A. Up-regulation of the Neuronal Nicotinc Receptor a7 by HIV-GP120 Potential Implications for HIV Associated Neurocognitive Disorder. J Biol Chem. 2011 Nov 14. PMID: 22084248.
Biomarkers provide critical information for diagnosis, prognostication and prediction of treatment response in cancer patients. We have used immunohistochemistry and molecular techniques to characterize biomarkers in various cancers and incorporate their use in clinical practice.
Aung P.P., Liu Y.C., Ballester L.Y., Robbins P.F., Rosenberg S.A., Lee CR. Expression of NY-ESO-1 in primary and metastatic malignant melanoma. Hum Pathol. 2014 Feb;45(2):259-67. PMID: 24290058.
Ballester L.Y., Sarabia S.F., Sayeed H., Patel N., Baalwa J., Fang E., Quintanilla N.M., Roy A., López-Terrada, D.H. Integrating Molecular Testing in the Diagnosis and Management of Children with Thyroid Lesions. Pediatr Dev Pathol. 2016 Mar-Apr;19(2):94-100. PMID: 26366474.
Ballester L.Y., Loghavi S., Kanagal-Shamanna R., Barkoh B.A., Lin P., Medeiros L.J., Luthra R., Patel K.P., Clinical Validation of a CXCR4 Mutation Screening Assay for Waldenstrom Macroglobulinemia. Clin Lymphoma Myeloma Leuk. 2016 Jul;16(7):395-403. PMID: 27268124.
Brain tumors are associated with significant morbidity and mortality. Biomarkers provide critical information for diagnosis, prognostication and prediction of treatment response in patients with brain tumors. We have used immunohistochemistry and molecular techniques to characterize biomarkers that can inform clinical practice.
Ballester L.Y., Wang Z., Shandylia S., Miettinen M., Burger P., Eberhart C., Rodriguez F., Raabe E., Nazarian J., Quezado M., Warren K. Morphologic characteristics and immunohistochemical profile of pediatric brainstem gliomas. Am. J. Surg. Path. 2013, 37(9): 1357-1364. PMID: 24076776.
Ballester L.Y., Olar A., Roy-Chowdhuri S. Next-Generation Sequencing of CNS Tumors: The Future of Personalized Patient Management. Neuro-Oncology. 2016 Mar;18(3):308-10. PMID: 26917589.
Lin, F.Y., Bergstrom K., Person R., Bavle A., Ballester L.Y., Scollon S., Raesz-Martinez R., Jea A., Birchansky S.,Wheeler D.A., Berg S.L., Murali C.M., Adesina A.M., Eng C., Roy A., Plon S.E., Parsons W. Integrated tumor and germline whole exome sequencing identifies mutations in MAPK and PI3K pathway genes in an adolescent with rosette-forming glioneuronal tumor of the fourth ventricle. Cold Spring Harb Mol Case Stud. 2016 Sep;2(5). PMID: 27626068.
Ballester L.Y., Fuller G.N., Powell S.Z., Sulman E.P., Patel K.P., Luthra R., Routbort M.J. Retrospective Analysis of Molecular and Immunohistochemical Characterization of 381 Primary Brain Tumors. J Neuropathol Exp Neurol. 2017 Mar 1;76(3):179-188. PMID: 28395087.
Honors and Awards
- 2000- Minority Access to Research Careers (MARC Program)
- 2002- T32 NS07491, Training Program in Ion Channel and Transporter Biology
- 2010- Haxhiu-N.E.U.R.O.N (New, Exciting, Unique Research on Neuroscience) Award, NINDs
- 2012- Finalist in Oral Abstract Competition, 2012 American Society of Clinical Pathology (ASCP) meeting
- 2012- Arthur Purdy Stout Society Stipend Award
- 2013- American Society of Dermatopathology Mentorship Award (ASDP)
- 2011 – NIH Loan Repayment Program
- 2015 – Houston Methodist Hospital, Department of Pathology and Genomic Medicine, Departmental grant