
1150 W. Medical Center Drive, MSRB 2, Room 4570
Ann Arbor, MI 48109
Available to mentor

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Postgraduate StudiesUniversity of Buenos Aires, Buenos Aires, 1984
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PhDUniversity of Buenos Aires School of Medicine, 1984
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MDUniversity of Buenos Aires School of Medicine, 1981
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Center MemberPrecision Health Initiative
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Center MemberRogel Cancer Center
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Center MemberCenter for Cell Plasticity and Organ Design
RESEARCH INTERESTS
(i) Self-organization of brain tumors: molecular, physiological, physical, and translational aspects
The current focus of my research program is to discover the cellular, molecular, and mathematical basis underlying the growth patterns of malignant brain tumors, the interactions between cancer cells with the tumor microenvironment in both experimental models and in human patients. In particular, my research program aims to understand how these interactions determine the responses of brain tumors to various types of treatments. To do so, we are probing how brain glioma cells migrate throughout the brain, from the very initial stages of brain tumor formation to later stages, when tumor growth results in the demise of the hosts’ neurons and glial cells. At this time, the tumors become symptomatic. Understanding the precise molecular basis of glioma cells’ growth and invasive behavior will uncover novel therapeutic targets.
My team is using endogenous models of brain tumor models induced by the Sleeping Beauty Transposase system encoding genetic lesions encountered in human gliomas (e.g., PDGF, CDK4, mIDH1, TP53, and ATRX mutations) and fluorescent proteins to determine the earliest growth patterns of models of endogenous brain tumors. We are also implementing these models to study the tumor microenvironment and the migration of immune cells into the macroscopic tumor mass. These models will be used to study the response to novel therapeutic agents. We have now discovered early and late growth patterns of tumors. We believe that understanding the physical and environmental constraints of glioma growth will provide novel therapeutic avenues for their treatment.
(ii) Adaptive immunity against brain tumors: from basic science to translational clinical trials.
In addition, we are uncovering the molecular mechanisms used by cytotoxic T cells to kill glioma cells, and especially, the mechanisms that also limit their clinical effectiveness in effectively eradicating large gliomas. These approaches will be used to develop novel translational therapeutic strategies for implementation in early phase clinical trials. We recently discovered the formation of tumor antigen specific immunological synapses between activated effector T cells and target tumor cells in an intracranial syngeneic brain tumor model; thus, my group has pioneered the development of immunological tools to address the interactions between glioma cells and immune cells and assess effector T cell functions in vivo, in real-time.
(iii) Phase I clinical trial for the treatment of malignant gliomas using a combined cytotoxic and immune-therapeutic approach.
GBM is the most aggressive primary brain tumor with a 5-year survival rate of <5%. Attempts at eliciting a clinically relevant anti-GBM immune response in these patients have met with limited success, due to tumor immune evasion, and a paucity of dendritic cells (DCs) within the brain. In light of the immunosuppressive nature of GBM, I hypothesized that stimulating an immune response directly from within the TME would elicit effective anti-tumor immunity. I showed that increasing the number of brain tumor infiltrating antigen presenting cells [elicited by expressing fms-like tyrosine kinase ligand (Flt3L) within the TME] in combination with the cytotoxic effects of TK (+GCV) induces effective tumor antigen (Ag) uptake, migration of DCs to draining lymph nodes (dLN), and presentation of tumor antigen to naïve T-cells culminating in effective anti-tumor immunity. This led to a Phase I clinical trial: “A non-randomized, open-label dose-finding trial of combined cytotoxic and immune‐stimulatory strategy for the treatment of primary GBM, utilizing Ad-hCMV-TK expressing herpes simplex virus thymidine kinase, and Ad-hCMV-Flt3L expressing fms-like tyrosine kinase ligand” currently ongoing at our institution (IND number BB14574, clinicaltrials.gov number NCT01811992).
In summary, I provide broad scientific expertise, inspired leadership, and high motivation to a multidisciplinary research team to achieve: (i) a thorough understanding of the cellular and molecular basis of gliomagenesis, early tumor growth, and invasion, (ii) a complete understanding of the capacity and limitations of T cells and NK cells to kill brain tumor cells; (iii) the development of novel potential translational therapeutic approaches for the treatment of human malignant brain tumors, and (iv) establish an active program of translational clinical trials at the interface of the Neurosciences and Oncology.
https://lowenstein-castrolab.com/
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Argento AE, Varela ML, Singh G, Visnuk DP, Jacobovitz B, Rutherford ME, Edwards MB, Chaboche Q, Orringer DA, Heth JA, Castro MG, Beller DA, Blanch-Mercader C, Lowenstein PR. 2025 Apr 21; bioRxiv,PreprintThree-dimensional topological defects and quasi-long-range order in biological liquid crystals
DOI:10.1101/2025.04.14.648711 -
Lowenstein PR, Varela ML, Castro MG. Cancer Cell, 2025 Apr 14; 43 (4): 611 - 618.Journal ArticleThe discrete charm of oncolytic viruses: Toward the finish line.
DOI:10.1016/j.ccell.2025.03.010 PMID: 40154484 -
Garcia-Fabiani MB, Haase S, Banerjee K, Zhu Z, McClellan BL, Mujeeb AA, Li Y, Tronrud CE, Varela ML, West MEJ, Yu J, Kadiyala P, Taher AW, Núñez FJ, Alghamri MS, Comba A, Mendez FM, Nicola Candia AJ, Salazar B, Nunez FM, Edwards MB, Qin T, Cartaxo RT, Niculcea M, Koschmann C, Venneti S, Vallcorba MP, Nasajpour E, Pericoli G, Vinci M, Kleinman CL, Jabado N, Chandler JP, Sonabend AM, DeCuypere M, Hambardzumyan D, Prolo LM, Mahaney KB, Grant GA, Petritsch CK, Welch JD, Sartor MA, Lowenstein PR, Castro MG. 2025 Feb 5;PreprintH3.3-G34R Mutation-Mediated Epigenetic Reprogramming Leads to Enhanced Efficacy of Immune Stimulatory Gene Therapy in Diffuse Hemispheric Gliomas.
DOI:10.1101/2023.06.13.544658 PMID: 37398299 -
Kondepudi A, Pekmezci M, Hou X, Scotford K, Jiang C, Rao A, Harake ES, Chowdury A, Al-Holou W, Wang L, Pandey A, Lowenstein PR, Castro MG, Koerner LI, Roetzer-Pejrimovsky T, Widhalm G, Camelo-Piragua S, Movahed-Ezazi M, Orringer DA, Lee H, Freudiger C, Berger M, Hervey-Jumper S, Hollon T. Nature, 2025 Jan; 637 (8045): 439 - 445.Journal ArticleFoundation models for fast, label-free detection of glioma infiltration.
DOI:10.1038/s41586-024-08169-3 PMID: PMC11711092 -
Alghamri MS, McClellan BL, Banerjee K, Peña Agudelo JA, Lowenstein PR, Castro MG. 2025 Jan 1; Methods in Cell Biology,ChapterPeripheral blood mononuclear cell (PBMC)- based functional evaluation of human T cell response to suppressive cells and immune-oncology therapeutics
DOI:10.1016/bs.mcb.2025.03.009 -
Haase S, Carney S, Varela ML, Mukherji D, Zhu Z, Li Y, Nuñez FJ, Lowenstein PR, Castro MG. Trends Cancer, 2024 Dec; 10 (12): 1147 - 1160.Journal ArticleEpigenetic reprogramming in pediatric gliomas: from molecular mechanisms to therapeutic implications.
DOI:10.1016/j.trecan.2024.09.007 PMID: PMC11631670 -
Barberis L, Condat CA, Faisal SM, Lowenstein PR. Sci Rep, 2024 Oct 25; 14 (1): 25435Journal ArticleThe self-organized structure of glioma oncostreams and the disruptive role of passive cells.
DOI:10.1038/s41598-024-74823-5 PMID: PMC11511870 -
Wilkinson GWG, Darley RL, Lowenstein PR. 2024 Nov 15; From Genetics to Gene Therapy the Molecular Pathology of Human Disease, 160 - 192.ChapterViral vectors for gene therapy
DOI:10.1201/9781003580096-10