A groundbreaking advancement in cancer immunotherapy has emerged from the laboratories of Memorial Sloan Kettering Cancer Center (MSK), where scientists have engineered a novel chimeric antigen receptor T-cell (CAR T) therapy that targets a protein known as urokinase plasminogen activator receptor (uPAR). This innovative CAR T cell therapy marks a significant stride in addressing the formidable challenges posed by solid tumors, which, unlike hematologic malignancies, have long evaded the curative promise of CAR T therapies due to their heterogeneous antigen expression and the protective tumor microenvironment.
Conventionally, CAR T therapy has demonstrated remarkable success in treating blood cancers such as leukemia and lymphoma by targeting specific, well-defined surface antigens like CD19 on malignant B cells. However, the extension of this approach to solid tumors has been thwarted by two critical hurdles: the lack of a consistently expressed surface antigen across tumor cells and the presence of a dense, immunosuppressive stroma composed of fibroblasts and myeloid cells that inhibit T cell infiltration and function. The new strategy presented by MSK researchers innovatively circumvents these barriers by targeting uPAR, a receptor highly expressed not only on malignant tumor cells but also on the supportive non-malignant cells within the tumor microenvironment.
uPAR is a cell surface receptor implicated in processes related to wound healing and tissue remodeling. In healthy tissues, its expression is limited primarily to myeloid immune cells; however, in the cancerous state, both tumor cells and the adjacent supportive niche cells abnormally upregulate uPAR. This upregulation signifies cellular states associated with malignancy, plasticity, fibrosis, and immunosuppression, thus marking uPAR as a pivotal molecule that orchestrates the tumor’s ecosystem. By leveraging this attribute, the MSK team designed CAR T cells that recognize and eradicate uPAR-positive cells, effectively dismantling the tumor itself and its protective microenvironment concurrently.
The preclinical evaluations, meticulously conducted through an array of cancer cell cultures, xenograft models harboring human tumors, and murine systems mimicking metastasis, demonstrated compelling evidence of the therapeutic potential of these uPAR-directed CAR T cells. Notably, in murine models of ovarian cancer, a notoriously therapy-resistant malignancy, these engineered T cells achieved the remarkable feat of eradicating metastatic lesions, eliciting sustained remission states. Furthermore, the persistence of these CAR T cells provided immunity against tumor rechallenge, highlighting the durability of the antitumor response.
The researchers also illuminated the utility of employing uPAR-targeted CAR T cells as adjunctive therapy post-surgical tumor debulking. In models where surgery alone rendered only temporary disease control, the administration of the CAR T cells significantly eliminated residual cancerous cells, proposing a paradigm shift in integrating cellular therapies with conventional surgical interventions to enhance long-term outcomes.
A profound insight into the molecular underpinnings of uPAR overexpression revealed a correlation with mutations in key oncogenes and tumor suppressors, including p53 and KRAS—mutations frequently encountered in aggressive and treatment-resistant cancers. This molecular association underscores the potential of uPAR-targeted therapy to address hard-to-treat cancers by attacking a common vulnerability linked to critical pathways driving malignancy and cellular plasticity.
Interestingly, the team capitalized on combining the uPAR CAR T cells with senescence-inducing chemotherapeutic agents such as cisplatin, which heighten uPAR expression on tumor cells, thereby enhancing the CAR T cells’ recognition and cytotoxicity. This combinatorial approach not only amplifies therapeutic efficacy but also exploits the dynamic changes within the tumor cell population induced by chemotherapy, addressing cancer’s notorious adaptability.
The innovation extends to molecular engineering sophistication: the designers selected uPAR binders that specifically target a form of the receptor less prone to being shed from the cell surface due to inflammatory signals. This specificity ensures sustained CAR T cell engagement, thereby optimizing the cytotoxic effect and circumventing a common mechanism by which tumors evade immune surveillance.
Crucially, this therapy’s dual-targeting capacity extends beyond malignant cells to encompass tumor-associated fibroblasts and immunosuppressive myeloid cells within the tumor microenvironment. This approach disrupts the cancer-supportive niche—a complex tissue landscape that enables tumor growth, immune evasion, and therapeutic resistance—introducing a multifaceted assault on the tumor ecosystem rather than a unidimensional attack on tumor cells alone.
The conceptual framework of this research is deeply rooted in viewing cancer through the lens of systems biology, recognizing tumors as dynamic ecosystems constituted by cancer cells and their intricate interactions with surrounding stroma and immune cells. Such an ecosystem-centered outlook empowers the development of interventions aimed at perturbing these critical intercellular networks, exemplified by the uPAR-targeted CAR T cells. This strategy reflects the paradigm of the Marie-Josée and Henry R. Kravis Cancer Ecosystems Project at MSK, which promotes innovative therapies by dissecting and targeting these interconnected cellular systems.
Beyond its applications in oncology, the therapeutic implications of targeting uPAR-positive cells extend to various fibrotic, inflammatory, and degenerative diseases wherein similar pathological cell types contribute to disease progression. Therefore, therapies built upon this foundation promise broader biomedical applications, opening new frontiers in treating diseases characterized by aberrant tissue remodeling and inflammation.
Monitoring the disease burden and therapeutic efficacy also benefits from the identification of uPAR-related biomarkers. The team demonstrated the potential of measuring soluble uPAR (suPAR) fragments in the bloodstream and utilizing uPAR-targeted positron emission tomography (PET) imaging to non-invasively visualize tumor presence and treatment response, which could revolutionize real-time disease surveillance and personalized medicine approaches.
The discovery and development of uPAR-targeted CAR T cells signify not only a technical tour de force in immunoengineering but also a conceptual leap in treating solid tumors by simultaneously targeting both the cancer cells and their supportive milieu. As this therapy progresses toward clinical evaluation, it heralds a potentially transformative advancement in cancer treatment modalities, offering hope for overcoming long-standing obstacles in solid tumor immunotherapy.
Subject of Research:
Article Title: A convergent uPAR-positive tumor ecosystem creates broad vulnerability to CAR T cell therapy
News Publication Date: 30-Mar-2026
Web References: https://www.cell.com/cell/fulltext/S0092-8674(26)00269-2, https://www.mskcc.org/cancer-care/diagnosis-treatment/cancer-treatments/immunotherapy/car-cell-therapy
References: DOI: 10.1016/j.cell.2026.03.002
Image Credits: Memorial Sloan Kettering Cancer Center
Keywords: CAR T cell therapy, uPAR, tumor microenvironment, solid tumors, immunotherapy, cancer biology, cellular senescence, tumor ecosystem, metastatic cancer, molecular oncology, immunoengineering, targeted therapy
Tags: CAR-T cell therapy for solid tumorschallenges of CAR T in solid tumorsfibroblast and myeloid cell targeting in tumorsheterogeneous antigen expression in tumorsimmunosuppressive stroma in cancerMSK cancer researchnovel CAR T cell engineeringovercoming CAR T therapy resistancesolid tumor antigen targetstumor microenvironment targetinguPAR in cancer immunotherapyurokinase plasminogen activator receptor targeting
