EXTH-17. A FOCUSED ULTRASOUND BLOOD BRAIN BARRIER DISRUPTION MODEL TO TEST THE INFLUENCE OF TIGHT JUNCTION GENES TO TREAT BRAIN TUMORS. (12th November 2021)

• Record Type: Journal Article
• Authors: Iyer, Jayashree; Akkad, Adam; Tang, Nanyun; Berens, Michael; Zenhausern, Frederic; Gu, Jian
• Is Part Of: Neuro-oncology. Volume 23: Supplement 6(2021)
• Page Start: vi167
• Page End: vi167
• Publication Date: 2021-11-12
• Subjects: Brain Neoplasms -- Periodicals; Brain -- Tumors -- Periodicals; Brain -- Cancer -- Periodicals; Nervous system -- Cancer -- Periodicals; 616.99481
• DOI: 10.1093/neuonc/noab196.656
• Languages: English
• ISSNs: 1522-8517

Abstract

Abstract: Treating primary or metastatic tumors in the brain (glioblastomas, melanoma, lung cancer, breast cancer) proves challenging by virtue of the protective function of the blood brain barrier (BBB). The tight junction proteins (TJPs) binding the specialized endothelial cells of the BBB largely contribute to the limited permeability of cancer-therapeutic drugs. In both preclinical and clinical models, low intensity focused ultrasound (LIFU) coupled with microbubbles has been proven to safely and transiently open the BBB. Despite this method being established, potential genetic influences on the durability and vulnerability of tight junctions to LIFU have not been elucidated, nor have the determinants of tight junction repair post LIFU been thoroughly investigated. We report the development of an ultrasound transparent organ-on-chip model populated by iPSC-derived endothelial cells (iPSC-EC) co-cultured with astrocytes. We aim to probe the contributions of various tight junction genes to barrier integrity along with the subsequent protein topology involved in reassembly post ultrasound. Thus, this model serves to determine parameters for ultrasound disruption for precision opening of the BBB. The BBB-On-Chip was successfully fabricated and assembled with an optimized technique that has an 80% yield of leak-free devices, with stable cavitation post nanobubble injection. Furthermore, Western blots show expression of claudin-5, a key TJP, in our iPSC-ECs. We have also demonstrated by confocal microscopy that another component of the TJP complex, ZO-1, can be visualized at iPSC-derived cell junctions. Further benchmarking of device-ultrasound interactions, successful iPSC differentiation, tight junction formation, and fabrication of nanobubbles and their assistance in ultrasound BBB disruption will be presented. Efforts are underway to characterize the contributions of tight junction genes and their variations to the integrity and disruption of the BBB.