Abstract 5040: Perfusion air culture of tissue slices: A new method to cultivate tumor tissue with minimal culture-dependent tissue stress

Abstract

Abstract Cultivation of tumor tissue slices provides an ex vivo model capturing both tumor heterogeneity and its native microenvironment. Slices are commonly cultured either free-floating in medium or filter-supported. These conditions lead both to culture-dependent stress (free-floating culture condition) and intra-slice gradients regarding proliferation, marker expression and oxygen supply (filter-supported culture condition) (Davies et al Sci Rep (2015) 10.1038/srep17178). To facilitate homogenous supply with nutrients and oxygen, we developed a new method to culture tumor tissue slices. The precision-cut tissue slices (150µm to 300µm thickness) are kept in-between two organotypic supports and fixed in a special chamber allowing continuous perfusion with medium and drugs. The chamber is settled vertically inside of a 50 ml tube with air exchange capacity and connected with a syringe pump via a silicon tube. The whole system is cultured inside the cell culture incubator. Several different types of mouse xenografts (MCF-7, H1437) and primary human tumor (lung and ovarian cancer) tissue slices have been cultured with this new system and compared with the commonly used filter-support culture. Both breast and lung xenograft tissues slices showed a gradient of proliferation, HIF-1α and hormone receptor (ER) expression in the filter-supported culture condition but not with the new perfusion air culture system. The same results were obtained with primary tumor samples. Primary lung tumor and ovarian cancer tissue slices also showed a gradient of HIF-1α expression after cultivation in the filter-supported system but not in the new perfusion air culture system when cotton membranes are used as scaffold. In addition, the choice of the material of the organotypic support allows a variety of biological studies. Scaffolds from de-cellularized porcine intestine provide niches for migrating cells and are suited for studying tumor invasiveness. When used as organotypic support, primary ovarian cancer can be cultured up to 7 days with good tissue morphology and structure and migrating cells into the scaffold can be counted as a measure of invasiveness. When the tissues are sandwiched between polycarbonate membranes (pore size: 12 µm), oxygen gradients can be generated similar to gradients observed around vessels in vivo. Our perfusion air culture system facilitates the cultivation of tumor tissue slices due to its flexibility and adjustability of all culture conditions such as oxygen, scaffolds and flow rate parameters. It allows studying tumor slices under conditions closely resembling the in vivo situation. Citation Format: Kathrin Boepple, Meng Dong, Emma Davis, Julia Schueler, Heike Walles, John Hickman, Walter E. Aulitzky, Heiko van der Kuip. Perfusion air culture of tissue slices: A new method to cultivate tumor tissue with minimal culture-dependent tissue stress [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5040.