Abstract B12: Establishment of paired primary neurosphere and monolayer cells of mouse xenograft derived from pediatric brain tumors
Authors: Du Yuchen , Qi Lin , Zhang Huiyuan , Kogiso Mari , Lindsay Holly B. , Zhao Sibo , Braun Frank , Li Xiaonan 
Published: March 2017

Abstract
Background: Stable and reproducible in vitro cell lines derived from clinical samples are currently considered as the best research tools to study human cancers in vitro. Currently there is very limited availability of tumor cell lines, especially paried neurosphere and nomolayer cells. Patient tumor is difficult to obtain and cannot be harvested by multiple times. Direct use of patient tumor is associated with low success rate in in vitro culture. Here we sought to establish a set of paired primary neurosphere and monolayer cells in vitro by taking advantage of patient derived orthotopic xenograft models we have already established.
Materials and Methods: We have established murine xenograft models that biologically and molecularly reciprocate their human counterparts. Those human tumor xenografts are able to provide a sustained and ample supply of tumor cells in ex vivo culture. Primary tumor cells could be continuously harvested from human tumor xenografts and are maintained both in serum-free medium to enrich neurosphere cells and in fetal bovine serum (FBS)-containing DMEM medium where tumor cells grow in monolayer.
Results: We have already developed in primary culture a panel of paired neurosphere and monolayer cells derived from pediatric glioblastoma (GBM), medulloblastoma (MB)and ependymoma (EPN) at different culture stage including three different GBM cells over 60 passages and four over 20 passages, one EPN cell over 40 passages and one MB cell at early stage of around 20 passages. In vitro cultures demonstrated typical cell morphology of adherent and sphere cells for all pediatric brain tumor cell lines we cultured so far. These cultured cells are tumorigenic even with small number of tumor cells and the relative abundances of putative cancer stem cells are different between neurospheres and monolayer culture. Furthermore, our preliminary data from one pair of GBM neurospheres and monolayer cells by high throughput-out drug screening employing hundred thousands of already-identified molecules showed a panel of promising target candidates. Neurospheres and monolayer cells do not respond equally toward the same library of chemotherapeutic agents.
Conclusion: Patient derived orthotopic xenograft (PDOX) can be a good source of human tumor cells for the establishment of in vitro model systems of pediatric brain tumors. The neurosphere and monolayer cells are morphologically and biologically different, which suggest that in future drug screening for both type of cells should be included.
Citation Format: Yuchen Du, Lin Qi, Huiyuan Zhang, Mari Kogiso, Holly B. Lindsay, Sibo Zhao, Frank Braun, Xiaonan Li. Establishment of paired primary neurosphere and monolayer cells of mouse xenograft derived from pediatric brain tumors. [abstract]. In: Proceedings of the AACR Special Conference: Patient-Derived Cancer Models: Present and Future Applications from Basic Science to the Clinic; Feb 11-14, 2016; New Orleans, LA. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(16_Suppl):Abstract nr B12.