Patient derived xenograft (PDX) model development

All aspects of cancer tissue sharing for model development were reviewed and approved by the Oregon Health & Science University Institutional Review Board. The PCB490 PDX model was generated at JAX (model number J00007860) by implanting surgical human tumor tissue into 4–6-week-old female immunodeficient NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ (NSG) mice without prior in vitro culturing of the tumor cells. Time from surgery to implantation was approximately 24 h. Once a xenografted tumor reached ~ 1000 mm³, the tumor was harvested and divided into 3–5 mm³ fragments. Fragments were implanted into five 6–8-week-old female NSG mice for expansion to P1. Other fragments were sent for quality control assessment (see below). The remaining fragments were cryopreserved in 10% DMSO. When P1 tumors reached 1000mm³ they were harvested and divided into quarters: ¼ for quality control, ¼ snap frozen for genomics, ¼ placed into RNALater (Ambion) for RNA-seq, and the remaining ¼ divided into 3–5 mm³ pieces and cryopreserved in 10% DMSO.

The quality control procedures employed for PDX model development included testing the patient tumor for LCMV (lymphocytic choriomeningitis virus), bacterial contamination, and tumor cell content. The engrafted tumors at P0 and P1 were DNA fingerprinted using a Short Tandem Repeat (STR) assay to ensure model provenance in subsequent passages.

Model details available online at:

http://tumor.informatics.jax.org/mtbwi/pdxDetails.do?modelID=J000078604

Immunohistochemistry (IHC) for human CD45 (IR75161–2, Agilent Technologies) was performed on paraffin embedded blocks of engrafted tumors to identify cases of lymphomagenesis which have been reported previously in PDXs. IHC for human ki67 (IR62661–2, Agilent Technologies) was used to ensure the propagated tumors were human in origin. H&E sections of engrafted tumors were reviewed by a board-certified pathologist (RGE) to evaluate concordance of the morphological features of the engrafted tumor to the patient tumor. Further, tissue was stained with vimentin (IR63061–2, Agilent Technologies) to confirm human origin.

Model information is publicly accessible at: http://tumor.informatics.jax.org/mtbwi/pdxSearch.do