Figure 2.

Fidelity was maintained to their corresponding patient tumors during the passage of CRLM PDXs regards to the pathological, protein and genetic properties, as well as chemosensitivity. (A) Representative histology of paired patient-PDX tumors. PDX models retained the histopathologic characteristics of original samples with different morphologic features including moderately differentiated phenotype (Case 05), poor-differentiated (Case 45) and mucinous adenocarcinoma (Cases 03 and 18). (B) PDX models demonstrated IHC marker expression patterns (including HER2, EGFR, MET, and CK) were preserved during passage. Positive staining was counted from five randomly selected areas in each slide at × 400 magnification. Scale bars = 100 μm. (C) The genetic alterations were compared among serial passages. For most cases, the genetic properties were conserved in PDX models, compared to corresponding parental tumors. The Venn diagram below demonstrated the number of variations during passage. (D) Chemosensitivity of PDX models was consistent to corresponding patients. Five PDX models of CRLM were evaluated for chemosensitivity compared to corresponding patients. Tumor volumes and proportion of tumor growth inhibition were expressed as means ± SD. The anti-tumor activity are depicted by %TGI (tumor growth inhibition). %TGI = (1-ΔT/ΔC) × 100%, (ΔT = Tumor volume change of the drug-treated group, ΔC = Tumor volume change of the control group on the final day of the study). (E) All of five PDX models had comparable therapeutic responses with patients including two progressive diseases, two stable diseases, and one partial response.