Genomic profiling of patient-derived xenografts identify high level “passenger” gene aberrations associated with better prognosis in non-small cell lung cancer

Patient-derived tumor xenografts (PDXs) increasingly are being used as preclinical models to study human cancers and to evaluate novel therapeutics, as they reflect clinical cancers more closely than established tumor cell lines. With >100 PDXs established from resected non-small cell lung carcinomas (NSCLC), we reported previously that xenograftability correlates significantly with poorer patient prognosis. In this study, genomic, transcriptomic, and proteomic profiling of 36 PDXs showed greater similarity in somatic alterations between PDX and primary tumors than with cell lines, using publicly available data on the latter. A higher number of somatic alterations among 865 frequently altered genes in the PDX tumors was associated with better overall patient survival (HR=0.15, p=0.00015) compared to patients with corresponding PDXs characterized by a lower number of alterations; this was validated with the TCGA lung cancer patient dataset (HR=0.28, p=0.000022). These passenger-like alterations, identified in PDXs, link cell-cell signaling and adhesion to patient prognosis. Total RNAs from xenograftswere amplified by DASL kit and hybridized to Illumina HT12v4 chip