Germline genetic determination of cancer progression and survival
We report the surprising finding that common germline polymorphisms of APOE, present in approximately 39% of Caucasians, predict survival outcomes in human melanoma. Analysis of The Cancer Genome Atlas revealed that carriers of the APOE2 variant experienced shorter survival relative to APOE3 homozygotes, while APOE4 variant carriers exhibited increased survival. Consistent with this, melanoma growth in human APOE knock-in mice followed the order of APOE2 > APOE3 > APOE4, revealing causal regulation of progression by APOE variants. Mechanistically, recombinant ApoE protein variants differentially suppressed melanoma cell invasion and endothelial recruitment phenotypes. Moreover, tumors in APOE4 mice exhibited greater immune cell infiltration and activation relative to tumors of APOE2 mice. These findings support the notion that human germline genetic makeup can impact the trajectory of a future malignancy.