Identification of Ankrd35 as a mediator of cisplatin response in non-small cell lung cancer by ex vivo 3D screening of primary tumor spheroids

Using pooled shRNA libraries, we performed a focused screen of 515 genes selected for involvement in response to chemotherapy. The results of this screen confirmed Notch signaling is important for primary tumor cell survival and the importance of key DNA damage response regulators for platinum-induced damage, including Ercc1. Our results establish Ankrd35, a previously uncharacterized ankyrin repeat domain protein, as an important mediator of chemoresistance in ex vivo cultures. Overall design: We analyze shRNA abundance at two different timepoints of 25 sample pools using 3 biological replicates for genes predicted to play a functional role in chemoresistance and re-growth after chemotherapy (25 sample pools x 3 replicates) in primary tumor cells grown in 3D ex vivo cultures and compare these results to LKR10 cells a similar murine NSCLC cell line grown in 2D culture (25 sample pools x 1 replicate). The first analysis compares untreated groups T1 v. T0 for ex vivo 3D vulnerabilities; the second analysis compares cisplatin treated T1 v. untreated T1 groups for chemosensitizers.