Autocrine Canonical Wnt Signaling Primes for Noncanonical Signaling through ROR1 in Metastatic Castration-Resistant Prostate Cancer

To identify genes and pathways downstream of Canonical WNT signaling in prostate cancer, we performed RNA sequencing to capture the transcriptional changes upon APC knockdown or RNF43 knockdown plus Wnt3a stimulation in VCaP cells. The global changes of gene expression were assessed by comparing APC knockdown with Control knockdown or RNF43 knockdown plus Wnt3a stimulation with RNF43 knockdown. By overlapping the genes differentially expressed under both conditions, we obtained a bona fide WNT/β catenin downstream effectors list in prostate cancer. Transcriptome profiling of mRNAs obtained from VCaP cells exposed for 72hrs with Control SiRNAs, SiAPC-2/3s, SiRNF43-3/4 and SiRNF43-3/4 with Wnt3a(100ng/ml) stimulation at the last 7hrs. Both APC and RNF43 knockdown were performed using twp independent SiRNAs. RNA sequencing was performed in biological duplicates for all samples. Differential gene expression was assessed by comparing APC versus control knockdown or RNF43i with Wnt3a stimulation versus RNF43 knockdown.