Frequent somatic CDH1 loss-of-function mutations in plasmacytoid variant bladder cancer

David Solit and colleagues report that inactivating CDH1 mutations are found in 84% of plasmacytoid bladder cancer samples tested and are not found in other bladder cancer subtypes. CRISPR/Cas9-mediated knockout of CDH1 in cell lines leads to enhanced cellular migration. Plasmacytoid bladder cancer is an aggressive histologic variant with a high risk of disease-specific mortality. Using whole-exome and targeted sequencing, we find that truncating somatic alterations in the CDH1 gene occur in 84% of plasmacytoid carcinomas and are specific to this histologic variant. Consistent with the aggressive clinical behavior of plasmacytoid carcinomas, which frequently recur locally, CRISPR/Cas9-mediated knockout of CDH1 in bladder cancer cells enhanced cell migration.