Gene expression analysis of NECTIN4 correlates. (A) Correlation between NECTIN4 and GATA3 mRNA expression across the Seiler 2017 (left), Sjödahl 2012 (middle), and TCGA (right) cohorts. (B) Correlation between NECTIN4 and FOXA1 mRNA expression across Seiler 2017 (left), Sjödahl 2012 (middle), and TCGA (right) cohorts. (C) Correlation between NECTIN4 and PPARG mRNA expression across Seiler 2017 (left), Sjödahl 2012 (middle), and TCGA (right) cohorts. (D) Centroid values from the consensus molecular classifier by Kamoun et al. for NECTIN4, FOXA1, GATA3, and PPARG. (E) Kaplan-Meier curves of overall survival stratified by quartiles of NECTIN4 mRNA expression in TCGA (p=0.11), Sjödahl 2012 (p=0.6), and Seiler 2017 (p=0.06) cohorts.
ARTICLE ABSTRACTEnfortumab vedotin (EV) is an antibody–drug conjugate (ADC) targeting NECTIN4 (encoded by the PVRL4/NECTIN4 gene) approved for treatment-refractory metastatic urothelial cancer. Factors that mediate sensitivity or resistance to EV are unknown. In this study, we sought to (i) examine heterogeneity of NECTIN4 gene expression across molecular subtypes of bladder cancer and (ii) determine whether NECTIN4 expression mediates EV sensitivity or resistance.
Molecular subtyping and NECTIN4 expression data from seven muscle-invasive bladder cancer clinical cohorts (n = 1,915 total specimens) were used to assess NECTIN4 expression across molecular subtypes. The outcome of the transcriptomic analysis was relative NECTIN4 expression in the consensus molecular subtypes of bladder cancer. Expression of NECTIN4 was validated in bladder cancer cell lines. NECTIN4 was stably overexpressed or knocked down in basal and luminal bladder cancer cell lines and EV drug sensitivity assays were performed, as measured by cell proliferation and clonogenic assays.
NECTIN4 expression is heterogenous across molecular subtypes of bladder cancer and significantly enriched in luminal subtypes. NECTIN4 expression is positively correlated with luminal markers GATA3, FOXA1, and PPARG across all cohorts. NECTIN4 expression is both necessary and sufficient for EV sensitivity in luminal and basal subtypes of urothelial bladder cancer cells. Downregulation of NECTIN4 leads to EV resistance.
Sensitivity to EV is mediated by expression of NECTIN4, which is enriched in luminal subtypes of bladder cancer. These findings may have implications for biomarker development, patient selection, and the inclusion of molecular subtyping in ongoing and future EV clinical trials.See related commentary by Teo and Rosenberg, p. 4950