Targeting claudin-3 suppresses stem cell-like phenotype in nonsquamous non-small-cell lung carcinoma

AIM: To determine the role of claudin-3 in cancer stemness in nonsquamous non-small-cell lung carcinoma (NSCLC). MATERIALS & METHODS: In vitro/vivo extreme limiting dilution analysis and the side population assay were used to investigate the role of claudin-3 in regulating cancer stemness in nonsquamous NSCLC. RESULTS & CONCLUSION: Claudin-3 depletion decreased the formation rates of spheres and tumors and increased cisplatin sensitivity. Claudin-3 was also identified as one downstream target of estrogen receptor-α in regulating cancer stemness. Moreover, targeting CLDN-3 transcription by small molecules including withaferin A, estradiol and fulvestrant suppressed cancer stemness and reversed chemoresistance. These results demonstrated claudin-3 is one positive regulator of cancer stemness in nonsuqamous NSCLC.