ABSTRACT Paclitaxel is a frequently employed chemotherapeutic agent for nasopharyngeal carcinoma (NPC) patients, and tumor cell resistance to paclitaxel poses a significant challenge to NPC treatment. This study investigated the impact and potential mechanisms of folate‐receptor 1 (FOLR1) on paclitaxel resistance in NPC cells. Levels of FOLR1 in NPC tissues and cells were measured using RT‐qPCR. Protein expression was analyzed by Western blot. IC50 of paclitaxel‐treated NPC cells was assessed by CCK‐8. EdU and Colony formation assay detected cell proliferation. Apoptosis and pyroptosis were evaluated utilizing flow cytometry. Expression and localization of ITCH and FOLR1 were detected by immunofluorescence staining. Interaction between ITCH and FOLR1 was tested by co‐immunoprecipitation (Co‐IP). The immunoprecipitation assay evaluated FOLR1 ubiquitination levels. An NPC xenograft model was constructed in nude mice. FOLR1 was overexpressed in NPC and correlates with a poor prognosis in NPC patients. Low levels of cell pyroptosis and elevated FOLR1 expression were strongly associated with paclitaxel resistance in NPC. Knockdown of FOLR1 reduced the chemoresistance of 5–8 F/paclitaxel cells to paclitaxel. ITCH was associated with FOLR1 and enhanced its degradation through ubiquitination. ITCH reduced paclitaxel resistance in NPC cells via downregulation of FOLR1. FOLR1 increased resistance to paclitaxel by suppressing pyroptosis in NPC through an NLRP3‐dependent mechanism. FOLR1 inhibited pyroptosis by inhibiting the mTOR pathway and promoting autophagy. Lowering FOLR1 expression suppressed tumor growth and boosted paclitaxel sensitivity in mice. FOLR1 plays a significant role in promoting chemoresistance of NPC cells to paclitaxel through NLRP3 signaling.
Zhang et al. (Sun,) studied this question.