ABSTRACT
Gemcitabine (GEM) based induction chemotherapy is a standard treatment for locoregionally advanced nasopharyngeal carcinoma (NPC). However, approximately 15â¯% of patients are still resistant to GEM-containing chemotherapy, which leads to treatment failure. Nevertheless, the underlying mechanisms of GEM resistance remain poorly understood. Herein, based on a microarray analysis, we identified 221 dysregulated lncRNAs, of which, DYNLRB2-AS1 was one of the most upregulated lncRNAs in GEM-resistance NPC cell lines. DYNLRB2-AS1 was shown to function as contain an oncogenic lncRNA that promoted NPC GEM resistance, cell proliferation, but inhibited cell apoptosis. Mechanistically, DYNLRB2-AS1 could directly bind to the DHX9 protein and prevent its interaction with the E3 ubiquitin ligase PRPF19, and thus blocking PRPF19-mediated DHX9 degradation, which ultimately facilitated the repair of DNA damage in the presence of GEM. Clinically, higher DYNLRB2-AS1 expression indicated an unfavourable overall survival of NPC patients who received induction chemotherapy. Overall, this study identified the oncogenic lncRNA DYNLRB2-AS1 as an independent prognostic biomarker for patients with locally advanced NPC and as a potential therapeutic target for overcoming GEM chemoresistance in NPC.
Subject(s)
DEAD-box RNA Helicases , Deoxycytidine , Gemcitabine , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms , RNA, Long Noncoding , Animals , Humans , Antimetabolites, Antineoplastic/pharmacology , Antimetabolites, Antineoplastic/therapeutic use , Apoptosis/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , DEAD-box RNA Helicases/metabolism , DEAD-box RNA Helicases/genetics , Deoxycytidine/analogs & derivatives , Deoxycytidine/pharmacology , Deoxycytidine/therapeutic use , Drug Resistance, Neoplasm/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Nasopharyngeal Carcinoma/drug therapy , Nasopharyngeal Carcinoma/genetics , Nasopharyngeal Carcinoma/pathology , Nasopharyngeal Carcinoma/metabolism , Nasopharyngeal Neoplasms/drug therapy , Nasopharyngeal Neoplasms/genetics , Nasopharyngeal Neoplasms/pathology , Nasopharyngeal Neoplasms/metabolism , Neoplasm Proteins , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Ubiquitination/drug effectsABSTRACT
Despite docetaxel combined with cisplatin and 5-fluorouracil (TPF) being the established treatment for advanced nasopharyngeal carcinoma (NPC), there are patients who do not respond positively to this form of therapy. However, the mechanisms underlying this lack of benefit remain unclear. DCAF7 is identified as a chemoresistance gene attenuating the response to TPF therapy in NPC patients. DCAF7 promotes the cisplatin resistance and metastasis of NPC cells in vitro and in vivo. Mechanistically, DCAF7 serves as a scaffold protein that facilitates the interaction between USP10 and G3BP1, leading to the elimination of K48-linked ubiquitin moieties from Lys76 of G3BP1. This process helps prevent the degradation of G3BP1 via the ubiquitinâproteasome pathway and promotes the formation of stress granule (SG)-like structures. Moreover, knockdown of G3BP1 successfully reversed the formation of SG-like structures and the oncogenic effects of DCAF7. Significantly, NPC patients with increased levels of DCAF7 showed a high risk of metastasis, and elevated DCAF7 levels are linked to an unfavorable prognosis. The study reveals DCAF7 as a crucial gene for cisplatin resistance and offers further understanding of how chemoresistance develops in NPC. The DCAF7-USP10-G3BP1 axis contains potential targets and biomarkers for NPC treatment.
ABSTRACT
Chemoresistance is a main reason for treatment failure in patients with nasopharyngeal carcinoma, but the exact regulatory mechanism underlying chemoresistance in nasopharyngeal carcinoma remains to be elucidated. Here, we identify PJA1 as a key E3 ubiquitin ligase involved in nasopharyngeal carcinoma chemoresistance that is highly expressed in nasopharyngeal carcinoma patients with nonresponse to docetaxel-cisplatin-5-fluorouracil induction chemotherapy. We find that PJA1 facilitates docetaxel resistance by inhibiting GSDME-mediated pyroptosis in nasopharyngeal carcinoma cells. Mechanistically, PJA1 promotes the degradation of the mitochondrial protein PGAM5 by increasing its K48-linked ubiquitination at K88, which further facilitates DRP1 phosphorylation at S637 and reduced mitochondrial reactive oxygen species production, resulting in suppression of GSDME-mediated pyroptosis and the antitumour immune response. PGAM5 knockdown fully restores the docetaxel sensitization effect of PJA1 knockdown. Moreover, pharmacological targeting of PJA1 with the small molecule inhibitor RTA402 enhances the docetaxel sensitivity of nasopharyngeal carcinoma in vitro and in vivo. Clinically, high PJA1 expression indicates inferior survival and poor clinical efficacy of TPF IC in nasopharyngeal carcinoma patients. Our study emphasizes the essential role of E3 ligases in regulating chemoresistance and provides therapeutic strategies for nasopharyngeal carcinoma based on targeting the ubiquitin-proteasome system.
Subject(s)
Docetaxel , Drug Resistance, Neoplasm , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms , Pyroptosis , Ubiquitin-Protein Ligases , Ubiquitination , Animals , Female , Humans , Male , Mice , Middle Aged , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Cell Line, Tumor , Cisplatin/pharmacology , Cisplatin/therapeutic use , Docetaxel/pharmacology , Docetaxel/therapeutic use , Drug Resistance, Neoplasm/genetics , Drug Resistance, Neoplasm/drug effects , Dynamins/metabolism , Dynamins/genetics , Fluorouracil/pharmacology , Fluorouracil/therapeutic use , Gasdermins , Gene Expression Regulation, Neoplastic/drug effects , Mice, Inbred BALB C , Mice, Nude , Mitochondria/metabolism , Mitochondria/drug effects , Mitochondrial Proteins/metabolism , Mitochondrial Proteins/genetics , Nasopharyngeal Carcinoma/drug therapy , Nasopharyngeal Carcinoma/genetics , Nasopharyngeal Carcinoma/metabolism , Nasopharyngeal Carcinoma/pathology , Nasopharyngeal Neoplasms/drug therapy , Nasopharyngeal Neoplasms/genetics , Nasopharyngeal Neoplasms/metabolism , Nasopharyngeal Neoplasms/pathology , Phosphoprotein Phosphatases/metabolism , Phosphoprotein Phosphatases/genetics , Phosphorylation/drug effects , Pyroptosis/drug effects , Pyroptosis/genetics , Reactive Oxygen Species/metabolism , Ubiquitin-Protein Ligases/metabolism , Ubiquitin-Protein Ligases/genetics , Ubiquitination/drug effects , Xenograft Model Antitumor AssaysABSTRACT
In the original publication [...].
ABSTRACT
Despite that the docectaxel-cisplatin-5-fluorouracil (TPF) induction chemotherapy has greatly improved patients' survival and became the first-line treatment for advanced nasopharyngeal carcinoma (NPC), not all patients could benefit from this therapy. The mechanism underlying the TPF chemoresistance remains unclear. Here, by analyzing gene-expression microarray data and survival of patients who received TPF chemotherapy, we identify transcription factor ATMIN as a chemoresistance gene in response to TPF chemotherapy in NPC. Mass spectrometry and Co-IP assays reveal that USP10 deubiquitinates and stabilizes ATMIN protein, resulting the high-ATMIN expression in NPC. Knockdown of ATMIN suppresses the cell proliferation and facilitates the docetaxel-sensitivity of NPC cells both in vitro and in vivo, while overexpression of ATMIN exerts the opposite effect. Mechanistically, ChIP-seq combined with RNA-seq analysis suggests that ATMIN is associated with the cell death signaling and identifies ten candidate target genes of ATMIN. We further confirm that ATMIN transcriptionally activates the downstream target gene LCK and stabilizes it to facilitate cell proliferation and docetaxel resistance. Taken together, our findings broaden the insight into the molecular mechanism of chemoresistance in NPC, and the USP10-ATMIN-LCK axis provides potential therapeutic targets for the management of NPC.
Subject(s)
Nasopharyngeal Neoplasms , Humans , Nasopharyngeal Carcinoma/pathology , Docetaxel/therapeutic use , Nasopharyngeal Neoplasms/pathology , Transcription Factors/therapeutic use , Drug Resistance, Neoplasm , Fluorouracil/therapeutic use , Chemoradiotherapy/methods , Cisplatin/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Ubiquitin ThiolesteraseABSTRACT
Both concurrent chemoradiotherapy (CCRT) and induction chemotherapy (ICT) followed by CCRT are standard care of advanced nasopharyngeal carcinoma (NPC). However, tailoring personalized treatment is lacking. Herein, we established a radiogenomic clinical decision support system to classify patients into three subgroups according to their predicted disease-free survival (DFS) with CCRT and ICT response. The CCRT-preferred group was suitable for CCRT since they achieved good survival with CCRT, which could not be improved by ICT. The ICT-preferred group was suitable for ICT plus CCRT since they had poor survival with CCRT; additional ICT could afford an improved DFS. The clinical trial-preferred group was suitable for clinical trials since they exhibited poor survival regardless of receiving CCRT or ICT plus CCRT. These findings suggest that our radiogenomic clinical decision support system could identify optimal candidates for CCRT, ICT plus CCRT, and clinical trials, and may thus aid in personalized management of advanced NPC.