DCAF7 Acts as A Scaffold to Recruit USP10 for G3BP1 Deubiquitylation and Facilitates Chemoresistance and Metastasis in Nasopharyngeal Carcinoma.

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 ubiquitin‒proteasome 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.

LncRNA DYNLRB2-AS1 promotes gemcitabine resistance of nasopharyngeal carcinoma by inhibiting the ubiquitination degradation of DHX9 protein.

Gemcitabine (GEM) based induction chemotherapy is a standard treatment for locoregionally advanced nasopharyngeal carcinoma (NPC). However, approximately 15 % 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.

PJA1-mediated suppression of pyroptosis as a driver of docetaxel resistance in nasopharyngeal carcinoma.

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.

Correction: Zhao et al. Hypermethylation of UCHL1 Promotes Metastasis of Nasopharyngeal Carcinoma by Suppressing Degradation of Cortactin (CTTN). Cells 2020, 9, 559.

In the original publication [...].

Transcription factor ATMIN facilitates chemoresistance in nasopharyngeal carcinoma.

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.

Oral chemotherapy versus observation alone in nasopharyngeal carcinoma patients with persistently detected circulating cell-free Epstein-Barr virus DNA during follow-up.

AIM: Despite the high risk of tumor recurrence, patients with nasopharyngeal carcinoma (NPC) with persistently (at least twice) detected circulating cell-free Epstein-Barr virus (EBV) DNA levels during follow-up are routinely recommended to keep observation. For these patients, whether administering more aggressive treatment could improve survival outcomes remains unknown. MATERIALS AND METHODS: We retrospectively included 431 patients with nonmetastatic NPC with persistently detected EBV DNA during follow-up, who do not have clinical or imaging evidence of recurrence. Among these patients, 79 were administered oral chemotherapy, and the remaining 352 underwent observation alone. Baseline characteristics were balanced with propensity score matching (PSM) analysis. The primary endpoint was modified disease-free survival (mDFS), defined as time from detectable EBV DNA result to tumor recurrence or death. The secondary endpoints were disease-free survival (DFS) and overall survival (OS). RESULTS: One-to-three PSM resulted in 251 eligible patients (oral chemotherapy group, 73; observation group, 178). In the matched cohort, the oral chemotherapy group had higher median mDFS (12.9 months [95 % confidence interval [CI] 9.6-16.3] vs. 6.8 months [95 % CI 5.8-7.8], p = 0.009) and DFS (24.1 months [95 % CI 18.5-29.7] vs. 16.7 months [95 % CI 14.4-19.1], p = 0.035) than the observation group. The median OS was numerically higher in the oral chemotherapy group than in the observation group (57.9 months [95 % CI 42.5-73.3] vs. 50.8 months [95 % CI 39.7-61.9], p = 0.71). A consistent benefit favoring oral chemotherapy was observed for mDFS in all subgroups analyses for male, <45 years, stage III-IVa disease, pretreatment EBV DNA load ≥ 4,000 copies/mL, no induction chemotherapy, or a detectable EBV DNA load ≥ 1,200 copies/mL. After adjusting for other confounders in the multivariate analysis, oral chemotherapy remained a significantly favorable factor for both mDFS (hazard ratio [HR] 0.67, 95 % CI 0.50-0.89; p = 0.006) and DFS (HR 0.68, 95 % CI 0.51-0.91; p = 0.01), but not a significant factor for OS (HR 0.89, 95 % CI 0.62-1.27; p = 0.52). CONCLUSIONS: In patients with NPC having persistently detected EBV DNA levels but without clinical or imaging evidence of recurrence during follow-up, oral chemotherapy significantly prolongs mDFS and DFS. Employing oral chemotherapy as a more aggressive treatment option, as opposed to mere observation, could potentially benefit these patients, although further prospective validation is necessitated.

A tumor microenvironment-associated circRNA predictor for tumor relapse and chemotherapy vulnerability in nasopharyngeal carcinoma.

Accurate risk stratification for patients with locoregionally advanced nasopharyngeal carcinoma (LA-NPC) is crucial for prognosis and treatment decisions. Here, we develop a tumor microenvironment-associated circular RNA (circRNA) signature that can stratify LA-NPC patients with different risks of relapse and vulnerability to induction chemotherapy (IC). Relapsed-related circRNAs are identified by comparing expression profiles between patients with and without relapse, followed by quantitative validation in the training cohort (n = 170). A nine-circRNA signature is constructed to classify patients into high-risk and low-risk groups. Low-risk patients have significantly favorable clinical survivals, which is validated in the internal (n = 170) and external (n = 150) cohorts. They are characterized by an immune-active microenvironment and can derive benefits from IC. Meanwhile, high-risk patients characterized with pro-relapse and DNA repair-associated features, are vulnerable to chemoresistance. Overall, the circRNA-based classifier serves as a reliable prognostic tool and might guide chemotherapy decisions for patients with LA-NPC.

Erratum: Long non-coding RNA DANCR stabilizes HIF-1α and promotes metastasis by interacting with NF90/NF45 complex in nasopharyngeal carcinoma: Erratum.

[This corrects the article DOI: 10.7150/thno.28538.].

VIRMA promotes nasopharyngeal carcinoma, tumorigenesis, and metastasis by upregulation of E2F7 in an m6A-dependent manner.

The N6-methyladenosine (m6A) modification possesses new and essential roles in tumor initiation and progression by regulating mRNA biology. However, the role of aberrant m6A regulation in nasopharyngeal carcinoma (NPC) remains unclear. Here, through comprehensive analyses of NPC cohorts from the GEO database and our internal cohort, we identified that VIRMA, an m6A writer, is significantly upregulated in NPC and plays an essential role in tumorigenesis and metastasis of NPC, both in vitro and in vivo. High VIRMA expression served as a prognostic biomarker and was associated with poor outcomes in patients with NPC. Mechanistically, VIRMA mediated the m6A methylation of E2F7 3'-UTR, then IGF2BP2 bound, and maintained the stability of E2F7 mRNA. An integrative high-throughput sequencing approach revealed that E2F7 drives a unique transcriptome distinct from the classical E2F family in NPC, which functioned as an oncogenic transcriptional activator. E2F7 cooperated with CBFB-recruited RUNX1 in a non-canonical manner to transactivate ITGA2, ITGA5, and NTRK1, strengthening Akt signaling-induced tumor-promoting effect.

TRIM21 inhibits irradiation-induced mitochondrial DNA release and impairs antitumour immunity in nasopharyngeal carcinoma tumour models.

Although radiotherapy can promote antitumour immunity, the mechanisms underlying this phenomenon remain unclear. Here, we demonstrate that the expression of the E3 ubiquitin ligase, tumour cell-intrinsic tripartite motif-containing 21 (TRIM21) in tumours, is inversely associated with the response to radiation and CD8+ T cell-mediated antitumour immunity in nasopharyngeal carcinoma (NPC). Knockout of TRIM21 modulates the cGAS/STING cytosolic DNA sensing pathway, potentiates the antigen-presenting capacity of NPC cells, and activates cytotoxic T cell-mediated antitumour immunity in response to radiation. Mechanistically, TRIM21 promotes the degradation of the mitochondrial voltage-dependent anion-selective channel protein 2 (VDAC2) via K48-linked ubiquitination, which inhibits pore formation by VDAC2 oligomers for mitochondrial DNA (mtDNA) release, thereby inhibiting type-I interferon responses following radiation exposure. In patients with NPC, high TRIM21 expression was associated with poor prognosis and early tumour relapse after radiotherapy. Our findings reveal a critical role of TRIM21 in radiation-induced antitumour immunity, providing potential targets for improving the efficacy of radiotherapy in patients with NPC.

Chemotherapy-Induced Senescence Reprogramming Promotes Nasopharyngeal Carcinoma Metastasis by circRNA-Mediated PKR Activation.

Senescence is associated with tumor metastasis and chemotherapy resistance, yet the mechanisms remain elusive. Here, it is identified that nasopharyngeal carcinoma (NPC) patients who developed distant metastasis are characterized by senescence phenotypes, in which circWDR37 is a key regulator. CircWDR37 deficiency limits cisplatin or gemcitabine-induced senescent NPC cells from proliferation, migration, and invasion. Mechanistically, circWDR37 binds to and dimerizes double-stranded RNA-activated protein kinase R (PKR) to initiate PKR autophosphorylation and activation. Independent of its kinase activity, phosphorylated PKR induces I-kappaB kinase beta (IKKß) phosphorylation, binds to and releases RELA from NF-κB inhibitor alpha (IκBα) to trigger nuclear factor kappa B (NF-κB) activation, thereby stimulating cyclin D1 (CCND1) and senescence-associated secretory phenotype component gene transcription in a circWDR37-dependent manner. Low circWDR37 levels correlate with chemotherapy response and favorable survival in NPC patients treated with gemcitabine or cisplatin induction chemotherapy. This study uncovers a new mechanism of circWDR37 activated PKR in senescence-driven metastasis and provides appealing therapeutic targets in NPC.

Association of Intratumoral Microbiota With Prognosis in Patients With Nasopharyngeal Carcinoma From 2 Hospitals in China.

Importance: Microbiota-tumor interactions have qualified microbiota as a promising prognostic biomarker in various types of cancers. Although the nasopharynx acts as a crucial niche of the upper respiratory tract microbiome, whether the intratumoral microbiota exists and its clinical significance in nasopharyngeal carcinoma (NPC) remain uncertain. Objective: To evaluate the clinical significance of intratumoral microbiota for individual prognostication in patients with NPC. Design, Setting, and Participants: This retrospective cohort study included NPC biopsy samples from 2 hospitals: Sun Yat-sen University Cancer Center (Guangzhou, China) and Zhejiang Cancer Hospital (Hangzhou, China) between January 2004 and November 2016, with follow-up through November 2020. A total of 802 patients were included according to the following criteria: with histologically proven NPC, without distant metastasis at initial diagnosis, had not received antitumor treatment before biopsy sampling, aged between 18 and 70 years, with complete medical records and regular follow-up, without a history of cancer, and successfully extracted enough DNA for experiments. Main Outcomes and Measures: The primary end point was disease-free survival, and the secondary end points included distant metastasis-free survival and overall survival. To assess the existence and load of intratumoral microbiota in 96 patients with NPC with or without tumor relapse, 16S rRNA sequencing and quantitative polymerase chain reaction were used. The associations between intratumoral bacterial load and clinical outcome were evaluated in 241 fresh-frozen NPC samples (training cohort) and validated in paraffin-embedded NPC samples of internal (n = 233) and external (n = 232) validation cohorts. Metagenomic and transcriptome analyses were performed to ascertain the origin and underlying mechanism of intratumoral bacteria. Results: A total of 802 patients with NPC (mean [SD] age, 46.2 [10.6] years; 594 [74.1%] male) were enrolled. Microbiota presented within NPC tumor tissues, among which Corynebacterium and Staphylococcus predominated. Patients with a high bacterial load in the training cohort had inferior rates of disease-free survival (hazard ratio [HR], 2.90; 95% CI, 1.72-4.90; P < .001), distant metastasis-free survival (HR, 3.18; 95% CI, 1.58-6.39; P < .001), and overall survival (HR, 3.41; 95% CI, 1.90-6.11, P < .001) than those with a low bacterial load, a finding that was validated by the internal and external validation cohorts. Single-nucleotide variant analysis revealed that the nasopharyngeal microbiota was the main origin of NPC intratumoral bacteria. Transcriptome and digital pathology analyses demonstrated that a higher intratumoral bacterial load was negatively associated with T-lymphocyte infiltration. Conclusions and Relevance: Intratumoral bacterial load was a robust prognostic tool for patients with NPC in this cohort study, indicating potential guidance for treatment decisions in patients at different levels of risk of malignant progression.

Final Overall Survival Analysis of Gemcitabine and Cisplatin Induction Chemotherapy in Nasopharyngeal Carcinoma: A Multicenter, Randomized Phase III Trial.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically on the based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We previously reported significantly improved failure-free survival using gemcitabine plus cisplatin induction chemotherapy in locoregionally advanced nasopharyngeal carcinoma. Here, we present the final overall survival (OS) analysis. In this multicenter, randomized trial, patients were assigned to be treated with concurrent chemoradiotherapy alone (standard therapy, n = 238) or gemcitabine and cisplatin induction chemotherapy before concurrent chemoradiotherapy (n = 242). With a median follow-up of 69.8 months, the induction chemotherapy group had a significantly higher 5-year OS (87.9% v 78.8%, hazard ratio, 0.51 [95% CI 0.34 to 0.78]; P = .001) and a comparable risk of late toxicities (≥ grade 3, 11.3% v 11.4%). Notably, the depth of the tumor response to induction chemotherapy correlated significantly and positively with survival (complete response v partial response v stable/progressive disease, 5-year OS, 100% v 88.4% v 61.5%, P = .005). Besides, patients with a low pretreatment cell-free Epstein-Barr virus DNA load (< 4,000 copies/mL) might not benefit from induction chemotherapy (5-year OS, 90.6% v 91.4%, P = .77). In conclusion, induction chemotherapy before concurrent chemoradiotherapy improved OS significantly in patients with locally advanced nasopharyngeal carcinoma, without increasing the risk of late toxicities. Tumor response to induction chemotherapy and pretreatment cell-free Epstein-Barr virus DNA might be useful to guide individualized treatment.

A lncRNA signature associated with tumor immune heterogeneity predicts distant metastasis in locoregionally advanced nasopharyngeal carcinoma.

Increasing evidence has revealed the roles of long noncoding RNAs (lncRNAs) as tumor biomarkers. Here, we introduce an immune-associated nine-lncRNA signature for predicting distant metastasis in locoregionally advanced nasopharyngeal carcinoma (LA-NPC). The nine lncRNAs are identified through microarray profiling, followed by RT-qPCR validation and selection using a machine learning method in the training cohort (n = 177). This nine-lncRNA signature classifies patients into high and low risk groups, which have significantly different distant metastasis-free survival. Validations in the Guangzhou internal (n = 177) and Guilin external (n = 150) cohorts yield similar results, confirming that the signature is an independent risk factor for distant metastasis and outperforms anatomy-based metrics in identifying patients with high metastatic risk. Integrative analyses show that this nine-lncRNA signature correlates with immune activity and lymphocyte infiltration, which is validated by digital pathology. Our results suggest that the immune-associated nine-lncRNA signature can serve as a promising biomarker for metastasis prediction in LA-NPC.

The immune modulation effects of gemcitabine plus cisplatin induction chemotherapy in nasopharyngeal carcinoma.

BACKGROUND: Studies are trying to add immunotherapy to gemcitabine and cisplatin (GP) induction chemotherapy, the standard therapy, in nasopharyngeal carcinoma (NPC) patients with locoregionally advanced disease. However, how the immune system responds to GP remains unknown. METHOD: We examined the dynamic changes of circulating immune cells and plasma cytokines in NPC patients administered with GP. RESULT: After GP administration, immunosuppressive myeloid cells, including CD11b+CD14+ monocytes, CD33+ myeloid cells, CD33+CD11+ myeloid cells, total MDSCs (CD33+CD11+HLA-DR-/low), monocytic MDSCs, and granulocytic MDSCs decreased significantly. The regulatory T cells and B cells, two important suppressive lymphocyte subpopulations, also decreased. On the other hand, the levels of CD3+ T cells, total B cells, central memory CD4+ T cells, and pro-inflammatory cytokines (including Interleukin [IL]-1ß, IL-6, IL-2, IL-5, and IL-8) increased significantly after GP administration. Besides, GP chemotherapy did not weaken the cytotoxic activity and proliferative capacity of T cells. CONCLUSION: Our results showed the immune modulation effect of GP induction chemotherapy in locoregionally advanced NPC, providing a solid basis for its combination with immunotherapy.

WTAP-mediated m6A modification of lncRNA DIAPH1-AS1 enhances its stability to facilitate nasopharyngeal carcinoma growth and metastasis.

As the most predominant RNA epigenetic regulation in eukaryotic cells, N6-methyladenosine (m6A) plays a critical role in human tumorigenesis and cancer progression. However, the biological function and molecular mechanism of m6A regulation in naso-pharyngeal carcinoma (NPC) remain elusive. Here, we showed that Wilms' tumor 1-associating protein (WTAP) expression was apparently upregulated in NPC, and increased WTAP was associated with poor prognosis. WTAP upregulated in NPC was fine-tuned by KAT3A-mediated H3K27 acetylation. Functionally, WTAP was required for the growth and metastasis of NPC. Mechanistically, lncRNA DIAPH1-AS1 was identified as a bona fide m6A target of WTAP. WTAP-mediated m6A modification of DIAPH1-AS1 enhanced its stability relying on the m6A reader IGF2BP2-dependent pathway. Furthermore, DIAPH1-AS1 acted as a molecular adaptor that promoted MTDH-LASP1 complex formation and upregulated LASP1 expression, ultimately facilitating NPC growth and metastasis. Thus, WTAP-mediated DIAPH1-AS1 m6A methylation is required for NPC tumorigenesis and metastasis.