Nasopharyngeal carcinoma (NPC) is an epithelial malignancy with a unique geographical distribution. The genomic abnormalities leading to NPC pathogenesis remain unclear. In total, 135 NPC tumors were examined to characterize the mutational landscape using whole-exome sequencing and targeted resequencing. An APOBEC cytidine deaminase mutagenesis signature was revealed in the somatic mutations. Noticeably, multiple loss-of-function mutations were identified in several NF-κB signaling negative regulators NFKBIA, CYLD, and TNFAIP3. Functional studies confirmed that inhibition of NFKBIA had a significant impact on NF-κB activity and NPC cell growth. The identified loss-of-function mutations in NFKBIA leading to protein truncation contributed to the altered NF-κB activity, which is critical for NPC tumorigenesis. In addition, somatic mutations were found in several cancer-relevant pathways, including cell cycle-phase transition, cell death, EBV infection, and viral carcinogenesis. These data provide an enhanced road map for understanding the molecular basis underlying NPC.nasopharyngeal carcinoma | somatic mutation landscape | NF-κB signaling | whole-exome sequencing | APOBEC-mediated signature

The outcomes for patients with metastatic or locally recurrent Epstein–Barr virus (EBV)-positive nasopharyngeal carcinoma (NPC) remain poor. Adoptive immunotherapy with EBV-specific cytotoxic T lymphocytes (EBV-CTLs) has proven clinical efficacy, but it has never been evaluated in the first-line treatment setting in combination with chemotherapy. To evaluate the safety and efficacy of a chemotherapy in combination with adoptive EBV-CTL transfer, we conducted a phase 2 clinical trial consisting of four cycles of gemcitabine and carboplatin (GC) followed by up to six doses of EBV-CTL. Thirty-eight patients were enrolled, and 35 received GC and EBV-CTL. GC-CTL therapy resulted in a response rate of 71.4% with 3 complete responses and 22 partial responses. With a median follow up of 29.9 months, the 2-year and 3-year overall survival (OS) rate was 62.9 and 37.1%, respectively. Five patients did not require further chemotherapy for more than 34 months since initiation of CTL. Infusion of CTL products containing T cells specific for LMP2 positively correlated with OS (hazard ratio: 0.35; 95% confidence interval: 0.14–0.84; P = 0.014). Our study achieved one of the best survival outcomes in patients with advanced NPC, setting the stage for a future randomized study of chemotherapy with and without EBV-CTL.

NF-κB is a well-characterized transcription factor, widely known as a key player in tumor-derived inflammation and cancer development. Herein, we present the functional and molecular relevance of the canonical NF-κB p65 subunit in nasopharyngeal carcinoma (NPC). Loss- and gain-of-function approaches were utilized to reveal the functional characteristics of p65 in propagating tumor growth, tumor-associated angiogenesis, and epithelial-to-mesenchymal transition in NPC cells. Extracellular inflammatory stimuli are critical factors that trigger the NF-κB p65 signaling; hence, we investigated the components of the tumor microenvironment that might potentially influence the p65 signaling pathway. This led to the identification of an extracellular matrix (ECM) protein that was previously reported as a candidate tumor suppressor in NPC. Our studies on the Latent Transforming Growth Factor-β Binding Protein 2 (LTBP2) protein provides substantial evidence that it can modulate the p65 transcriptional activity. Re-expression of LTBP2 elicits tumor suppressive effects that parallel the inactivation of p65 in NPC cells. LTBP2 was able to reduce phosphorylation of p65 at Serine 536, inhibit nuclear localization of active phosphorylated p65, and impair the p65 DNA-binding ability. This results in a consequential down-regulation of p65-related gene expression. Therefore, the data suggest that the overall up-regulation of p65 expression and the loss of this candidate ECM tumor suppressor are milestone events contributing to NPC development.