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Abstract Epitranscriptomic remodeling such as N6‐methyladenosine (m6A) modification plays a critical role in tumor development. However, little is known about the underlying mechanisms connecting m6A modification and nasopharyngeal carcinoma (NPC) progression. Here, CBX1 is identified, a histone methylation regulator, to be significantly upregulated with m6A hypomethylation in metastatic NPC tissues. The m6A‐modified CBX1 mRNA transcript is recognized and destabilized by the m6A reader YTHDF3. Furthermore, it is revealed that CBX1 promotes NPC cell migration, invasion, and proliferation through transcriptional repression of MAP7 via H3K9me3‐mediated heterochromatin formation. In addition to its oncogenic effect, CBX1 can facilitate immune evasion through IFN‐γ‐STAT1 signaling‐mediated PD‐L1 upregulation. Clinically, CBX1 serves as an independent predictor for unfavorable prognosis in NPC patients. The results reveal a crosstalk between epitranscriptomic and epigenetic regulation in NPC progression, and shed light on the functions of CBX1 in tumorigenesis and immunomodulation, which may provide an appealing therapeutic target in NPC.

Abstract Background Famitinib is a tyrosine kinase inhibitor against multiple targets, including vascular endothelial growth factor receptor 2/3, platelet-derived growth factor receptor, and stem cell factor receptor (c-kit). Previous studies have demonstrated anti-tumour activities of famitinib against a wide variety of advanced-stage solid cancers. We aimed to determine the safety and efficacy of famitinib with concurrent chemoradiotherapy (CCRT) in patients with locoregionally advanced nasopharyngeal carcinoma (NPC). We also evaluated the feasibility of contrast-enhanced ultrasound (D-CEUS) as a predictor of early tumour response to famitinib and to correlate functional parameters with clinical efficacy. Methods The trial was conducted in subjects with stage III or IVa-b NPC using a 3 + 3 design of escalating famitinib doses. Briefly, subjects received 2 weeks of famitinib monotherapy followed by 7 weeks of famitinib plus CCRT. D-CEUS of the neck lymph nodes was performed at day 0, 8 and 15 after famitinib was administered before starting concurrent chemoradiotherapy. End points included safety, tolerability and anti-tumour activity. Results Twenty patients were enrolled (six each for 12.5, 16.5 and 20 mg and two for 25 mg). Two patients in the 25 mg cohort developed dose-limiting toxicities, including grade 4 thrombocytopenia and grade 3 hypertension. The most common grade 3/4 adverse events were leukopenia, neutropenia and radiation mucositis. D-CEUS tests showed that more than 60% of patients achieved a perfusion parameter response after 2 weeks taking famitinib alone, and the parameter response was associated with disease improvement. In the famitinib monotherapy stage, three patients (15%) showed partial responses. The complete response rate was 65% at the completion of treatment and 95% 3 months after the treatment ended. After a median follow-up of 44 months, the 3-year progression-free survival (PFS) and distant metastasis-free survival were 70% and 75%, respectively. Subjects with a decrease of perfusion parameter response, such as peak intensity decreased at least 30% after 1 week of famitinib treatment, had higher 3-year PFS (90.9% vs. 44.4%, 95% CI 73.7%–100% vs. 11.9%–76.9%, P