Table_4_Multi-omics analysis reveals the association between elevated KIF18B expression and unfavorable prognosis, immune evasion, and regulatory T cell activation in nasopharyngeal carcinoma.xlsx

BackgroundNasopharyngeal carcinoma (NPC) is prevalent in Southern China. The expression profile and functions of kinesin family member 18B (KIF18B) remain unclear in NPC.
MethodsBulk and single-cell transcriptome data for NPC were downloaded. KIF18B expression differences in NPC and normal tissues and its prognostic value were validated by immunohistochemistry and Cox model. We performed multi-faceted functional enrichment analysis on KIF18B. Immune infiltration was analyzed comprehensively by the CIBERSORT, EPIC, and quanTIseq algorithms and the BisqueRNA package and confirmed by immunofluorescence assay. The intercellular communication were investigated by the CellChat package. We explored the dynamics of KIF18B expression by pseudotime trajectory. M6A modification analysis rely on SRAMP platform. The treatment response were evaluated by Tumor Immune Dysfunction and Exclusion (TIDE) score, immunophenoscore and IC50 value.
ResultsKIF18B overexpression in NPC led to unfavorable prognosis, and significantly associated with advanced T, N, and stage classifications. Functional analysis demonstrated that KIF18B was involved in immune suppression, epithelial-mesenchymal transition (EMT), N6-methyladenosine (m6A) modification and therapeutic responses. The deconvolution algorithm indicated that activated regulatory T cells (Tregs) had the strongest positive correlation with KIF18B among immune cells (R = 0.631). Validated by immunofluorescence assay, the high KIF18B expression group displayed a notable rise in Tregs infiltration, accompanied by a substantial decrease in the infiltration of CD8+ T cells and macrophages. In the intercellular communication network, malignant cells with high KIF18B expression implicated in more interactions, and activated and recruited Tregs by modulating cytokines, chemokines, and immune checkpoints. KIF18B was upregulated in more advanced malignant cells and influenced EMT by regulating ITGA6, VIM, and ZEB1/2. KIF18B expression was positively related to m6A “writer” and “reader” genes, and negatively related to “eraser” genes. The KIF18B high expression group exhibited a higher TIDE score and elevated IC50 values for the commonly used chemotherapy drugs, gemcitabine, oxaliplatin, and 5-fluorouracil.
ConclusionKIF18B is a significant prognostic marker in NPC, and may modulate immune evasion and EMT. M6A modification may account for the aberrant overexpression of KIF18B in NPC. Furthermore, KIF18B may predict response to immunotherapy and chemotherapy.

背景：鼻咽癌（Nasopharyngeal carcinoma, NPC）在中国南方高发，而驱动蛋白家族成员18B（kinesin family member 18B, KIF18B）在鼻咽癌中的表达谱与功能仍未明确。
方法：本研究下载了鼻咽癌的批量转录组与单细胞转录组数据。通过免疫组化实验与Cox模型，验证了KIF18B在鼻咽癌组织与正常组织中的表达差异及其预后价值。本研究对KIF18B开展了多维度功能富集分析。通过CIBERSORT、EPIC、quanTIseq算法及BisqueRNA包对肿瘤免疫浸润情况进行了全面分析，并通过免疫荧光实验对分析结果予以验证。本研究利用CellChat包探究了细胞间通信网络情况。通过拟时序轨迹分析，解析了KIF18B表达的动态变化过程。本研究依托SRAMP平台完成m6A修饰相关分析。通过肿瘤免疫功能异常与排斥（Tumor Immune Dysfunction and Exclusion, TIDE）评分、免疫评分及半数抑制浓度（IC50）值，评估了肿瘤的治疗响应情况。
结果：KIF18B在鼻咽癌中高表达会导致不良预后，且与晚期T分期、N分期及总体分期显著相关。功能富集分析结果表明，KIF18B参与免疫抑制、上皮间质转化（epithelial-mesenchymal transition, EMT）、N6-甲基腺苷（N6-methyladenosine, m6A）修饰及治疗响应相关生物学过程。细胞反卷积算法分析结果显示，在所有免疫细胞中，活化调节性T细胞（regulatory T cells, Tregs）与KIF18B的正相关性最强（R=0.631）。经免疫荧光实验验证，KIF18B高表达组的调节性T细胞浸润水平显著升高，同时CD8阳性T细胞与巨噬细胞的浸润水平大幅降低。在细胞间通信网络中，KIF18B高表达的恶性细胞参与了更多的细胞间相互作用，并通过调控细胞因子、趋化因子及免疫检查点，活化并招募调节性T细胞。KIF18B在更晚期的恶性细胞中表达上调，并通过调控ITGA6、VIM及ZEB1/2基因影响上皮间质转化过程。KIF18B表达水平与m6A修饰的“写入器”及“读取器”基因呈正相关，与“擦除器”基因呈负相关。KIF18B高表达组的TIDE评分更高，且吉西他滨、奥沙利铂及5-氟尿嘧啶等常用化疗药物的半数抑制浓度（IC50）值也显著升高。
结论：KIF18B是鼻咽癌的重要预后标志物，可能参与调控肿瘤免疫逃逸与上皮间质转化过程。m6A修饰可能是KIF18B在鼻咽癌中异常高表达的潜在机制。此外，KIF18B可用于预测肿瘤对免疫治疗与化疗的响应情况。