WNT3 Promotes Chemoresistance in Oral Squamous Cell Carcinoma via Activating the Canonical β-catenin Pathway. WNT3 Promotes Chemoresistance in Oral Squamous Cell Carcinoma via Activating the Canonical β-catenin Pathway

Oral squamous cell carcinoma (OSCC) represents a major malignancy in the oral and maxillofacial region. The primary therapeutic agents, 5-fluorouracil (5FU) and oxaliplatin (OXA), often encounter the challenge of chemoresistance, leading to treatment failure. The WNT/β-catenin signaling pathway, closely tied with chemoresistance, offers a promising therapeutic avenue. This study delves into this potential connection. 5FU-resistant and OXA-resistant cell lines were established by gradually elevating the drug concentration in the culture medium. Differential gene expressions between parental and resistant cells were analyzed by RNA sequencing analysis, which was then substantiated via RT-qPCR and western blot. The influence of the WNT signaling on OSCC drug resistance was ascertained through WNT3 knockdown or overexpression. The WNT inhibitor, MSAB, was probed for its capacity to boost the efficacy of 5FU or OXA. Through transcriptome sequencing, successfully derived 5FU-resistant and OXA-resistant cell lines revealed a conspicuous activation of the WNT/β-catenin signaling pathway in the drug-resistant cells. WNT3 was identified as a pivotal factor contributing to chemoresistance in OSCC. Counteracting β-catenin notably augmented the therapeutic potency of 5FU and OXA. Our study underscored the activation of the WNT/β-catenin signaling pathway in resistant OSCC cell lines. By modulating WNT signaling activity, drug resistance in OSCC cells may be effectively circumvented. Overall design: To elucidate the chemoresistance mechanism, we established 5FU-resistant and OXA-resistant cells. We extracted RNA and employed RNA-seq to identify key differentially expressed genes between parental and resistant cells.

口腔鳞状细胞癌（Oral squamous cell carcinoma, OSCC）是口腔颌面部的主要恶性肿瘤。其临床一线治疗药物5-氟尿嘧啶（5-fluorouracil, 5FU）与奥沙利铂（oxaliplatin, OXA）常面临化疗耐药难题，进而导致治疗失败。WNT/β-连环蛋白（WNT/β-catenin）信号通路与化疗耐药紧密相关，是极具潜力的治疗靶点，本研究围绕二者的潜在关联展开探索。本研究通过逐步提升培养基中的药物浓度，成功构建5FU耐药与OXA耐药细胞系。采用RNA测序分析亲本细胞与耐药细胞的差异基因表达，并通过逆转录实时定量聚合酶链反应（RT-qPCR）与蛋白质印迹（western blot）进行验证。通过敲低或过表达WNT3，明确WNT信号通路对OSCC化疗耐药的调控作用；同时探究了WNT抑制剂MSAB增强5FU或OXA疗效的潜力。转录组测序结果显示，成功构建的耐药细胞系中WNT/β-连环蛋白信号通路显著激活。WNT3被鉴定为驱动OSCC化疗耐药的关键因子，抑制β-连环蛋白可显著提升5FU与OXA的抗肿瘤活性。本研究证实，OSCC耐药细胞系中WNT/β-连环蛋白信号通路存在异常激活，通过调控该通路活性，可有效逆转OSCC细胞的化疗耐药性。实验整体设计：为阐明OSCC化疗耐药的分子机制，本研究构建了5FU耐药与OXA耐药细胞系。提取细胞总RNA并通过RNA-seq鉴定亲本细胞与耐药细胞间的关键差异表达基因。