Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, P.R. China.
Department of Hepato-Biliary-Pancreatic Surgery, General Surgery, Huadong Hospital Affiliated to Fudan University, Shanghai, 200040, P.R. China.
Cell Death Dis. 2024 Oct 21;15(10):767. doi: 10.1038/s41419-024-07110-w.
Chemotherapy resistance has been a great challenge in pancreatic ductal adenocarcinoma(PDAC) treatments. Current first-line chemotherapy regimens for PDAC include gemcitabine-based regimens such as AG regimen (albumin paclitaxel and gemcitabine), fluorouracil-based regiments such as FOLFIRINOX regimen ((5-fluorouracil5-FU), oxaliplatin, Irinotecan) and platinum-based regimens for patients with BRCA mutations. large amounts of work have been done on exploring the mechanism underlying resistance of gemcitabine-based and platinum-based regimens, while little research has been achieved on the mechanism of FOLFIRINOX regimens resistance. Hence, we identified Polypeptide N-Acetylgalactosaminyltransferase 5, (GALNT5) as a vital regulator and a potential therapeutic target in FOLFIRINOX regimens resistance. Colony formation assays and flow cytometry assays were performed to explore the roles of GALNT5 in cell proliferation and apoptosis in PDAC treated with FOLFIRINOX. IC50 alterations were calculated in GALNT5 knockdown and overexpressed cell lines. RNA-seq followed by GSEA (gene set enrichment analysis) was displayed to explore the potential mechanism. WB (western blotting), real-time PCR, and IF (immunofluorescence) were performed to validate relative pathways. The mouse orthotopic xenograft PDAC model was established to examine GALNT5 functions in vivo. GALNT5 was highly expressed in PDAC tissues and predicted poor prognosis in PDAC. Upregulation of GALNT5 in PDAC cells conferred FOLFIRINOX resistance on PDAC by inhibiting DNA damage. Moreover, GALNT5 interacted with MYH9, thus participating in the activation of the NOTCH pathways, resulting in hampering FOI-induced DNA damage. Functions of GALNT5 promoting FOLFIRINOX resistance were validated in vivo. In this study, we found that aberrantly overexpressed GALNT5 in PDAC took part in the activation of the NOTCH pathway by interacting with MYH9, thus inhibiting the DDR to achieve FOLFIRINOX resistance and causing poor prognosis. We identified GALNT5 as a potential therapeutic target for PDAC patients resistant to FOLFIRINOX chemotherapy.
化疗耐药性一直是胰腺导管腺癌 (PDAC) 治疗的巨大挑战。目前 PDAC 的一线化疗方案包括吉西他滨为基础的方案，如 AG 方案（白蛋白紫杉醇联合吉西他滨），氟尿嘧啶为基础的方案，如 FOLFIRINOX 方案（5-氟尿嘧啶 5-FU、奥沙利铂、伊立替康）和铂类方案适用于 BRCA 突变的患者。大量的工作已经致力于探索吉西他滨为基础和铂类方案耐药的机制，而对于 FOLFIRINOX 方案耐药的机制研究甚少。因此，我们鉴定出多肽 N-乙酰半乳糖胺基转移酶 5（GALNT5）作为 FOLFIRINOX 方案耐药中的一个重要调节因子和潜在的治疗靶点。进行集落形成实验和流式细胞术实验来探索 GALNT5 在 FOLFIRINOX 治疗的 PDAC 细胞增殖和凋亡中的作用。在 GALNT5 敲低和过表达细胞系中计算 IC50 改变。进行 RNA-seq 联合 GSEA（基因集富集分析）显示潜在机制。进行 WB（western blotting）、实时 PCR 和 IF（免疫荧光）验证相关通路。建立小鼠原位异种移植 PDAC 模型以在体内检查 GALNT5 的功能。GALNT5 在 PDAC 组织中高表达，并预测 PDAC 的预后不良。在 PDAC 细胞中上调 GALNT5 通过抑制 DNA 损伤赋予 PDAC 对 FOLFIRINOX 的耐药性。此外，GALNT5 与 MYH9 相互作用，从而参与 NOTCH 通路的激活，导致阻碍 FOI 诱导的 DNA 损伤。在体内验证了 GALNT5 促进 FOLFIRINOX 耐药的功能。在这项研究中，我们发现 PDAC 中异常过表达的 GALNT5 通过与 MYH9 相互作用参与 NOTCH 通路的激活，从而抑制 DDR 以实现 FOLFIRINOX 耐药并导致预后不良。我们将 GALNT5 鉴定为对 FOLFIRINOX 化疗耐药的 PDAC 患者的潜在治疗靶点。
