Wu Zheng, Ye Qing, Zhang Shan, Hu Li-Peng, Wang Xiao-Qi, Yao Lin-Li, Zhu Lei, Xiao Shu-Yu, Duan Zong-Hao, Zhang Xue-Li, Jiang Shu-Heng, Zhang Zhi-Gang, Liu De-Jun, Li Dong-Xue, Yang Xiao-Mei
State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, P.R. China.
Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, P.R. China.
Clin Transl Med. 2025 Jan;15(1):e70191. doi: 10.1002/ctm2.70191.
Vitamin K-dependent γ-glutamic acid carboxylation (Gla) proteins are calcium-binding and membrane-associated, participating in coagulation, bone turnover, and cancer biology. The molecular function of transmembrane proline-rich Gla proteins (PRRGs) remains unexplored.
Analysis of pancreatic ductal adenocarcinoma (PDAC) datasets, including transcription profiles, clinical data, and tissue microarrays, was conducted to evaluate PRRG1 expression and its clinical relevance. PDAC cell lines with overexpressed, knockdown, and mutated PRRG1 were developed to study biological functions and pathways using RNA-seq, co-immunoprecipitation with mass spectrometry, Western blotting, and immunofluorescence. In vivo xenograft and orthotopic models assessed PRRG1's impact on PDAC progression, with and without warfarin treatment.
PRRG1 was significantly upregulated in PDAC compared to normal pancreas, correlating with poorer patient survival. PRRG1 knockdown reduced PDAC cell proliferation, anchorage-independent growth in vitro, and tumor growth in vivo. PRRG1 localized at the plasma membrane, interacted with the HECT E3 ligase NEDD4 via the C-terminal PPXY motif, and promoted NEDD4 self-ubiquitination, reducing its protein levels. PRRG1 knockdown elevated NEDD4, destabilizing the oncoprotein KRAS and receptor EGFR, and attenuating downstream signaling and macropinocytosis under nutrient deprivation. The vitamin K-dependent Gla modification of PRRG1 was crucial for its membrane localization and pro-tumorigenic effects, and was inhibited by low-dose warfarin, a clinical vitamin K antagonist.
This study identifies PRRG1 as a key regulator of pro-tumorigenic signaling in PDAC, suggesting the potential of repurposing the anticoagulant warfarin as a therapeutic strategy.
PRRG1 is identified as the transmembrane Gla protein mediating PDAC malignancy. PRRG1 recruits and induces self-ubiquitination of membrane-anchoring E3 ligase NEDD4. PRRG1 exerts a protective role toward KRAS and EGFR by inhibiting NEDD4. The anticoagulant warfarin can be utilized to inhibit PRRG1 and PDAC advancement.
维生素K依赖的γ-谷氨酸羧化（Gla）蛋白可结合钙并与膜相关，参与凝血、骨转换和癌症生物学过程。富含脯氨酸的跨膜Gla蛋白（PRRGs）的分子功能仍未得到探索。
对胰腺导管腺癌（PDAC）数据集进行分析，包括转录谱、临床数据和组织微阵列，以评估PRRG1的表达及其临床相关性。构建PRRG1过表达、敲低和突变的PDAC细胞系，使用RNA测序、质谱共免疫沉淀、蛋白质免疫印迹和免疫荧光研究其生物学功能和信号通路。体内异种移植和原位模型评估了PRRG1对PDAC进展的影响，以及华法林治疗与否的情况。
与正常胰腺相比，PRRG1在PDAC中显著上调，与患者较差的生存率相关。PRRG1敲低降低了PDAC细胞增殖、体外非锚定依赖性生长和体内肿瘤生长。PRRG1定位于质膜，通过C端PPXY基序与HECT E3连接酶NEDD4相互作用，促进NEDD4自身泛素化，降低其蛋白水平。PRRG1敲低使NEDD4升高，使癌蛋白KRAS和受体EGFR不稳定，并在营养剥夺条件下减弱下游信号传导和巨胞饮作用。PRRG1的维生素K依赖的Gla修饰对其膜定位和促肿瘤作用至关重要，并被临床维生素K拮抗剂低剂量华法林抑制。
本研究确定PRRG1是PDAC中促肿瘤信号传导的关键调节因子，提示将抗凝剂华法林重新用作治疗策略的潜力。
PRRG1被确定为介导PDAC恶性肿瘤的跨膜Gla蛋白。PRRG1招募并诱导膜锚定E3连接酶NEDD4的自身泛素化。PRRG1通过抑制NEDD4对KRAS和EGFR发挥保护作用。抗凝剂华法林可用于抑制PRRG1和PDAC进展。
