Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
J Transl Med. 2023 Oct 17;21(1):730. doi: 10.1186/s12967-023-04549-x.
Lysosomes are closely linked to autophagic activity, which plays a vital role in pancreatic ductal adenocarcinoma (PDAC) biology. The survival of PDAC patients is still poor, and the identification of novel genetic factors for prognosis and treatment is highly required to prevent PDAC-related deaths. This study investigated the germline variants related to lysosomal dysfunction in patients with PDAC and to analyze whether they contribute to the development of PDAC.
The germline putative pathogenic variants (PPV) in genes involved in lysosomal storage disease (LSD) was compared between patients with PDAC (n = 418) and healthy controls (n = 845) using targeted panel and whole-exome sequencing. Furthermore, pancreatic organoids from wild-type and Kras mice were used to evaluate the effect of lysosomal dysfunction on PDAC development. RNA sequencing (RNA-seq) analysis was performed with established PDAC patient-derived organoids (PDOs) according to the PPV status.
The PPV in LSD-related genes was higher in patients with PDAC than in healthy controls (8.13 vs. 4.26%, Log OR = 1.65, P = 3.08 × 10). The PPV carriers of LSD-related genes with PDAC were significantly younger than the non-carriers (mean age 61.5 vs. 65.3 years, P = 0.031). We further studied a variant of the lysosomal enzyme, galactosylceramidase (GALC), which was the most frequently detected LSD variant in our cohort. Autophagolysosomal activity was hampered when GALC was downregulated, which was accompanied by paradoxically elevated autophagic flux. Furthermore, the number of proliferating Ki-67 cells increased significantly in pancreatic organoids derived from Galc knockout Kras mice. Moreover, GALC PPV carriers tended to show drug resistance in both PDAC cell line and PDAC PDO, and RNA-seq analysis revealed that various metabolism and gene repair pathways were upregulated in PDAC PDOs harboring a GALC variant.
Genetically defined lysosomal dysfunction is frequently observed in patients with young-onset PDAC. This might contribute to PDAC development by altering metabolism and impairing autophagolysosomal activity, which could be potentially implicated in therapeutic applications for PDAC.
溶酶体与自噬活性密切相关，自噬活性在胰腺导管腺癌（PDAC）生物学中起着至关重要的作用。PDAC 患者的生存率仍然很低，因此需要鉴定新的遗传因素来预测和治疗，以防止与 PDAC 相关的死亡。本研究调查了与 PDAC 患者溶酶体功能障碍相关的种系变体，并分析它们是否有助于 PDAC 的发展。
使用靶向panel 和全外显子测序比较了 418 名 PDAC 患者和 845 名健康对照者中涉及溶酶体贮积病（LSD）的基因中的种系潜在致病性变异（PPV）。此外，使用野生型和 Kras 小鼠的胰腺类器官来评估溶酶体功能障碍对 PDAC 发展的影响。根据 PPV 状态，对已建立的 PDAC 患者来源的类器官（PDOs）进行 RNA 测序（RNA-seq）分析。
与健康对照组相比，PDAC 患者 LSD 相关基因的 PPV 更高（8.13%比 4.26%，Log OR=1.65，P=3.08×10）。携带 LSD 相关基因 PPV 的 PDAC 患者明显比不携带的患者年轻（平均年龄 61.5 岁比 65.3 岁，P=0.031）。我们进一步研究了溶酶体酶半乳糖脑苷脂酶（GALC）的变体，该变体是我们队列中最常检测到的 LSD 变体。当 GALC 下调时，自噬溶酶体活性受到阻碍，同时自噬通量异常升高。此外，在 Galc 敲除 Kras 小鼠来源的胰腺类器官中，增殖 Ki-67 细胞的数量显著增加。此外，GALC PPV 携带者在 PDAC 细胞系和 PDAC PDO 中均表现出耐药性，RNA-seq 分析显示，在携带 GALC 变体的 PDAC PDO 中，各种代谢和基因修复途径上调。
在年轻起病的 PDAC 患者中，经常观察到遗传定义的溶酶体功能障碍。这可能通过改变代谢和损害自噬溶酶体活性来促进 PDAC 的发展，这可能与 PDAC 的治疗应用有关。
