Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
Ann Surg Oncol. 2022 Aug;29(8):4937-4946. doi: 10.1245/s10434-022-11668-0. Epub 2022 Apr 10.
The outcome of pancreatic ductal adenocarcinoma (PDAC) is unsatisfactory, and the identification of novel therapeutic targets is urgently needed. Clinical studies on the antisense oligonucleotide that targets clusterin (CLU) expression have been conducted and have shown efficacy in other cancers. We aimed to investigate the effects of CLU in PDAC and the underlying mechanisms with a view to the clinical application of existing drugs.
We knocked down CLU in PDAC cells and evaluated changes in cell proliferation. To elucidate the mechanism responsible for these changes, we performed western blot analysis, cell cycle assay, and senescence-associated β-galactosidase (SA-β-gal) staining. To evaluate the clinical significance of CLU, immunohistochemistry was performed, and CLU expression was analyzed in specimens resected from PDAC patients not treated with preoperative chemotherapy.
Knockdown of CLU significantly decreased cell proliferation and did not induce apoptosis, but did induce cellular senescence by increasing the percentage of G1-phase and SA-β-gal staining-positive cells. A marker of DNA damage such as γH2AX and factors related to cellular senescence, such as p21 and the senescence-associated secretory phenotype, were upregulated by knockdown of CLU. CLU expression in resected PDAC specimens was located in the cytoplasm of tumor cells and revealed significantly better recurrence-free survival and overall survival in the CLU-low group than in the CLU-high group.
We identified that CLU inhibition leads to cellular senescence in PDAC. Our findings suggest that CLU is a novel therapeutic target that contributes to the prognosis of PDAC by inducing cellular senescence.
胰腺导管腺癌（PDAC）的治疗效果并不理想，因此急需寻找新的治疗靶点。已有临床研究针对靶向细胞外基质蛋白聚糖（CLU）表达的反义寡核苷酸进行了评估，并在其他癌症中显示出了疗效。我们旨在研究 CLU 在 PDAC 中的作用及其潜在机制，以期为现有药物的临床应用提供参考。
我们通过敲低 PDAC 细胞中的 CLU 来评估细胞增殖的变化。为了阐明导致这些变化的机制，我们进行了 Western blot 分析、细胞周期检测和衰老相关β-半乳糖苷酶（SA-β-gal）染色。为了评估 CLU 的临床意义，我们进行了免疫组织化学检测，并分析了未经术前化疗的 PDAC 患者切除标本中的 CLU 表达情况。
敲低 CLU 可显著降低细胞增殖，但不会诱导细胞凋亡，而是通过增加 G1 期细胞比例和 SA-β-gal 染色阳性细胞数诱导细胞衰老。CLU 敲低后，DNA 损伤标志物如 γH2AX 以及与细胞衰老相关的因子，如 p21 和衰老相关分泌表型（SASP）均上调。在切除的 PDAC 标本中，CLU 表达定位于肿瘤细胞质中，CLU 低表达组的无复发生存期和总生存期均明显长于 CLU 高表达组。
我们发现 CLU 抑制可导致 PDAC 发生细胞衰老。我们的研究结果表明，CLU 是一种新的治疗靶点，通过诱导细胞衰老来影响 PDAC 的预后。
