Cellular senescence frequently occurs during anti-cancer treatment, and persistent senescent tumor cells (STCs) unfavorably promote tumor progression through paracrine secretion of the senescence-associated secretory phenotype (SASP). Extracellular vesicles (EVs) have recently emerged as a novel component of the SASP and primarily mediate the tumor-promoting effect of the SASP. Of note, the potential effect of EVs released from STCs on tumor progression remains largely unknown. We collected tumor tissues from two cohorts of colorectal cancer (CRC) patients to examine the expression of p16, p21, and SERPINE1 before and after anti-cancer treatment. Cohort 1 included 22 patients with locally advanced rectal cancer (LARC) who received neoadjuvant therapy before surgical resection. Cohort 2 included 30 patients with metastatic CRC (mCRC) who received first-line irinotecan-contained treatment. CCK-8, transwell, wound-healing assay, and tumor xenograft experiments were carried out to determine the impacts of EVs released from STCs on CRC progression in vitro and in vivo. Quantitative proteomic analysis was applied to identify protein cargo inside EVs secreted from STCs. Immunoprecipitation and mass spectrometer identification were utilized to explore the binding partners of SERPINE1. The interaction of SERPINE1 with p65 was verified by co-immunoprecipitation, and their co-localization was confirmed by immunofluorescence. Chemotherapeutic agents and irradiation could potently induce senescence in CRC cells in vitro and in human CRC tissues. The more significant elevation of p16 and p21 expression in patients after anti-cancer treatment displayed shorter disease-free survival (DFS) for LARC or progression-free survival (PFS) for mCRC. We observed that compared to non-STCs, STCs released an increased number of EVs enriched in SERPINE1, which further promoted the progression of recipient cancer cells. Targeting SERPINE1 with a specific inhibitor, tiplaxtinin, markedly attenuated the tumor-promoting effect of STCs-derived EVs. Additionally, the patients with greater increment of SERPINE1 expression after anti-cancer treatment had shorter DFS for LARC or PFS for mCRC. Mechanistically, SERPINE1 bound to p65, promoting its nuclear translocation and subsequently activating the NF-κB signaling pathway. We provide the in vivo evidence of the clinical prognostic implications of therapy-induced senescence. Our results revealed that STCs were responsible for CRC progression by producing large amounts of EVs enriched in SERPINE1. These findings further confirm the crucial role of therapy-induced senescence in tumor progression and offer a potential therapeutic strategy for CRC treatment.

中文翻译：

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治疗诱导的衰老肿瘤细胞来源的细胞外囊泡通过 SERPINE1 介导的 NF-κB p65 核转位促进结直肠癌进展

细胞衰老在抗癌治疗过程中经常发生，持续性衰老肿瘤细胞（STC）通过旁分泌衰老相关分泌表型（SASP）不利地促进肿瘤进展。细胞外囊泡（EV）最近作为 SASP 的新成分出现，主要介导 SASP 的肿瘤促进作用。值得注意的是，STC 释放的 EV 对肿瘤进展的潜在影响仍然很大程度上未知。我们收集了两组结直肠癌 (CRC) 患者的肿瘤组织，以检测抗癌治疗前后 p16、p21 和 SERPINE1 的表达。第 1 组包括 22 名局部晚期直肠癌 (LARC) 患者，他们在手术切除前接受了新辅助治疗。第 2 组包括 30 名接受一线伊立替康治疗的转移性 CRC (mCRC) 患者。进行 CCK-8、transwell、伤口愈合测定和肿瘤异种移植实验，以确定 STC 释放的 EV 对体外和体内 CRC 进展的影响。应用定量蛋白质组分析来鉴定 STC 分泌的 EV 内的蛋白质货物。利用免疫沉淀和质谱仪鉴定来探索 SERPINE1 的结合伴侣。通过免疫共沉淀验证了 SERPINE1 与 p65 的相互作用，并通过免疫荧光证实了它们的共定位。化疗药物和辐射可以有效诱导体外结直肠癌细胞和人类结直肠癌组织的衰老。抗癌治疗后患者的 p16 和 p21 表达显着升高，显示 LARC 的无病生存期 (DFS) 较短，mCRC 的无进展生存期 (PFS) 较短。我们观察到，与非 STC 相比，STC 释放了更多数量的富含 SERPINE1 的 EV，这进一步促进了受体癌细胞的进展。使用特定抑制剂 tiplaxtinin 靶向 SERPINE1，可显着减弱 STC 衍生的 EV 的肿瘤促进作用。此外，抗癌治疗后SERPINE1表达增加较大的患者的LARC的DFS或mCRC的PFS较短。从机制上讲，SERPINE1 与 p65 结合，促进其核转位，随后激活 NF-κB 信号通路。我们提供了治疗引起的衰老的临床预后影响的体内证据。我们的结果表明，STC 通过产生大量富含 SERPINE1 的 EV，从而导致 CRC 进展。这些发现进一步证实了治疗诱导的衰老在肿瘤进展中的关键作用，并为结直肠癌的治疗提供了潜在的治疗策略。