Wu Nisha, Wang Jinxiang, Fan Mingming, Liang Yanling, Wei Qi Xiao, Deng Fan, Zeng Fangyin
Department of Clinical Laboratory, The Fifth Affiliated Hospital, Southern Medical University, Guangzhou, China.
Department of Breast and Thyroid Surgery, Southwest Hospital, Army Medical University, Chongqing, P.R. China.
Cell Oncol (Dordr). 2024 Dec;47(6):2163-2181. doi: 10.1007/s13402-024-00998-8. Epub 2024 Oct 28.
The small leucine-rich proteoglycan decorin (DCN) is recognized for its diverse roles in tissue homeostasis and malignant progression. Nevertheless, the regulatory effects of DCN on bladder cancer stem cells (BCSCs) and the underlying mechanisms in muscle-invasive bladder cancer (MIBC) remain to be elucidated.
The study obtained data (including scRNA-seq, clinicopathological characteristics, and survival) were acquired from TCGA and GEO. The BCSCs were cultured by enriching the suspension culture in a serum-free medium, followed by flow cytometry sorting. Overexpression/knockdown was constructed by utilizing lentivirus. The surface biomarkers of cancer stem cells were identified via flow cytometry. Cell proliferation and self-renewal were evaluated by CCK8 and Sphere formation assays, and in vivo tumor growth was evaluated with subcutaneous xenografts.
Total DCN expression was significantly elevated in muscle-invasive bladder cancer (MIBC) and was associated with poor prognosis. The ΔDCN isoform, which lacks glycosylation sites, was identified in bladder cancer stem cells (BCSCs) derived from clinical tissue samples and bladder cancer cell lines. Suppression of ΔDCN expression resulted in a reduction of BCSC stemness. Both in vitro and in vivo experiments indicated that overexpression of full-length DCN inhibited stemness within the extracellular matrix. Conversely, overexpression of ΔDCN and the introduction of exogenous recombinant decorin protein in ΔDCN-knockdown BCSC-SW780 cell lines enhanced stemness within the cytoplasm. The ΔDCN isoform exhibited resistance to gemcitabine chemotherapy in vitro.
Non-glycanated ΔDCN isoforms were identified in bladder cancer stem cells (BCSCs), where they exhibited differential cytoplasmic localization and promoted oncogenic effects by inducing a stemness phenotype and conferring resistance to gemcitabine chemotherapy. These oncogenic effects are in stark contrast to the anti-tumor functions of glycosylated DCN in the extracellular matrix. The ratio of ΔDCN isoforms to glycosylated DCN is pivotal in predicting tumor progression and therapeutic resistance.
富含亮氨酸的小分子蛋白聚糖核心蛋白聚糖（DCN）因其在组织稳态和恶性进展中的多种作用而受到认可。然而，DCN对膀胱癌干细胞（BCSCs）的调节作用以及在肌层浸润性膀胱癌（MIBC）中的潜在机制仍有待阐明。
本研究从TCGA和GEO获取数据（包括单细胞RNA测序、临床病理特征和生存数据）。通过在无血清培养基中富集悬浮培养，然后进行流式细胞术分选来培养BCSCs。利用慢病毒构建过表达/敲低载体。通过流式细胞术鉴定癌症干细胞的表面生物标志物。通过CCK8和球体形成试验评估细胞增殖和自我更新，并通过皮下异种移植评估体内肿瘤生长。
在肌层浸润性膀胱癌（MIBC）中，总DCN表达显著升高，且与预后不良相关。在源自临床组织样本和膀胱癌细胞系的膀胱癌干细胞（BCSCs）中鉴定出缺乏糖基化位点的ΔDCN异构体。抑制ΔDCN表达导致BCSC干性降低。体外和体内实验均表明，全长DCN的过表达抑制细胞外基质内的干性。相反，ΔDCN的过表达以及在敲低ΔDCN的BCSC-SW780细胞系中引入外源性重组核心蛋白聚糖蛋白增强了细胞质内的干性。ΔDCN异构体在体外对吉西他滨化疗表现出抗性。
在膀胱癌干细胞（BCSCs）中鉴定出非糖基化的ΔDCN异构体，它们表现出不同的细胞质定位，并通过诱导干性表型和赋予对吉西他滨化疗的抗性来促进致癌作用。这些致癌作用与细胞外基质中糖基化DCN的抗肿瘤功能形成鲜明对比。ΔDCN异构体与糖基化DCN的比例对于预测肿瘤进展和治疗抗性至关重要。
