Abstract:
Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies nowadays. The available chemo- and immunotherapies are often ineffective in treating PDAC due to its immunosuppressive and highly desmoplastic tumor immune microenvironment (TIME), which is hardly reproduced in the existing preclinical models. The PDAC TIME results from a peculiar spatial organization between different cell types. For this reason, developing new human models recapitulating the tissue organization and cell heterogeneity of PDAC is highly desirable. We developed human 3D heterocellular tumor spheroids of PDAC formed by cancer cells, endothelial cells, pancreatic stellate cells (PSC), and monocytes. As a control, we formed spheroids using immortalized epithelial pancreatic ductal cells (non-cancerous spheroids) with cellular heterogeneity similar to the tumor spheroids. Normal spheroids containing endothelial cells formed a complex 3D endothelial network significantly compromised in tumor spheroids. Monocyte/macrophages within the 4-culture tumor spheroids were characterized by a higher expression of CD163, CD206, PD-L1, and CD40 than those in the non-cancerous spheroids suggesting their differentiation towards an immunosuppressive phenotype. The heterocellular tumor spheroids presented a hypoxic core populated with PSC and monocytes/macrophages. The 4-culture tumor spheroids were characterized by spatial proximity of PSC and monocytes to the endothelial cells and a cytokine signature with increased concentrations of CXCL10, CCL2, and IL-6, which have been observed in PDAC patients and associated with poor survival. Further, 4-culture tumor spheroids decreased the concentrations of T-cell chemoattracting cytokines, i.e., CCL4, CCL5, and CXCL9, when compared with the non-cancerous spheroids, revealing a critical immunosuppressive feature of the different types of cells forming the tumor spheroids. Our results showed that the 4-culture tumor spheroids better resembled some critical features of patients\' PDAC TIME than monoculture tumor spheroids. Using the proposed human 3D spheroid model for therapy testing at the preclinical stage may reveal pitfalls of chemo- and immuno-therapies to help the development of better anti-tumor therapies.
摘要:
胰腺导管腺癌(PDAC)是当今最致命的恶性肿瘤之一。由于PDAC具有免疫抑制性和高度增生性肿瘤免疫微环境(TIME),因此可用的化学疗法和免疫疗法通常对治疗PDAC无效。这在现有的临床前模型中很难复制。PDACTIME由不同细胞类型之间的特殊空间组织产生。出于这个原因,非常需要开发新的人类模型来概括PDAC的组织组织和细胞异质性。我们开发了由癌细胞形成的PDAC的人类3D异形细胞肿瘤球体,内皮细胞,胰腺星状细胞(PSC),和单核细胞。作为一种控制,我们使用永生化的上皮胰腺导管细胞(非癌性球体)形成了球体,其细胞异质性与肿瘤球体相似。含有内皮细胞的正常球体形成复杂的3D内皮网络,在肿瘤球体中明显受损。4培养的肿瘤球体中的单核细胞/巨噬细胞的特征在于CD163,CD206,PD-L1和CD40的表达高于非癌球体中的表达,表明它们向免疫抑制表型分化。异型细胞肿瘤球体呈现一个充满PSC和单核细胞/巨噬细胞的低氧核心。4培养的肿瘤球状体的特征在于PSC和单核细胞与内皮细胞的空间接近度以及具有CXCL10,CCL2和IL-6浓度增加的细胞因子特征,这已在PDAC患者中观察到并与低生存率相关。Further,4培养的肿瘤球体降低了T细胞化学吸引细胞因子的浓度,即,CCL4、CCL5和CXCL9与非癌性球体相比,揭示了形成肿瘤球体的不同类型细胞的关键免疫抑制特征。我们的结果表明,与单培养的肿瘤球体相比,4培养的肿瘤球体更类似于患者PDACTIME的某些关键特征。在临床前阶段使用拟议的人类3D球体模型进行治疗测试可能会揭示化学疗法和免疫疗法的陷阱,以帮助开发更好的抗肿瘤疗法。