肿瘤微环境样条件改变胰腺癌细胞的代谢和行为

肿瘤微环境复杂且动态，特征包括血管供应不足、营养有限、缺氧和酸性pH值。这一环境在驱动癌症进展中起关键作用。然而，用于体外研究癌细胞生物学的标准细胞培养条件未能模拟肿瘤的体内环境。近年来，开发出更接近人血浆的"生理"培养基（如Plasmax、HPLM），以及更频繁采用生理氧条件（1%-8% O2）。但仍需进一步优化肿瘤特异性培养条件。本研究基于小鼠胰腺导管腺癌（PDAC）肿瘤间质液，建立了一种肿瘤微环境培养基（TMEM）。RNA测序显示，在肿瘤样条件（TMEM，pH 7.0，1.5% O2）中培养的小鼠PDAC细胞（KPCY）与血浆样条件（鼠血浆培养基，pH 7.4，5% O2）相比，基因表达发生了显著变化。尤其在细胞迁移、生物合成、血管生成及上皮-间充质转化相关的基因和通路发生改变，提示肿瘤样条件促进转移表型和代谢重塑。通过功能性检测验证RNA-seq数据，确认在1.5% O2/TMEM条件下细胞迁移性增强，尽管细胞增殖减少。此外，检测葡萄糖摄取和乳酸生成以及线粒体呼吸表明，细胞代谢显著偏向糖酵解。综上所述，培养于1.5% O2/TMEM条件下会改变多种生物学反应，模拟癌症特征更为贴切，有助于标准化肿瘤微环境条件在癌症研究中的应用。本研究强调了在癌症研究中建立肿瘤微环境样条件的重要性。

The tumor microenvironment is complex and dynamic, characterized by poor vascularization, limited nutrient availability, hypoxia, and an acidic pH. This environment plays a critical role in driving cancer progression. However, standard cell culture conditions used to study cancer cell biology in vitro fail to replicate the in vivo environment of tumors. Recently, "physiological" cell culture media that closely resemble human plasma have been developed (e.g., Plasmax, HPLM), along with more frequent adoption of physiological oxygen conditions (1%-8% O2). Nonetheless, further refinement of tumor-specific culture conditions may be needed. In this study, we describe the development of a tumor microenvironment medium (TMEM) based on murine pancreatic ductal adenocarcinoma (PDAC) tumor interstitial fluid. Using RNA-sequencing, we show that murine PDAC cells (KPCY) cultured in tumor-like conditions (TMEM, pH 7.0, 1.5% O2) exhibit profound differences in gene expression compared with plasma-like conditions (mouse plasma medium, pH 7.4, 5% O2). Specifically, the expression of genes and pathways associated with cell migration, biosynthesis, angiogenesis, and epithelial-to-mesenchymal transition were altered, suggesting tumor-like conditions promote metastatic phenotypes and metabolic remodeling. Using functional assays to validate RNA-seq data, we confirmed increased motility at 1.5% O2/TMEM, despite reduced cell proliferation. Moreover, a hallmark shift to glycolytic metabolism was identified via measurement of glucose uptake/lactate production and mitochondrial respiration. Taken together, these findings demonstrate that growth in 1.5% O2/TMEM alters several biological responses in ways relevant to cancer biology, and more closely models hallmark cancerous phenotypes in culture. This highlights the importance of establishing tumor microenvironment-like conditions in standard cancer research. NEW & NOTEWORTHY Standard cell culture conditions do not replicate the complex tumor microenvironment experienced by cells in vivo. Although currently available plasma-like media are superior to traditional supraphysiological media, they fail to model tumor-like conditions. Using RNA-seq analysis and functional metabolic and migratory assays, we show that tumor microenvironment medium (TMEM), used with representative tumor hypoxia, better models cancerous phenotypes in culture. This emphasizes the critical importance of accurately modeling the tumor microenvironment in cancer research.