Objectives: To investigate the efficacy and underlying mechanisms of IBCar’s biological activity in breast cancer models, both in cell culture and in mice, and to compare its effects on cancer versus normal cells.Methods: The cytotoxicity of IBCar was evaluated using the MTS assay to assess metabolic activity and the clonogenic assay to determine reproductive integrity. The impact of IBCar on microtubule integrity, mitochondrial function, and multiple signaling pathways was analyzed using Western blotting, microarray analysis, and live cell imaging. The therapeutic effectiveness of orally administered IBCar was assessed in a transgenic mouse model of Luminal B breast cancer and in mice implanted with subcutaneous triple-negative breast cancer xenografts.Results: IBCar demonstrated potent cytotoxicity across a diverse panel of breast cancer cell lines, including those with mutant or wild-typeTP53, and cell lines with short and long doubling times. Comparative analysis revealed distinct responses between normal and cancer cells, including differences in IBCar’s effects on the mitochondrial membrane potential, endoplasmic reticulum stress and activation of cell death pathways. In breast cancer cells, IBCar was cytotoxic at nanomolar concentrations, caused irreversible microtubule depolymerization leading to sustained mitochondrial dysfunction, endoplasmic reticulum stress, and induced apoptosis. In normal cells, protective mechanisms included reversible microtubule depolymerization and activation of pro-survival signaling via the caspase-8 and riptosome pathways. The therapeutic potential of IBCar was confirmed in mouse models of Luminal B and triple negative BC, where it exhibited strong antitumor activity without detectable toxicity.Conclusions: These findings collectively support IBCar as a promising, effective, and safe therapeutic candidate for breast cancer treatment.
目的：旨在探究IBCar在乳腺癌模型（包括细胞培养和小鼠模型）中的生物活性疗效及其潜在机制，并比较其对癌细胞与正常细胞的作用差异。 方法：采用MTS法评估代谢活性及克隆形成实验测定增殖完整性，以评价IBCar的细胞毒性。通过蛋白质印迹法、微阵列分析和活细胞成像技术，系统分析IBCar对微管结构完整性、线粒体功能及多重信号通路的影响。在Luminal B型乳腺癌转基因小鼠模型及三阴性乳腺癌皮下移植瘤模型中，评估口服IBCar的治疗效果。 结果：IBCar对多种乳腺癌细胞系均表现出强效细胞毒性，其作用不受TP53基因突变状态及细胞倍增时间长短的影响。对比分析显示，正常细胞与癌细胞对IBCar的响应存在显著差异，主要体现在线粒体膜电位变化、内质网应激及细胞死亡通路激活等方面。在乳腺癌细胞中，纳摩尔浓度水平的IBCar即可产生细胞毒性，引发不可逆的微管解聚，导致持续性线粒体功能障碍、内质网应激并诱导细胞凋亡。而在正常细胞中，保护性机制包括可逆性微管解聚以及通过caspase-8和riptosome通路激活促生存信号。在Luminal B型及三阴性乳腺癌小鼠模型中，IBCar展现出显著的抗肿瘤活性且未检测到毒性反应，证实了其治疗潜力。 结论：本研究综合表明，IBCar是一种具有前景、高效且安全的乳腺癌治疗候选药物。
肿瘤(癌症)患者之家