Rabab Kaneez E, Buchanan Paul J, Colley Grace, White Anita, Murphy Aisling, McCormack Chloe, Eustace Alex J
Life Sciences Institute, Dublin City University, D09 NR58 Dublin, Ireland.
School of Nursing, Psychotherapy and Community Health, Dublin City University, D09 Y8VX Dublin, Ireland.
Cancers (Basel). 2025 May 10;17(10):1614. doi: 10.3390/cancers17101614.
Triple-negative breast cancer (TNBC) is an aggressive subtype lacking estrogen, progesterone, and HER2 receptors, and is associated with poor prognosis and limited targeted therapeutic options. TP53 mutations occur in the majority of TNBC cases, disrupting p53's role in DNA repair and apoptosis. Beyond gene regulation, p53 also influences calcium signalling through store-operated calcium entry (SOCE), a critical pathway for cell survival and death. However, the impact of different TP53 mutation types on calcium signalling remains unclear. Calcium channel gene expression was analysed using publicly available TNBC datasets. Calcium channel expression and SOCE activity were assessed in TNBC cell lines with different TP53 mutations using quantitative PCR and calcium imaging (Fura-2AM). Cell proliferation was measured using acid phosphatase assays, while apoptosis was evaluated through caspase 3/7 activation using the Incucyte live-cell fluorescent imager. The p53 reactivator COTI-2 was tested for its ability to restore TP53 function and modulate calcium signalling. Analysis revealed significant downregulation of CACNA1D in TP53-mutant TNBCs. TNBC cell lines harbouring frameshift and stop TP53 mutations exhibited reduced SOCE, lower CACNA1D expression, and resistance to thapsigargin-induced apoptosis compared to wild-type cells. In contrast, cells with the TP53 R273H missense mutation demonstrated similar calcium signalling and proliferation to TP53 wild-type cels. COTI-2 treatment restored CACNA1D expression and SOCE in frameshift and stop mutant cells, enhancing apoptotic sensitivity. Combined treatment with COTI-2 and thapsigargin resulted in a synergistic increase in apoptosis. This study identifies a novel link between TP53 mutation type and calcium signalling in TNBC. Reactivating mutant p53 with COTI-2 restores calcium-mediated apoptosis, supporting combination strategies targeting both TP53 dysfunction and calcium signalling.
三阴性乳腺癌（TNBC）是一种侵袭性亚型，缺乏雌激素、孕激素和HER2受体，与预后不良及有限的靶向治疗选择相关。大多数TNBC病例中会发生TP53突变，破坏了p53在DNA修复和细胞凋亡中的作用。除了基因调控外，p53还通过储存性钙内流（SOCE）影响钙信号传导，这是细胞存活和死亡的关键途径。然而，不同类型的TP53突变对钙信号传导的影响仍不清楚。利用公开可用的TNBC数据集分析钙通道基因表达。使用定量PCR和钙成像（Fura-2AM）评估具有不同TP53突变的TNBC细胞系中的钙通道表达和SOCE活性。使用酸性磷酸酶测定法测量细胞增殖，同时使用Incucyte活细胞荧光成像仪通过半胱天冬酶3/7激活评估细胞凋亡。测试了p53重新激活剂COTI-2恢复TP53功能和调节钙信号传导的能力。分析显示，在TP53突变的TNBC中，CACNA1D显著下调。与野生型细胞相比，携带移码和终止TP53突变的TNBC细胞系表现出SOCE降低、CACNA1D表达降低以及对毒胡萝卜素诱导的细胞凋亡具有抗性。相比之下，具有TP53 R273H错义突变的细胞表现出与TP53野生型细胞相似的钙信号传导和增殖。COTI-2处理恢复了移码和终止突变细胞中的CACNA1D表达和SOCE，增强了细胞凋亡敏感性。COTI-2和毒胡萝卜素联合处理导致细胞凋亡协同增加。这项研究确定了TNBC中TP53突变类型与钙信号传导之间的新联系。用COTI-2重新激活突变型p53可恢复钙介导的细胞凋亡，支持针对TP53功能障碍和钙信号传导的联合策略。
