Vishnubalaji Radhakrishnan, Alajez Nehad M
Translational Oncology Research Center (TORC), Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), Doha P.O. Box 34110, Qatar.
College of Health & Life Sciences, Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), Doha P.O. Box 34110, Qatar.
Cancers (Basel). 2024 Dec 23;16(24):4273. doi: 10.3390/cancers16244273.
Chemoresistance in triple-negative breast cancer (TNBC) presents a significant clinical hurdle, limiting the efficacy of treatments like doxorubicin. This study aimed to explore the molecular changes associated with doxorubicin resistance and identify potential therapeutic targets to overcome this resistance, thereby improving treatment outcomes for TNBC patients.
Doxorubicin-resistant (DoxR) TNBC models (MDA-MB-231 and BT-549) were generated by exposing cells to increasing concentrations of doxorubicin. RNA sequencing (RNA-Seq) was performed using the Illumina platform, followed by bioinformatics analysis with CLC Genomics Workbench and iDEP. Functional assays assessed proliferation, sphere formation, migration, and cell cycle changes. Protein expression and phosphorylation were confirmed via Western blotting. Pathway and network analyses were conducted using Ingenuity Pathway Analysis (IPA) and STRING, while survival analysis was performed using Kaplan-Meier Plotter database.
DoxR cells exhibited reduced proliferation, sphere formation, and migration, but showed enhanced tolerance to doxorubicin. Increased CHK2 and p53 phosphorylation indicated cellular dormancy as a resistance mechanism. RNA-Seq analysis revealed upregulation of cytokine signaling and stress-response pathways, while cholesterol and lipid biosynthesis were suppressed. Activation of the IL1β cytokine network was prominent in DoxR cells, and CRISPR-Cas9 screens data identified dependencies on genes involved in rRNA biogenesis and metabolism. A 27-gene signature associated with doxorubicin resistance was linked to worse clinical outcomes in a large breast cancer cohort (HR = 1.76, FDR < 2.0 × 10).
This study uncovers potential therapeutic strategies for overcoming TNBC resistance, including dormancy reversal and targeting onco-ribosomal pathways and cytokine signaling networks, to improve the efficacy of doxorubicin-based treatments.
三阴性乳腺癌（TNBC）中的化疗耐药是一个重大的临床障碍，限制了阿霉素等治疗方法的疗效。本研究旨在探索与阿霉素耐药相关的分子变化，并确定克服这种耐药性的潜在治疗靶点，从而改善TNBC患者的治疗效果。
通过将细胞暴露于浓度递增的阿霉素中，建立阿霉素耐药（DoxR）TNBC模型（MDA-MB-231和BT-549）。使用Illumina平台进行RNA测序（RNA-Seq），随后使用CLC基因组工作台和iDEP进行生物信息学分析。功能测定评估增殖、球体形成、迁移和细胞周期变化。通过蛋白质印迹法确认蛋白质表达和磷酸化。使用Ingenuity通路分析（IPA）和STRING进行通路和网络分析，同时使用Kaplan-Meier Plotter数据库进行生存分析。
DoxR细胞的增殖、球体形成和迁移减少，但对阿霉素的耐受性增强。CHK2和p53磷酸化增加表明细胞休眠是一种耐药机制。RNA-Seq分析显示细胞因子信号传导和应激反应通路上调，而胆固醇和脂质生物合成受到抑制。IL1β细胞因子网络的激活在DoxR细胞中很突出，CRISPR-Cas9筛选数据确定了对参与rRNA生物合成和代谢的基因的依赖性。在一个大型乳腺癌队列中，与阿霉素耐药相关的27个基因特征与较差的临床结果相关（HR = 1.76，FDR < 2.0 × 10）。
本研究揭示了克服TNBC耐药的潜在治疗策略，包括逆转休眠以及靶向癌核糖体途径和细胞因子信号网络，以提高基于阿霉素的治疗效果。
