Yang Liuxu, Wang Ruizhe, Zhang Lun
Department of Hepatobiliary Surgery, the First Affiliated Hospital of Xi'an JiaoTong University, Xian, Shaanxi, 710061, China.
Health Science Center, Xi'an JiaoTong University, Xian, Shaanxi, 710061, China.
Naunyn Schmiedebergs Arch Pharmacol. 2025 May 14. doi: 10.1007/s00210-025-04228-2.
Chemotherapy resistance contributes to the unsatisfied prognosis in pancreatic cancer (PC) patients. Heat shock protein beta-1 (HSPB1) plays a tumor promoting role in PC by inhibiting ferroptosis. This study aims to explore whether high expression of HSPB1 was responsible for ferroptosis and gemcitabine (GEM) resistance in PC. Here, we found that HSPB1 was upregulated in GEM-resistant PC cells and tumor tissues, as confirmed by RT-qPCR and Western blotting assays. Knockdown of HSPB1 enhanced GEM sensitivity, decreased the abilities of proliferation and invasion, and promoted apoptosis in GEM-resistant PC cells. Utilizing commercial kits, HSPB1 inhibition triggered ferroptosis, as indicated by increased levels of reactive oxygen species, malondialdehyde, and Fe, along with reduced glutathione (GSH) levels. Furthermore, the methylation specific PCR (MSP) results demonstrated a significant decrease in the methylation level of annexin A2 (ANXA2) CpG. The Chromatin immunoprecipitation (ChIP), ChIP-Re-ChIP, and Co-IP experiments revealed that HSPB1 interacts with lysine-specific histone demethylase 1A (KDM1A), recruiting KDM1A-CoREST complex to the ANXA2 promoter to enhance ANXA2 expression through demethylation of H3K9me2. Additionally, ANXA2 depletion further inhibited cell proliferation and invasion and induced ferroptosis in KDM1A-silenced cells, whereas ANXA2 overexpression produced the opposite effects. Finally, HSPB1 overexpression reduced gemcitabine sensitivity by promoting tumor growth in nude mice. Altogether, HSPB1 promoted ANXA2 expression by facilitating H3K9me2 demethylation through the recruitment of KDM1A-CoREST complex to the ANXA2 promoter, thereby inhibiting ferroptosis and enhancing GEM resistance in PC. These data provided a new insight for overcoming GEM-resistant PC.
化疗耐药导致胰腺癌（PC）患者预后不佳。热休克蛋白β-1（HSPB1）通过抑制铁死亡在PC中发挥促肿瘤作用。本研究旨在探讨HSPB1的高表达是否与PC中的铁死亡和吉西他滨（GEM）耐药有关。在此，我们发现HSPB1在GEM耐药的PC细胞和肿瘤组织中上调，这通过RT-qPCR和蛋白质印迹分析得到证实。敲低HSPB1可增强GEM敏感性，降低增殖和侵袭能力，并促进GEM耐药PC细胞的凋亡。使用商业试剂盒，HSPB1抑制引发铁死亡，表现为活性氧、丙二醛和铁水平升高，同时谷胱甘肽（GSH）水平降低。此外，甲基化特异性PCR（MSP）结果显示膜联蛋白A2（ANXA2）CpG的甲基化水平显著降低。染色质免疫沉淀（ChIP）、ChIP-Re-ChIP和免疫共沉淀（Co-IP）实验表明，HSPB1与赖氨酸特异性组蛋白去甲基化酶1A（KDM1A）相互作用，将KDM1A-CoREST复合物招募到ANXA2启动子，通过H3K9me2去甲基化增强ANXA2表达。此外，ANXA2缺失进一步抑制KDM1A沉默细胞的增殖和侵袭并诱导铁死亡，而ANXA2过表达则产生相反的效果。最后，HSPB1过表达通过促进裸鼠肿瘤生长降低吉西他滨敏感性。总之，HSPB1通过将KDM1A-CoREST复合物招募到ANXA2启动子促进H3K9me2去甲基化，从而促进ANXA2表达，进而抑制铁死亡并增强PC中的GEM耐药性。这些数据为克服GEM耐药的PC提供了新的见解。
