Kim Soo Yeon, Tang Miaolu, Chih Stephen Y, Sallavanti Jessica, Gao Yan, Qiu Zhiqiang, Wang Hong-Gang, Li Wei
Division of Hematology and Oncology, Department of Pediatrics, Penn State College of Medicine, Hershey, PA, USA.
Medical Scientist Training Program, Penn State College of Medicine, Hershey, PA, USA.
Cell Death Dis. 2025 Jan 14;16(1):12. doi: 10.1038/s41419-025-07335-3.
The association of necrosis in tumors with poor prognosis implies a potential tumor-promoting role. However, the mechanisms underlying cell death in this context and how damaged tissue contributes to tumor progression remain unclear. Here, we identified p38 mitogen-activated protein kinases (p38 MAPK, a.k.a. p38) as a key player in promoting cell death and the inflammatory response to ischemic stress associated with necrotic tumors. We found that glioblastoma (GBM) cells expressing patient-derived Kirsten rat sarcoma (KRAS) or phosphoinositide-3-kinase (PI3K) active mutants showed enhanced cell death under ischemia-mimetic conditions in vitro and were more likely to develop into necrotic tumors in vivo. Cell death in both settings depended on p38, which is also required for tumor progression driven by KRAS or PI3K. Under ischemia-mimetic conditions, GBM cells undergo reactive oxygen species (ROS)-dependent cell death. Gene expression in these cells recapitulated multiple features observed in peri-necrotic tumors from patient GBM. Further studies showed the involvement of a positive feedback loop between the p38-MAPK-activated protein kinase 2 (MAPKAPK2, a.k.a. MK2) signaling axis and the unfolded protein response signaling components activating transcription factor 4 (ATF4) and inositol-requiring enzyme 1 (IRE1α) in driving ischemic tumor cell death. This signaling cascade was further potentiated by RAS or PI3K activation under ischemic conditions, contributing to the inflammatory gene expression response. Therefore, our study suggests that p38 could be targeted to relieve the inflammatory response in necrotic tumors and inhibit GBM progression.
肿瘤中的坏死与预后不良相关，这意味着其具有潜在的促肿瘤作用。然而，在这种情况下细胞死亡的潜在机制以及受损组织如何促进肿瘤进展仍不清楚。在此，我们确定p38丝裂原活化蛋白激酶（p38 MAPK，又称p38）是促进细胞死亡以及对与坏死性肿瘤相关的缺血应激产生炎症反应的关键因子。我们发现，表达患者来源的 Kirsten 大鼠肉瘤（KRAS）或磷酸肌醇-3-激酶（PI3K）活性突变体的胶质母细胞瘤（GBM）细胞在体外模拟缺血条件下表现出增强的细胞死亡，并且在体内更有可能发展为坏死性肿瘤。两种情况下的细胞死亡均依赖于p38，而p38也是KRAS或PI3K驱动的肿瘤进展所必需的。在模拟缺血条件下，GBM细胞经历依赖活性氧（ROS）的细胞死亡。这些细胞中的基因表达重现了患者GBM坏死周围肿瘤中观察到的多个特征。进一步的研究表明，p38丝裂原活化蛋白激酶激活的蛋白激酶2（MAPKAPK2，又称MK2）信号轴与激活转录因子4（ATF4）和肌醇需求酶1（IRE1α）的未折叠蛋白反应信号成分之间的正反馈回路参与驱动缺血性肿瘤细胞死亡。在缺血条件下，RAS或PI3K激活进一步增强了这一信号级联反应，促进了炎症基因表达反应。因此，我们的研究表明，可以靶向p38以减轻坏死性肿瘤中的炎症反应并抑制GBM进展。
