Bien-Möller Sandra, Grober Antonia, Albrecht Judith, Paland Heiko, Weitmann Kerstin, Bialke Angela, Marx Sascha, Vogelgesang Silke, Tzvetkov Mladen V, Hoffmann Wolfgang, Schroeder Henry W S, Rauch Bernhard H
Department of Pharmacology, University Medicine Greifswald, Greifswald, Germany.
Clinic of Neurosurgery, University Medicine Greifswald, Greifswald, Germany.
Front Oncol. 2025 Jul 22;15:1582996. doi: 10.3389/fonc.2025.1582996. eCollection 2025.
Glioblastoma (GBM) remains the most aggressive and common malignant brain tumor in adults, often accompanied by venous thromboembolism due to hypercoagulability. Protease-activated receptors (PAR1-4) are thought to influence GBM progression, which in this study led to examine their expression in both tissue from GBM patients and in a GBM cell model.
Using quantitative PCR and immunoblot analyses, we investigated the expression of PAR1-4 in human GBM samples compared to non-malignant brain and evaluated its role in patient survival. In addition, the expression of PAR1-4 in adherent LN-18 GBM cells in comparison to their stem cell-like neurosphere counterparts was analyzed. Finally, the influence of PAR1-4 modulation by specific agonists and antagonists on cell viability was investigated using this GBM cell model.
PAR1-4 mRNA levels were significantly higher in GBM than in non-tumoral brain tissue, though this did not affect patient survival. Notably, PAR4 protein levels were lower in GBM, while PAR1, 2, and 3 were unchanged. However, high PAR1 protein levels were linked to poorer patient survival, with a similar trend observed for PAR4, though not statistically significant. Patients with high levels of both PAR1 and PAR3 or PAR4 faced an even greater risk of poor outcomes, but the most severe prognosis was seen in those patients with high PAR3 and PAR4 protein level. In stem-like LN-18 GBM neurospheres, PAR1-4 mRNA was significantly increased, with PAR3 protein elevated and PAR4 reduced. Inhibition of PAR1, PAR2, or PAR4 reduced the viability of adherent GBM cells but not stem-like neurospheres.
These findings suggest that PARs impact GBM patient survival and that tumor stem cells may respond differently to PAR inhibition compared to conventional tumor cells.
胶质母细胞瘤（GBM）仍是成人中最具侵袭性和常见的恶性脑肿瘤，常因高凝状态伴有静脉血栓栓塞。蛋白酶激活受体（PAR1 - 4）被认为会影响GBM的进展，因此在本研究中对其在GBM患者组织和GBM细胞模型中的表达进行了检测。
我们使用定量PCR和免疫印迹分析，研究了PAR1 - 4在人类GBM样本与非恶性脑组织中的表达情况，并评估了其在患者生存中的作用。此外，分析了贴壁LN - 18 GBM细胞与其干细胞样神经球对应物中PAR1 - 4的表达。最后，使用该GBM细胞模型研究了PAR1 - 4特异性激动剂和拮抗剂对细胞活力的影响。
GBM中PAR1 - 4的mRNA水平显著高于非肿瘤脑组织，尽管这并不影响患者生存。值得注意的是，GBM中PAR4蛋白水平较低，而PAR1、2和3未发生变化。然而，PAR1蛋白水平高与患者较差的生存相关，PAR4也观察到类似趋势，但无统计学意义。PAR1和PAR3或PAR4水平都高的患者面临更差预后的风险更大，但PAR3和PAR4蛋白水平高的患者预后最差。在干细胞样LN - 18 GBM神经球中，PAR1 - 4 mRNA显著增加，PAR3蛋白升高而PAR4降低。抑制PAR1、PAR2或PAR4可降低贴壁GBM细胞的活力，但对干细胞样神经球无效。
这些发现表明PARs影响GBM患者生存，并且肿瘤干细胞与传统肿瘤细胞相比，对PAR抑制的反应可能不同。
