Alajeyan Iman A, Alsughayyir Jawaher, Alfhili Mohammad A
Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
Dose Response. 2025 Jan 15;23(1):15593258251314825. doi: 10.1177/15593258251314825. eCollection 2025 Jan-Mar.
Cytokinins are plant hormones that regulate cell growth and differentiation. In particular, zeatin (ZTN) delays cellular senescence of human fibroblasts and keratinocytes and exhibits anticancer activity. Chemotherapy-induced anemia is a major side effect of anticancer therapy secondary to premature senescence of red blood cells (RBCs). Herein, we investigated the biochemical and molecular mechanisms underlying ZTN action in human RBCs. Colorimetric assays were used to quantify hemolysis and related markers and flow cytometric analysis was applied to examine eryptosis through phosphatidylserine (PS) exposure by annexin-V-FITC, intracellular Ca by Fluo4/AM, reactive oxygen species (ROS) by HDCFDA, and cell size from forward scatter (FSC). ZTN at 200 μM induced significant hemolysis and K, Na, AST, and LDH leakage. ZTN also caused a significant increase in annexin-V-positive cells along with increased Fluo4 and DCF fluorescence and reduced FSC. Importantly, L-NAME, staurosporin, D4476, urea, sucrose, and polyethylene glycol 8000 (PEG) significantly ameliorated ZTN cytotoxicity. ZTN stimulates PS exposure, intracellular Ca elevation, oxidative stress, and cell shrinkage. The hemolytic potential of ZTN, mediated through nitric oxide synthase/protein kinase C/casein kinase 1α signaling axis, is sensitive to isosmotic urea, sucrose, and PEG availability. Altogether, the anticancer potential of ZTN must be reconsidered with prudence.
细胞分裂素是调节细胞生长和分化的植物激素。特别是玉米素(ZTN)可延缓人成纤维细胞和角质形成细胞的细胞衰老,并具有抗癌活性。化疗引起的贫血是抗癌治疗的主要副作用,继发于红细胞(RBC)过早衰老。在此,我们研究了ZTN在人红细胞中作用的生化和分子机制。采用比色法测定溶血及相关标志物的含量,并应用流式细胞术分析膜联蛋白-V-FITC检测磷脂酰丝氨酸(PS)暴露、Fluo4/AM检测细胞内钙、HDCFDA检测活性氧(ROS)以及前向散射(FSC)检测细胞大小来检测红细胞凋亡。200μM的ZTN可诱导显著的溶血以及钾、钠、天冬氨酸转氨酶(AST)和乳酸脱氢酶(LDH)泄漏。ZTN还导致膜联蛋白-V阳性细胞显著增加,同时Fluo4和二氯荧光素(DCF)荧光增加,FSC降低。重要的是,L-硝基精氨酸甲酯(L-NAME)、星形孢菌素、D4476、尿素、蔗糖和聚乙二醇8000(PEG)可显著改善ZTN的细胞毒性。ZTN刺激PS暴露、细胞内钙升高、氧化应激和细胞收缩。ZTN的溶血潜能通过一氧化氮合酶/蛋白激酶C/酪蛋白激酶1α信号轴介导,对等渗尿素、蔗糖和PEG的可用性敏感。总之,必须谨慎重新考虑ZTN的抗癌潜力。