Tarnowski Maciej, Tkacz Marta, Piotrowska Katarzyna, Zgutka Katarzyna, Pawlik Andrzej
Department of Physiology, Pomeranian Medical University, Szczecin, Poland.
Arch Med Sci. 2018 Apr 26;16(2):414-427. doi: 10.5114/aoms.2018.75506. eCollection 2020.
Adenosine and its receptors are involved deeply in the regulation of tumour biology. Purine nucleotides are released from stressed cells in states of hypoxia or radiochemotherapy-induced cell damage. Adenosine exerts its effect through the P1 family of selective receptors. The purpose of the study was to evaluate the exact role of extracellular role on biology of Rhabdomyosarcoma (RMS) cells.
Series of studies accompanied by immunohistochemical, RQ-PCR and shRNA methods have characterised adenosine receptor expression on Rhabdomyosarcoma cell lines, normal skeletal muscle and effect of adenosine on Rhabdomyosarcoma growth and migration.
Extracellular adenosine (highest at 50 μM, < 0.05) and AMP (highest at 300 μM, < 0.05) markedly enhanced chemotaxis in the Boyden chamber assay The reaction is mostly governed by the A1 receptor, which is greatly overexpressed in Rhabdomyosarcoma as compared with normal skeletal muscle. Cell migration induced by adenosine and AMP is blocked by pertussis toxin, phospholipase C and MAP kinase inhibitor, which demonstrates the importance of these signalling pathways. High doses of adenosine have a detrimental effect on cellular proliferation, in a receptor-independent manner (≥ 500 μM; < 0.05). The blockage of adenosine transporter by dipyridamole abolishes this effect, indicating involvement of an intrinsic pathway. Further increase of adenosine concentration, induced by deaminase inhibitors, augment the effect.
Our results suggest that adenosine and AMP trigger cell migration by binding to P1 receptors and directing cancer cells to the sites of hypoxia or cellular damage. Specifically by A1 receptor which is overexpressed in RMS.
腺苷及其受体在肿瘤生物学调节中发挥着重要作用。嘌呤核苷酸在缺氧或放化疗诱导的细胞损伤状态下从应激细胞中释放出来。腺苷通过P1选择性受体家族发挥作用。本研究的目的是评估细胞外腺苷在横纹肌肉瘤（RMS）细胞生物学中的具体作用。
采用免疫组织化学、RQ-PCR和shRNA方法进行了一系列研究，以表征腺苷受体在横纹肌肉瘤细胞系、正常骨骼肌中的表达，以及腺苷对横纹肌肉瘤生长和迁移的影响。
在Boyden小室试验中，细胞外腺苷（50μM时最高，<0.05）和AMP（300μM时最高，<0.05）显著增强趋化作用。该反应主要由A1受体介导，与正常骨骼肌相比，A1受体在横纹肌肉瘤中大量过表达。腺苷和AMP诱导的细胞迁移被百日咳毒素、磷脂酶C和丝裂原活化蛋白激酶抑制剂阻断，这表明这些信号通路的重要性。高剂量腺苷以受体非依赖方式对细胞增殖产生有害影响（≥500μM；<0.05）。双嘧达莫对腺苷转运体的阻断消除了这种作用，表明存在一条内在途径。脱氨酶抑制剂诱导的腺苷浓度进一步升高增强了这种作用。
我们的结果表明，腺苷和AMP通过与P1受体结合并将癌细胞导向缺氧或细胞损伤部位来触发细胞迁移。特别是通过在RMS中过表达的A1受体。
