Escola de Medicina, Programa de Pós-Graduação em Medicina e Ciências da Saúde, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Escola de Ciências, Programa de Pós-Graduação em Biologia Celular e Molecular, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Purinergic Signal. 2019 Mar;15(1):95-105. doi: 10.1007/s11302-018-9642-3. Epub 2019 Jan 14.
Prostate cancer is among the major malignancies that affect men around the world. Adenine nucleotides are important signaling molecules that mediate innumerous biological functions in pathophysiological conditions, including cancer. These molecules are degraded by several ectoenzymes named ectonucleotidases that produce adenosine in the extracellular medium. Some of these ecto-enzymes can be found in soluble in the blood stream. Thus, the present study aimed to evaluate the hydrolysis of adenine nucleotides (ATP, ADP, and AMP) in the plasma blood of patients with prostate cancer. Peripheral blood samples were collected, and questionnaires were filled based on the clinical data of the medical records. The nucleotide hydrolysis was performed by Malachite Green method using ATP, ADP, and AMP as substrates. Plasma from prostate cancer patients presented an elevated hydrolysis of all nucleotides evaluated when compared to healthy individuals. NTPDase inhibitor (ARL67156) and the alkaline phosphatase inhibitor (levamisole) did not alter ATP hydrolysis. However, AMP hydrolysis was reduced by the CD73 inhibitor, APCP, and by levamisole, suggesting the action of a soluble form of CD73 and alkaline phosphatase. On microvesicles, it was observed that there was a low expression and activity of CD39 and almost absent of CD73. The correlation of ATP, ADP, and AMP hydrolysis with clinic pathological data demonstrated that patients who received radiotherapy showed a higher AMP hydrolysis than those who did not, and patients with lower clinical stage (CS-IIA) presented an elevated ATP hydrolysis when compared to those with more advanced clinical stages (CS-IIB and CS-III). Patients of all clinical stages presented an elevated AMPase activity. Therefore, we can suggest that the nucleotide hydrolysis might be attributed to soluble ecto-enzymes present in the plasma, which, in a coordinate manner, produce adenosine in the blood stream, favoring prostate cancer progression.
前列腺癌是影响全球男性的主要恶性肿瘤之一。腺嘌呤核苷酸是重要的信号分子，在生理病理条件下介导许多生物学功能，包括癌症。这些分子被几种称为核苷酸酶的细胞外酶降解，在细胞外基质中产生腺苷。其中一些细胞外酶可以在血液中以可溶性形式存在。因此，本研究旨在评估前列腺癌患者血浆中腺嘌呤核苷酸（ATP、ADP 和 AMP）的水解。采集外周血样，并根据病历的临床数据填写问卷。核苷酸水解通过 Malachite Green 法进行，使用 ATP、ADP 和 AMP 作为底物。与健康个体相比，前列腺癌患者的血浆表现出所有核苷酸水解的升高。NTPDase 抑制剂（ARL67156）和碱性磷酸酶抑制剂（左旋咪唑）并未改变 ATP 水解。然而，CD73 抑制剂 APCP 和左旋咪唑降低了 AMP 水解，表明存在可溶性形式的 CD73 和碱性磷酸酶的作用。在微泡上，观察到 CD39 的表达和活性较低，CD73 几乎不存在。ATP、ADP 和 AMP 水解与临床病理数据的相关性表明，接受放疗的患者比未接受放疗的患者 AMP 水解更高，临床分期（CS-IIA）较低的患者与临床分期较高的患者（CS-IIB 和 CS-III）相比，ATP 水解升高。所有临床分期的患者 AMPase 活性均升高。因此，我们可以认为核苷酸水解可能归因于存在于血浆中的可溶性细胞外酶，这些酶协同作用在血液中产生腺苷，促进前列腺癌的进展。
