Department of Experimental Medicine, Tor Vergata University of Rome, 00133 Rome, Italy.
Int J Mol Sci. 2020 Jan 25;21(3):788. doi: 10.3390/ijms21030788.
Besides their vital role in hemostasis and thrombosis, platelets are also recognized to be involved in cancer, where they play an unexpected central role: They actively influence cancer cell behavior, but, on the other hand, platelet physiology and phenotype are impacted by tumor cells. The existence of this platelet-cancer loop is supported by a large number of experimental and human studies reporting an association between alterations in platelet number and functions and cancer, often in a way dependent on patient, cancer type and treatment. Herein, we shall report on an update on platelet-cancer relationships, with a particular emphasis on how platelets might exert either a protective or a deleterious action in all steps of cancer progression. To this end, we will describe the impact of (i) platelet count, (ii) bioactive molecules secreted upon platelet activation, and (iii) microvesicle-derived miRNAs on cancer behavior. Potential explanations of conflicting results are also reported: Both intrinsic (heterogeneity in platelet-derived bioactive molecules with either inhibitory or stimulatory properties; features of cancer cell types, such as aggressiveness and/or tumour stage) and extrinsic (heterogeneous characteristics of cancer patients, study design and sample preparation) factors, together with other confounding elements, contribute to "the Janus face" of platelets in cancer. Given the difficulty to establish the univocal role of platelets in a tumor, a better understanding of their exact contribution is warranted, in order to identify an efficient therapeutic strategy for cancer management, as well as for better prevention, screening and risk assessment protocols.
除了在止血和血栓形成中发挥重要作用外，血小板还被认为与癌症有关，在癌症中它们起着意想不到的核心作用：它们积极影响癌细胞的行为，但另一方面，血小板的生理和表型也受到肿瘤细胞的影响。大量的实验和人类研究报告了血小板数量和功能的改变与癌症之间的关联，这支持了这种血小板-癌症循环的存在，这种关联通常依赖于患者、癌症类型和治疗。在此，我们将报告血小板与癌症关系的最新进展，特别强调血小板在癌症进展的所有阶段可能发挥保护作用或有害作用。为此，我们将描述(i)血小板计数、(ii)血小板激活后分泌的生物活性分子和(iii)微泡衍生的 miRNAs 对癌症行为的影响。还报告了对冲突结果的潜在解释：内在因素（血小板衍生的生物活性分子具有抑制或刺激特性的异质性；癌症细胞类型的特征，如侵袭性和/或肿瘤分期）和外在因素（癌症患者、研究设计和样本制备的异质性特征），以及其他混杂因素，共同导致了血小板在癌症中的“两面性”。鉴于很难确定血小板在肿瘤中的明确作用，需要更好地了解它们的确切贡献，以便为癌症管理确定有效的治疗策略，以及更好的预防、筛查和风险评估方案。
