Platelet Integrins in Tumor Metastasis: Do They Represent a Therapeutic Target? Cancers (Basel). 2017;9. [PMID: 28956830 PMCID: PMC5664072 DOI: 10.3390/cancers9100133]

Combination of the Preoperative Systemic Immune-Inflammation Index and Monocyte-Lymphocyte Ratio as a Novel Prognostic Factor in Patients with Upper-Tract Urothelial Carcinoma

BACKGROUND

This study aimed to evaluate the clinical significance of the preoperative systemic immune-inflammation index (SII) combined with the monocyte-lymphocyte ratio (MLR) for patients with upper-tract urothelial carcinoma (UTUC).

METHODS

The clinical data of 424 patients who underwent radical nephroureterectomy from January 2007 to June 2017 were analyzed. Kaplan-Meier analyses and Cox proportional hazards models were used to evaluate associations of preoperative systemic immune-inflammatory biomarkers with overall survival (OS), cancer-specific survival (CSS), and progression-free survival (PFS). Moreover, logistic regression preoperative models were applied to predict advanced disease.

RESULTS

Multivariate analyses showed that SII significantly influenced both OS and CSS (both P < 0.05), whereas MLR exhibited the most significant association with OS (P = 0.008). In particular, simultaneously high SII and MLR values correlated significantly with OS, CSS, and PFS (all P < 0.05). Logistic regression preoperative models showed that the combination of high SII and high MLR was a significant predictor of non-organ-confined UTUC (P = 0.001). Furthermore, Kaplan-Meier analysis showed that the combination of high SII and high MLR was significantly linked with poor OS, CSS, and PFS in non-organ-confined UTUC (all P < 0.05).

CONCLUSION

The study reviewed serum inflammation biomarkers in a subset of patients with UTUC and demonstrated the ability of combined SII and MLR to predict disease progression and survival. Patients with both high SII and high MLR were significantly more likely to have non-organ-confined disease and poor survival outcomes.

Anti-platelet treatments in cancer: Basic and clinical research

Over the past few decades the central role that platelets play in cancer development and progression, and especially in metastasis, has been elucidated. The molecular mechanisms responsible for initiating and mediating tumor cell-induced platelet aggregation and secretion have been largely unravelled. Considerable mechanistic insight into how platelets contribute to tumor angiogenesis, immunoevasion and cancer cell invasion have been clarified and, consequently, platelets have been identified as potential new drug targets for cancer therapy. This article gives an overview of the platelet-targeted pharmacologic approaches that have been attempted in the prevention of cancer development, progression and metastasis, including the application of antiplatelet drugs currently used for cardiovascular disease and of new and novel strategies.

Human Cancer and Platelet Interaction, a Potential Therapeutic Target

Cancer patients experience a four-fold increase in thrombosis risk, indicating that cancer development and progression are associated with platelet activation. Xenograft experiments and transgenic mouse models further demonstrate that platelet activation and platelet-cancer cell interaction are crucial for cancer metastasis. Direct or indirect interaction of platelets induces cancer cell plasticity and enhances survival and extravasation of circulating cancer cells during dissemination. In vivo and in vitro experiments also demonstrate that cancer cells induce platelet aggregation, suggesting that platelet-cancer interaction is bidirectional. Therefore, understanding how platelets crosstalk with cancer cells may identify potential strategies to inhibit cancer metastasis and to reduce cancer-related thrombosis. Here, we discuss the potential function of platelets in regulating cancer progression and summarize the factors and signaling pathways that mediate the cancer cell-platelet interaction.

IL-17A promotes the formation of deep vein thrombosis in a mouse model

Deep venous thrombosis (DVT) is a significant problem in the health care industry worldwide. However, the factors and signaling pathways that trigger DVT formation are still largely unknown. In this study, we investigated the role of interleukin-17A (IL-17A) in DVT formation, focusing on the role of platelet aggregation, neutrophil infiltration, and endothelium cell (EC) activation. Notably, IL-17A levels increased in DVT patients as well as in a mouse DVT model. The DVT model mice were injected with recombinant mouse-IL-17A (rIL-17A) or anti-IL-17A monoclonal antibody (mAb) to further evaluate the effects of this cytokine. We found that rIL-17A promotes DVT formation, while IL-17A mAb represses DVT formation. Furthermore, platelet activation, highlighted by CD61 and CD49β expression, and aggregation were enhanced in platelets of rIL-17A-treated mice. rIL-17A also enhanced neutrophil infiltration by regulating the expression of macrophage inflammatory protein-2 (MIP-2) and the release of neutrophil extracellular traps (NETs). IL-17A mAb treatment inhibited both platelet activation and neutrophil activity. Moreover, rIL-17A appears to promote vein EC activation, while IL-17A mAb deters it. Taken together, these data suggest that IL-17A promotes DVT pathogenesis by enhancing platelet activation and aggregation, neutrophil infiltration, and EC activation and that anti-IL-17A mAb could be used for the treatment of DVT.

Direct Fibrinolytic Snake Venom Metalloproteinases Affecting Hemostasis: Structural, Biochemical Features and Therapeutic Potential

Snake venom metalloproteinases (SVMPs) are predominant in viperid venoms, which provoke hemorrhage and affect hemostasis and thrombosis. P-I class enzymes consist only of a single metalloproteinase domain. Despite sharing high sequence homology, only some of them induce hemorrhage. They have direct fibrin(ogen)olytic activity. Their main biological substrate is fibrin(ogen), whose Aα-chain is degraded rapidly and independently of activation of plasminogen. It is important to understand their biochemical and physiological mechanisms, as well as their applications, to study the etiology of some human diseases and to identify sites of potential intervention. As compared to all current antiplatelet therapies to treat cardiovascular events, the SVMPs have outstanding biochemical attributes: (a) they are insensitive to plasma serine proteinase inhibitors; (b) they have the potential to avoid bleeding risk; (c) mechanistically, they are inactivated/cleared by α2-macroglobulin that limits their range of action in circulation; and (d) few of them also impair platelet aggregation that represent an important target for therapeutic intervention. This review will briefly highlight the structure–function relationships of these few direct-acting fibrinolytic agents, including, barnettlysin-I, isolated from Bothrops barnetti venom, that could be considered as potential agent to treat major thrombotic disorders. Some of their pharmacological advantages are compared with plasmin.