The TICONC (Ticagrelor-Oncology) Study: Implications of P2Y12 Inhibition for Metastasis and Cancer-Associated Thrombosis

Role and recent progress of P2Y12 receptor in cancer development

P2Y12 receptor (P2Y12R) is an adenosine-activated G protein-coupled receptor (GPCR) that plays a central role in platelet function, hemostasis, and thrombosis. P2Y12R activation can promote platelet aggregation and adhesion to cancer cells, promote tumor angiogenesis, and affect the tumor immune microenvironment (TIME) and tumor drug resistance, which is conducive to the progression of cancers. Meanwhile, P2Y12R inhibitors can inhibit this effect, suggesting that P2Y12R may be a potential therapeutic target for cancer. P2Y12R is involved in cancer development and metastasis, while P2Y12R inhibitors are effective in inhibiting cancer. However, a new study suggests that long-term use of P2Y12R inhibitors may increase the risk of cancer and the mechanism remains to be explored. In this paper, we reviewed the structural and functional characteristics of P2Y12R and its role in cancer. We explored the role of P2Y12R inhibitors in different tumors and the latest advances by summarizing the basic and clinical studies on the effects of P2Y12R inhibitors on tumors.

P2 purinergic receptors regulate the progression of colorectal cancer

More and more studies have revealed that P2 purinergic receptors play a key role in the progression of colorectal cancer (CRC). P2X and P2Y purinergic receptors can be used as promoters and regulators of CRC and play a dual role in the progression of CRC. CRC microenvironment is rich in ATP and its cleavage products (ADP, AMP, Ado), which act as activators of P2X and P2Y purinergic receptors. The activation of P2X and P2Y purinergic receptors regulates the progression of CRC mainly by regulating the function of immune cells and mediating different signal pathways. In this paper, we focus on the specific mechanisms and functional roles of P2X7, P2Y12, and P2Y2 receptors in the growth and progression of CRC. The antagonistic effects of these selective antagonists of P2X purinergic receptors on the growth, invasion, and metastasis of CRC were further discussed. Moreover, different studies have reported that P2X7 receptor can be used as an effective predictor of patients with CRC. All these indicate that P2 purinergic receptors are a key regulator of CRC. Therefore, antagonizing P2 purinergic receptors may be an innovative treatment for CRC.

Platelet-Based Nanoparticles with Stimuli-Responsive for Anti-Tumor Therapy

In addition to hemostasis and coagulation, years of studies have proved that platelets are involved in the whole process of tumor progression, including tumor invasion, intravasation, extravasation, and so on. It means that this property of platelets can be used in anti-tumor therapy. However, traditional platelet-based antitumor drugs often cause autologous platelet damage due to lack of targeting, resulting in serious side effects. Therefore, the researchers designed a variety of anti-tumor drug delivery systems based on platelets by targeting platelets or platelet membrane coating. The drug delivery systems have special response modes, which is crucial in the design of nanoparticles. These modes enhance the targeting and improve the anti-tumor effect. Here, we present a review of recent discoveries in the field of the crosstalk between platelets and tumors and the progress of platelet-based anti-tumor nanoparticles.

Acute reperfusion treatment and secondary prevention of cancer-related stroke: comprehensive overview and proposal of clinical algorithm

Cancer-related stroke (CRS), referring to ischemic stroke occurring in cancer patients without other clear etiology, represents a clinical challenge, as it is associated with unfavorable clinical outcomes including high rates of recurrence and mortality. There are scarce international recommendations and limited consensus statements on CRS management. For this comprehensive overview, the available studies/reviews/meta-analyses on the use of acute reperfusion and secondary prevention treatments for cancer patients with ischemic stroke, focusing on antithrombotic agents, were collected and summarized. A practical management algorithm was designed per the available data. In short, acute reperfusion in the form of intravenous thrombolysis and mechanical thrombectomy appears to be safe in CRS and can be considered for eligible patients, though the functional outcomes are often poor, and mostly defined by the preexisting condition. Many patients carry indications for anticoagulation, in which case vitamin K antagonists are not preferred, while low-molecular weight heparins remain the treatment of choice; direct oral anticoagulants can be alternatively considered but are contraindicated for gastrointestinal malignancies. For patients without clear anticoagulation indications, no net benefit for anticoagulation compared to aspirin has been shown. Other targeted treatment options should be evaluated in an individualized approach, alongside the appropriate management of conventional cerebrovascular risk factors. Oncological treatment should be swiftly initiated/continued. In conclusion, acute CRS remains a clinical challenge, with many patients suffering recurrent stroke, despite preventive measures. More randomized-controlled clinical trials are urgently needed to pinpoint the most effective management options for this subset of stroke patients.

The Signaling Pathway of the ADP Receptor P2Y12 in the Immune System: Recent Discoveries and New Challenges

P2Y12 is a G-protein-coupled receptor that is activated upon ADP binding. Considering its well-established role in platelet activation, blocking P2Y12 has been used as a therapeutic strategy for antiplatelet aggregation in cardiovascular disease patients. However, receptor studies have shown that P2Y12 is functionally expressed not only in platelets and the microglia but also in other cells of the immune system, such as in monocytes, dendritic cells, and T lymphocytes. As a result, studies were carried out investigating whether therapies targeting P2Y12 could also ameliorate inflammatory conditions, such as sepsis, rheumatoid arthritis, neuroinflammation, cancer, COVID-19, atherosclerosis, and diabetes-associated inflammation in animal models and human subjects. This review reports what is known about the expression of P2Y12 in the cells of the immune system and the effect of P2Y12 activation and/or inhibition in inflammatory conditions. Lastly, we will discuss the major problems and challenges in studying this receptor and provide insights on how they can be overcome.

Interactions between Platelets and Tumor Microenvironment Components in Ovarian Cancer and Their Implications for Treatment and Clinical Outcomes

Platelets, the primary operatives of hemostasis that contribute to blood coagulation and wound healing after blood vessel injury, are also involved in pathological conditions, including cancer. Malignancy-associated thrombosis is common in ovarian cancer patients and is associated with poor clinical outcomes. Platelets extravasate into the tumor microenvironment in ovarian cancer and interact with cancer cells and non-cancerous elements. Ovarian cancer cells also activate platelets. The communication between activated platelets, cancer cells, and the tumor microenvironment is via various platelet membrane proteins or mediators released through degranulation or the secretion of microvesicles from platelets. These interactions trigger signaling cascades in tumors that promote ovarian cancer progression, metastasis, and neoangiogenesis. This review discusses how interactions between platelets, cancer cells, cancer stem cells, stromal cells, and the extracellular matrix in the tumor microenvironment influence ovarian cancer progression. It also presents novel potential therapeutic approaches toward this gynecological cancer.

The role and pharmacological properties of P2Y12 receptor in cancer and cancer pain

The G protein-coupled P2Y12 receptor (P2Y12R) was cloned in platelets and found to play a key role in maintaining platelet function in hemostasis and thrombosis, and these effects could be mediated by the P2Y12R. However, it has recently been found that P2Y12R-mediated the progression of tumor through interactions between platelets and tumor and stromal cells, as well as through products secreted by platelets. During tumor progression, tumor cells or other cells in the tumor microenvironment (such as immune cells) can secrete large amounts of ATP into the extracellular matrix, and extracellular ATP can be hydrolyzed into ADP. ADP is a P2Y12R activator and plays an important regulatory role in the proliferation and metastasis of tumor cells. P2Y12R is involved in platelet-cancer cell crosstalk and become a potential target for anticancer therapy. Moreover, tumor progression can induce pain, which seriously affects the quality of life of patients. P2Y12R is expressed in microglia and mediates the activities of microglial and participates in the occurrence of cancer pain. Conversely, inhibiting P2Y12R activation and down-regulating its expression has the effect of inhibiting tumor progression and pain. Therefore, P2Y12R can be a common therapeutic target for both. In this article, we explored the potential link between P2Y12R and cancer, discussed the intrinsic link of P2Y12R in cancer pain and the pharmacological properties of P2Y12R antagonists in the treatment of both.

The role of microvesicles as biomarkers in the screening of colorectal neoplasm

Background

Colorectal cancer (CRC) is the second cause of cancer death worldwide. The role of circulating microvesicles as a screening tool is a novel, yet effective approach that warrants prioritised research.

Methods

In a two‐gate diagnostic accuracy study, 35 patients with benign colorectal polyps (BCRP) (n = 16) and colorectal cancer (CRC) (n = 19) were compared to 17 age‐matched healthy controls. Total annexin‐V positive microvesicles and sub‐populations positive for selected biomarkers relevant to bowel neoplasm were evaluated in patients' plasma using flow cytometry. Statistical methods including factor analysis utilising two component factors were performed to obtain optimal diagnostic accuracy of microvesicles in identifying patients with colorectal neoplasms.

Results

Total plasma microvesicles, and sub‐populations positive for CD31, CD42a, CD31+/CD42a‐, EPHB2, ICAM and LGR5 (component factor‐1) were able to identify patients with BCRP and CRC with a receiver operator curve (AUC) accuracy of a 100% (95% CI: 100%–100%) and 95% (95% CI: 88%–100%), respectively. To identify patients with BCRP, a cut‐off point value of component factor‐1761 microvesicles/μl demonstrated a 100% sensitivity, specificity and negative predictive value (NPV) and a 93% positive predictive value (PPV). To identify patients with CRC, a cut‐off value of component factor‐1 ³439 microvesicles/μl demonstrated a 100% sensitivity, specificity and NPV and a 65% PPV. CEA+ microvesicles sub‐population were significantly (p < 0.02) higher in CRC in comparison to BCRP.

Conclusions

Microvesicles as biomarkers for the early and accurate detection of CRC is a simple and effective tool that yields a potential breakthrough in clinical management.

Antiplatelet Agents Affecting GPCR Signaling Implicated in Tumor Metastasis

Metastasis requires that cancer cells survive in the circulation, colonize distant organs, and grow. Despite platelets being central contributors to hemostasis, leukocyte trafficking during inflammation, and vessel stability maintenance, there is significant evidence to support their essential role in supporting metastasis through different mechanisms. In addition to their direct interaction with cancer cells, thus forming heteroaggregates such as leukocytes, platelets release molecules that are necessary to promote a disseminating phenotype in cancer cells via the induction of an epithelial-mesenchymal-like transition. Therefore, agents that affect platelet activation can potentially restrain these prometastatic mechanisms. Although the primary adhesion of platelets to cancer cells is mainly independent of G protein-mediated signaling, soluble mediators released from platelets, such as ADP, thromboxane (TX) A2, and prostaglandin (PG) E2, act through G protein-coupled receptors (GPCRs) to cause the activation of more additional platelets and drive metastatic signaling pathways in cancer cells. In this review, we examine the contribution of the GPCRs of platelets and cancer cells in the development of cancer metastasis. Finally, the possible use of agents affecting GPCR signaling pathways as antimetastatic agents is discussed.

Common Pathophysiology in Cancer, Atrial Fibrillation, Atherosclerosis, and Thrombosis: JACC: CardioOncology State-of-the-Art Review

Cardiovascular disease and cancer are the 2 leading causes of death worldwide. Emerging evidence suggests common mechanisms between cancer and cardiovascular disease, including atrial fibrillation and atherosclerosis. With advances in cancer therapies, screening, and diagnostics, cancer-specific survival and outcomes have improved. This increase in survival has led to the coincidence of cardiovascular disease, including atrial fibrillation and atherosclerosis, as patients with cancer live longer. Additionally, cancer and cardiovascular disease share several risk factors and underlying pathophysiologic mechanisms, including inflammation, cancer-related factors including treatment effects, and alterations in platelet function. Patients with cancer are at increased risk for bleeding and thrombosis compared with the general population. Although optimal antithrombotic therapy, including agent choice and duration, has been extensively studied in the general population, this area remains understudied in patients with cancer despite their altered thrombotic and bleeding risk. Future investigation, including incorporation of cancer-specific characteristics to traditional thrombotic and bleeding risk scores, clinical trials in the cancer population, and the development of novel antithrombotic and anti-inflammatory strategies on the basis of shared pathophysiologic mechanisms, is warranted to improve outcomes in this patient population.

Metastasis Prevention: Focus on Metastatic Circulating Tumor Cells

Metastasis is the main cause of cancer death. Metastatic foci are derived from tumor cells that detach from the primary tumor and then enter the circulation. Circulating tumor cells (CTCs) are generally associated with a high probability of distant metastasis and a negative prognosis. Most CTCs die in the bloodstream, and only a few cells form metastases. Such metastatic CTCs have a stem-like and hybrid epithelial-mesenchymal phenotype, can avoid immune surveillance, and show increased therapy resistance. Targeting metastatic CTCs and their progenitors in primary tumors and their descendants, particularly disseminated tumor cells, represents an attractive strategy for metastasis prevention. However, current therapeutic strategies mainly target the primary tumor and only indirectly affect metastasis-initiating cells. Here, we consider potential methods for preventing metastasis based on targeting molecular and cellular features of metastatic CTCs, including CTC clusters. Also, we emphasize current knowledge gaps in CTC biology that should be addressed to develop highly effective therapeutics and strategies for metastasis suppression.

Platelets: the point of interconnection among cancer, inflammation and cardiovascular diseases

INTRODUCTION

The association between thrombosis, cancer and inflammation is well-established. Platelets play a major role in atherosclerosis, inflammation and immune response. Furthermore, growing evidence suggests that they are also significantly involved in tumor development and progression so that anti-platelet agents may prevent cancer and improve outcomes in oncological patients. In this review, we aimed at analyzing the relationship between platelets, cardiovascular diseases and cancer. A comprehensive study in the main educational platforms was performed and high-quality original articles and reviews were included.

AREAS COVERED

This review will focus on the role of platelets in cardiovascular disease and in cancer genesis and progression, analyzing their function as immune cells that link inflammation to thrombosis. Finally, it will examine the recent controversies on the use of anti-platelet agents as cancer medications, in particular the already known anti-tumor properties of aspirin, as well as the new perspectives regarding P2Y12 inhibitors.

EXPERT OPINION

Platelet-cancer crosstalk generates a vicious feed-back loop involving tumor cells and secreting molecules that activate platelets, which in turn promote cancer-associated inflammation, proliferation, spreading and immune system evasion. Therefore, platelets inhibition may represent an innovative therapeutical strategy offered to cancer patients, in the perspective of personalized medicine.

An updated drug profile of ticagrelor with considerations on the treatment of patients with coronary artery disease and diabetes mellitus

INTRODUCTION

Ticagrelor is an antiplatelet agent acting through direct and reversible competitive inhibition of the platelet P2Y₁₂ receptor. While the clinical merits of ticagrelor in patients who experienced an acute coronary syndrome are widely accepted, its role in stable coronary artery disease is less established. Recently, large-scale trials of ticagrelor have been published in this setting, including a trial in patients with diabetes mellitus (DM).

AREAS COVERED

This review aims to inform about recent findings on ticagrelor, by appraising the current body of evidence on its use in different clinical scenarios, particularly in DM, ranging from pharmacology to clinical outcomes and future directions.

EXPERT OPINION

The results of the THEMIS trial, conducted in DM patients with stable coronary artery disease and no prior stroke or myocardial infarction, showed that although ticagrelor in addition to aspirin reduced the risk of ischemic events, this was associated with a parallel increase in bleeding complications. However, patients with history of percutaneous coronary intervention seemed to benefit more from adjunctive ticagrelor therapy. Careful bleeding and ischemic risk stratification remains crucial to define the best antithrombotic strategy for the individual patient.