Quercetin-loaded platelets as a potential targeted therapy for glioblastoma multiforme cell line U373-MG

The role of platelets in the regulation of tumor growth and metastasis: the mechanisms and targeted therapy

Platelets are a class of pluripotent cells that, in addition to hemostasis and maintaining vascular endothelial integrity, are also involved in tumor growth and distant metastasis. The tumor microenvironment is a complex and comprehensive system composed of tumor cells and their surrounding immune and inflammatory cells, tumor-related fibroblasts, nearby interstitial tissues, microvessels, and various cytokines and chemokines. As an important member of the tumor microenvironment, platelets can promote tumor invasion and metastasis through various mechanisms. Understanding the role of platelets in tumor metastasis is important for diagnosing the risk of metastasis and prolonging survival. In this study, we more fully elucidate the underlying mechanisms by which platelets promote tumor growth and metastasis by modulating processes, such as immune escape, angiogenesis, tumor cell homing, and tumor cell exudation, and further summarize the effects of platelet-tumor cell interactions in the tumor microenvironment and possible tumor treatment strategies based on platelet studies. Our summary will more comprehensively and clearly demonstrate the role of platelets in tumor metastasis, so as to help clinical judgment of the potential risk of metastasis in cancer patients, with a view to improving the prognosis of patients.

Onco-Pathogen Mediated Cancer Progression and Associated Signaling Pathways in Cancer Development

Infection with viruses, bacteria, and parasites are thought to be the underlying cause of about 8-17% of the world's cancer burden, i.e., approximately one in every five malignancies globally is caused by an infectious pathogen. Oncogenesis is thought to be aided by eleven major pathogens. It is crucial to identify microorganisms that potentially act as human carcinogens and to understand how exposure to such pathogens occur as well as the following carcinogenic pathways they induce. Gaining knowledge in this field will give important suggestions for effective pathogen-driven cancer care, control, and, ultimately, prevention. This review will mainly focus on the major onco-pathogens and the types of cancer caused by them. It will also discuss the major pathways which, when altered, lead to the progression of these cancers.

Quercetin and Its Nano-Formulations for Brain Tumor Therapy—Current Developments and Future Perspectives for Paediatric Studies

The development of efficient treatments for tumors affecting the central nervous system (CNS) remains an open challenge. Particularly, gliomas are the most malignant and lethal form of brain tumors in adults, causing death in patients just over 6 months after diagnosis without treatment. The current treatment protocol consists of surgery, followed using synthetic drugs and radiation. However, the efficacy of these protocols is associated with side effects, poor prognosis and with a median survival of fewer than two years. Recently, many studies were focused on applying plant-derived products to manage various diseases, including brain cancers. Quercetin is a bioactive compound derived from various fruits and vegetables (asparagus, apples, berries, cherries, onions and red leaf lettuce). Numerous in vivo and in vitro studies highlighted that quercetin through multitargeted molecular mechanisms (apoptosis, necrosis, anti-proliferative activity and suppression of tumor invasion and migration) effectively reduces the progression of tumor cells. This review aims to summarize current developments and recent advances of quercetin’s anticancer potential in brain tumors. Since all reported studies demonstrating the anti-cancer potential of quercetin were conducted using adult models, it is suggested to expand further research in the field of paediatrics. This could offer new perspectives on brain cancer treatment for paediatric patients.

A Flavonoid on the Brain: Quercetin as a Potential Therapeutic Agent in Central Nervous System Disorders

Quercetin is one of the most common, naturally occurring flavonoids, structurally classified to the flavonol subfamily. This compound, found in many edible and medicinal plants either as a free or glycosidated form, has been scientifically exploited for many years, and one could hardly expect it could be a hero of some additional story. Commonly recognized as an anti-inflammatory agent, quercetin not only limits capillary vessel permeability by inhibiting hyaluronidase but also blocks cyclooxygenases and lipoxygenases. As a typical flavonoid, it is also known for its antioxidant effect, which was confirmed by many in vitro and in vivo studies. Throughout the years, numerous other activities were reported for quercetin, including antidiabetic, anti-proliferative, or anti-viral. Of note, recent data have revealed its potential role as a therapeutic agent for several central nervous system disorders. This review provides an overview of available experimental data on quercetin and its complexes with respect to central nervous system diseases, with a main focus on some aspects that were not discussed previously, such as anti-anxiolytic effects, anti-Huntington’s disease activity, or therapeutic potential in brain cancer. Moreover, quercetin’s protective role in some of these diseases is discussed, especially as an anti-neuroinflammatory agent. Bearing in mind the poor bioavailability of this compound, possible options that would enhance its delivery to the site of action are also presented.

Quercetin Alleviates the Progression of Breast Cancer-Related Depression via Inhibiting the Pyroptosis and Promoting the Immune Response

Background. Breast cancer-related depression (BCRD) seriously inhibits the life quality of patients with breast cancer. The Xiaoyao Kangai Jieyu Formula is known to inhibit the progression of depression. However, the detailed function of the Xiaoyao Kangai Jieyu Formula in BCRD remains unclear. Methods. Network pharmacology was constructed to assess the downstream target of the Xiaoyao Kangai Jieyu Formula in BCRD. In addition, the tail suspension test, sucrose preference test, and forced swimming test were used to test the symptom of depression in mice. Fluoro-Jade B staining was performed to observe the structure of neurons. RT-qPCR and western blot were applied to evaluate mRNA and protein levels. Besides, ELISA was performed to test the inflammatory responses and the immune response-related cytokines. Results. Quercetin was identified as the key component of the Xiaoyao Kangai Jieyu Formula. Quercetin significantly inhibited BCRD-induced neuron pyroptosis via downregulation of PYD and card domain containing (ASC), NLR family pyrin domain containing 3 (NLRP3), and caspase-1, and quercetin could reverse BCRD-caused inhibition of neuron viability. Quercetin significantly attenuated the symptom of BCRD in mice, and it could reverse the contents of 5-hydroxytryptamine (5-HT), dopamine (DA), and neutrophil elastase (NE) in mice. Moreover, quercetin could promote the immune responses in xenograft mice via upregulation of interleukin- (IL-) 2, interferon-γ (IFN-γ), and IL-10. Conclusion. Quercetin, the active ingredient of the Xiaoyao Kangai Jieyu Formula, effectively mitigated the progression of BCRD by inhibiting pyroptosis, promoting immune response, and improving serum metabolism.