Tumor-stroma cross talk and platelets: Curse of cancers

Platelets are essential part of our vascular system, named as thrombocytes and their main role is to stop bleeding; by clumping and aggregating at damaged vascular location. Embryonically the platelets originate in bone marrow from megakaryocytes. These are smallest structures among blood cells, with average dimensions less than 4 microns in size, biconvex or straight ends and normally are colorless without nucleus [1].


Introduction
Platelets are essential part of our vascular system, named as thrombocytes and their main role is to stop bleeding; by clumping and aggregating at damaged vascular location. Embryonically the platelets originate in bone marrow from megakaryocytes. These are smallest structures among blood cells, with average dimensions less than 4 microns in size, biconvex or straight ends and normally are colorless without nucleus [1].
Routinely these blood components help in clot formation and repair of tissue after trauma or injury, but on the other hand their close association is noticed in various malignancies and infections. This is possible due to following qualities such as; a) Attachment on surface: Formation of meshwork at suitable environment, that is helpful during anchorage for travelling cells.
b) Aggregation: This quality helps them to group together during activated form to form meshwork. c) Agglutination: It is the clumping together of platelets.
The above properties play signifi cant role during distant journey of malignant cells, helping them to withstand mechanical damage [2]. Concept of thromboembolic events and coagulation cascade was highlighted by Armand Trousseau in1865. Recently this is understood that, platelet driven growth factors help growth and proliferation of cancers [3].

Historical background
Around two centuries back platelets became familiar to scientists, after discovery of compound microscope in 1830; by Joseph Jackson Lister. The fi rst picture was made by George Gulliver in 1841, and a year later in 1842; William Addison drew picture of platelet-fi brin clot. However maximum awareness was generated when Lionel Beale fi rst published his sketches of platelets in 1864. In 1865 Max Schultzer identifi ed very small structures, which were smaller than red blood cells and termed as, "spherules". But actual scientifi c explanation of platelets was put forward by Dr Richard Hill Norris in 1880.
Previous studies are helpful to understand pathophysiologic association of blood platelets during routine reparative phenomenon as well as carcino-angiogenic concepts respectively [4][5][6].

Discussion
The aggregating nature of this micro structure of blood plays important role to attract disseminated membrane bound vesicles, later on these Platelet-related microparticles (PMP) alarm to initiate tissue proteins such as cytokine molecules and interleukins. Later on these charged energy driven substances help in growth, proliferation and distant spread of many cancerous cells. Apart from this; platelets also play signifi cant role during venous thromboembolic events and vascular anastomosis [7].

Goubran H. A. et al suggested that, there is direct communication between blood platelets and Extracellular
Matrix (ECM) of tumors, as this intra cellular cross-talk activates to release multiple platelet derived growth factors. These charged cellular products orchestrate entire scenario of neoangiogenesis, proliferation and distant spread of malignant cells. Henceforth modifi cation in this molecular concept of platelets and their antagonist companions may be helpful step towards restricting the growing cancers [8].
During process of tumor-stroma cross talk; cancer cells hijack genetic phenotype and remodel growth factors of platelets, which further act as immune mediators during rapid progress of neoplastic cells [9]. Along with this, Cancer cells have skill to change genetic phenotype of extracellular matrix and by this virtue they collect platelets in early stages of metastasis. This collection of platelets is known as Tumor Cell-https://www.peertechz.com/journals/annals-of-molecular-and-genetic-medicine and GPIIb/IIIa activate platelets to present P-selectins; which are responsible for interaction of leukocytes and platelets. In this manner platelets make cyto-cellular structure to provide safe and comfortable environment to cancer cells for further growth, progress and proliferation (Figure 1) [10]. related deaths are due to metastasis of cancers, and this is quite possible because of inadvertent nature of platelets and associated growth factors. So understanding this basic pathophysiology of these blood cells, can be guiding force in the fi eld of molecular biology during interventions of various cancers.