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Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Stem Cells. Nov 26, 2020; 12(11): 1237-1254
Published online Nov 26, 2020. doi: 10.4252/wjsc.v12.i11.1237
Role of platelets and breast cancer stem cells in metastasis
Gretel Mendoza-Almanza, Luis Burciaga-Hernández, Vilma Maldonado, Jorge Melendez-Zajgla, Jorge Olmos
Gretel Mendoza-Almanza, CONACYT, Universidad Autónoma de Zacatecas., Zacatecas 98060, Mexico
Luis Burciaga-Hernández, Maestría en Ciencias Biomédicas, Universidad Autónoma de Zacatecas, Zacatecas 98160, Mexico
Vilma Maldonado, Laboratorio de Epigenética, Instituto Nacional de Medicina Genómica, Ciudad de México 14610, Mexico
Jorge Melendez-Zajgla, Génómica funcional del cáncer, Instituto Nacional de Medicina Genómica, Ciudad de México 14610, Mexico
Jorge Olmos, Biotecnología Marina, Centro de Investigación Científica y de Estudios Superiores de Ensenada, Ensenada 22860, Mexico
Author contributions: All authors contributed equally to this paper with regard to cited literature and initial draft preparation; Mendoza-Almanza G and Olmos J were involved in manuscript conceptualization; all authors read and approved the final version of the manuscript.
Conflict-of-interest statement: No potential conflicts of interest. No financial support.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Jorge Olmos, DSc, Professor, Biotecnología Marina, Centro de Investigación Científica y de Estudios Superiores de Ensenada, Carretera Ensenada-Tijuana, Ensenada, Ensenada 22860, Mexico. jolmos@cicese.mx
Received: July 1, 2020
Peer-review started: July 1, 2020
First decision: August 9, 2020
Revised: August 23, 2020
Accepted: September 22, 2020
Article in press: September 22, 2020
Published online: November 26, 2020
Processing time: 148 Days and 4.4 Hours
Abstract

The high mortality rate of breast cancer is mainly caused by the metastatic ability of cancer cells, resistance to chemotherapy and radiotherapy, and tumor regression capacity. In recent years, it has been shown that the presence of breast cancer stem cells is closely associated with the migration and metastatic ability of cancer cells, as well as with their resistance to chemotherapy and radiotherapy. The tumor microenvironment is one of the main molecular factors involved in cancer and metastatic processes development, in this sense it is interesting to study the role of platelets, one of the main communicator cells in the human body which are activated by the signals they receive from the microenvironment and can generate more than one response. Platelets can ingest and release RNA, proteins, cytokines and growth factors. After the platelets interact with the tumor microenvironment, they are called "tumor-educated platelets." Tumor-educated platelets transport material from the tumor microenvironment to sites adjacent to the tumor, thus helping to create microenvironments conducive for the development of primary and metastatic tumors. It has been observed that the clone capable of carrying out the metastatic process is a cancer cell with stem cell characteristics. Cancer stem cells go through a series of processes, including epithelial-mesenchymal transition, intravasation into blood vessels, movement through blood vessels, extravasation at the site of the establishment of a metastatic focus, and site colonization. Tumor-educated platelets support all these processes. 

Keywords: Breast cancer stem cells; Platelets; Metastasis; Tumor microenvironment; Epithelial-mesenchymal transition

Core Tip: Cancer is a complex disease with several unknown mechanisms. The main aim of this work is to highlight the key role of platelets as communicator cells and their crucial role in cancer progression and second metastatic foci. This review focuses on the role of platelets in the tumor microenvironment as well as the interaction of molecules from platelets and breast cancer stem cells involved in cancer.