• Cancer Stem Cells: The past, present and future of cancer treatment
  • Nima Abedini,1 Mahtab Moghaddam,2 Zahra Kakavand ,3 Mahmood Talkhabi,4,*
    1. Department of Animal Sciences and Marine Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
    2. Department of Animal Sciences and Marine Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
    3. Department of Animal Sciences and Marine Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
    4. Department of Animal Sciences and Marine Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran


  • Introduction: cancer is the result of accumulation of genetic and epigenetic changes that bring about uncontrolled cell division and invasive functions. This disease is one of the major medical challenges of the present century and has a considerable financial toll on health care systems. According to WHO statistics in 2020 alone, close to ten million individuals have died of cancer. In The past few decades, the focus of scientist, biologists and physicians has shifted to the concept of cancer stem cells (CSC) in order to explain the origins, metastasis and recurrence of cancers. Breast cancer is one of the most prevalent and important cancers in humans, affecting millions of women each year.
  • Methods: This study is a review, conducted by searching databases such as: Google scholar, PubMed, ResearchGate and Medline. 12 articles were chosen based on the keyword entries. Chosen articles fall into two categories: information and background on the subject and data on clinical trials.
  • Results: Cancer stem cells or CSCs were first identified in acute myeloid leukemia (AML). These cells are a small subset of neoplastic cells which can create tumors and sustain tumorigenic cell populations. The presence of these cells has been reported in melanomas, sarcomas, mammary tumors, colon cancers and other solid tumors. Another type of these cells called circulating cancer stem cells gain mesenchymal properties through a process called EMT which adds to their invasive and metastatic abilities. Depending on the tumor type these cells use different energetic and metabolic pathways, some use aerobic glycolysis and others use oxidative phosphorylation, fatty acid oxidation is the most common source of energy production in these cells. Due to the importance of these cells their identification and isolation is very important, some of the methods used in this process including the use of special dyes, establishment cultures and cellular markers. Multiple studies have suggested non-malignant stem or progenitor cells as the possible source of these cells. Signal transduction pathways such as Wnt، Notch، Hedgehog and Hippo are crucial in creating and maintaining the special characteristics of these cells. Surface markers include CD44، CD133، CD34، CD38 and CD24 and Aldehyde dehydrogenase1 (ALDH1) is an intracellular marker. The presence of these markers is important for features such as carcinogenesis, invasiveness, stemness, self-renewal and migration. In cancer research breast cancer stem cell (BCSC) are cells that can form transplantable tumors and re- stablish heterogenic tumors. CD44+, ALDH1+ and CD24-/low are the most common markers of BCSCs. BCSCs are located in the tumor microenvironment which is rich in stromal cells, ECM, cytokines and growth factors.
  • Conclusion: Studying the right target for treatment and intervention is crucial in diagnosis, treatment and relapse prevention in cancers due to the high financial and human cost. In this study we review the latest findings in cancer stem cells and their different roles in cancer particularly in breast cancer.
  • Keywords: Cancer stem cells, Metastasis, Tumor, Signal transduction pathways, Cancer