165Alfred K. Lam (ed.), Esophageal Adenocarcinoma: Methods and Protocols, Methods in Molecular Biology, vol. 1756,
https://doi.org/10.1007/978-1-4939-7734-5_15, © Springer Science+Business Media, LLC 2018
Chapter 15
Identification of Cancer Stem Cells in Esophageal
Adenocarcinoma
Farhadul Islam, Vinod Gopalan, and Alfred K. Lam
Abstract
Cancer stem cells (CSCs) are a subpopulation of cancer cells that have the ability to self-renew and to
generate differentiated cells of various lineages. Due to their specific morphological and biological features,
they are often resistant to therapy and in turn lead to metastasis and cancer recurrence. Because of their
crucial roles in carcinogenesis and patient prognosis, identification and isolation of CSCs have become an
important part of improved cancer management regime. Isolation, characterization, and development of
targeted therapy against CSCs have potential efficacy in treating esophageal cancer. In addition, CSCs can
act as a predictive tool for chemoradiotherapy response in esophageal adenocarcinoma. Different methods
including functional assays, cell sorting using various intracellular, and cell surface markers and xenotrans-
plantation techniques are used for the identification and separation of CSCs in different cancers. None of
these methods solely can guarantee complete isolation of CSC population, thus a combination of methods
could be used for reliable detection and isolation of CSCs. Here, we describe the identification and
isolation of CSCs from esophageal adenocarcinoma cells by cell sorting after Hoechst 33342 staining
followed by in vitro functional assays, and in vivo xenograft techniques.
Key words Cancer stem cell, Esophageal adenocarcinoma, Spheres formation assay, FACS, fluores-
cence-activated cell sorting, Xenotransplantation1 Introduction
Cancer stem cells (CSCs), a subpopulation of cancer cells with the
properties of self-renewal and multi-lineage differentiation, are
attributed to the therapy failure as well as distant metastasis and
cancer recurrence in various cancers including esophageal adeno-
carcinoma [ 1 – 9 ]. Identification and isolation of CSCs in esopha-
geal adenocarcinoma might have huge potential to improve the
therapeutic management of these patients. As normal stem cells
and CSCs share numbers of functional characteristics such as
membrane transport, DNA repair, self-renewal, and multi-lineage
differentiation, challenges remain to differentiate these subpopu-
lation of cells in different cancers. Identification of CSCs from
non-CSCs with specific single method has not been reported yet.