An update on the biology of cancer stem cells in breast cancer

Abstract

Breast cancer stem cells are defined as cancer cells with self-renewal capacity. These cells represent a small subpopulation endowed with the ability to form new tumours when injected in nude mice. Markers of differentiation have been used to identify these cancer cells. In the case of breast cancer, CD44+/CD24- select a population with stem cell properties. The fact that these cells have self-renewal ability has suggested that this population could be responsible for new tumour formation and cancer relapse. These cells have been shown to be more resistant to chemotherapy and radiotherapy than normal cancer cells. The identification of the molecular druggable alterations responsible for the initiation and maintenance of cancer stem cells is an important goal. In this article we will review all these points with special emphasis on the possible role of new drugs designed to interact with molecular pathways of cancer stem cells.

Tumor and host factors that may limit efficacy of chemotherapy in non-small cell and small cell lung cancer

“…In breast cancers, cells that are CD44-positive but also CD24-negative are highly invasive650, have stem cell properties651 and are chemotherapy-resistant651. CD44 is a transmembrane glycoprotein that plays a role in cell adhesion and in angiogenesis652, while CD24 is a mucin-like adhesion molecule653 that may recruit beta1integrins into membrane lipid raft domains654.…”

Cutaneous mesenchymal stem cells: status of current knowledge, implications for dermatopathology

“…Malignancies are increasingly being suspected to arise from mutated stem cells, a concept which led to the cancer stem cell hypothesis 95 . Originally developed within the conceptual framework of the hematopoietic system, 96 brain tumors 97 and breast cancers 98 are now also being discussed as diseases with an underlying genetic defects affecting stem cells. The etiology of epithelial cutaneous malignancies as of late is being viewed as possibly affecting clonal stem cells, 99–102 and melanoma was suggested as a tumor based on a mutant stem cell 103,104 .…”

Dermatofibrosarcoma protuberans: a tumour of nestin-positive cutaneous mesenchymal stem cells?

“…An early indication supporting this theory was found in the haematopoietic system in which leukaemic transformation was demonstrated to involve genetic alterations of haematopoietic stem cells 1 . Among other tumours that may originate from mutated stem cells are brain tumours 2 and breast cancer 3 . These experimental data culminated in the cancer stem cell hypothesis (reviewed in reference 4), which is now expanding into the world of cutaneous malignancies 5–8 .…”