The evolving cancer stem cell paradigm: Implications in veterinary oncology

- Experimental evidence supports the cancer stem cell model.
- Lineage tracing and clonal analysis experiments support the clonal evolution and the cancer stem cell models.
- Drugs that can target cancer stem cells could have clinical benefits.

The existence of subpopulations of cells in cancer with increased tumour-initiating ability, self-renewal potential, and intrinsic resistance to conventional therapeutics formed the basis of the cancer stem cell model. Some tumours have since been viewed as aberrant tissues with a unidirectional hierarchical structure consisting of cancer stem cells at the apex, driving tumour growth, metastasis and relapse after therapy. Here, recent developments in cancer stem cell research are reviewed with a focus on tumour heterogeneity, cellular plasticity and cancer stem cell reprogramming. The impact of these findings on the cancer stem cell model is discussed.