Proposed Stem-like Characteristics

Corresponding Assays

Tumour initiation/ maintenance of tumour growth

•      In vivo transplantation

The capacity for both symmetrical division (self renewal) and assymmetrical division (differentiation)

It is impossible to assay for both attributes in a single cell/assay. Self renewal can be assayed for:
•      in vitro by the tumour sphere assay [48]
•      in vivo by serial transplantation

Resistance to Anoikis
(the form of apoptosis induced by cellular detachment)

      In vitro Tumour sphere assay [48]
      In vivo analysis of circulating tumour cells

Metastasis formation
(Combination of anoikis resistance and tumour initiation)

      in vivo metastasis models e.g. by tail vein or intra-cardiac injection

Drug resistance

•      In vitro/in vivo Cell survival following drug treatment
Table 1: Stem-like characterisitics associated with tumour cells and the corresponding assays used to test for them.