Differentiation Potential of Human Retinoblastoma Cells

Retinoblastoma (RB), an intraocular tumor of childhood, contains small subpopulation(s) of stem-like cells expressing the ABCG2 drug transporter that can efflux standard chemotherapies. Since chemo-resistant stem-like cells appear to be a driving force in tumor progression and metastasis for a variety of cancers, innovative treatment strategies are necessary to eradicate these rare cell populations. Terminal differentiation, as a means to deplete the pool of stem-like cells in RB, is an intriguing approach to cancer therapeutics. However, the full extent of RB differentiation remains unknown. Differentiation of RB cells has been examined in response to a variety of different agents, including retinoic acid/sodium butyrate, Pigment Epithelial-Derived Factor, as well as Succinylated Concanavalin A. RB cells exhibit morphologic and phenotypic responses to these differentiating agents, although the permanence of these effects is questionable due to reversibility. Further study of differentiation programs may lead to new approaches in the design of strategies to combat the initiation and progression of RB in vivo.