Stem cell markers: ABCG2 and MCM2 expression in retinoblastoma

Abstract

Backgound/aim: The authors studied the expression of cancer stem cell surface marker, ABCG2, and neural stem cell marker, MCM2, in retinoblastoma and correlated clinicopathologically. Methods: Among 39 retinoblastomas, 18 tumours were not subjected to preoperative/postoperative chemotherapy, 15 tumours underwent postoperative chemotherapy, and six tumours had preoperative chemotherapy. There were 20 tumours with no invasion and 19 tumours with invasion of choroid/optic nerve. ABCG2 and MCM2 expression was studied by immunohistochemistry. Results: ABCG2 was positive in six of six and MCM2 was positive in five of six tumours that had recurred in the orbit or metastasised. ABCG2 was positive in 15/19 tumours with invasion. MCM2 was positive in 16/19 tumours with invasion. Invasive tumours showed higher expression of ABCG2 (p,0.01) and MCM2 (p,0.01) proteins. There was no correlation with differentiation and laterality of the tumours. Nonneoplastic retina was positive for ABCG2 and MCM2. Conclusion: ABCG2 and MCM2 were expressed more in invasive tumours. Further studies are needed to understand the significance of ABCG2 and MCM2 expression in retinoblastoma.

Identification of tumorigenic retinal stem‐like cells in human solid retinoblastomas

“…16,[38][39][40][41] In addition, immunohistochemical examination on RB pathological specimens demonstrated that RBs exhibited phenotypic heterogeneity, being composed of cells expressing both undifferentiated and differentiated markers. [10][11][12][13][14][15]20,[42][43][44] Hence, these investigators inferred that RB might come from multipotent or bipotent retinal cells. In the present study, we established a link between normal retinal genesis and tumorigenesis of RB with the application of principles for study of normal neural or retinal stem cells to RB tumor cell populations.…”

Isolation and characterization of a new cell line of retinoblastoma

“…[28][29][30][31] As shown in other studies, CD90, a differentiated retinal cell marker, is positive in IRB-1 cells. [31][32][33][34] Neurosphere in RB cells is an indicator of self-renewal and cycling in the stem cells, especially Y79 and WERI-Rb1. 35 IRB-1 showed the capacity to form neurospheres, an indicator of stem cell self-renewal.…”

Expression of immature and mature retinal cell markers in retinoblastoma

“…11 More recent study demonstrated that retinoblastoma cells were positively stained with cancer stem cell surface markers such as ABCG2 and MCM2, supporting that retinoblastoma is derived from stem cells. 12 Other investigators have suggested that the retinoblastoma cells have the same origin as the photoreceptor cells. [13][14][15][16] In contrast to the controversy over the cell origin of retinoblastomas, it has become generally accepted that several types of cancers of the central nervous system arise from the tumour stem cells, 17 which are derived from the transformation of the neural stem cells, and are thought to have self-replication ability and differentiation potency.…”

“…7 It has also been suggested that primitive neuroectodermal cells with their potential for both neural and glial cell lineage are the cell origin of retinoblastomas. [8][9][10][11][12] Additionally, when cells from retinoblastoma cultures were investigated with a scanning electron microscope, glial, and neuronal cells were observed, suggesting the cell origin of the retinoblastoma is a multipotential retinal stem cell. 11 More recent study demonstrated that retinoblastoma cells were positively stained with cancer stem cell surface markers such as ABCG2 and MCM2, supporting that retinoblastoma is derived from stem cells.…”