Abstract
Purpose :
Retinoblastoma (RB) is a primary intraocular malignancy in childhood, and may develop relapse and metastatic disease. This study was to identify the stemness properties of primary retinoblastoma cells critical to tumorigenesis and metastasis.
Methods :
Archival materials of RB tissues were obtained from RB patients with enucleation, and primary RB cells were cultured under optimized conditions with two RB cell-lines Weri-RB1 and Y79 used for comparison. Expressions of retinal-development related biomarkers (CD133, OCT4, Nestin, GFAP, MAP2 and Recoverin) were evaluated by quantitative RT-PCR, flow-cytometry, immunofluorescence and immunohistochemistry. The sub-retinol xenograft was performed for tumorigenicity in nude BALB/c mice.
Results :
The primary RB cells from enucleation were well grown and formed spheres with stem-cell like morphology in stem-cell culture medium. The primary RB cells exhibited a stem-cell like expression pattern of biomarkers, with significantly higher levels of stem-cell markers, CD133, Nestin, OCT4, but lower expression of a photoreceptor marker recoverin than that expressed by Weri-RB1 and Y79. In contrast, these two cell lines expressed the upregulated levels of retinal-cell markers, GFAP, MAP2 and recoverin although Weri-RB1 also showed the intensive expression of CD133. Interestingly, CD133 expression increased gradually in the prolonged culture of primary RB cells, suggesting a potential subset of self-renewal stem cells isolated from original tumor. Furthermore, xenograft demonstrated the strongest tumorigenicity and progression of the subretinal tumor induced by primary RB cells when compared with two RB cell lines. Immunohistochemistry confirmed the originality of xenograft tumors in mice with the similar expression pattern of these biomarkers.
Conclusions :
Our findings demonstrated the stem-cell like properties of primary RB cells with highly expressed stem-cell markers, self-regenerative growth in in vitro, and extensively tumorigenicity in vivo, in comparison with RB cell lines.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.