Konstantinos Sousounis



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Notophthalmus viridescens, the red-spotted newt, shows astonishing regenerative capabilities. Part of the heart and brain, limbs, tail and eye tissues like the lens, are some of the organs that can be regenerated after removal. Studies show that newt tissues undergoing regeneration are resistant to cancer formation. This study was intended to investigate this linkage at the cellular level. Lens regeneration serves as a good model for this kind of study since lens is regenerated from the dorsal iris pigmented epithelial (IPE) cells and ventral iris can serve as a natural control. Primary goal was to create an immortalized IPE cell line. Iris pigmented epithelial cells (IPE) were isolated from the eye cup by surgery and enzymatic treatments. These cultured IPE cells were transfected with pSV3neo, a plasmid vector that expresses the simian virus 40 (SV40) Large T antigen. This protein is commonly used to immortalize cells that can create tumors. The transfected cells were selected with G418, a selective marker that pSV3neo has. Comparison between transfected and non-transfected cultured IPE cells revealed that these cells are resistant to the selective marker G418 in the concentrations that was tested even if they are not transfected. In addition, the IPE cells transdifferentiated to lens cells but they did not form lentoids as in cultured cells that G418 was not applied. The mechanism behind these initial observations is not known. Furthermore, using immunocytochemistry, it has been shown that SV40 Large T antigen positive cells are limited (<0.01%) and in combination to the fact that transfected cultured IPE cells with pSV3neo show to have more dead cells, it leads to a working hypothesis that the SV40 Large T antigen promotes apoptosis. In addition other vectors will be tried as well.

Publication Date


Project Designation

Graduate Research

Primary Advisor

Panagiotis A. Tsonis

Primary Advisor's Department



Stander Symposium poster

Regulating Proliferation and Differentiation of Notophthalmus viridescens' Immortal Cells in vivo