Characterizing cancer cells with cancer stem cell-like features in 293T human embryonic kidney cells.
BACKGROUND
Since the first suggestion of prospectively identifiable cancer stem cells in solid tumors, efforts have been made to characterize reported cancer stem cell surrogates in existing cancer cell lines, and cell lines rich with these surrogates have been used to screen for cancer stem cell targeted agents. Although 293T cells were derived from human embryonic kidney, transplantation of these cells into the mammary fat pad yields aggressive tumors that self-renew as evidenced by serial xenograft passages through transplantation. Herein we fully characterize cancer stem cell-like features in 293T human embryonic kidney cells.


RESULTS
293T cells can be readily cultured and passaged as spheres in serum-free stem cell promoting culture conditions. Cells cultured in vitro as three-dimensional spheres (3D) were shown to contain higher ALDH1 and CD44+/CD24- population compared to monolayer cells. These cells were also resistant to radiation and upregulate stem cell survival signaling including beta-catenin, Notch1 and Survivin in response to radiation. Moreover, 3D spheres generated from the 293T cells have increased expression of mesenchymal genes including vimentin, n-cadherin, zeb1, snail and slug as well as pro-metastatic genes RhoC, Tenascin C and MTA1. In addition, microRNAs implicated in self-renewal and metastases were markedly reduced in 3D spheres.


CONCLUSIONS
293T cells exhibit a cancer stem cell-like phenotype when cultured as 3D spheres and represent an important research tool for studying the molecular and biological mechanisms of cancer stem cells and for testing and developing novel targets for cancer therapy.
Debeb
Bisrat G
BG
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Zhang
Xiaomei
X
Krishnamurthy
Savitri
S
Gao
Hui
H
Cohen
Evan
E
Li
Li
L
Rodriguez
Angel A
AA
Landis
Melissa D
MD
Lucci
Anthony
A
Ueno
Naoto T
NT
Robertson
Fredika
F
Xu
Wei
W
Lacerda
Lara
L
Buchholz
Thomas A
TA
Cristofanilli
Massimo
M
Reuben
James M
JM
Lewis
Michael T
MT
Woodward
Wendy A
WA
D002460:Cell Line; D016895:Culture Media, Serum-Free; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000196:embryology*; D035683:MicroRNAs / Q000235:genetics; D009362:Neoplasm Metastasis / Q000473:pathology; D009369:Neoplasms / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000473:pathology*; D011446:Prospective Studies; D015854:Up-Regulation
D016895:Culture Media, Serum-Free; D035683:MicroRNAs