A human pituitary adenoma cell line proliferates and maintains some differentiated functions following expression of SV40 large T-antigen

1998 ◽  
Vol 9 (2) ◽  
pp. 169-184 ◽  
Author(s):  
Long Jin ◽  
Elzbieta Kulig ◽  
Xiang Qian ◽  
Bernd W. Scheithauer ◽  
Norman L. Eberhardt ◽  
...  
Keyword(s):  
Pituitary Adenoma ◽  
Cell Line ◽  
T Antigen ◽  
Large T Antigen ◽  
Sv40 Large T Antigen ◽  
Human Pituitary ◽  
Human Pituitary Adenoma ◽  
Adenoma Cell

Growth Properties of Neural Cell Lines Immortalized with the Tsa58 Allele of Sv40 Large T Antigen

1997 ◽  
Vol 6 (3) ◽  
pp. 231-238 ◽  
Author(s):  
M.E. Truckenmiller ◽  
Ora Dillon-Carter ◽  
Carlo Tornatore ◽  
Henrietta Kulaga ◽  
Hidetoshi Takashima ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cell Line ◽  
Cell Lines ◽  
T Antigen ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Large T Antigen ◽  
Wild Type ◽  
Sv40 Large T Antigen ◽  
Growth Properties

In vitro growth properties of three CNS-derived cell lines were compared under a variety of culture conditions. The M213-20 and J30a cell lines were each derived from embryonic CNS culture with the temperature-sensitive (ts) allele of SV40 large T antigen, tsA58, while the A7 cell line was immortalized using wild-type SV40 large T antigen. Cells immortalized with tsA58 SV40 large T proliferate at the permissive temperature, 33° C, while growth is expected to be suppressed at the nonpermissive temperature, 39.5°C. Both the M213-20 and J30a cell lines were capable of proliferating at 39.5°C continuously for up to 6 mo. All three cell lines showed no appreciable differences in growth rates related to temperature over a 7-day period in either serum-containing or defined serum-free media. The percentage of cells in S-phase of the cell cycle did not decrease or was elevated at 39.5°C for all three cell lines. After 3 wk at 39.5°C, the three cell lines also showed positive immunostaining using two monoclonal antibodies reacting with different epitopes of SV40 large T antigen. Double strand DNA sequence analyses of a 300 base pair (bp) fragment of the large T gene from each cell line, which included the ts locus, revealed mutations in both the J30a and M213-20 cell lines. The J30a cell line ts mutation had reverted to wild type, and two additional loci with bp substitutions with predicted amino acid changes were also found. While the ts mutation of the M213-20 cells was retained, an additional bp substitution with a predicted amino acid change was found. The A7 cell line sequence was identical to the reference wild-type sequence. These findings suggest that (a) nucleic acid sequences in the temperature-sensitive region of the tsA58 allele of SV40 large T are not necessarily stable, and (b) temperature sensitivity of cell lines immortalized with tsA58 is not necessarily retained.

scholarly journals Synergy between Apc min and an activated ras mutation is sufficient to induce colon carcinomas.

1996 ◽  
Vol 16 (3) ◽  
pp. 884-891 ◽  
Author(s):  
G M D'Abaco ◽  
R H Whitehead ◽  
A W Burgess
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Cell Lines ◽  
Soft Agar ◽  
T Antigen ◽  
Colonic Epithelial Cell ◽  
Large T Antigen ◽  
Ras Gene ◽  
Sv40 Large T Antigen ◽  
Epithelial Cell Lines

Colon carcinomas appear to arise from the cumulative effect of mutations to several genes (APC, DCC, p53, ras, hMLH1, and hMSH2). By using novel colonic epithelial cell lines derived from the Immorto mouse, named the YAMC (young adult mouse colon) cell line, and an Immorto-Min mouse hybrid, named the IMCE (Immorto-Min colonic epithelial) cell line, carrying the Apc min mutation, we investigated the effect of an activated v-Ha-ras gene on tumor progression. The YAMC and IMCE cell lines are normal colonic epithelial cell lines which are conditionally immortalized by virtue of expression of a temperature-sensitive simian virus 40 (SV40) large T antigen. Under conditions which permit expression of a functional SV40 large T antigen (33 degrees C plus gamma interferon), neither the YAMC nor the IMCE cell line grows in soft agar or is tumorigenic in nude mice. In vitro, when the SV40 large T antigen is inactivated (39 degrees C without gamma interferon), the cells stop proliferating and die. By infecting the YAMC and IMCE cell lines with a replication-defective psi2-v-Ha-ras virus, we derived cell lines which overexpress the v-Ha-ras gene (YAMC-Ras and IMCE-Ras). In contrast to the parental cell lines, under conditions in which the SV40 large T antigen is inactive, both the YAMC-Ras and IMCE-Ras cell lines continue to proliferate. Initally YAMC-Ras cells do not form tumors; however, tumors are visible after 90 days of incubation. IMCE-Ras cells form colonies in soft agar under both permissive and nonpermissive culture conditions. Furthermore, IMCE-Ras cells form tumors in nude mice within 3 weeks. The phenotype of the IMCE-Ras cell line thus clearly demonstrates that a defective Apc allele and an activated ras gene are sufficient to transform normal colonic epithelial cells and render them tumorigenic.

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