Gonadal tumorigenesis in transgenic mice bearing the mouse inhibin alpha-subunit promoter/simian virus T-antigen fusion gene: characterization of ovarian tumors and establishment of gonadotropin- responsive granulosa cell lines

1995 ◽  
Vol 9 (5) ◽  
pp. 616-627 ◽  
Author(s):  
K. Kananen
Keyword(s):  
Transgenic Mice ◽  
Granulosa Cell ◽  
Cell Lines ◽  
Fusion Gene ◽  
Simian Virus ◽  
T Antigen ◽  
Ovarian Tumors ◽  
Alpha Subunit ◽  
Gene Characterization

Establishment of renal proximal tubule cell lines by targeted oncogenesis in transgenic mice using the L-pyruvate kinase-SV40 (T) antigen hybrid gene

1993 ◽  
Vol 104 (3) ◽  
pp. 695-704 ◽  
Author(s):  
N. Cartier ◽  
R. Lacave ◽  
V. Vallet ◽  
J. Hagege ◽  
R. Hellio ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Proximal Tubule ◽  
Pyruvate Kinase ◽  
Cell Lines ◽  
Cultured Cells ◽  
Simian Virus ◽  
T Antigen ◽  
Regulatory Sequence ◽  
Proximal Tubule Cell ◽  
Proximal Tubule Cells

Targeted oncogenesis allowed us to obtain two cell lines which have been derived from the proximal tubule of kidney from transgenic mice harbouring the simian virus (SV40) large T and small t antigens placed under the control of the 5′ regulatory sequence from the rat L-type pyruvate kinase (L-PK) gene. The cell lines (PKSV-PCT and PKSV-PR cells) were derived from early (PCT) and late (Pars Recta, PR) microdissected proximal tubules grown in D-glucose-enriched medium. In such conditions of culture, both cell lines exhibited L-PK transcripts, a stable expression of SV40-encoded nuclear large T antigen, a prolonged life span but failed to induce tumors when injected sub-cutaneously into athymic (nu-nu) mice. Confluent cells, grown on plastic support or porous filters, were organized as monolayers of polarized cuboid cells with well developed apical microvilli and formed domes. Both cell lines exhibited morphological features of proximal tubule cells with villin located in the apical brush-border and substantial amounts of hydrolase activity. By immunofluorescence studies using specific antibodies, aminopeptidase N appeared restricted to the apical microvillar domain, whereas the H2 histocompatibility antigen was distributed in the cytoplasm and lateral membranes. These results demonstrate that the proximal morphological phenotype has been fully preserved in these cultured cells derived from tissue-specific targeted oncogenesis in transgenic mice.

scholarly journals Immortalization of equine trophoblast cell lines of chorionic girdle cell lineage by simian virus-40 large T antigen

2001 ◽  
Vol 171 (1) ◽  
pp. 45-55 ◽  
Author(s):  
TM Thway ◽  
CM Clay ◽  
JK Maher ◽  
DK Reed ◽  
KJ McDowell ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cell Lineage ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Alpha Subunit ◽  
Subunit Gene ◽  
Immortalized Cell Lines ◽  
Subunit Expression ◽  
Immortalized Cell

Immortalized cell lines have many potential experimental applications including the analysis of molecular mechanisms underlying cell-specific gene expression. We have utilized a recombinant retrovirus encoding the simian virus-40 (SV-40) large T antigen to construct several immortalized cell lines of equine chorionic girdle cell lineage - the progenitor cells that differentiate into the equine chorionic gonadotropin (eCG) producing endometrial cups. Morphologically, the immortalized cell lines appear similar to normal chorionic girdle cells. Derivation of the immortalized cell lines from a chorionic girdle cell lineage was verified by immunological detection of cell-surface antigens specific to equine invasive trophoblasts. The cell lines differed, however, from mature chorionic girdle cells or endometrial cup cells in that they did not produce eCG and did express MHC class I molecules. Thus, these cell lines appear to have been arrested at a stage of development prior to final differentiation into endometrial cup cells. It was also determined that some of these cell lines as well as endometrial cups express the estrogen receptor-related receptor beta gene, but not the glial cell missing gene (GCMa) both of which are expressed in the murine and human placenta. Among these cell lines, three (eCG 50.5, 100.6 and 500.1) express eCG alpha mRNA. Since regulation of eCG alpha subunit gene is largely unknown, we investigated the signal transduction pathways regulating the eCG alpha subunit gene. Both activators of protein kinase A (PKA) and protein kinase C (PKC) induced the expression of eCG alpha subunit expression 3.2 (P<0.05)- and 1.9 (P<0.05)-fold respectively, in the eCG 500.1 cell line. However, activation of these pathways failed to induce eCG beta subunit expression. In conclusion, lines of equine trophoblast cells have been immortalized that display markers characteristic of those with the equine chorionic girdle and endometrial cup cell lineage. A subset of these cells expresses the eCG alpha subunit gene which is responsive to activators of the PKA and PKC signal transduction pathways.

scholarly journals Long-term testosterone treatment prevents gonadal and adrenal tumorigenesis of mice transgenic for the mouse inhibin-alpha subunit promoter/simian virus 40 T-antigen fusion gene

2000 ◽  
Vol 166 (1) ◽  
pp. 77-85 ◽  
Author(s):  
◽  
J Kero ◽  
T Paukku ◽  
I Huhtaniemi
Keyword(s):  
Fusion Gene ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Alpha Subunit ◽  
Adrenal Tumors ◽  
Microscopical Examination ◽  
Cell Hyperplasia ◽  
Testosterone Treatment

We have developed a transgenic (TG) mouse model for tumorigenesis of gonadal somatic cells using a 6 kb fragment of the mouse inhibin-alpha subunit promoter (Inh-alpha) fused with the simian virus 40 T-antigen (Tag) coding sequence. Gonadal tumors, of Leydig or granulosa cell origin, develop in the TG mice with 100% penetrance by the age of 5-8 months. Conspicuously, if the mice are gonadectomized, they develop adrenal tumors. Gonadal and adrenal tumorigenesis in these mice seem to be gonadotropin dependent. On the other hand, testosterone stimulates the proliferation of a cell line (C alpha 1) established from one of the adrenal tumors. The purpose of the present study was therefore to investigate further whether testosterone affects the growth of these gonadal and adrenal tumors in vivo. Two experimental models were used: (1) Tag TG/hypogonadotropic (hpg) double mutant mice and (2) castrated Tag TG mice. Both were treated between 1-2 and 7-8 months of age with Silastic rods (length 2 cm) containing testosterone. None of the control or testosterone-treated Tag/hpg mice developed gonadal or adrenal tumors. The castrated Tag TG mice displayed, upon microscopical examination, early stages of adrenal tumors, whereas those receiving testosterone did not show such changes. Testosterone increased the weights of gonads in the Tag/hpg mice, and those of uteri and seminal vesicles in both groups. In contrast, the adrenal weights were significantly reduced in both groups by testosterone treatment. Gonadal histology of the testosterone-treated mice showed hyperplasia of testicular Leydig cells and ovarian stroma. Spermatogenesis was induced by testosterone in the Tag/hpg mice. Adrenal histology of the testosterone-treated animals demonstrated the disappearance of the X-zone. Serum levels of FSH in testosterone-treated Tag/hpg mice were significantly increased, while those of serum LH were decreased. In conclusion, the present result indicate that the suppression of gonadotropins by testosterone implants in castrated Inh-alpha/Tag TG mice prevents the tumorigenesis of their adrenals. In intact Tag/hpg mice, testosterone implants were not able to induce gonadal or adrenal tumorigenesis. Although testosterone treatment was able to induce interstitial cell hyperplasia in gonads of the Inh-alpha/Tag mice, direct gonadotropin action is responsible for gonadal and adrenal tumorigenesis.

scholarly journals Haploid-specific transcription of protamine-myc and protamine-T-antigen fusion genes in transgenic mice.

1988 ◽  
Vol 8 (4) ◽  
pp. 1748-1755 ◽  
Author(s):  
T A Stewart ◽  
N B Hecht ◽  
P G Hollingshead ◽  
P A Johnson ◽  
J A Leong ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Fusion Gene ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Fusion Genes ◽  
Sv40 T Antigen ◽  
Early Region ◽  
Myc Gene ◽  
Sv40 Early Region

The protamines are small, basic, arginine-rich proteins synthesized postmeiotically in the testes. Analysis of the regulation of synthesis of the protamine mRNA and protein is restricted by the difficulty in culturing and manipulating the cells in which transcription and translation occur. To avoid these problems, we have produced transgenic mice carrying fusion genes in which sequences 5' to the mouse protamine-2 gene have been linked to exons 2 and 3 of the mouse c-myc gene and, separately, to the simian virus 40 (SV40) early region. We show here that the prot.myc gene is correctly regulated; transcription is detected only in the round spermatids. In one family of transgenic mice carrying the 5' protamine-SV40 T-antigen fusion gene, SV40 early-region mRNA accumulated to the highest level in the testes but was also detected in the thymuses, brains, hearts, and preputial glands of the animals. Although we have demonstrated specific transcription of these fusion genes in the round spermatids, we were not able to detect the SV40 T-antigen protein.

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