Half-life of the duck hepatitis B virus covalently closed circular DNA pool in vivo following inhibition of viral replication.
AuthorsAddison WR, Walters KA, Wong WW, Wilson JS, Madej D, Jewell LD, Tyrrell DL,
JournalJ Virol
PubMed ID12021368
'Covalently closed circular DNA (cccDNA) is a crucial intermediate in the replication of hepadnaviruses. We inhibited the replication of duck hepatitis B virus in congenitally infected ducks with a combination of lamivudine and a dideoxyguanosine prodrug. Inhibition of viral replication should prevent renewal of the cccDNA pool, and its decay ... More
The neurosteroid allopregnanolone promotes proliferation of rodent and human neural progenitor cells and regulates cell-cycle gene and protein expression.
AuthorsWang JM, Johnston PB, Ball BG, Brinton RD,
JournalJ Neurosci
PubMed ID15888646
'Our previous research demonstrated that the neuroactive progesterone metabolite allopregnanolone (3alpha-hydroxy-5alpha-pregnan-20-one) rapidly induced hippocampal neuron neurite regression (Brinton, 1994). We hypothesized that allopregnanolone-induced neurite regression was a prelude to mitogenesis initiated by a rise in intracellular calcium. Supporting this hypothesis, the current data demonstrate that allopregnanolone, in a dose-dependent manner, ... More
Grg1 acts as a lung-specific oncogene in a transgenic mouse model.
AuthorsAllen T, van Tuyl M, Iyengar P, Jothy S, Post M, Tsao MS, Lobe CG,
JournalCancer Res
PubMed ID16452182
'Groucho proteins are transcriptional corepressors that are recruited to gene regulatory regions by numerous transcription factors. Long isoforms, such as Grg1, have all the domains of the prototype Drosophila Groucho. Short Groucho proteins, such as Grg5, have only the amino-terminal Q and G/P domains. We generated Grg1 and Grg5 transgenic ... More
Support for the immortal strand hypothesis: neural stem cells partition DNA asymmetrically in vitro.
AuthorsKarpowicz P, Morshead C, Kam A, Jervis E, Ramunas J, Ramuns J, Cheng V, van der Kooy D
JournalJ Cell Biol
PubMed ID16115957
The immortal strand hypothesis proposes that asymmetrically dividing stem cells (SCs) selectively segregate chromosomes that bear the oldest DNA templates. We investigated cosegregation in neural stem cells (NSCs). After exposure to the thymidine analogue 5-bromo-2-deoxyuridine (BrdU), which labels newly synthesized DNA, a subset of neural precursor cells were shown to ... More
Patched1 functions as a gatekeeper by promoting cell cycle progression.
Mutations in the Hedgehog receptor, Patched 1 (Ptch1), have been linked to both familial and sporadic forms of basal cell carcinoma (BCC), leading to the hypothesis that loss of Ptch1 function is sufficient for tumor progression. By combining conditional knockout technology with the inducible activity of the Keratin6 promoter, we ... More
The mammalian target of rapamycin-p70 ribosomal S6 kinase but not phosphatidylinositol 3-kinase-Akt signaling is responsible for fibroblast growth factor-9-induced cell proliferation.
Fibroblast growth factor-9 (FGF9) is a potent mitogen that stimulates normal and cancer cell proliferation though the signaling mechanism is not fully understood. In this study, we aimed to unravel the signaling cascades mediate FGF9 actions in human uterine endometrial stromal cell. Our results demonstrate that the mitogenic effect of ... More
CD98hc (SLC3A2) mediates integrin signaling.
AuthorsFeral CC, Nishiya N, Fenczik CA, Stuhlmann H, Slepak M, Ginsberg MH,
JournalProc Natl Acad Sci U S A
PubMed ID15625115
Integrins regulate cellular behaviors through signaling pathways, including Rho GTPases and kinases. CD98 heterodimers, comprised of a heavy chain (CD98hc, SLC3A2) and one of several light chains, interact with integrins through CD98hc. CD98hc overexpression leads to anchorage-independent cell growth and tumorigenesis in 3T3 fibroblasts and activates certain integrin-regulated signaling pathways. ... More
Zone-specific cell proliferation during compensatory adrenal growth in rats.
AuthorsEngeland WC, Ennen WB, Elayaperumal A, Durand DA, Levay-Young BK,
JournalAm J Physiol Endocrinol Metab
PubMed ID15367395
Compensatory adrenal growth after unilateral adrenalectomy (ULA) leads to adrenocortical hyperplasia. Because zonal growth contributions are not clear, we characterized the phenotype of cortical cells that proliferate using immunofluorescence histochemistry and zone-specific cell counting. Rats underwent ULA, sham adrenalectomy (sham), or no surgery and were killed at 2 or 5 ... More