Endocrinology Vol. 142, No. 2 795-801
Copyright © 2001 by The Endocrine Society
Cell Type-Specific Adenoviral Transgene Expression in the Intact Ovine Pituitary Gland after Stereotaxic Delivery: An in VivoSystem for Long-Term Multiple Parameter Evaluation of Human Pituitary Gene Therapy1
J. R. E. Davis,
J. McVerry,
G. A. Lincoln,
S. Windeatt,
P. R. Lowenstein2,
M. G. Castro and
A. S. McNeilly
Endocrine Sciences Research Group and Molecular Medicine and Gene
Therapy Unit (S.W., P.R.L., M.G.C.), University of Manchester,
Manchester, United Kingdom M13 9PT; and Medical Research Council Human
Reproductive Sciences Unit (J.M., G.A.L., A.S.M.), Edinburgh, United
Kingdom EH3 9ET
Address all correspondence and requests for reprints to: Prof. J. R. E. Davis, Endocrine Sciences Research Group, University of Manchester, Stopford Building, Oxford Road, Manchester, United Kingdom M13 9PT. E-mail: julian.davis{at}man.ac.uk
 |
Abstract
|
|---|
Ablative therapies for pituitary tumors commonly cause irreversible
damage to normal pituitary cells. Toxin gene therapy should therefore
ideally be targeted to specific cell types to avoid collateral cell
damage. To evaluate cell-type-specific adenoviral gene transfer in the
intact pituitary gland we have used stereotaxic transcranial delivery
of recombinant adenoviruses in the sheep with continuous assessment of
endocrine function. Adenoviral ß-galactosidase expression was driven
either by the human cytomegalovirus (hCMV) promoter or the human PRL
gene promoter. The hCMV promoter directed adenoviral ß-galactosidase
expression in all pituitary cell types, but the PRL promoter restricted
this exclusively to lactotropic cells, indicating that this promoter
conferred appropriate cell type specificity in the context of
adenoviral transduction in vivo. Serial measurements of
plasma hormones showed no disruption of endocrine function over 7 days
after intrapituitary injection. In summary, this work shows cell
type-specific expression of an adenoviral transgene in the mixed cell
population of the intact pituitary gland in vivo in a
large animal model and indicates that stereotaxic intrapituitary
delivery does not disrupt normal endocrine function.
 |
Introduction
|
|---|
THE ANTERIOR PITUITARY gland contains a
mixed cell population of endocrine cells (lactotropic, somatotropic,
thyrotropic, corticotropic, and gonadotropic cells, secreting PRL, GH,
TSH, corticotropin, and gonadotropins, respectively) together with
folliculo-stellate and endothelial cells. Thus, a series of diverse
endocrine functions depends on a complex organization of seven
different cell types that are closely intermingled. Pituitary adenomas
comprise clonal expansions of one of these cell types (1).
Thus, any therapy designed to achieve permanent ablation of a pituitary
tumor risks collateral damage to the other normal cells, and existing
ablative therapies commonly result in a series of irreversible hormonal
deficiencies that require life-long treatment (2, 3).
Surgical therapy has variable success according to tumor type and size,
and the best results are generally disappointing (4, 5).
The development of specific ablation therapy through expression
of toxin genes can now be contemplated because of the growth in
knowledge of the mechanisms of cell type specificity of hormone
gene expression in the pituitary (1, 6). The anterior
pituitary gland is an attractive model system in which to study this
approach to cell type targeting in vivo, as the cell types
can be readily monitored structurally by immunocytochemistry, and
functionally by serial measurements of their secreted hormone products
in peripheral blood.
Recombinant adenoviruses have become increasingly used as
effective tools for gene transfer and are under intensive investigation
in human gene therapy protocols. Previous reports have confirmed their
efficacy in vitro using cultured pituitary cells (7, 8), in vivo in pituitary tumors propagated in nude
mice (9), and in the intact rat pituitary after
estrogen/sulpiride administration (10, 11). Further
development of such a strategy for potential human therapy requires
substantial validation using suitable in vivo systems, in
which normal pituitary function should not be disrupted.
The aims of this study were therefore to evaluate cell type-specific
adenoviral gene transfer in a large animal pituitary gland as a model
of potential human pituitary gene therapy. We used stereotaxic
transcranial injection of recombinant adenoviruses into the sheep
pituitary gland in vivo and measured effects on anterior
pituitary gland function using serial hormone measurements over 7 days.
Adenoviral ß-galactosidase expression was driven either by the human
cytomegalovirus (hCMV) promoter or the human PRL (hPRL) promoter in an
effort to achieve lactotroph-specific expression.
 |
Materials and Methods
|
|---|
Recombinant adenovirus vector construction
The recombinant adenovirus vectors were based on adenovirus type
5, in which the E1 and part of the E3 regions were deleted. In one of
these, RAd-CMV-ß-gal (also termed RAd-35) the ß-galactosidase gene
is driven by the short immediate-early hCMV (sMIEhCMV) promoter
inserted in place of the E1 deletion, as previously described
(7). In the other vector (RAd-hPRL-ß-gal) the promoter
element comprised a -4429/+14 fragment from the pituitary-specific
promoter of the human PRL gene (11, 12, 13, 14), constructed as
previously described (11).
Animals and stereotaxic pituitary injection
Anestrous Suffolk ewes (23 yr old, 3545 kg) were
anesthetized with thiopentone and maintained with fluothane and nitrous
oxide during the surgical procedure. Using a stereotaxic frame
(14A ), a burr-hole was made in the skull 2 cm anterior to
the bregma. A spinal needle was inserted 2 mm lateral to the midline
angled cranio-caudally 30° from the vertical and lowered until its
tip reached the lateral ventricle, judged by free flow of cerebrospinal
fluid (CSF). One milliliter of radioopaque dye (Omnipaque, Birmingham,
UK) was instilled into the CSF, and a lateral radiograph was taken 30
sec later (75 kV, 50 mA, 0.4 sec) to allow visualization of the
cerebral ventricles (Fig. 1A
). The
location of the pituitary gland was deduced from the positions of the
infundibular and mammillary recesses of the third ventricle
(15). A fine-bore metal cannula was inserted through the
spinal needle and lowered to the base of the pituitary fossa. It was
withdrawn 2 mm, and 250 µl viral vector were injected into the
pituitary gland at each of three levels. The cannula and guide needle
were left in place for 1 min, then both were completely withdrawn and
reintroduced 2 mm anteriorly, and the procedure was repeated. A third
injection procedure was carried out posterior to the initial injection
site. A total of nine injection sites were used to inject virus, using
a total volume of approximately 2.2 ml, usually taking 5060 min. The
procedure was initially validated using injection of India ink (Fig. 1B
), confirming accurate targeting of injectate within the pituitary
gland. Virus suspensions of RAd-hPRL-ß-Gal or RAd-hCMV-ß-Gal were
prepared at a concentration that delivered approximately 1.5 x
108 plaque-forming units/site, giving a total of
approximately 14 x 108 plaque-forming units
injected into the gland.

View larger version (50K):
[in this window]
[in a new window]
|
Figure 1. Stereotaxic injection of pituitary gland. A,
Lateral radiograph and diagram showing radioopaque dye in lateral and
third ventricles and the position of the guide needle to direct
injection into the pituitary gland. B, Low power photomicrograph of
sequential thick sagittal sections (200 µm) through the right lobe of
an India ink-injected pituitary gland, with the infundibulum located
anteriorly to the upper left, oriented as in the
radiograph. Note the distribution of ink along needle tracks and at the
base of the gland. C, Distribution of adenoviral transgene expression
within the pituitary. Low power photomicrograph of ß-galactosidase
immunostaining in sections from one lobe of a sheep anterior pituitary
gland injected with RAd-CMV-ßgal. The adenoviral transgene expression
(stained brown) in the injected gland is distributed
along two visible needle tracks and at the base of the gland
(arrowed). Sections were 5 µm thick and taken at
150-µm intervals, visualized with diaminobenzidine and lightly
counterstained with hematoxylin (magnification, x4). The
infundibulum is to the upper left of each section,
oriented as in A.
|
|
Blood samples were taken daily 28 and 4 h before surgery and then
daily via an indwelling jugular catheter. Samples were analyzed for
hormones by RIA and for routine hematology. Animals were killed 47
days after virus injection with an overdose of iv pentobarbitone. The
dura overlying the pituitary gland was examined for puncture holes, and
the pituitary glands were dissected, divided sagittally into thirds,
and placed into Bouins fixative within 5 min of death. All
experimental procedures were conducted in accordance with the Home
Office Animals (Scientific Procedures) Act 1986 of the United
Kingdom.
Immunocytochemistry
Sections of each pituitary gland were cut after preparation
exactly as described previously (16). Initially,
ß-galactosidase staining was assessed at 50-µm intervals to
determine the general distribution of expression within the whole
pituitary gland. For this initial single staining screen, sections were
treated with hydrogen peroxide in methanol to block endogenous
peroxidase activity and microwaved in sodium citrate buffer, pH 6.0,
before staining with monoclonal anti-ß-galactosidase antibody (1:200;
Promega Corp., Madison, WI) with visualization using
diaminobenzidine (DAKO Corp.).
Regions of the pituitary glands identified in this way as containing
large numbers of ß-galactosidase-positive cells were then subjected
to dual immunofluorescence for ß-galactosidase and pituitary hormones
(16) using the following rabbit polyclonal antibodies: 1)
PRL, ASMcN-R51, 1:2500; 2) LH, ASMcN-R23, 1:100; 3) FSH, M91, 1:100; 4)
GH, 1:500, (NIDDK, NIH); 5) TSH, 1:100, (Dr. J. G. Pierce); and 6)
ACTH, 1:300. Sections were treated with
H2O2 in methanol,
microwaved as described above, and incubated with
anti-ß-galactosidase antibody (1:50) in blocking buffer (normal goat
serum, 10% in Tris-buffered saline) overnight at 4 C in a humidity
chamber. Second antibody (goat antimouse Ig biotinylated, DAKO Corp.) was added, sections were washed, and avidin and
biotinylated horseradish peroxidase complex (DAKO Corp.)
were added for 30 min at room temperature. The ß-galactosidase signal
was amplified using a tyramide step, and sections were incubated with
avidin-fluorescein isothiocyanate conjugate (Sigma, St.
Louis, MO). Anti-hormone antibodies were then added at the
dilutions indicated above and incubated overnight at 4 C. The hormone
signal was visualized using goat antirabbit tetramethylrhodamine
isothiocyanate conjugate (Sigma). Dual immunofluorescence
images were obtained using an Olympus Corp. Provis
fluorescence microscope (New Hyde Park, NY). For each hormone, 40300
cells were identified in each of two sections taken from two widely
separated regions of each pituitary gland to ensure representative
estimates of transgene expression in different cell types. A mean
result for each animal was generated from these four sections to
provide an overall mean for each group of five animals.
Hormone assays and hematology
Plasma concentrations of PRL (17), LH and FSH
(18), TSH (19), and GH and cortisol
(20) were measured by RIAs as described previously. All
samples were measured in one assay, with sensitivities of 0.5 ng (PRL,
LH), 0.1 ng (FSH, GH), 0.2 ng (TSH), and 1 ng (cortisol) per ml plasma
and intraassay coefficients of variation less than 8% for all assays.
Routine hematology was analyzed by the Diagnostic Services Clinical
Laboratories, Royal (Dick) Veterinary School (Edinburgh, UK).
 |
Results
|
|---|
Initial studies in two sheep using India ink confirmed that the
stereotaxic approach targeted the pituitary gland accurately, with a
satisfactory distribution of dye within the gland after slow injection
(Fig. 1B
). Ten sheep were studied after injection of RAd-hCMV-ß-gal
(n = 5), or RAd-hPRL-ß-gal (n = 5). All animals recovered
uneventfully, and showed normal behavior thereafter. During removal of
pituitary glands at the end of the experimental period, small blood
clots were found in the CSF in relation to the needle track in two
animals that had been apparently well, but in all the others the CSF
was free of blood-staining.
The overall distribution of adenovirally mediated ß-
galactosidase expression in the pituitary gland was assessed in
animals injected with RAd-hCMV-ß-gal, and an example is shown in Fig. 1C
. Intense staining was seen in relation to the needle tracks and at
the base of the pituitary, with stronger expression in the animals
injected with RAd-CMV-ßgal than in those injected with
RAd-hPRL-ßgal.
Dual immunofluorescence staining for ß-galactosidase with each of the
six pituitary hormones (Fig. 2
) showed
that in animals injected with RAd-hCMV-ß-gal, ß-galactosidase
staining was colocalized with hormone staining in all six endocrine
cell types (Fig. 2
, left panels) and also in S-100-staining
folliculo-stellate cells (data not shown). Transgene expression was
detected in varying proportions of all six endocrine cell types, and
this was quantitated in multiple sections of the pituitary glands. As
the ß-galactosidase expression was regional, sections were chosen for
quantitation from ß-galactosidase-positive areas that also contained
sufficient numbers of cells that were positive for each of the six
hormones, and percentages of the ß-galactosidase-positive cells that
expressed each of the pituitary hormones were calculated. Of the
ß-galactosidase-positive cells, 2992% of cells coexpressed PRL in
the five animals studied (mean, 69 ± 28%); of the other
hormones, coexpression with ß-galactosidase varied from 8% (ACTH) to
33% (TSH) (Fig. 3A
). In contrast, in
animals injected with the RAd-hPRL-ß-gal vector, 93.0 ± 3.9%
of cells staining for ß-galactosidase coexpressed PRL, 45% stained
for LH or FSH, and less than 2% stained for GH, TSH, or ACTH (Fig. 2
, right panels, and Fig. 3B
). It should be noted that because
of the regional clustering of different cell types within different
areas of the anterior pituitary gland, the apparent prevalence of the
different endocrine cell types was overestimated by this method, but
the approach was used to avoid selection bias and to ensure that
adequate numbers of each endocrine cell type were assessed to allow
genuine quantitation.

View larger version (102K):
[in this window]
[in a new window]
|
Figure 2. Cell type specificity of adenoviral transgene
expression. Left panels, Representative dual
immunofluorescence staining of pituitary sections from animals treated
with RAd-CMV-ßgal injection. ß-Galactosidase staining is shown in
green (left panels),
hormone staining in red (center panels),
and overlay plots show colocalization of ß-galactosidase with hormone
as yellow (right panels).
ß-Galactosidase expression colocalized with (top to
bottom) PRL, LH, FSH, TSH, GH, and ACTH, indicating
expression of the viral transgene in all endocrine cell types. All
images were taken using a x40 magnification lens. White
bar, 50 µm. Right panels, Representative dual
immunofluorescence staining of pituitary sections from animals treated
with RAd-hPRL-ßgal injection. Panels are presented as in left-hand
series, and overlay plots show colocalization of ß-galactosidase only
with PRL (top right panel) and not with LH, FSH, GH,
TSH, or ACTH. All images were taken using a x40 magnification lens.
White bar, 50 µm.
|
|

View larger version (20K):
[in this window]
[in a new window]
|
Figure 3. Quantitative analysis of cell type specificity of
adenoviral transgene expression. A, Cell type specificity of
RAd-CMV-ßgal transgene expression. The histogram shows the percentage
of ß-galactosidase-positive cells that costained for each of the six
pituitary hormones. Data shown are the mean ± SD
(n = 5 animals, derived from four separate pituitary sections in
each case, with 40200 cells counted/section). B, Cell type
specificity of RAd-hPRL-ßgal transgene expression. The histogram
shows the percentage of ß-galactosidase-positive cells that costained
for each of the six pituitary hormones. Data shown are means ±
SD (n = 5 animals, derived from four separate
pituitary sections, with 40100 cells counted/section).
|
|
Measurement of plasma hormones (Fig. 4
)
showed transient rises in cortisol in all animals and in PRL in five of
nine animals, immediately after surgery, an expected stress response
after a general anesthetic. Other hormones showed no abnormal
responses. In particular, normal fluctuations were noted in LH and GH
secretion, and there was no persistent abnormal elevation of PRL that
might have suggested pituitary stalk disruption.

View larger version (26K):
[in this window]
[in a new window]
|
Figure 4. Pituitary function before and after adenovirus
injection. Plasma levels of the pituitary hormones PRL, LH, FSH, TSH,
and GH and plasma cortisol plotted before (-28 and -4 h) and then
daily for 7 days after RAd injection at 0 h. Four animals injected
with RAd-hCMV-ß-gal are shown in the left panels, and
five injected with RAd-hPRL-ß-gal are shown in the right
panels.
|
|
Routine hematological testing 7 days after injection shortly before
sacrifice showed normal red and white cell indexes in all animals
tested, except in one animal that showed postmortem evidence of some
bleeding into the CSF and had a mildly raised neutrophil count
(8.09 x 109/liter; reference range,
0.45.0 x 109/liter).
 |
Discussion
|
|---|
This report demonstrates adenoviral transgene expression in the
intact eutopic sheep pituitary gland in vivo for at least 7
days and shows that stereotaxic delivery is reliable, accurate, and
safe in a large animal. Furthermore, by quantitation of the six
endocrine cell types expressing the transgene, we have shown that the
PRL gene promoter confers appropriate cell type specificity to
transgene expression in vivo in the context of a recombinant
adenoviral vector. Most important, in terms of potential clinical
application, we found no deleterious effect of adenoviral injection on
endocrine function of the pituitary gland.
A large animal model is essential for evaluation of this potential
human application of endocrine gene therapy, as multiparameter
longitudinal assessment is needed to determine the effects of
adenoviral gene transduction on pituitary function. The ability to take
serial blood samples to track hormonal changes over days or weeks is
severely limited in small animals such as rats or mice. We selected the
sheep as a suitable model because the pituitary gland is of similar
size, configuration, and accessibility to the human pituitary and has
been the subject of careful immunohistochemical evaluation
(16). In addition we have previous experience in
longitudinal evaluation of pituitary hormone secretion
(19). The sheep pituitary is 1012 mm in antero-posterior
diameter, and the results reported here indicate that a local injection
of recombinant adenovirus can achieve effective transgene expression
across substantial regions of the gland. This suggests that direct
adenoviral injection of a pituitary tumor at transsphenoidal surgery
may in principle be able to achieve adequate expression of desired
suicide genes for future potential tumor therapy applications, as
discussed below.
A key point of this study was to employ transcriptional targeting of
transgene expression to a single cell type within a mixed cell
population by exploiting the known cell type specificity of PRL gene
expression. The human PRL gene promoter was used to generate the
recombinant adenovirus vector RAd-hPRL-ß-gal in view of potential
future therapeutic applications (11, 21). This gene
promoter has been extensively studied in vitro, and the
promoter fragment used here confers appropriate hormonal regulation
onto reporter gene expression in pituitary cells in both transient and
stable transfection systems (12, 13, 14, 22). The present
study confirms that the PRL promoter in the context of a recombinant
adenovirus is activated specifically in lactotropic cells in
vivo, with minimal reporter gene transcription in other cell
types. In other words, although the adenovirus vectors are capable of
infecting all of the cell types found in the pituitary (Refs.
7 and 11 and the present data), the PRL
promoter restricts the activation of adenoviral transgene expression
effectively to the lactotroph cell population. The RAd-hPRL-ß-gal
vector has also been used in primary cultures of rat anterior pituitary
cells and in the rat pituitary gland in vivo, with similar
restriction of transgene expression mainly to lactotropic cells
(11). The slightly higher than expected transgene
expression from this vector in gonadotropic cells may be explained by
the intimate relation between lactotropic and gonadotropic cells
in vivo (16), which could result in
overestimation of apparent transgene expression in gonadotrophs. Recent
work (23) has used the GH gene promoter to achieve similar
restriction of transgene expression to the rat pituitary gland in
vivo.
An important goal in this study was to assess the effect of adenoviral
injection on the endocrine function of the normal pituitary gland in a
large animal model, and the size of the sheep allowed us to track
circulating plasma hormone levels. Single time point analysis 10 days
after transcranial or transauricular injection of the rat pituitary
indicated little or no major change in circulating hormone levels
(10, 11). In the present, more extensive, longitudinal
evaluation, we were able to monitor pituitary function serially over 7
days. We found a transient rise in plasma cortisol and PRL, a well
recognized feature of an anesthetic stress response in sheep
(19). In the following 7 days hormone levels and secretory
patterns remained normal, however, with no evidence to suggest
disruption of pituitary function. It is encouraging that even injection
of relatively large volumes of virus into a tightly organized tissue
appears to cause no adverse endocrine or other systemic effects.
If adenoviral gene transfer into the normal eutopic pituitary gland can
be confirmed to be safe and effective over the longer term, without
disrupting pituitary function as our data suggest, it may be possible
to consider the potential for ablative therapy for pituitary tumors
using suicide or cytotoxic genes. Although pituitary tumors are not
usually lethal in themselves, their treatment remains unsatisfactory,
and ablative therapy frequently damages residual pituitary function.
Pituitary tumors have the advantage of well understood cell biology,
and they are a suitable target for further development of adenoviral
gene transfer approaches (21, 24). Future developments are
likely to include more heavily deleted ("gutless") adenovirus
vectors (see Ref. 24 for review), which will enable use of
combinations of tissue-specific promoters together with regulatable
transcription factors to obtain highly controlled transgene expression
(25, 26, 27). Extensive validation will be required to
establish their safety and efficacy in different circumstances
(28, 29), and the system presented in this report will be
valuable in this effort.
 |
Acknowledgments
|
|---|
We thank Ian Swanston and Fiona Pitt for hormone assays, Joan
Docherty and Norah Anderson and other staff at the Marshall Building
for expert technical assistance and animal care, and Ted Pinner and
Axel Thompson for assistance with preparation of the figures. We
acknowledge the excellent technical assistance of Ms. Tricia Maleniak
in the Molecular Medicine and Gene Therapy Unit.
 |
Footnotes
|
|---|
1 This work was supported by the Medical Research Council, the
Biotechnology and Biological Sciences Research Council, and the
Royal Society. 
2 Research Fellow of the Lister Institute of Preventive
Medicine. 
Received August 9, 2000.
 |
References
|
|---|
-
Asa SL, Ezzat S 1998 The cytogenesis and
pathogenesis of pituitary adenomas. Endocr Rev 19:798827[Abstract/Free Full Text]
-
Ahmed S, Elsheikh M, Stratton IM, Page RCL, Adams CBT,
Wass JAH 1999 Outcome of transphenoidal surgery for acromegaly and
its relationship to surgical experience. Clin Endocrinol (Oxf) 50:561567[CrossRef][Medline]
-
Littley MD, Shalet SM, Beardwell CG, Ahmed SR,
Applegate G, Sutton ML 1991 Hypopituitarism following external
radiotherapy for pituitary tumours in adults. Q J Med 70:145160
-
Molitch ME, Thorner MO, Wilson C 1997 Management
of prolactinomas. J Clin Endocrinol Metab 82:996997[Free Full Text]
-
Soule SG, Conway GS, Jacobs HS 1996 The outcome of
hypophysectomy for prolactinomas in the era of dopamine agonist
therapy. Clin Endocrinol (Oxf) 44:711716[CrossRef][Medline]
-
Treier M, Gleiberman AS, OConnell SM, Szeto DP,
McMahon JA, McMahon AP, Rosenfeld MG 1998 Multistep signaling
requirements for pituitary organogenesis in vivo. Genes Dev 12:16911704[Abstract/Free Full Text]
-
Castro MG, Goya RG, Sosa YE, Rowe J, Larregina A,
Morelli A, Lowenstein PR 1997 Expression of transgenes in normal
and neoplastic anterior pituitary cells using recombinant adenoviruses:
long term expression, cell cycle dependency, and effects on hormone
secretion. Endocrinology 138:21842194[Abstract/Free Full Text]
-
Neill JD, Lois C, Musgrove L, Duck W, Sellers JC 1998 High efficiency method for gene transfer in normal pituitary
gonadotropes: adenoviral-mediated expression of G protein-coupled
receptor kinase 2 supresses luteinizing hormone secretion.
Endocrinology 140:25622569[Abstract/Free Full Text]
-
Lee EJ, Anderson LM, Thimmapaya B, Jameson JL 1999 Targeted expression of toxic genes directed by pituitary hormone
promoters: a potential strategy for adenovirus-mediated gene therapy of
pituitary tumors. J Clin Endocrinol Metab 84:786794[Abstract/Free Full Text]
-
Windeatt S, Southgate TD, Dewey RA, Bolognani F, Perone
MJ, Larregina AT, Maleniak TC, Morris ID, Goya RG, Klatzmann,
Lowenstein PR, Castro MG 2000 Adenovirus-mediated herpes simplex
virus type-1 thymidine kinase gene therapy suppresses oestrogen-induced
pituitary prolactinomas. J Clin Endocrinol Metab 85:12961305[Abstract/Free Full Text]
-
Southgate TD, Windeatt S, Smith-Arica, Gerdes CA, Perone
MJ, Morris ID, Davis JRE, Klatzmann D, Lowenstein PR, Castro MG 2000 Transcriptional targeting to anterior pituitary lactotrophic cells
using recombinant adenovirus vectors in vitro and in
vivo in normal and estrogen/sulpiride-induced hyperplasic anterior
pituitaries. Endocrinology 141:34933505[Abstract/Free Full Text]
-
Berwaer M, Monget P, Peers B, Mathy-Hartert M,
Bellefroid E, Davis JRE, Belayew A, Martial JA 1991 Multihormonal
regulation of the human prolactin gene-expression from 5000bp of its
upstream sequence. Mol Cell Endocrinol 80:5364[CrossRef][Medline]
-
Hoggard N, Davis JRE, Berwaer M, Monget P, Peers B,
Belayew A, Martial JA 1991 Pit-1 binding sequences permit calcium
regulation of human prolactin gene expression. Mol Endocrinol 5:17481754[CrossRef][Medline]
-
Takasuka N, White MRH, Wood CD, Robertson WR, Davis
JRE 1998 Dynamic changes in prlactin promoter activation in
individual living lactotrophic cells. Endocrinology 139:13611368[Abstract/Free Full Text]
-
Mori Y, Takeuchi Y, Shimada M, Hayashi S, Hoshino K 1990 Stereotaxic approach to hypothalamic nuclei of the Shiba goat with
radiographic monitoring. Jpn J Vet Sci 52:339349
-
Lignereux Y, Regodon S, Marty M-H, Franco A, Bubien
A 1991 Encephalic ventricles of the ewe (Ovis aries
L.): conformation, relations and stereotaxic topography. Acta Anat 141:8284[Medline]
-
Tortonese DJ, Brooks J, Ingleton PM, McNeilly
AS 1998 Detection of prolactin gene expression in the sheep
pituitary gland and visualization of the specific translation of the
signal in gonadotrophs. Endocrinology 139:52155223[Abstract/Free Full Text]
-
McNeilly AS, Land RB 1979 Effect of suppression of
plasma prolactin on ovulation, plasma gonadotrophins and corpus luteum
function in LH-RH-treated anoestrous ewes. J Reprod Fertil 56:601609[Abstract/Free Full Text]
-
McNeilly AS, Crow WJ, Fraser HM 1992 Suppression of
pulsatile luteinizing hormone secretion by gonadotrophin-releasing
hormone antagonist does not affect episodic progesterone secretion or
corpus luteum function in ewes. J Reprod Fertil 96:865874[Abstract/Free Full Text]
-
Fraser HM, McNeilly AS 1982 Effect of chronic
immunoneutralization of thyrotropin-releasing hormone. Endocrinology 111:19641973[Medline]
-
McNeilly AS, Brooks AN, Baxter G, Webb R 1994 Sheep
adrenal inhibin. In: Burger HG, Findlay JK, deKretser D, Petraglia F
(eds) Inhibin and Inhibin-Related Proteins. Frontiers in Endocrinology.
Ares-Serono Symposia, Rome, vol 3:261269
-
Davis JRE, Lowenstein PR, McNeilly AS, Castro MG 1999 Gene therapy for pituitary tumours. Endocr Relat Cancer 6:475483[CrossRef][Medline]
-
Peers B, Voz ML, Monget P, Mathy-Hartert M, Berwaer M,
Belayew A, Martial JA 1990 Regulatory elements controlling the
expression of the human prolactin gene. Mol Cell Biol 10:46904700[Abstract/Free Full Text]
-
Lee EJ, Thimmapaya B, Jameson JL 2000 Stereotactic
injection of adenoviral vectors that target gene expression to
specific pituitary cell types: implication for gene therapy.
Neurosurgery 46:14611468[CrossRef][Medline]
-
Castro MG 1999 Gene therapy strategies for the
treatment of pituitary tumours. J Mol Endocrinol 22:918[CrossRef][Medline]
-
Yoshida Y, Hamada H 1997 Adenovirus-mediated
inducible gene expression through tetracycline-controllable
transactivator with nuclear localization signal. Biochem Biophys Res
Commun 230:426430[CrossRef][Medline]
-
Harding TC, Geddes BJ, Murphy D, Knight D, Uney JB 1998 Switching transgene expression in the brain using an adenoviral
tetracycline-regulatable system. Nat Biotechnol 16:553555[CrossRef][Medline]
-
Castro MG, Windeatt S, Smith-Arica J, Lowenstein
PR 1999 Cell-type specific expression in the pituitary: physiology
and gene therapy. Biochem Soc Trans 27:858863[Medline]
-
Dewey RA, Morrissey G, Cowsill CM, Stone D,
Bolognani F, Dodd NJF, Southgate TD, Klatzmann D, Lassmann H, Castro
MG, Lowenstein PR 1999 Chronic brain inflammation and persistent
herpes simplex virus 1 thymidine kinase expression in survivors of
syngeneic glioma treated by adenovirus-mediated gene therapy:
implications for clinical trials. Nat Med 5:12561263[CrossRef][Medline]
-
Cowsill C, Southgate TD, Morrissey G, Dewey RA, Morrelli
AE, Maleniak TC, Forrest Z, Klatzmann D, Wilkinson GWG, Lowenstein PR,
Castro MG 2000 Central nervous toxicity of two adenoviral vectors
encoding variants of the herpes simplex virus type 1 thymidine kinase:
reduced cytotoxicity of a truncated HSV-1 TK. Gen Ther 7:679685[CrossRef][Medline]
This article has been cited by other articles:

|
 |

|
 |
 
M. P. Gillam, M. E. Molitch, G. Lombardi, and A. Colao
Advances in the Treatment of Prolactinomas
Endocr. Rev.,
August 1, 2006;
27(5):
485 - 534.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M Candolfi, G Jaita, D Pisera, L Ferrari, C Barcia, C Liu, J Yu, G Liu, M G Castro, and A Seilicovich
Adenoviral vectors encoding tumor necrosis factor-{alpha} and FasL induce apoptosis of normal and tumoral anterior pituitary cells.
J. Endocrinol.,
June 1, 2006;
189(3):
681 - 690.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
E. J. Lee and J L. Jameson
Gene therapy of pituitary diseases
J. Endocrinol.,
June 1, 2005;
185(3):
353 - 362.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. Roche, A. J Zamora, D. Taieb, E. Lavaque, R. Rasolonjanahary, H. Dufour, C. Bagnis, A. Enjalbert, and A. Barlier
Lentiviral vectors efficiently transduce human gonadotroph and somatotroph adenomas in vitro. Targeted expression of transgene by pituitary hormone promoters
J. Endocrinol.,
October 1, 2004;
183(1):
217 - 233.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
U. B. Kaiser
Editorial: Pituitary Gene Therapy--Hypotheses on the Hypophysis
Endocrinology,
February 1, 2001;
142(2):
528 - 531.
[Full Text]
[PDF]
|
 |
|