
Clinical Cancer Research Vol. 6, 3354-3360, August 2000
© 2000 American Association for Cancer Research
Experimental Therapeutics, Preclinical Pharmacology |
Efficient Inhibition of In Vivo Human Malignant Glioma Growth and Angiogenesis by Interferon-ß Treatment at Early Stage of Tumor Development1
Yong-Kil Hong2,
Dong-Sup Chung3,
Young-Ae Joe3,
Youn-Joo Yang,
Kyung-Mi Kim,
Young-Sup Park,
W. K. Alfred Yung and
Joon-Ki Kang
Departments of Neurosurgery [Y-K. H., D-S. C., Y-J. Y., Y-S. P., J-K. K.] and Pathology [K-M. K.] and Cancer Research Institute [Y-K. H., Y-A. J.], The Catholic University of Korea, 137-040 Seoul, Korea, and Department of Neuro-Oncology, M. D. Anderson Cancer Center, Houston, Texas 77030 [W. K. A. Y.]
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ABSTRACT
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Malignant gliomas are highly angiogenic and aggressive tumors. IFN-ß
has been used for the treatment of patients with malignant glioma;
however, its antitumor mechanism in vivo remains
unclear. To understand the in vivo antitumor effect and
mechanism of recombinant human IFN-ß (rhIFN-ß) depending on the
stages of tumor development or progression, we used orthotopic
xenograft brain tumors generated by stereotactic intracerebral
implantation of U-87 human glioma cells in nude mice. Mice bearing
tumors 7 days (group 1) and 21 days (group 2) postimplant were treated
with 2 x 105 IU/day of rhIFN-ß or saline i.p. for
15 days, respectively. Tumor growth was suppressed by 69.6% in group 1
and 10.8% in group 2 compared with tumors of each control group
treated with saline. rhIFN-ß-treated group 1 animals showed 38%
reduction in vascularization along with a 2.5-fold increase of the
apoptotic index and no change in the proliferative index as compared
with untreated tumors. The expression level of vascular endothelial
cell growth factor and basic fibroblast growth factor was not affected
by rhIFN-ß treatment. rhIFN-ß showed inhibitory activity on
proliferation of U-87 cells, human umbilical vein endothelial cells,
and PAM 212 murine keratinocytes in vitro. Our results
indicate that the in vivo antitumor effect of rhIFN-ß
on malignant gliomas may be mediated, at least in part, via
angiogenesis inhibition rather than antiproliferative activity and that
rhIFN-ß may be more effective for the treatment of malignant glioma
patients at an early stage with minimal or microscopic tumor burdens
rather than at an advanced stage of tumor development.
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INTRODUCTION
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Malignant gliomas, the most common primary brain tumors, are very
aggressive tumors with a dismal prognosis despite advances in surgery,
radiation therapy, and chemotherapy (1)
. Recent
experimental evidence indicates that angiogenesis is an essential
biological event encountered in tumor growth and progression, and
inhibition of tumor-related angiogenesis may provide an alternative
approach for tumor therapy (2)
. Malignant gliomas are
characterized by rapid cell proliferation activity, high invasiveness
into the surrounding brain, and increased degree of vascularity
(1
, 3) . Morphological features of dense vascularity and
endothelial cell proliferation of malignant gliomas are readily
recognizable indications that distinguish them from other brain
tumors, i.e., astrocytomas. Recent studies showed that
tumor-related angiogenesis contributes significantly to the malignant
phenotype of tumors (4)
. Blood-brain barrier or
blood-tumor barrier, which hinders drug delivery into brain tissue, is
considered to be one of the main problems associated with chemotherapy
of brain tumors (1
, 5)
. Therefore, an antiangiogenic
approach targeting endothelial cells rather than tumor cells may be
especially suitable for the treatment of malignant brain tumors.
Several angiogenesis inhibitors were reported to induce regression or
dormancy in a variety of primary and metastatic tumors
(6, 7, 8, 9, 10, 11, 12, 13)
, and we also previously reported that recombinant
kringles 13 of human plasminogen effectively inhibit angiogenesis and
growth of intracerebral malignant glioma in nude mice
(11)
. Neither the antitumor mechanism nor the effective
therapeutic guidelines of angiogenesis inhibitors were clearly defined.
Recently, it has been reported that the antiangiogenic or antitumor
effect of angiogenesis inhibitors may differ depending on the stages of
tumor progression including angiogenic phenotype and tumor burden
(14)
.
IFN-ß has been used for patients with solid tumors including
malignant gliomas with only marginal benefit, and a therapeutic
guideline for the best clinical efficacy has not been determined
(15
, 16) . There have been several in vitro
(17
, 18)
and in vivo (19, 20, 21, 22, 23, 24)
studies demonstrating antiangiogenic activity of IFN-ß in other
tumors, and it has been reported that IFN-
and IFN-ß can
specifically down-regulate mRNA expression and protein production of
bFGF4
in human bladder carcinomas (18
, 24)
. However, the
in vivo antiangiogenic property of IFN-ß has not been
studied in malignant gliomas. Here, we studied the in vivo
antitumor effect and mechanism of rhIFN-ß using orthotopic xenograft
brain tumors generated by stereotactic intracerebral implantation
of U-87 human glioma cells in nude mice.
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MATERIALS AND METHODS
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Brain Tumor Animal Model.
A brain tumor animal model was made as described previously
(11)
. Briefly, 6- to 8-week-old athymic nude
(nu/nu) mice were housed in laminar-flow cabinets
under specific-pathogen-free conditions. Animals were anesthetized by
i.p. injection of xylazine (Rompun; Cutter Laboratories, Shawnee, KS)
12 mg/kg and ketamine (Ketalar; Parke-Davis & Co., Morris Plains, NJ)
30 mg/kg. Mice were held in a stereotactic frame with an ear bar. Human
glioblastoma cell line U-87 (American Type Culture Collection,
Manassas, VA), 2 x 105 cells in a volume of
3 µl PBS, was injected slowly into the brain with a Hamilton syringe.
Treatment of Mice with rhIFN-ß.
To see whether the antitumor effect of IFN-ß is influenced by the
tumor burden or tumorigenesis stage, the animals were divided into two
groups according to the time of treatment. Group 1 animals
(n = 20) were treated from 7 days and those of group 2
(n = 20) from 21 days after the tumor cell inoculation.
The mice of each group were treated with rhIFN-ß (Beta-Feron;
Cheiljedang, Seoul, Korea) at 2 x 105 IU
(treated group, n = 10) or normal saline (control
group, n = 10) i.p. once a day for 15 days. Two days
after the final treatment, the animals were sacrificed, and the brains
were removed. The presence of tumor in the brain was evaluated by
serial coronal cutting with 1 mm thickness from the tumor cell
inoculation site. The midcoronal sections of the whole tumors were
processed for histological and immunohistochemical analyses.
Tumor Size Measurement.
The maximal area of the tumor in coronal section stained with H&E was
selected and transcribed onto paper (x4.0 actual size) by a zoom
stereo microscope (SZH-111; Olympus Optical Co., Tokyo, Japan) with a
drawing attachment (SZH-DA; Olympus Optical Co.). The transcribed area
of the tumor was then measured with a planimeter (KP-21; Koizumi,
Japan).
Immunohistochemical Staining.
Formalin-fixed paraffin-embedded specimens obtained from the brains of
the group 1 mice were studied as described previously
(11)
. Immunohistochemical staining was performed by the
avidin-biotin complex method for proliferation index, microvessel
quantitation, and expression of VEGF and bFGF. The archived blocks were
sectioned consecutively at a thickness of 5 µm and mounted on
poly-L-lysine-coated slides. After routine
deparaffinization, rehydration, and blockade of endogenous peroxidase
activity, antigen retrieval was performed. Sections were subjected to
microwave antigen retrieval by immersion in citrate buffer, pH 6.0. To
detect Ki-67, VEGF, and bFGF proteins, we used 1: 50 dilution of a
rabbit polyclonal antibody for Ki-67 (Dako A/S, Denmark), VEGF (Santa
Cruz Biotechnology, Santa Cruz, CA), and bFGF (Santa Cruz
Biotechnology). For human von Willebrand factor (factor VIII), we used
1:300 dilution of the antibodies (Dako, Carpinteria, CA). Fast Red
(Amresco, Solon, OH) was used as a chromogen. The slides were lightly
counterstained with hematoxylin. All reagents except the primary
antibody were used in the negative controls.
Ki-67 labeling index was determined by the percentage of immunopositive
nuclei to the total number of nuclei in a high-power field (x400). An
average of
2000 nuclei were selected in each section randomly.
All blood vessels were determined by light microscopy according to the
procedure described previously (25)
. After the area of
highest neovascularization was identified, microvessels were counted at
x400 magnification. Any red-staining endothelial cell, or
endothelial-cell cluster that was clearly separate from adjacent
microvessels, tumor cells, and other connective tissue elements was
considered a single, countable microvessel. Each count was expressed as
the highest number of microvessels identified within a field. All
counts were also performed by a pathologist who did not have any prior
information about these specimens.
The immunohistochemical stained sections for VEGF and bFGF were rated
on an arbitrary 0- to 3-point scale based on staining intensity that
was interpreted as relative immunoreactivity by a pathologist blinded
to the study. Ratings were designated as follows: no staining = 0,
mild staining = 1, moderate staining = 2, and intense
staining = 3.
Assessment of Apoptotic Cells.
To determine the presence of apoptotic cells, we used the terminal
deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling
procedure, which allows in situ labeling of DNA breaks in
tissue sections (26)
. We used the ApopTag in
situ apoptosis detection kit (Oncor, Gaithersburg, MD), and all of
the procedures were performed according to the manufacturers
instructions. The slides were lightly counterstained with hematoxylin.
In every specimen,
5000 tumor cells were counted in at least 10
randomly chosen fields. The condensed nuclei were counted for this
study because it was often difficult to compute the numbers of
apoptotic cells derived from the fragmented nuclei.
Cell Proliferation Assay and Western Blotting.
U-87, HUVECs, and PAM 212 murine keratinocytes (American Type
Culture Collection) were seeded into six-well plates (1 x
104
cells/ml) and allowed to adhere overnight. The cultures
were then washed and refed with control medium or medium containing
rhIFN-ß at concentrations of 51000 IU/ml. Antiproliferative
activity was determined by cell count assay from day 1 to day 10. U-87
cells (1 x 104
cells/ml) were plated into
100-mm dishes and treated with medium containing rhIFN-ß at
concentrations of 0500 IU/ml for 24 and 72 h; Western blot assay
was performed as described previously (11)
.
Immunodetection of VEGF and bFGF was accomplished with sc-152G goat
polyclonal antibody for VEGF (1:1000 dilution in 1% BSA), sc-79G
polyclonal antibody for bFGF (1:1000 dilution in 1% BSA; Santa Cruz),
or mouse monoclonal antibody for bFGF (1:5000 dilution in 1% BSA;
Sigma), followed by incubation with horseradish peroxidase-coupled
rabbit antigoat IgG or rabbit antimouse IgG (Santa Cruz).
Statistical Analysis.
The significance of the data was determined with Students
t test (two-tailed) or the Wilcoxon rank sum test.
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RESULTS
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Effect of rhIFN-ß on Brain Tumor Growth.
Inhibitory effect of rhIFN-ß on intracerebral glioma growth was
significant in group 1, in which the treatment began 7 days after U-87
cell inoculation, and only minimal in group 2. The means of maximal
area of tumors was 10.74 ± 2.88 mm2 in
control animals treated with saline and 3.27 ± 2.13
mm2 in animals treated with rhIFN-ß in group 1
(P = 0.029), whereas 16.43 ± 6.67
mm2 in control animals and 14.65 ± 7.87
mm2 in treated animals in group 2 (Fig. 1)
. Microscopically, the treated tumors showed minimally decreased
cellularity, lymphocyte infiltration, and mitosis compared with
controls. No necrosis was found in both treated and control tumors
(data not shown).

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Fig. 1. Growth inhibition of brain tumors by systemic
administration of rhIFN-ß. Seven days (group 1) and 21 days (group 2)
after the stereotactic intracerebral injection of U-87 human glioma
cells in nude mice, the animals received 2 x 105 IU
rhIFN-ß or normal saline (control) i.p. once a day for 15 days. Two
days after the last treatment, the animals were sacrificed and the
brains were removed. In A, the tumor size was measured
and calculated after H&E staining of a coronal section of the
brain at the maximal brain tumor dimension (values shown are mean ± SD). B, representative brain tumors of control and
treated animals stained with H&E. Arrowheads, the
brain tumor. Bars, 1 mm; *, P =
0.029.
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Angiogenesis, Proliferation, and Apoptosis.
We studied the effect of rhIFN-ß on vascularity, proliferative
activity, and apoptosis of the tumors in group 1. The number of blood
vessels was 140.00 ± 14.27 in the tumors of control animals and
54.17 ± 17.23 in the treated tumors (P = 0.0001;
Fig. 2
A). The Ki-67 labeling index was 34.00 ± 5.33 in the
control tumors and 36.33 ± 4.03 in the treated tumors
(P = 0.4125; Fig. 2
B). The apoptotic index
was 1.28 ± 0.21% in the control tumors and 2.72 ± 0.27%
in the treated tumors (P = 0.0001; Fig. 2
C).
To further determine the antiangiogenic property of rhIFN-ß in mouse
brain tumor models, we studied its effect on in vitro
culture of glioma cells, human endothelial cells, and murine cells. As
shown in Fig. 3
, rhIFN-ß inhibited the proliferation of U-87, HUVECs, and PAM 212
cells by >51.7%, 42.6%, and 46.8%, respectively, at doses of
100-1000 IU/ml.

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Fig. 2. Analysis of blood vessel density, proliferation
index, and apoptosis in histological sections of the brain tumors from
control and rhIFN-ß-treated animals. A, vessel density
was determined by counting the number of capillary blood vessels per
high power field (HPF) in sections stained with antibody
against factor VIII (von Willebrands factor). The capillary density
of the tumors from treated mice was reduced to 38% of that of controls
(P = 0.0001). B, there was no
significant difference in the proliferative index of tumor cells
assessed by immunohistochemical staining with antibody to Ki-67 antigen
in the treated versus control tumors
(P = 0.4125). C, apoptotic index
measured by terminal deoxynucleotidyl transferase-mediated dUTP-biotin
nick end labeling (TUNEL) increased >2.5-fold in
treated tumors (P = 0.0001). Bars, 30
µm.
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Fig. 3. Antiproliferative effects of rhIFN-ß. Human
glioma cells (U-87 MG), HUVECs, and murine keratinocytes (PAM 212) of 1
x 104 cells/ml were seeded into six-well plates and
allowed to adhere overnight. The cultures were then washed and refed
with control medium or medium containing rhIFN-ß at concentrations of
5500 IU/ml from day 1 to day 10.
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Angiogenic Growth Factors.
To examine whether angiogenesis inhibition of rhIFN-ß is mediated
by the modulation of VEGF and/or bFGF expression, we studied their
expression in brain tumor tissues by immunohistochemical analysis. The
point scale of each VEGF and bFGF expression of control tumors was
1.50 ± 0.55 and that of treated tumors was 1.33 ± 0.52
(P = 0.6404; Fig. 4
A). The very small brain tumor tissues of the treated
animals were not adequate for Western blot analysis, and instead we
performed in vitro studies on U-87 cells. As shown in Fig. 4
B, the level of VEGF and bFGF expression of U-87 cells was
not influenced by rhIFN-ß treatment at concentrations from 10500 IU/ml.

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Fig. 4. rhIFN-ß effect on bFGF and VEGF expressions in
intracerebral tumors (in vivo) and U-87 cells (in
vitro). In A, bFGF and VEGF expression was
analyzed by immunohistochemical staining of the brain tumors of control
and treated animals and assessed by the point scales based on staining
intensity. In B, protein was extracted from the U-87
cell cultures after treatment with media containing rhIFN-ß, 0500
IU/ml, for 24 and 72 h, and Western blot analysis was done. The
expression level of bFGF and VEGF protein was not affected by rhIFN-ß
treatment in malignant gliomas.
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DISCUSSION
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IFNs are known to have multiple biological actions including
modulation of gene expression and their protein products,
immunomodulation, slowing of cell proliferation, and alterations in
differentiation (27)
. The antiangiogenic property has been
suggested to be another mechanism of the antitumor effect of IFNs.
Several clinical observations have substantiated the antiangiogenic
properties of IFNs. The chronic administration of IFN-
to patients
with Kaposi sarcoma, pulmonary hemangiomatosis or life-threatening
hemangiomas of infancy have resulted in regression of tumors
(28, 29, 30)
. IFNs inhibit endothelial cell growth in
vitro (17)
and in experimental models of
tumor-induced angiogenesis (19
, 20)
. Treatment of tumor
cells with IFNs in vitro before injection into untreated
mice also inhibited tumor-induced angiogenesis, suggesting that IFNs
can directly modulate the angiogenic potential of tumor cells
(19)
. Both IFN-
and IFN-ß have been known to possess
common receptors (31)
and tumoristatic activity against
human glioma cells in culture (32)
and xenograft in nude
mice (33
, 34)
. In vitro studies have suggested
that IFN-ß has a more potent growth-inhibitory effect than IFN-
when tested against human glioma cell lines (35
, 36)
.
IFN-ß has been used in patients with malignant or recurrent glioma,
but its therapeutic efficacy was only marginal (15
, 16)
,
and the molecular details associated with in vivo antiglioma
effects of IFN-ß remain largely unknown.
Our results showed that suppression of brain tumor growth in nude mice
by systemic treatment with rhIFN-ß was more prominent in group 1, in
which rhIFN-ß treatment began 7 days post-tumor implant, but less
significant in group 2, in which rhIFN-ß treatment began 21 days
post-tumor implant. In our preliminary experiments, the brain tumors of
the control group were very small (<1 mm2) or
invisible at 7 days postimplant and 10.74 ± 2.88
mm2 at 21 days postimplant (data not shown).
These results suggest that rhIFN-ß may be tumoristatic rather than
tumoricidal and may be more effective for the treatment of malignant
glioma patients at an early stage with minimal or microscopic tumor
burdens rather than at an advanced stage of tumor development. Our
results also strongly support the notion of Bergers et al.
(14)
that antiangiogenic drugs may prove most efficacious
when they are targeted to specific stages of cancers.
Despite the clinical activity of IFN-ß on malignant gliomas
(15
, 16) , its antitumor mechanism in vivo is
still unclear. Böethius et al. (37)
reported that systemic administration of IFN-
to patients with
glioblastoma multiforme induced marked changes in the tumor
vasculature, which supports the notion that IFN-
may have an effect
on tumor vessels. In our study, vascularity of the tumors was reduced
to near one-third of the controls in vivo, and proliferation
of HUVECs and PAM 212 murine cells was inhibited in vitro by
rhIFN-ß. Cook et al. (36)
and we found that
IFN-ß inhibited proliferation of U-87 cells in vitro. Our
results, showing that intracerebral tumor of nude mice maintained a
high proliferation index after rhIFN-ß therapy, is dissociated with
the well-known in vitro antiproliferative effects of IFNs on
tumor cells. Considering these in vitro and in
vivo results, it can be postulated that the in vivo
antiproliferative effect of rhIFN-ß may differ from that of the
in vitro, or the concentration of rhIFN-ß administered may
be lower than that necessary to inhibit tumor cell proliferation.
Delivery of rhIFN-ß to intracerebral tumor cells was reported to be
hindered by the blood-brain barrier or blood-tumor barrier from the
systemic circulation (38)
. These strongly suggest that the
in vivo antitumor effect of rhIFN-ß in malignant gliomas
may be mediated, at least in part, via the angiogenesis inhibition
rather than the antiproliferative activity on tumor cells and that
rhIFN-ß may inhibit angiogenesis more efficiently at early stage,
before angiogenic phenotype change develops, than at advanced stage of
tumor development.
IFNs have been known to inhibit angiogenesis not only by affecting
endothelial cells but also by inhibiting production or release from
tumor cells or lymphocytes of factors which may stimulate host response
(19
, 22) . Slowing of the cell cycles and inhibition of
cell proliferation have been known to be general properties of IFN
activity (27
, 39) . However, the inhibition
mechanism of endothelial cell growth by rhIFN-ß has not been
determined in detail. To determine whether rhIFN-ß induces apoptosis
in endothelial cells, we treated HUVECs with rhIFN-ß and stained with
4',6-diamidino-2-phenylindole (Sigma), in which apoptosis induction was
not observed by the rhIFN-ß treatment (data not shown). Contrary to
the results of Singh et al. (18)
, which showed
that IFN-
and IFN-ß can specifically down-regulate mRNA expression
and protein production of bFGF in bladder carcinoma, our study
demonstrated that bFGF and VEGF expression of U-87 glioma was not
influenced by rhIFN-ß. These suggest that the mechanism of
angiogenesis inhibition in vivo by rhIFN-ß may be not
simple and involve pathways other than bFGF and VEGF in human malignant
gliomas.
Our results of a high cell proliferation index balanced by a high
apoptosis rate in intracerebral tumors indicate that rhIFN-ß may
limit tumor growth by elevating the incidence of apoptosis to a steady
state as a balance between apoptosis and proliferation of malignant
glioma cells. The mechanism by which IFN therapy leads to an increase
in tumor cell apoptosis is unknown, although it has been postulated
that apoptosis is induced by IFN-
in colorectal adenocarcinoma via
the up-regulation of Fas and Bax antigen and down-regulation of Bcl-2
(40)
, and IFN-
has been found to induce regression of
basal cell carcinoma by apoptosis induction via CD95 (Apo-1/Fas)-CD95
ligand interaction (41)
. Another explanation is that
antiangiogenic activity of rhIFN-ß may result in increased apoptosis.
This is supported by the study of Sidky et al.
(19)
showing that inhibition of tumor-induced angiogenesis
by IFNs can be expressed in the absence of antiproliferative effects on
tumor cells in vivo and by our study demonstrating the
antiangiogenic effect with apoptosis induction by rhIFN-ß in
intracerebral malignant gliomas. This pattern of tumor inhibition seems
to be a general trait of various antiangiogenic therapies including
TNP-470 (42)
, angiostatin (9
, 11)
, and
endostatin (10)
which also result in increased apoptotic
rates. The mechanism by which antiangiogenic therapy induces an
increase in apoptosis in tumor cells is also unknown. Inhibition of
angiogenesis may induce a decrease of survival and growth factor
production required by the endothelium (9)
and/or suppress
the secretions of endothelial-derived paracrine factors and cytokines
needed by tumor cells (2
, 43)
, hence resulting in
increased apoptosis.
In conclusion, the in vivo antitumor effect of rhIFN-ß in
malignant glioma patients may be mediated via the inhibition of tumor
angiogenesis, and its therapeutic efficacy may be strengthened by
fine-tuning it to specific stages of the tumor progression. Further
studies for detailed mechanisms underlying angiogenesis inhibition and
apoptosis induction will be necessary to develop more efficient use of
rhIFN-ß for the treatment of malignant gliomas.
 |
ACKNOWLEDGMENTS
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We thank Dr. Anil Sehgal for reviewing this paper.
 |
FOOTNOTES
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
1 This work was supported in part by grants from
the Catholic Medical Center, Catholic Cancer Center, Our Lady of Mercy
Hospital, and Korea Research Foundation (98-005-F00126). 
2 To whom requests for reprints should be
addressed, at Department of Neurosurgery, Kangnam St. Marys Hospital,
The Catholic University of Korea, Banpo-dong 505, Seocho-gu, Seoul
137-040, Korea. Phone: 82-2-590-2732; Fax: 82-2-594-4248; E-mail: hongyk{at}cmc.cuk.ac.kr 
3 These authors contributed equally to this
work. 
4 The abbreviations used are: bFGF, basic
fibroblast growth factor; rhIFN-ß, recombinant human interferon-ß;
VEGF, vascular endothelial growth factor; HUVECs, human umbilical vein
endothelial cells. 
Received 2/16/00;
revised 5/16/00;
accepted 5/17/00.
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REFERENCES
|
|---|
-
Kornblith P. K., Welch W. C., Bradley M. K. The future of therapy for glioblastoma. Surg. Neurol., 39: 538-543, 1993.[CrossRef][Medline]
-
Folkman J. The role of angiogenesis in tumor growth. Semin. Cancer Biol., 3: 65-71, 1992.[Medline]
-
Brem S., Cotran R., Folkman J. Tumor angiogenesis: a quantitative method for histological grading. J. Natl. Cancer Inst., 48: 347-356, 1972.
-
Brem H., Thomson D., Long D. M., Patz A. Human brain tumors: differences in ability to stimulate angiogenesis. Surg. Forum, 31: 471-476, 1980.
-
Risau W., Esser S., Englehardt B. Differentiation of blood-brain barrier endothelial cells. Pathol. Biol., 46: 171-175, 1998.[Medline]
-
Kim K. J., Li B., Winer J., Armanini M., Gillet N., Phillips H. S., Ferrara N. Inhibition of vascular endothelial cell growth factor-induced angiogenesis suppresses tumor growth in vivo.. Nature (Lond)., 362: 841-844, 1993.[CrossRef][Medline]
-
Millauer B., Shawer L. K., Plate K. H., Risau W., Ullrich A. Glioblastoma growth inhibited in vivo by a dominant negative FLK1 mutant. Nature (Lond)., 367: 576-579, 1994.[CrossRef][Medline]
-
Brooks P. C., Montgomery A. M. P., Rosenfeld M., Reisfeld R. A., Hu T., Klier G., Cheresh D. A. Integrin
vß 3 antagonists promote tumor regression by inducing apoptosis of angiogenic blood vessels. Cell, 79: 1157-1164, 1994.[CrossRef][Medline]
-
OReilly M. S., Holmgren L., Chen C., Folkman J. Angiostatin induces and sustains dormancy of human primary tumors in mice. Nat. Med., 2: 689-692, 1996.[CrossRef][Medline]
-
OReilly M. S., Boehm T., Shing Y., Fukai N., Vasios G., Lane W. S., Flynn E., Birkhead J. R., Olsen B. R., Folkman J. Endostain: an endogenous inhibitor of angiogenesis and tumor growth. Cell, 88: 277-285, 1997.[CrossRef][Medline]
-
Joe Y. A., Hong Y. K., Chung D. S., Yang Y. J., Kang J. K., Lee Y. S., You W. K., Chang S. I., Lee H. S., Chung S. I. Inhibition of human malignant glioma growth in vivo by human recombinant plasminogen kringles 13. Int. J. Cancer, 82: 694-699, 1999.[CrossRef][Medline]
-
Dong Z., Greene G., Pettaway C., Dinney C. P., Eue I., Lu W., Bucana C. D., Balbay M. D., Bielenberg D., Fidler I. J. Suppression of angiogenesis, tumorigenicity, and metastasis by human prostate cancer cells engineered to produce interferon-ß. Cancer Res., 59: 872-879, 1999.[Abstract/Free Full Text]
-
OReilly M. S., Pirie-Shepherd S., Lane W. S., Folkman J. Antiangiogenic activity of the cleaved conformation of the serpin antithrombin. Science (Washington DC), 285: 1926-1928, 1999.[Abstract/Free Full Text]
-
Bergers G., Javaherian K., Lo K-M., Folkman J., Hanahan D. Effects of angiogenesis inhibitors on multistage carcinogenesis in mice. Science (Washington DC), 284: 808-812, 1999.[Abstract/Free Full Text]
-
Yung W. K. A., Prados M., Levin V. A., Fetell M. R., Bennett J., Mahaley M., Salcman M., Etcubanas E. Intravenous recombinant interferon ß in patients with recurrent malignant gliomas: a Phase I/II study. J. Clin. Oncol., 9: 1945-1949, 1991.[Abstract/Free Full Text]
-
Yoshida J., Kajita Y., Wakabayashi T., Sugita K. Long-term follow-up results of 175 patients with malignant glioma: importance of radical tumor resection and postoperative adjuvant therapy with interferon, ACNU, and radiation. Acta Neurochir. (Wien), 127: 55-59, 1994.[CrossRef][Medline]
-
Ruszczak Z., Detmar M., Imcke E., Orfanos C. E. Effects of rIFN
, ß, and
on the morphology, proliferation, and cell surface antigen expression of human dermal microvascular endothelial cells in vitro.. J. Invest. Dermatol., 95: 693-699, 1990.[CrossRef][Medline]
-
Singh R. K., Gutman M., Bucana C. D., Sanchez R., Llansa N., Fidler I. J. Interferons
and ß down-regulate the expression of basic fibroblast growth factor in human carcinomas. Proc. Natl. Acad. Sci USA, 92: 4562-4566, 1995.[Abstract/Free Full Text]
-
Sidky Y. A., Borden E. C. Inhibition of angiogenesis by interferons: effects on tumor- and lymphocyte-induced vascular responses. Cancer Res., 47: 5155-5161, 1987.[Abstract/Free Full Text]
-
Dvorak H., Gresser I. Microvascular injury in pathogenesis of interferon-induced necrosis of subcutaneous tumors in mice. J. Natl. Cancer Inst., 81: 497-502, 1989.[Abstract/Free Full Text]
-
Brem H., Gresser I., Grosfeld J., Folkman J. The combination of antiangiogenic agents to inhibit primary tumor growth and metastasis. J. Pediatr. Surg., 28: 1253-1257, 1993.[Medline]
-
Lindner D. J., Borden E. C. Effects of tamoxifen and interferon-ß or the combination on tumor-induced angiogenesis. Int. J. Cancer, 71: 456-461, 1997.[CrossRef][Medline]
-
Parangi S., OReilly M., Christofori G., Holmgren L., Grosfeld J., Folkman J., Hanahan D. Antiangiogenic therapy of transgenic mice impairs de novo tumor growth. Proc. Natl. Acad. Sci. USA, 93: 2002-2007, 1996.[Abstract/Free Full Text]
-
Dinney C. P., Bielenberg D. R., Perrotte P., Reich R., Eve B. Y., Bucana C. D., Fidler I. J. Inhibition of basic fibroblast growth factor expression, angiogenesis, and growth of human bladder carcinoma in mice by systemic interferon-
administration. Cancer Res., 58: 808-814, 1998.[Abstract/Free Full Text]
-
Weidner N., Semple J. P., Welch W. R., Folkman J. Tumor angiogenesis and metastasis-correlation in invasive breast carcinoma. N. Engl. J. Med., 324: 1-8, 1991.[Abstract]
-
Gavrieli Y., Sherman Y. , and Ben Sasson, S. A. Identification of programmed cell death in situ via specific labeling of nuclear DNA fragmentation. J. Cell Biol., 119: 493-501, 1992.[Abstract/Free Full Text]
-
Gutterman J. U. Cytokine therapeutics: lessons from interferon
. Proc. Natl. Acad. Sci. USA, 91: 1198-1205, 1994.[Abstract/Free Full Text]
-
Real F. X., Oettgen H. F., Krown S. E. Kaposis sarcoma and the acquired immunodeficiency syndrome: treatment with high and low doses of recombinant leukocyte A interferon. J. Clin. Oncol., 4: 544-551, 1986.[Abstract/Free Full Text]
-
White C. W., Sondheimer H. M., Crouch E. C., Wilson H., Fan L. L. Treatment of pulmonary hemangiomatosis with recombinant interferon alfa-2a. N. Engl J. Med., 320: 1197-1200, 1989.[Medline]
-
Ezekowitz R. A. B., Mulliken J. B., Folkman J. Interferon alfa-2a therapy for life-threatening hemangiomas of infancy. N. Engl J. Med., 326: 1456-1463, 1992.[Abstract]
-
Aguet M., Belardelli R., Blanchard B., Marcucci F., Gresser I. High affinity binding of 125I-labelled mouse interferon to a specific cell surface receptor. Virology, 117: 541-544, 1982.[CrossRef][Medline]
-
Lundblad D., Lungren E. Block of a glioma cell line in S phase by interferon. Int J. Cancer, 27: 749-754, 1981.[Medline]
-
Nakamura O., Maruo K., Ueyama Y., Nomura K., Takakura K. Interaction of human fibroblast interferon with chemotherapeutic agents and radiation against human gliomas in nude mice. Neurol. Res., 8: 152-156, 1986.[Medline]
-
Yagi K., Hayashi Y., Ishida N., Ohbayashi M., Ohishi N., Mizuno M., Yoshida J. Interferon-ß endogenously produced by intratumoral injection of cationic liposome-encapsulated gene: cytocidal effect on glioma transplanted into nude mouse brain. Biochem. Mol. Biol. Int., 32: 167-171, 1994.[Medline]
-
Bradley N. J., Darling J. L., Oktar N., Bloom H. J. G., Thomas D. G. T., Davies A. J. S. The failure of human leukocyte interferon to influence the growth of human glioma cell population: in vitro and in vivo studies. Br. J. Cancer, 48: 819-825, 1983.[Medline]
-
Cook A. W., Carter W. A., Nidzgorski F., Akhtar L. Human brain tumor-derived cell lines: growth rate reduced by human fibroblast interferon. Science (Washington DC), 219: 881-883, 1983.[Abstract/Free Full Text]
-
Böethius J., Blomgren H., Collins V. P., Greitz T., Strander H. The effect of human interferon-
administration to patients with glioblastoma multiforme. Acta Neurochir., 68: 239-251, 1983.[CrossRef][Medline]
-
Wiranowska M., Prockop L. D., Naidu A. K., Saporta S., Kori S., Kulkarni A. P. Interferon entry through the blood-brain-barrier in glioma and its effect on lipoxygenase activity. Anticancer Res., 14: 1121-1122, 1994.[Medline]
-
Taylor-Papadimitrion J. Effect of interferons on cell growth and function. Interferon, 2: 13-46, 1980.
-
Koshiji, M., Adachi, Y., Sogo, S., Taketani, S., Oyaizu, N., Than, S., Inaba, M., Phawa, S., Hioki, K., and Ikehara, S. Apoptosis of colorectal adenocarcinoma (COLO 201) by tumor necrosis factor-alpha (TNF-
) and/or interferon-
(IFN-gamma), resulting from down-modulation of Bcl-2 expression. Clin. Exp. Immunol. 111: 211218, 1998.
-
Buechner S. A., Wernli M., Harr T., Hahn S., Itin P., Erb P. Interferon-
treatment is mediated by CD95 (Apo-1/Fas)-CD95 ligand-induced suicide. J. Clin. Invest., 100: 2691-2696, 1997.[Medline]
-
Holmgren L., OReilly M. S., Folkman J. Dormancy of micrometastases: balanced proliferation and apoptosis in the presence of angiogenesis suppression. Nat. Med., 1: 149-153, 1995.[CrossRef][Medline]
-
Hamada J., Cavanaugh P. G., Lotan O., Nocolson G. L. Separable growth and migration factors for large-cell lymphoma cells secreted by microvascular endothelial cells derived from target organs for metastasis. Br. J. Cancer, 66: 349-354, 1992.[Medline]
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