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Experimental Therapeutics, Preclinical Pharmacology |
Cattedra di Oncologia Medica, Dipartimento di Endocrinologia e Oncologia Molecolare e Clinica, Facoltà di Medicina e Chirurgia, Università degli Studi di Napoli Federico II, 5-80131 Naples, Italy [F. C., R. B., V. D., R. C., G. P., S. D. P., A. R. B., G. T.]; Divisione di Anatomia Patologica, Dipartimento di Oncologia, Università di Pisa, 56126 Pisa, Italy [G. F.]; and University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030 [J. M.]
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ABSTRACT |
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 Top ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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(TGF-)-epidermal growth factor receptor (EGFR)
autocrine pathway controls in part the production of angiogenic factors
such as vascular endothelial growth factor (VEGF) and basic fibroblast
growth factor (bFGF) in cancer cells. In this study, we have evaluated
the antiangiogenic and antitumor activity of monoclonal antibody (MAb)
C225, an anti-EGFR chimeric human-mouse MAb, alone and in combination
with a human VEGF antisense (AS) 21-mer phosphorothioate
oligonucleotide (VEGF-AS) in human GEO colon cancer cells. MAb C225
treatment determined a dose-dependent inhibition of VEGF, bFGF, and
TGF- production by GEO cells in vitro. Treatment with
VEGF-AS caused a selective inhibition in VEGF expression by GEO cells
in vitro. Treatment of immunodeficient mice bearing
established, palpable GEO xenografts for 3 weeks with VEGF-AS or with
MAb C225 determined a cytostatic reversible inhibition of tumor growth.
In contrast, a prolonged inhibition of tumor growth was observed in all
mice treated with the two agents, in combination with a
significant improvement in mice survival compared with controls
(P < .001), to MAb C225 (P <
.001), or to VEGF-AS (P < .001) treated mice. All
mice died within 4, 6, and 8 weeks after tumor cell injection in the
control, VEGF-AS and MAb C225 groups, respectively. In contrast, 50%
of mice treated with the combination of VEGF-AS and MAb C225 were alive
at 13 weeks. Ten % of mice treated with VEGF-AS plus MAb C225 were
alive at 20 weeks and had no histological evidence of GEO tumors.
Immunohistochemical analysis of GEO tumor xenografts demonstrated a
significant reduction of VEGF expression after treatment with VEGF-AS
with a parallel reduction in microvessel count. MAb C225 treatment
determined a reduction in the expression of VEGF, bFGF, and TGF-
with a reduction in microvessel count. Finally, a significant
potentiation in inhibition of VEGF expression and little or no
microvessels were observed in GEO tumors after the combined treatment
with the two agents. |
INTRODUCTION |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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-EGFR
autocrine pathway plays an important role in the development and the
progression of human epithelial cancers, including colorectal cancer
(3)
. Enhanced expression of TGF- and/or EGFR has been
detected in the majority of human carcinomas (3)
and is
generally an indicator of poor prognosis (4)
. For these
reasons, the blockade of the TGF-EGFR autocrine pathway has been
proposed as anticancer therapy (5, 6, 7, 8, 9, 10, 11, 12, 13)
. Different
anti-EGFR blocking MAbs that inhibit the in vitro and
in vivo growth of human cancer cell lines that express
TGF- and EGFR have been developed (14, 15, 16, 17)
. MAb C225 is
a chimeric human-mouse IgG1, binds to the EGFR, blocks ligand-induced
activation of the EGFR tyrosine kinase, and is currently being
evaluated in clinical studies in cancer patients (7
, 18
, 19)
.
Angiogenesis, the process leading to the formation of new blood
vessels, plays a central role in the survival of cancer cells, in local
tumor growth, and in the development of distant metastasis
(20)
. The development of blood vessels within the tumor
mass is regulated by the production of several growth factors and
growth inhibitors (21)
. In this respect, different growth
factors, such as bFGF, VEGF, and TGF-, have been identified as
positive regulators of angiogenesis and are secreted by cancer cells to
stimulate normal endothelial cell growth through paracrine mechanisms
(22, 23, 24)
. VEGF is a potent and specific mitogen for
endothelial cells, activates the angiogenic switch in vivo,
and enhances vascular permeability (24)
. Enhanced
expression of VEGF has been observed in human cancer cell lines and in
cancer patients with different malignancies including colorectal,
breast, non-small cell lung, and ovarian cancers and is directly
correlated with increased neovascularization, as measured by MVC within
the tumor (24)
. The increasing understanding of the
biological mechanisms of tumor-induced angiogenesis has stimulated the
development of agents able to interfere with the molecules involved in
this process (25
, 26)
. Several approaches have been
proposed for blocking VEGF-induced endothelial cell proliferation and
subsequent tumor angiogenesis. An anti-VEGF MAb that inhibits the
growth of a variety of human cancer xenografts in nude mice has been
generated (27, 28, 29)
. This MAb has been recently humanized
and is under clinical development (30)
. Another promising
approach is the development of MAbs raised against the VEGF-specific
flk-1/KDR receptor (31)
or of selective inhibitors of the
flk-1/KDR tyrosine kinase (32)
. Finally, experimental
evidence has been provided for the potential therapeutic effect of
blocking VEGF production by plasmid or viral expression vectors
containing VEGF AS mRNA sequences or by VEGF AS oligonucleotides
(33, 34, 35, 36, 37)
.
In the present study, we have evaluated the effects of treatment with
the blocking anti-EGFR MAb C225 on the production of TGF-, bFGF, and
VEGF in GEO colon cancer cells in vitro and in
vivo. We have also determined the ability of an antihuman VEGF
phosphorothioate 21-mer antisense oligonucleotide (VEGF-AS; Ref.
37
) to interfere with the production of VEGF in these
cells. Finally, we have evaluated the antiangiogenic and antitumor
activity on GEO tumor xenografts of the combined treatment with VEGF-AS
and MAb C225.
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MATERIALS AND METHODS |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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Cell Cultures.
GEO human colon cancer cells were obtained from the American Type
Culture Collection (Rockville, MD). Cells were maintained in DMEM
supplemented with 10% heat-inactivated fetal bovine serum, 20
mM HEPES (pH 7.4), 100 UI/ml penicillin, 100 µg/ml
streptomycin, and 4 mM glutamine (ICN, Irvine, United
Kingdom) in a humidified atmosphere of 95% air and 5%
CO2 at 37°C.
Growth in Soft Agar.
Cells (104 cells/well) were suspended in 0.5 ml
of 0.3% Difco Noble agar (Difco, Detroit, MI) supplemented with
complete culture medium. This suspension was layered over 0.5 ml of
0.8% agar-medium base layer in 24-multiwell cluster dishes (Becton
Dickinson, Lincoln Park, NJ) and treated with different concentrations
of oligonucleotides or of MAb C225. After 10–14 days, the cells were
stained with nitro blue tetrazolium (Sigma Chemical Co., St. Louis,
MO), and colonies <0.05 mm were counted as described previously
(38)
.
Evaluation of TGF-, VEGF, and bFGF Secretion.
The concentration of TGF-, VEGF, or bFGF in the CM obtained from GEO
cells was measured using commercially available ELISA kits and
according to the manufacturers’ instructions. The ELISA kits for VEGF
and for bFGF were purchased from R&D Systems, Inc. (Minneapolis, MN).
The ELISA kit for TGF- was purchased from Oncogene Research Products
(Cambridge, MA). GEO cells were plated in 60-mm dishes (Becton
Dickinson) and treated for 4 days with different concentrations of MAb
C225, VEGF-AS oligonucleotide, or control oligonucleotide. Assays were
performed using 24-h-collected, serum-free CM.
Western Blotting.
Protein extracts (50 µg of total protein/lane) from GEO cells treated
with different concentrations of VEGF-AS or of the control
oligonucleotide were separated by SDS-PAGE on 12% precast gels
(Bio-Rad Laboratories, Milan, Italy), transferred to nitrocellulose
filters, and incubated with a rabbit polyclonal antihuman VEGF
antiserum (Santa Cruz Biotechnologies, Inc., Santa Cruz, CA).
Immunoreactive proteins were visualized by a chemiluminescence ECL
Western blotting kit (Amersham, Milan, Italy).
GEO Xenografts in Nude Mice.
Female BALB/c athymic (nu+/nu+) mice, 5–6 weeks of age,
were purchased from Charles River Laboratories (Milan, Italy). The
research protocol was approved, and mice were maintained in accordance
to institutional guidelines of the University of Naples Animal Care and
Use Committee. Mice were acclimated to the University of Naples Medical
School Animal Facility for 1 week prior to injection of cancer cells.
Mice received injections s.c. with 107 GEO cells
that had been resuspended in 200 µl of Matrigel (Collaborative
Biomedical Products, Bedford, MA). After 7 days, when established
tumors of approximately 0.2–0.3 cm3
in diameter
were detected, 10 mice/group were treated i.p. with VEGF-AS (5 or 10
mg/kg/dose; days 1–5 each week for 3 weeks) or with scramble control
oligonucleotide (10 mg/kg/dose; days 1–5 each week for 3 weeks). In a
second series of experiments, groups of 10 mice bearing established GEO
tumors of approximately 0.2–0.3 cm3
in diameter
were treated i.p. with VEGF-AS alone (10 mg/kg/dose; days 1–5 each
week for 3 weeks) or with MAb C225 alone (0.5 mg/dose, twice weekly on
days 1 and 4 for 3 weeks) or with both agents. This experiment was
repeated for three times with a total of 30 mice for each group. Tumor
size was measured using the formula 
/6 x larger diameter x (smaller diameter)2
, as reported previously
(39)
.
Immunohistochemical Analysis.
Immunocytochemistry was performed on cell cultures of GEO cells
or on formalin-fixed, paraffin-embedded tissue sections (5 µm) of GEO
xenografts processed as reported previously (38
, 39)
.
After overnight incubation with the appropriate primary antibody at
4°C, sections were washed and treated with an appropriate secondary
biotinylated goat antibody (1:200 dilution; Vectastain ABC kit; Vector
Laboratory, Burlingame, CA), washed, reacted with avidin-biotinylated
horseradish peroxidase H complex, and incubated in diaminobenzidine and
hydrogen peroxide, as described previously (38
, 40)
. The
slides were then rinsed in distilled water, counterstained with
hematoxylin, and mounted. The following antibodies were used: an
anti-Ki67 monoclonal antibody (clone MIB1; DBA, Milan, Italy)
used at 1:100 dilution; an anti-VEGF rabbit polyclonal antibody (Santa
Cruz) used at 1:50 dilution; an anti-bFGF rabbit polyclonal antibody
(Santa Cruz) used at 1:200 dilution; and an antihuman TGF- mouse MAb
(Ab-2; Oncogene Science, Manhasset, NY) used at 1:100 dilution. Novel
blood vessels were detected as described by Weidner et al.
(41)
, using a monoclonal antibody raised against the human
factor VIII-related antigen (Dako, Milan, Italy) at the dilution of
1:50 and stained with a standard immunoperoxidase method (Vectastain
ABC kit). Each slide was scanned at low power (x10–100), and the area
with the higher number of new vessels was identified (hot spot). This
region was then scanned at x250 (0.37 mm2
). Five
fields were analyzed, and for each of them, the number of stained blood
vessels was counted. MVC was scored by averaging the five field counts
of five individual tumors for each group.
Statistical Analysis.
The Mantel-Cox log-rank test (42)
was used to evaluate the
statistical significance of the results. All Ps represent
two-sided tests of statistical significance. All analyses were
performed with the BMDP New System statistical package version 1.0 for
Microsoft Windows (BMDP Statistical Software, Los Angeles, CA).
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RESULTS |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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, bFGF, and VEGF. As illustrated in
Fig. 1
, a dose-dependent inhibition in
the secretion of these three growth factors was observed. An 
50%
reduction in the secretion of TGF-, bFGF, and VEGF was detected
after treatment with MAb C225 (1 µg/ml).
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, a dose-dependent
reduction in VEGF expression was observed by Western blotting in GEO
cells treated with VEGF-AS as compared with control
oligonucleotide-treated cells. Similarly, an immunocytochemical
analysis revealed a reduction of both the percentage of GEO cells
specifically stained with an anti-VEGF antibody and the intensity of
the cytoplasmic staining (Table 1
and
data not shown). Furthermore, an ELISA assay of CM obtained from GEO
cells demonstrated a dose-dependent reduction in VEGF protein after
VEGF-AS treatment but not after control scramble oligonucleotide
treatment (Fig. 3)
. We have reported
previously that GEO cells do not express specific receptors for VEGF
(43)
. In fact, no significant effect of VEGF-AS treatment
was observed on GEO cell growth in soft agar (data not shown). In
contrast, the anti-EGFR MAb C225 determined a dose-dependent inhibition
of GEO growth with an IC50 of 0.75 µg/ml
under the same culture conditions.
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, bFGF, and VEGF when
injected s.c. in immunodeficient mice (39)
. When
established GEO tumors of approximately 0.2–0.3
cm3
were detectable, mice were treated i.p. with
VEGF-AS (5 or 10 mg/kg/dose, days 1–5 each week for 3 weeks) or with
scramble control oligonucleotide (10 mg/kg/dose, days 1–5 each week
for 3 weeks). As illustrated in Fig. 4
,
treatment for 3 weeks with the AS oligonucleotide targeting VEGF but
not with the scramble control oligonucleotide determined a
dose-dependent reduction of GEO tumor growth. This effect was mainly
cytostatic and reversible, because shortly after the end of the 3 weeks
of treatment, GEO tumors resumed the growth rate of untreated or of
control oligonucleotide-treated tumors. We next evaluated the effects
of the combination of VEGF-AS and MAb C225 on GEO tumor xenografts.
Mice bearing established GEO tumors of approximately 0.2–0.3
cm3
were treated i.p. with VEGF-AS (10
mg/kg/dose, days 1–5 each week for 3 weeks) alone or in combination
with MAb C225 (0.5 mg/dose, twice weekly on days 1 and 4 for 3 weeks;
Fig. 5
). Similarly to VEGF-AS treatment,
the anti-EGFR MAb had a mostly cytostatic and reversible
growth-inhibitory effect. In contrast, when the two agents were used in
combination, an almost complete suppression of tumor growth in all mice
was observed. Furthermore, GEO tumor growth was significantly delayed
in mice that received MAb C225 plus VEGF-AS treatment. In fact, tumors
grew very slowly for 30 days after the end of treatment when they
resumed a growth rate similar to controls (Fig. 5)
. As shown in Fig. 6
, GEO tumors reached a size not
compatible with normal life in all untreated mice within 4 weeks. A
small increase in survival was observed in the group treated with
VEGF-AS alone (P < 0.05). MAb C225 treatment
determined a longer survival as compared with the control group
(P < 0.01) and with the VEGF-AS-treated group
(P < 0.05). The delayed GEO tumor growth in the MAb
C225 plus VEGF-AS-treated group was accompanied by a significantly
prolonged survival as compared with controls (P <
0.001), with the MAb C225-treated group (P < 0.001),
or with the VEGF-AS-treated group (P < 0.001). In
fact, all mice died within 4, 6, and 8 weeks after tumor cell injection
in the control, VEGF-AS, and MAb C225 groups, respectively. In
contrast, 50% of mice treated with the combination of VEGF-AS and MAb
C225 were alive at 13 weeks. Moreover, no histological evidence of
tumor was found in 3 of 30 (10%) mice that were treated with the
combination of VEGF-AS and MAb C225 and that were sacrificed at 20
weeks after tumor cell injection. The combined treatment with MAb C225
and VEGF-AS was well tolerated. No weight loss or other signs of acute
or delayed toxicity were observed in any mouse.
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and Fig. 7
, high levels of VEGF-specific staining
were detected in 65% of control untreated GEO cells. A strong
reduction in VEGF expression was observed after treatment with VEGF-AS
(8–10% positive cells with a weaker staining). This effect was
accompanied by a reduction in MVC as compared with control tumors.
VEGF-AS treatment had no effect on bFGF and TGF- expression. Control
scramble oligonucleotide treatment did not affect VEGF, bFGF, or
TGF- expression and MVC. Treatment with the anti-EGFR blocking MAb
inhibited the expression of VEGF, bFGF, and TGF- and significantly
reduced the number of tumor microvessels. The combined treatment with
MAb C225 and VEGF-AS determined a further reduction in VEGF expression
and an almost complete suppression of neovessel formation (Table 2
and
Fig. 7
).
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DISCUSSION |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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, can up-regulate the production of VEGF in
human cancer cells (20
, 24)
. We have reported previously
that treatment of GEO xenografts with MAb C225 determined a significant
reduction of various endogenous growth factors of the EGF family, such
as TGF-, amphiregulin, and CRIPTO (39)
. In this study,
we have extended our previous observations and have demonstrated that
MAb C225 treatment significantly inhibits the expression of TGF-,
bFGF, and VEGF in GEO colon cancer cells both in vitro and
in vivo. This effect is accompanied by a relevant reduction
in angiogenesis in GEO tumor xenografts in nude mice as assessed by
MVC. The results of our study are in agreement with recent studies on
the effect of EGFR blockade on angiogenesis. Petit et al.
(44)
reported that MAb C225 treatment inhibited the
production of VEGF and neovascularization in A431 human epidermoid
carcinoma xenografts. More recently, it has been demonstrated that MAb
C225 treatment inhibited angiogenesis in a model of human transitional
cell carcinoma grown orthotopically in nude mice by blocking the
secretion of various angiogenic factors, including VEGF, bFGF, and
interleukin 8 (45)
. Taken together, these data suggest
that MAb C225 treatment has an antitumor effect in vivo that
is attributable to direct blockade of the EGFR-dependent mitogenic
pathway and, at least in part, to inhibition of the secretion of
various paracrine growth factors that are necessary to sustain the
proliferation and the functional differentiation of intratumor vessels. In this study, we have also demonstrated that a 21-mer phosphorothioate oligonucleotide raised against the human VEGF mRNA (37) efficiently blocks the production of VEGF in human GEO colon cancer cells. The inhibition of VEGF production is of biological and potential therapeutic relevance. Treatment of nude mice bearing GEO tumor xenografts for 3 weeks with the VEGF-AS determines a significant inhibition of tumor growth. This effect is probably attributable to the inhibition of the paracrine stimulation of host endothelial cell proliferation and function by VEGF secreted from GEO cancer cells. In fact, reduction of GEO tumor growth in VEGF-AS-treated mice is accompanied by a significant inhibition of tumor angiogenesis as measured by MVC, suggesting that VEGF is a major paracrine angiogenic growth factor secreted by GEO human colon cancer cells. These data are in agreement with a previous study by Warren et al. (28) that have shown a high level of VEGF expression in several human colon cancer cell lines and in human colorectal liver metastasis.
We have treated nude mice bearing established GEO xenografts with the combination of the VEGF-AS and MAb C225. The combined treatment with these two agents determined an almost complete tumor growth suppression after 3 weeks of treatment. Although this effect was reversible, a sustained inhibition of GEO tumor growth was observed for at least 1 month after the end of treatment. As a result of the combined treatment, mice survival was significantly improved as compared with single agent treatment. The antitumor effect of VEGF-AS and MAb C225 combined treatment was accompanied by an almost complete suppression of tumor angiogenesis. Furthermore, in 10% of this group of mice, no histological evidence of GEO cancer cells was found after 20 weeks from tumor cell injection, suggesting that in these cases tumor eradication of established GEO tumor xenografts was achieved.
The combined inhibition of EGFR mitogenic signaling and VEGF expression
has potential therapeutic relevance, because the antitumor activity of
this combination could be explored in a clinical setting. In fact,
Phase I clinical studies have shown that MAb C225 can be given to
patients with advanced cancer at doses that produce receptor-saturating
levels in the blood without relevant toxicity (19)
.
Furthermore, Phase II-III clinical studies of MAb C225 in combination
with cytotoxic drugs or with radiation therapy are currently ongoing
(7
, 46
, 47)
. On the other hand, phosphorothioate AS
oligonucleotides targeting various genes involved in cancer development
and/or progression, such as bcl-2, c-raf-1, and
protein kinase C, are in clinical evaluation in cancer patients
(48, 49, 50)
.
The drugs used in the present study have a different mechanism of action and do not antagonize the effects of cytotoxic therapy. Therefore, a combination of anti-EGFR MAb C225 and VEGF-AS after chemotherapy could be investigated in advanced colorectal cancer, a disease which is poorly responsive to cytotoxic drugs.
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ACKNOWLEDGMENTS |
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FOOTNOTES |
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1 This study was supported by a grant from the
Associazione Italiana per la Ricerca sul Cancro, Regione
Campania-Ricerca Sanitaria Finalizzata, and from the Consiglio
Nazionale delle Ricerche Target Project on Biotechnologies. 
2 To whom requests for reprints should be
addressed, at Cattedra di Oncologia Medica, Dipartimento di
Endocrinologia e Oncologia Molecolare e Clinica, Università degli
Studi di Napoli Federico II, via S. Pansini, 5-80131 Naples, Italy.
Phone: 39-081-7462061; Fax: 39-081-7462066; E-mail: fortunatociardiello{at}yahoo.com
3 The abbreviations used are: TGF, transforming
growth factor; EGFR, epidermal growth factor receptor; MAb, monoclonal
antibody; MVC, microvessel count; bFGF, basic fibroblast growth factor;
AS, antisense; CM, conditioned medium; EGF, epidermal growth factor;
VEGF, vascular endothelial growth factor.
Received 3/23/00; revised 6/23/00; accepted 6/26/00.
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REFERENCES |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
-Pseudomonas exotoxin 40 fusion protein. Cancer Res., 54: 4703-4709, 1994.-PE40 to EGFR-positive cell lines: selective protection of low EGFR-expressing cell lines by EGF. Br. J. Cancer, 69: 988-994, 1994.[Medline]
. Br. J. Cancer, 74: 853-862, 1996.[Medline]
, in patients with advanced cancer. J. Clin. Oncol., 17: 3586-3595, 1999.This article has been cited by other articles:
|
|
 |
|
  A. Kleespies, I. Ischenko, M. E. Eichhorn, H. Seeliger, C. Amendt, O. Mantell, K.-W. Jauch, and C. J. Bruns Matuzumab Short-Term Therapy in Experimental Pancreatic Cancer: Prolonged Antitumor Activity in Combination with Gemcitabine Clin. Cancer Res., September 1, 2008; 14(17): 5426 - 5436. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Bianco, R. Rosa, V. Damiano, G. Daniele, T. Gelardi, S. Garofalo, V. Tarallo, S. De Falco, D. Melisi, R. Benelli, et al. Vascular Endothelial Growth Factor Receptor-1 Contributes to Resistance to Anti-Epidermal Growth Factor Receptor Drugs in Human Cancer Cells Clin. Cancer Res., August 15, 2008; 14(16): 5069 - 5080. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Baselga and J. Tabernero Combined Antiangiogenesis and Antiepidermal Growth Factor Receptor Targeting in the Treatment of Cancer: Hold Back, We Are Not There Yet J. Clin. Oncol., October 10, 2007; 25(29): 4516 - 4518. [Full Text] [PDF]
|
|
|
|
 |
|
 W. Wu, M. S. O'Reilly, R. R. Langley, R. Z. Tsan, C. H. Baker, N. Bekele, X. M. Tang, A. Onn, I. J. Fidler, and R. S. Herbst Expression of epidermal growth factor (EGF)/transforming growth factor-{alpha} by human lung cancer cells determines their response to EGF receptor tyrosine kinase inhibition in the lungs of mice Mol. Cancer Ther., October 1, 2007; 6(10): 2652 - 2663. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Gridelli, P. Maione, A. Rossi, and F. De Marinis The Role of Bevacizumab in the Treatment of Non-Small Cell Lung Cancer: Current Indications and Future Developments Oncologist, October 1, 2007; 12(10): 1183 - 1193. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Lu, X. Li, K. Liang, R. Luwor, Z. H. Siddik, G. B. Mills, J. Mendelsohn, and Z. Fan Epidermal Growth Factor Receptor (EGFR) Ubiquitination as a Mechanism of Acquired Resistance Escaping Treatment by the Anti-EGFR Monoclonal Antibody Cetuximab Cancer Res., September 1, 2007; 67(17): 8240 - 8247. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Sandler Bevacizumab in Non Small Cell Lung Cancer Clin. Cancer Res., August 1, 2007; 13(15): 4613s - 4616s. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. O. Hanrahan and J. V. Heymach Vascular Endothelial Growth Factor Receptor Tyrosine Kinase Inhibitors Vandetanib (ZD6474) and AZD2171 in Lung Cancer Clin. Cancer Res., August 1, 2007; 13(15): 4617s - 4622s. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Damiano, R. Caputo, S. Garofalo, R. Bianco, R. Rosa, G. Merola, T. Gelardi, L. Racioppi, G. Fontanini, S. De Placido, et al. TLR9 agonist acts by different mechanisms synergizing with bevacizumab in sensitive and cetuximab-resistant colon cancer xenografts PNAS, July 24, 2007; 104(30): 12468 - 12473. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Gridelli, M. A. Bareschino, C. Schettino, A. Rossi, P. Maione, and F. Ciardiello Erlotinib in Non-Small Cell Lung Cancer Treatment: Current Status and Future Development Oncologist, July 1, 2007; 12(7): 840 - 849. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Van Cutsem, C. Verslype, and P. A. Grusenmeyer Lessons Learned in the Management of Advanced Pancreatic Cancer J. Clin. Oncol., May 20, 2007; 25(15): 1949 - 1952. [Full Text] [PDF]
|
|
|
|
|
|
F. Morgillo, W.-Y. Kim, E. S. Kim, F. Ciardiello, W. K. Hong, and H.-Y. Lee Implication of the Insulin-like Growth Factor-IR Pathway in the Resistance of Non small Cell Lung Cancer Cells to Treatment with Gefitinib Clin. Cancer Res., May 1, 2007; 13(9): 2795 - 2803. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Giaccone The Potential of Antiangiogenic Therapy in Non-Small Cell Lung Cancer Clin. Cancer Res., April 1, 2007; 13(7): 1961 - 1970. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Tabernero The Role of VEGF and EGFR Inhibition: Implications for Combining Anti-VEGF and Anti-EGFR Agents Mol. Cancer Res., March 1, 2007; 5(3): 203 - 220. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Jimeno, B. Rubio-Viqueira, M. L. Amador, V. Grunwald, A. Maitra, C. Iacobuzio-Donahue, and M. Hidalgo Dual mitogen-activated protein kinase and epidermal growth factor receptor inhibition in biliary and pancreatic cancer Mol. Cancer Ther., March 1, 2007; 6(3): 1079 - 1088. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Van Cutsem Challenges in the Use of Epidermal Growth Factor Receptor Inhibitors in Colorectal Cancer Oncologist, October 1, 2006; 11(9): 1010 - 1017. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Sandler and R. Herbst Combining targeted agents: blocking the epidermal growth factor and vascular endothelial growth factor pathways. Clin. Cancer Res., July 15, 2006; 12(14): 4421s - 4425s. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
