IsoTis OrthoBiologics Receives FDA 510(k) Clearance for OrthoBlast(R) II Bone Grafting Material

    LAUSANNE, Switzerland, IRVINE, California, December 8
/PRNewswire-FirstCall/ — IsoTis OrthoBiologics (SWX/Euronext:
ISON) (TSX:
ISO) today announced it received 510(k) clearance from the US Food and
Drug
Administration (FDA) for the use of OrthoBlast II(R) in orthopedic
applications.
    IsoTis OrthoBiologics has previously obtained 510(k) clearances for
DynaGraft II(TM), Accell Connexus (TM), OsSatura(TM), and its bone
marrow
aspiration kit Aspirex. Accell(R) DBM100 and Accell TBM(TM), having no
excipient carriers, are regulated by the FDA as human tissue and not as
medical devices requiring premarket clearance.
    Pieter Wolters, President and CEO of IsoTis said: “With the 510(k)
clearance of OrthoBlast II, all IsoTis' marketed products are in
compliance
with FDA regulations, and we can continue to focus on servicing the
orthopedic profession with products that are first in class in the bone
grafting market. The increased uptake of our innovative Accell product
line
as a result of the high levels of BMPs it contains, and the solid market
position of first generation products like OrthoBlast II, provide us
with a
healthy basis for growth in the years to come.”
    OrthoBlast II is a combination of demineralized bone matrix (DBM)
with
cancellous bone chips delivered in a reverse phase medium. The reverse
phase
medium becomes more viscous at body temperature, but less viscous at
cooler
temperatures. Therefore, it is malleable at operating room
temperatures, but
thickens when placed in the operative site. This allows the DBM to be
contained at the graft site with minimal loss through irrigation and
suction.
    IsoTis OrthoBiologics has a product portfolio with several
innovative and
proprietary natural and synthetic bone graft substitutes on the market
and
others in development, an established North American independent
distribution
network, and an expanding international presence. The company's main
commercial operations are based out of Irvine, CA; its international
sales
headquarters is based in Lausanne, Switzerland.
    Certain statements in this Press Release are “forward-looking
statements”
within the meaning of Section 21E of the Securities Exchange Act of
1934, as
amended, including those that refer to management's plans and
expectations
for future operations, prospects and financial condition. Words such as
'strategy,' 'expects,' 'plans,' 'anticipates,' 'believes,' 'will,'
'continues,' 'estimates,' 'intends,' 'projects,' 'goals,' 'targets' and
other
words of similar meaning are intended to identify such forward-looking
statements. One can also identify them by the fact that they do not
relate
strictly to historical or current facts. Such statements are based on
the
current expectations of the management of IsoTis S.A. only. Undue
reliance
should not be placed on these statements because, by their nature, they
are
subject to known and unknown risks and can be affected by factors that
are
beyond the control of IsoTis. Actual results could differ materially
from
current expectations due to a number of factors and uncertainties
affecting
IsoTis' business, including but not limited to the timely commencement
and
success of IsoTis' clinical trials and research endeavors, delays in
receiving U.S. FDA or other regulatory approvals (a.o. EMEA, CE), market
acceptance of the Company's products, development of competing therapies
and/or technologies, the terms of any future strategic alliances, the
need
for additional capital, the inability to obtain, or meet conditions
imposed
for the required governmental and regulatory approvals and consents.
IsoTis
expressly disclaims any intent or obligation to update these
forward-looking
statements except as required by law. For a more detailed description
of the
risk factors and uncertainties affecting IsoTis, refer to the Company's
Annual Report on Form 20-F for the fiscal year ended December 31, 2004,
filed
with the SEC and to IsoTis' reports filed from time to time with the
Swiss
Stock Exchange (SWX), Euronext Amsterdam N.V., and SEDAR at http://www.sedar.com,
as
well as the Toronto Stock Exchange (TSX).

SOURCE IsoTis OrthoBiologics

Temozolomide and intravenous irinotecan for treatment of advanced Ewing sarcoma

Pediatr Blood Cancer. 2005 Nov 29

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16317751&query_hl=1

Full Text of Article: http://www3.interscience.wiley.com/cgi-bin/abstract/112163116/ABSTRACT

Temozolomide and intravenous irinotecan for treatment of advanced Ewing sarcoma

Division of Hematology/Oncology, Primary Children's Medical Center, Salt Lake City, Utah.
Lars M. Wagner, MD (1) *, Nancy McAllister, MD (1), Robert E. Goldsby, MD (1), Aaron R. Rausen, MD (3), René Y. McNall-Knapp, MD (4), M. Beth McCarville, MD (5), Karen Albritton, MD (1) (2)

(1)  Division of Hematology/Oncology, Primary Children's Medical Center, Salt Lake City, Utah
(2)  Division of Oncology, Huntsman Cancer Institute, Salt Lake City, Utah
(3)  Division of Pediatric Hematology/Oncology, New York University Medical Center, New York, New York
(4)  Division of Pediatric Hematology/Oncology, University of Oklahoma Health Sciences Center, Oklahoma
(5)  Department of Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, Tennessee
email: Lars M. Wagner (lars.wagner@cchmc.org)

*Correspondence to Lars M. Wagner, Division of Hematology/Oncology, MLC 7015, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229

BACKGROUND: Preclinical models show sequence-dependent synergy with the combination of temozolomide and irinotecan, and a Phase I trial has demonstrated the combination to be tolerable and active in children with relapsed solid tumors. Because responses were seen in patients with Ewing sarcoma (ES) on that trial, additional patients were treated with this combination following study completion. PROCEDURE: We reviewed data from all ES patients treated with temozolomide and irinotecan at four institutions, including seven patients treated on the above Phase I trial. RESULTS: Sixteen patients received a total of 95 courses, with a median of five courses per patient. All patients had either progressive disease (PD) during initial therapy (n = 5) or relapse within 2 years of diagnosis (n = 11). Twelve patients had metastatic disease at diagnosis, including 5 with bone and/or marrow metastases. Patients received oral temozolomide 100 mg/m(2)/day on days 1-5 plus intravenous irinotecan 10-20 mg/m(2)/day on days 1-5 and 8-12, with courses repeated every 21-28 days. We observed 1 complete, 3 partial, and 3 minor responses in 14 evaluable patients, with a median duration of response of 30 weeks. Planned 21-day courses were tolerable and no more toxic than 28-day courses. Myelosuppression was minimal despite heavy pretreatment. Grade 3-4 diarrhea occurred in 11% of courses and was related to higher irinotecan doses. Over 600 irinotecan doses were administered uneventfully at home. CONCLUSIONS: Temozolomide and protracted intravenous irinotecan given in 21-day courses was tolerable and active in patients with advanced ES. Home administration of irinotecan with temozolomide was safe and is reasonable palliative therapy. A formal Phase II study using a uniform dose and schedule is warranted to better define activity. (c) 2005 Wiley-Liss, Inc.

PMID: 16317751 [PubMed – as supplied by publisher]

Arrowhead Accelerates Capital Contribution to Insert Therapeutics as Nanotech Cancer Drug Heads toward Human Clinical Trials

http://www.nsti.org/press/PRshow.html?id=432

October 11, 2005 07:00 AM US Eastern Timezone

Arrowhead Accelerates Capital Contribution to Insert Therapeutics as Nanotech Cancer Drug Heads toward Human Clinical Trials

PASADENA, Calif.–(BUSINESS WIRE)–Oct. 11, 2005–Arrowhead Research Corp. (Nasdaq:ARWR), a diversified nanotechnology company providing the missing link between lab and marketplace, has accelerated its investment of an additional $3 million to majority-owned subsidiary Insert Therapeutics, Inc.

Insert's lead anti-cancer drug, IT-101, has achieved complete remission of non-small cell lung cancer and Ewing's sarcoma, and significant knockdown of other tumor types in preclinical results in mouse xenografts, showing promise across a wide range of cancers. The company is currently preparing to enter IT-101 into human clinical trials at the City of Hope Comprehensive Cancer Center in Duarte, Calif.

“We have continued confidence in the power of Insert's technology,” said R. Bruce Stewart, president of Arrowhead. “This contribution satisfies our funding obligation and solidifies our 68.5 percent ownership in this subsidiary.”

Insert Therapeutics controls a portfolio of U.S. and foreign issued patents and pending applications covering therapeutics based on linear cyclodextrin-containing polymers, which comprises Insert's Cyclosert(TM) family of drug delivery polymers. IT-101 is a combination of Insert's proprietary Cyclosert platform and the potent anti-cancer compound camptothecin. Camptothecin has never been approved for use in humans due to its insolubility, toxicity, instability in human blood serum and poor pharmacokinetics, but approved analogues of the drug, irinotecan and topotecan, have demonstrated $1 billion in reported annual sales worldwide. In the mouse xenograft studies against a variety of cancer types, camptothecin enhanced by conjugation with Cyclosert proved to be more effective at lower doses compared to irinotecan.

Cyclosert was invented in the Caltech lab of chemical engineering professor and Insert founder Dr. Mark Davis, who used “molecular design” to create Cyclosert. This methodology involves the design and construction of functional materials using molecular building blocks.

For more information about Cyclosert and Insert's preclinical results, visit Insert's website at http://www.insertt.com.

About Arrowhead Research Corporation

Arrowhead Research Corporation (http://www.arrowheadresearch.com) is a diversified nanotechnology company structured to commercialize products expected to have revolutionary impacts on a variety of industries, including materials, electronics, life sciences, and energy.

There are three strategic components to Arrowhead's business model:

— Outsourced R&D Program: Arrowhead identifies patented or patent-pending technologies at universities or government labs and funds additional development of those technologies in exchange for exclusive rights to commercialize the resulting prototypes. Leveraging the resources and infrastructure of these institutions provides Arrowhead with a highly cost-effective development pipeline. Currently, Arrowhead is supporting efforts in stem cell technology, and nanosensors at the California Institute of Technology and Stanford University.

— Commercialization Program: After prototypes have been sufficiently developed in the laboratories, Arrowhead forms or acquires majority-owned subsidiaries to commercialize the technology and provides the subsidiaries with strategic, managerial, and operational support. At present, Arrowhead owns majority interest in subsidiaries commercializing diverse technologies, including anti-cancer drugs, RNAi therapeutics, and compound semiconductor materials.

— The Patent Toolbox: Arrowhead has acquired or exclusively licensed patents and patent applications covering a broad range of nanotechnology. The Company is actively seeking to add to this intellectual property portfolio.

Safe Harbor Statement under the Private Securities Litigation Reform Act of 1995:

This news release contains forward-looking statements within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995. These statements are based upon our current expectations and speak only as of the date hereof. Our actual results may differ materially and adversely from those expressed in any forward-looking statements as a result of various factors and uncertainties, including the recent economic slowdown affecting technology companies, the future success of our scientific studies, our ability to successfully develop products, rapid technological change in our markets, changes in demand for our future products, legislative, regulatory and competitive developments and general economic conditions. Our Annual Report on Form 10-K and 10-K/A, recent and forthcoming Quarterly Reports on Form 10-Q and 10-Q/A, recent Current Reports on Forms 8-K and 8-K/A, our Registration Statement on Form S-3, and other SEC filings discuss some of the important risk factors that may affect our business, results of operations and financial condition. We undertake no obligation to revise or update publicly any forward-looking statements for any reason.
   
Contacts
       
   
Arrowhead Research Corporation
R. Bruce Stewart, 626-792-5549
bruce@arrowres.com
   

Phase I and Pharmacokinetic Study of Gefitinib in Children With Refractory Solid Tumors: A Children's Oncology Group Study.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16135484&query_hl=3

J Clin Oncol. 2005 Sep 1;23(25):6172-6180.

    Phase I and Pharmacokinetic Study of Gefitinib in Children With
Refractory Solid Tumors: A Children's Oncology Group Study.

    Daw NC, Furman WL, Stewart CF, Iacono LC, Krailo M, Bernstein ML,
Dancey JE, Speights RA, Blaney SM, Croop JM, Reaman GH, Adamson PC.

    Department of Hematology-Oncology, Mail Stop 260, St Jude
Children's Research Hospital, 332 N Lauderdale, Memphis, TN 38105-2794;
e-mail: najat.daw@stjude.org.

    PURPOSE Epidermal growth factor receptor is expressed in pediatric
malignant solid tumors. We conducted a phase I trial of gefitinib, an
epidermal growth factor receptor tyrosine kinase inhibitor, in children
with refractory solid tumors. PATIENTS AND METHODS Gefitinib (150, 300,
400, or 500 mg/m(2)) was administered orally to cohorts of three to six
patients once daily continuously until disease progression or
significant toxicity. Pharmacokinetic studies were performed during
course one (day 1 through 28). Results Of the 25 enrolled patients, 19
(median age, 15 years) were fully evaluable for toxicity and received
54 courses. Dose-limiting toxicity was rash in two patients treated
with 500 mg/m(2) and elevated ALT and AST in one patient treated with
400 mg/m(2). The maximum-tolerated dose was 400 mg/m(2)/d. The most
frequent non-dose-limiting toxicities were grade 1 or 2 dry skin,
anemia, diarrhea, nausea, and vomiting. One patient with Ewing's
sarcoma had a partial response.
Disease stabilized for 8 to >/=
60 weeks in two patients with Wilms' tumor and two with brainstem
glioma (one exophytic). At 400 mg/m(2), the median peak gefitinib
plasma concentration was 2.2 mug/mL (range, 1.2 to 3.6 mug/mL) and
occurred at a median of 2.3 hours (range, 2.0 to 8.3 hours) after drug
administration. The median apparent clearance and median half-life were
14.8 L/h/m(2) (range, 3.8 to 24.8 L/h/m(2)) and 11.7 hours (range, 5.6
to 22.8 hours), respectively. Gefitinib systemic exposures were
comparable with those associated with antitumor activity in adults.
CONCLUSION Oral gefitinib is well tolerated in children. Development of
the drug in combination with cytotoxic chemotherapy will be pursued.

    PMID: 16135484 [PubMed – as supplied by publisher]

Zoledronic acid inhibits primary bone tumor growth in Ewing sarcoma.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=16121404&dopt=Abstract

http://www3.interscience.wiley.com/cgi-bin/abstract/111082718/ABSTRACT

Cancer. 2005 Aug 24; [Epub ahead of print]     Related Articles, Links
  
    Zoledronic acid inhibits primary bone tumor growth in Ewing sarcoma.

    Zhou Z, Guan H, Duan X, Kleinerman ES.

    Division of Pediatrics, The University of Texas M. D. Anderson
Cancer Center, Houston, Texas.
    email: Eugenie S. Kleinerman (ekleiner@mail.mdanderson.org)

*Correspondence to Eugenie S. Kleinerman, Division of Pediatrics, Unit
87, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe
Blvd., Houston, TX 77030, Fax: (713) 794-5042

    BACKGROUND: Zoledronic acid has been shown to be effective in the
treatment of osteoporosis, hypercalcemia, and metastatic bone tumors.
The efficacy of zoledronic acid on primary bone tumors has not been
investigated. METHODS: A primary bone tumor mouse model was
established. Intratibia injection of TC71 cells resulted in an
osteolytic bone tumor. Four days after injection the mice were treated
with zoledronic acid alone, paclitaxel alone, or zoledronic acid plus
paclitaxel. Control mice were treated with phosphate-buffered saline.
Bone tumor growth was assessed using a Faxitron Specimen Radiography
System. The gene expression was detected by reverse-transcription
polymerase chain reaction (RT-PCR), ELISA, and immunohistochemistry.
Osteoclast formation was determined by tartrate-resistant acid
phosphatase (TRAP) staining. RESULTS: Zoledronic acid induced apoptosis
in TC71 human Ewing sarcoma cells and inhibited cell proliferation.
Five weeks after injection, 89% of mice in the control group developed
osteolytic bone tumors. Paclitaxel had little effect on bone tumor
growth, with 78% of mice developing tumors. By contrast, 44% of mice
treated with zoledronic acid developed bone tumors. The most effective
treatment was zoledronic acid plus paclitaxel. Tumor incidence in the
combination therapy group was only 22%. Osteoclasts were quantified
using TRAP staining. There was a decrease in TRAP-positive osteoclasts
in tumor tissues from zoledronic acid-treated animals compared to
control animals. RT-PCR, immunohistochemistry, and ELISA assay
demonstrated that zoledronic acid up-regulated osteoprotegerin
expression. CONCLUSIONS: These results suggest that zoledronic acid
induces apoptosis and inhibits primary bone tumor growth in Ewing
sarcoma through a mechanism involving the up-regulation of
osteoprotegerin. Zoledronic acid may provide a novel therapeutic
approach for the treatment of patients with Ewing sarcoma. Cancer 2005.
(c) 2005 American Cancer Society.

    PMID: 16121404 [PubMed – as supplied by publisher]

Role of heat treatment in childhood cancers: Distinct resistance profiles of solid tumor cell lines towards combined thermochemotherapy

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15929134&query_hl=1

http://www3.interscience.wiley.com/cgi-bin/abstract/110506993/ABSTRACT

Research Article

Role of heat treatment in childhood cancers: Distinct resistance
profiles of solid tumor cell lines towards combined thermochemotherapy

Anette Debes, PhD 1, Reinhart Willers, PhD 2, Ulrich Göbel, MD 1,
Rüdiger Wessalowski, MD 1 *
1 Clinic of Pediatric Oncology, Hematology and Immunology,
Heinrich-Heine-University, Düsseldorf, Germany
2 Computer Center, Heinrich-Heine-University Düsseldorf, Düsseldorf,
Germany

email: Rüdiger Wessalowski (wessalowski@med.uni-duesseldorf.de)

*Correspondence to Rüdiger Wessalowski, Clinic of Pediatric Oncology,
Hematology and Immunology, Heinrich-Heine-University, Moorenstreet 5,
40225 Düsseldorf, Germany.

Funded by:
Elterninitiative Kinderkrebsklinik e.V. Düsseldorf

Keywords
chemosensitivity • pediatric tumors • thermosensitivity • XTT-assay

Abstract

Background
Since information on the efficacy of hyperthermia in combination with
chemotherapy on pediatric tumors is limited, we performed a systematic
analysis on the synergistic effects of a combined application of heat
and chemotherapy on 20 tumor cell lines derived from patients with
neuroblastomas, Ewing tumors, germ cell tumors (GCT), and osteosarcomas.

Methods
Cisplatin (cDDP), a cross-linking agent, and etoposide (VP-16), a
topoisomerase II inhibitor, were examined either alone or in
combination with heat (42°C, 43°C) by using the XTT-assay [1].

Results
Our data demonstrate that heat stress at 43°C for 1 hr, but not at
42°C, leads to a notable cytotoxic effect on the different tumor cells.
The comparison of mean survival fractions reveals values between 62%
for neuroblastoma cells and 76% for Ewing tumor cells. Analyzing the
sensitivity to chemotherapy alone, our results show that cDDP (5 g/ml)
reduces cell growth to 47% in Ewing tumor cells, to 61% in
neuroblastoma cells, to 75% in GCT cells, and to 76% in osteosarcoma
cells. Treatment with VP-16 (10 g/ml) decreases cell survival to mean
values between 58% (neuroblastomas) and 77% (osteosarcomas).
Simultaneous application of heat and chemotherapy enhances
synergistically cDDP cytotoxicity in all tumor types tested, whereas
the efficacy of VP-16 is only slightly influenced by additional
application of hyperthermia. The cytotoxicity of cDDP (5 g/ml) can be
increased by a factor of between 1.5 and 2.5 at 42°C and from 2.6 to
14.0 at 43°C. Furthermore, the results show that the sensitivity to
heat (43°C) as well as the sensitivity to chemotherapy and combined
thermochemotherapy varies considerably between cell lines of the same
tumor group.

Conclusions
Simultaneous application of hyperthermia synergistically enhances the
cytotoxicity of the alkylating agent cDDP, but not of the topoisomerase
II inhibitor VP-16, in a defined spectrum of cell lines from different
pediatric tumor entities.

© 2005 Wiley-Liss, Inc.

Pediatric Trials for Sarcoma or Solid Tumors


1) A Children's Oncology Group Phase I Study of Bevacizumab in Refractory
Solid Tumors. This study is being conducted in:
    - Cincinnati, OH
 http://www.centerwatch.com/patient/studies/stu73002.html
2) A Children's Oncology Group Phase I Study of Single Agent OSI-774
 (Tarceva) Followed by OSI-774 with Temozolomide for Patients with Selected
 Recurrent/Refractory Solid Tumors, Including Brain Tumors. This study is
 being conducted in:
    - Cincinnati, OH
 http://www.centerwatch.com/patient/studies/stu73003.html
3) A Phase I Study of 17-AAG in Relapsed / Refractory Pediatric Patients
 with Solid Tumors or Leukemia. This study is being conducted in:
    - Cincinnati, OH
 http://www.centerwatch.com/patient/studies/stu73000.html
4) A Phase I Study of Pemetrexed (LY231514, Alimta) in Children and
 Adolescents with Recurrent Solid Tumors. This study is being conducted in:
    - Cincinnati, OH
 http://www.centerwatch.com/patient/studies/stu73005.html
5) A Phase I Trial of G3139 (BCL-2 ANTISENSE) Combined with Cytotoxic
 Chemotherapy in Relapsed Childhood Solid Tumors. This study is being
 conducted in:
    - Cincinnati, OH
 http://www.centerwatch.com/patient/studies/stu72996.html
6) A Phase I Study of Decitabine in Combination with Doxorubicin and
 Cyclophosphamide in the Treatment of Relapsed or Refractory Solid Tumors.
 This study is being conducted in:
    - Cincinnati, OH
 http://www.centerwatch.com/patient/studies/stu72999.html
7) A Phase I Study of Depsipeptide in Pediatric Patients with Refractory
 Solid Tumors and Leukemias. This study is being conducted in:
    - Cincinnati, OH
 http://www.centerwatch.com/patient/studies/stu72997.html
Additional educational resource that may be of interest to you:
Volunteering for a Clinical Trial, a brief educational pamphlet. If you
 would like to order this pamphlet click here:
 http://www.centerwatch.com/bookstore/pubs_cons_brochureform.html

Long-term follow up of high-dose chemotherapy with autologous stem cell rescue in adults with Ewing tumor.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=15923805

Am J Clin Oncol. 2005 Jun;28(3):301-9.

http://www.amjclinicaloncology.com/pt/re/ajco/abstract.00000421-200506000-00015.htm

Long-term follow up of high-dose chemotherapy with autologous stem cell
rescue in adults with Ewing tumor.

Laurence V, Pierga JY, Barthier S, Babinet A, Alapetite C, Palangie T,
de Pinieux G, Anract P, Pouillart P.

Department of Medical Oncology, Institut Curie, Paris, France.

Ewing tumors remain of poor prognosis, with 5-year overall survival of
55% to 65% in localized patients and not exceeding 25% in primarily
metastatic disease. Several reports, mainly in children, have reported
that some patients with poor-risk Ewing tumors may benefit from
high-dose chemotherapy (HDCT) with autologous stem cell rescue. This
retrospective study analyzed 46 patients treated in our institution
between 1987 and 2000 for localized or primary metastatic Ewing tumors
by HDCT followed by stem cell rescue. Median follow up was 7.1 years.
Median age was 21 years (range, 15-46 years). Twenty-two percent of
patients had metastases at diagnosis. The tumor site was axial in 56% of
patients. Median tumor size was 9.5 cm. The treatment regimen consisted
of induction chemotherapy, local treatment, maintenance chemotherapy,
and consolidation HDCT based on alkylating agents. No toxic death was
observed in the intensive therapy phase. Five-year overall survival and
progression-free survival were 63 +/- 7.7% and 47 +/- 7.6%,
respectively. Pejorative prognostic factors in this population were
metastases at diagnosis (5-year overall survival 34% vs.71%, P = 0.017)
and poor pathologic response (5-year overall survival 44% vs.77%, P =
0.03). This retrospective study shows a high long-term survival rate
with high-dose chemotherapy in adults.

PMID: 15923805 [PubMed – indexed for MEDLINE]

Preclinical p38MAPK-Dependent Sensitivity of Ewing's Sarcoma Family of Tumors to Fenretinide-Induced Cell Death

http://clincancerres.aacrjournals.org/cgi/content/abstract/11/8/3136

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&list_uids=15837770&dopt=Abstract

Clinical Cancer Research Vol. 11, 3136-3148, April 15, 2005
© 2005 American Association for Cancer Research
Cancer Therapy: Preclinical
p38MAPK-Dependent Sensitivity of Ewing's Sarcoma Family of Tumors to
Fenretinide-Induced Cell Death
Stephen S. Myatt1, Christopher P.F. Redfern2 and Susan A. Burchill1

Authors' Affiliations: 1 Candlelighter's Children's Cancer Research
Laboratory, Cancer Research UK Clinical Centre, Leeds, United Kingdom
and 2 Northern Institute for Cancer Research, University of Newcastle
upon Tyne, Newcastle upon Tyne, United Kingdom

Requests for reprints: Susan A. Burchill, Candlelighter's Children's
Cancer Research Laboratory, Cancer Research UK Clinical Centre, St.
James's University Hospital, Beckett Street, Leeds LS9 7TF, United
Kingdom. Phone: 44-113-2065873; Fax: 44-113-2429886; E-mail:
S.A.Burchill@leeds.ac.uk.

Purpose: There is an urgent need for new therapeutic strategies in
Ewing's sarcoma family of tumors (ESFT). In this study, we have
evaluated the effect of fenretinide [N-(4-hydroxyphenyl)retinamide] in
ESFT models.

Experimental Design: The effect of fenretinide on viable cell number and
apoptosis of ESFT cell lines and spheroids and growth of s.c. ESFT in
nu/nu mice was investigated. The role of the stress-activated kinases
p38MAPK and c-Jun NH2-terminal kinase in fenretinide-induced death was
investigated by Western blot and inhibitor experiments. Accumulation of
reactive oxygen species (ROS) and changes in mitochondrial transmembrane
potential were investigated by flow cytometry.

Results: Fenretinide induced cell death in all ESFT cell lines examined
in a dose- and time-dependent manner. ESFT cells were more sensitive to
fenretinide than the neuroblastoma cell lines examined. Furthermore,
fenretinide induced cell death in ESFT spheroids and delayed s.c. ESFT
growth in mice. p38MAPK was activated within 15 minutes of fenretinide
treatment and was dependent on ROS accumulation. Inhibition of p38MAPK
activity partially rescued fenretinide-mediated cell death in ESFT but
not in SH-SY5Y neuroblastoma cells. c-Jun NH2-terminal kinase was
activated after 4 hours and was dependent on ROS accumulation but not on
activation of p38MAPK. After 8 hours, fenretinide induced mitochondrial
depolarization ({Delta}{psi}m) and release of cytochrome c into the
cytoplasm in a ROS- and p38MAPK-dependent manner.

Conclusions: These data show that the high sensitivity of ESFT cells to
fenretinide is dependent in part on the rapid and sustained activation
of p38MAPK. The efficacy of fenretinide in preclinical models demands
the evaluation of fenretinide as a potential therapeutic agent in ESFT.

Key Words: stress-activated kinases • retinamides • ESFT • neuroblastoma

Vascular Endothelial Growth Factor: A Therapeutic Target for Tumors of the Ewing's Sarcoma Family

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15788688

Clin Cancer Res. 2005 Mar 15;11(6):2364-2378.

Vascular Endothelial Growth Factor: A Therapeutic Target for Tumors of
the Ewing's Sarcoma Family.

Dalal S, Berry AM, Cullinane CJ, Mangham DC, Grimer R, Lewis IJ,
Johnston C, Laurence V, Burchill SA.

Candlelighter's Children's Cancer Research Laboratory, Departments of
Pathology and Paediatric Oncology, Cancer Research UK Clinical Centre,
St. James's University Hospital, Leeds, United Kingdom and Department of
Musculoskeletal Pathology and Royal Orthopaedic Hospital, Birmingham,
United Kingdom.

PURPOSE: We have reported previously that intratumoral microvessel
density (MVD) is a significant prognostic indicator of event-free
survival in the Ewing's sarcoma family of tumors (ESFT). Here, the
angiogenic growth factor expression profile and its relationship with
MVD has been investigated in ESFT.Experimental Design and RESULTS: Using
ESFT model systems, the potential of these factors as therapeutic
targets has been evaluated. A significant correlation (P = 0.02) was
observed between vascular endothelial growth factor (VEGF) expression
and MVD, consistent with the hypothesis that VEGF regulates the
development of microvessels in ESFT. There was no correlation between
MVD and any of the other growth factors studied. All six ESFT cell lines
studied produced and secreted VEGF; five of six cell lines also secreted
placental growth factor, one cell line (A673) at high levels. Tumor
conditioned medium induced proliferation of human umbilical vein
endothelial cells. Expression of VEGF receptors Flt-1 and Flk-1/KDR was
heterogeneous across the cell lines. Both receptor tyrosine kinase
inhibitors SU6668 (targets Flk-1/KDR, platelet-derived growth factor
receptor-beta, and fibroblast growth factor receptor 1) and SU5416
(targets Flk-1/KDR) as well as anti-VEGF agents rhuMAb-VEGF
(bevacizumab) and VEGF Trap delayed s.c. growth of ESFT in mice compared
with untreated groups: SU6668 (100 mg/kg/d), SU5416 (25 mg/kg/d),
rhuMAb-VEGF (10 mg/kg twice weekly), and VEGF Trap (2.5 or 25 mg/kg
twice weekly).CONCLUSIONS: These data suggest that VEGF is the single
most important regulator of angiogenesis in ESFT and may be exploited
for therapeutic advantage.

PMID: 15788688 [PubMed – as supplied by publisher]