Novel Drug Delivery Methods: Getting Drugs to Tumors Quickly and with Less Toxicity
SAN DIEGO, April 16, 2008 – As promising cancer
therapies and drugs emerge, researchers strive to find ways to
deliver them to patients with minimal side effects. At the 2008
Annual Meeting of the American Association for Cancer Research,
April 12-16, researchers report that therapies delivered by
“trojan horse” peptides and through the use of
nanotechnology may enhance the effectiveness of cancer
treatment.
Kousparou C, et al. Antennapedia ‘trojan’ peptide
delivers p21 protein resulting in tumor eradication: Abstract
4908
Researchers report that using the Antennapedia protein as a
“trojan horse” to pierce the outer layer of a cancer
cell and deliver p21, a known tumor suppressor protein,
successfully reduces malignant tumors in mice.
Christina Kousparou, Ph.D., head of research at Trojantec Ltd, said
intravenous treatment with p21 by this method brought the cancer
cell growth and death cycle to a halt and slowed tumor growth. Mice
given this protein also lived longer than a control group of
animals, she reports.
Researchers had speculated that p21 would increase sensitivity to
chemotherapy. The combination of p21 with chemotherapy resulted in
total tumor eradication in 40 percent of animals and a reduction in
tumor burden in 100 percent of animals, Kousparou reports.
“The efficacy of our anti-tumor growth modality in
combination with conventionally used medication suggests that it
can be considered as a promising therapeutic drug for the
management of a wide range of carcinomas,” said
Kousparou.
Siddiqui IA, et al. Nanochemoprevention: introducing a novel
concept in cancer chemoprevention with a proof of principle for
superior activity of green tea polyphenol
epigallocatechin-3-gallate encapsulated in PLGA/PVA nanoparticles:
Abstract 2102
Researchers may have found a way to effectively deliver green tea
to a tumor, increasing its utility as a
“chemopreventive” agent.
Although green tea has been shown in preclinical studies to have
significant cancer prevention potential, its therapeutic use has
been limited by lack of a method for delivering effective doses to
cancer cells.
“Most biological processes, including those that are
cancer-related, occur at the nanoscale, so we hypothesized that
nanoparticle delivery of green tea polyphenol epigallocatechin-3
would be a possible method,” said Imtiaz A. Siddiqui, Ph.D.,
a research associate at the University of Wisconsin.
Researchers encapsulated green tea polyphenol
epigallocatechin-3-gallate in synthetic nanoparticles and evaluated
the response in human prostate cancer cells.
An initial treatment with the nanoparticles alone without green tea
showed negligible response, Siddiqui said. Adding tiny amounts of
green tea to the nanoparticles, however, produced a significant
response that persisted for 48 to 72 hours.
Further experiments showed that treatment with
nanoparticle-delivered green tea increased the rate of cancer cell
death and decreased the number of new cell colonies.
“Validation of these cell culture data to animal model
systems could pave the way for developing new avenues of cancer
chemoprevention,” said Siddiqui. # # #
The mission of the American Association for Cancer Research is to
prevent and cure cancer. Founded in 1907, AACR is the world's
oldest and largest professional organization dedicated to advancing
cancer research. The membership includes nearly 27,000 basic,
translational, and clinical researchers; health care professionals;
and cancer survivors and advocates in the United States and more
than 70 other countries. AACR marshals the full spectrum of
expertise from the cancer community to accelerate progress in the
prevention, diagnosis and treatment of cancer through high-quality
scientific and educational programs. It funds innovative,
meritorious research grants. The AACR Annual Meeting attracts more
than 17,000 participants who share the latest discoveries and
developments in the field. Special Conferences throughout the year
present novel data across a wide variety of topics in cancer
research, treatment, and patient care. AACR publishes five major
peer-reviewed journals: Cancer Research; Clinical Cancer Research;
Molecular Cancer Therapeutics; Molecular Cancer Research; and
Cancer Epidemiology, Biomarkers & Prevention. Its most recent
publication and its sixth major journal, Cancer Prevention
Research, is the only journal worldwide dedicated exclusively to
cancer prevention, from preclinical research to clinical trials.
The AACR also publishes CR, a magazine for cancer survivors,
patient advocates, their families, physicians, and scientists. CR
provides a forum for sharing essential, evidence-based information
and perspectives on progress in cancer research, survivorship, and
advocacy.
Media Contact:
Staci Vernick Goldberg
267-646-0616
Staci.goldberg@aacr.org
In San Diego (4/12 – 4/16):
(619) 525-6370
