|AACR 2002 MEETING
Dr. Hirendranath Banerjee
Elizabeth City State University
our lab are working on the role of tyrosine kinase inhibitors and
other novel therapeutic agents on treatment of the brain cancer
Astrocytoma. Thus visiting the AACR 2002 annual meeting at San Francisco,
CA was very fruitful for them in experiencing and learning about
the current progress in cancer therapy, diagnosis and epidemiology.
The following is a brief description of the meeting and coverage
of the major events.
A major theme
at the meeting was the elucidation of molecular reasons why combination
chemotherapy has proved so effective, and why blockbuster drugs
are unlikely to provide cures single handedly. Cancer proceeds by
numerous pathways, and more than one must be blocked to conquer
from the miracle drugs they were predicted to be, angiogenesis inhibitors
will soon be an effective adjuvant therapy to treat cancer, used
in combination with other therapies, leading experts agreed at the
conference. The drugs show promise in lung cancer, but reaching
their full potential depends critically on adequate patient profiling,
which has yet to exist, they said.
have only recently discovered the involvement of hematopoietic and
endothelial stem cells in tumor growth. Tumors recruit bone marrow-derived
endothelial and hematopoietic progenitor cells by two separate mechanisms,
each of which must be blocked to inhibit tumor growth, Cornell University
researcher Shahin Rafii said. The new paradigm creates several new
targets for therapy, and a new mechanism for detecting cancer.
legend Judah Folkman revealed to a packed audience that a simple
variation in the classic corneal assay allows disassociation of
blood vessel formation from the development of lymphatic vessels.
Based on the assay, he said, vascular endothelial growth factor-A
(VEGF-A) mediates blood vessel formation, while VEGF-C and D promote
lymphatic vessel formation.
As with the
angiogenesis inhibitors, drugs - like anti-BCL2 compounds - designed
to target only one branch of the apoptosis pathway are likely to
fail in hard-to-treat acute myeloid leukemia cases, researchers
reported in the late-breaking abstracts session.
Among the outstanding
successes in cancer research is Gleevec, the product of rational
drug design. Few if any similar drug targets in cancer have delivered
the same level of effectiveness, and researchers are now learning
from the initial Gleevec clinical trials. It is very likely that
all of the new molecular-target based drugs will work best in combination.
So, very likely,
will therapeutic antibodies, after more than 20 years in development,
they are finally producing promising clinical results in cancer
treatment. But significant challenges remain in designing these
antibodies for optimal use in humans.
a very preliminary clinical trial suggest that adoptive T-cell therapy
may prolong the lives of patients with metastatic melanoma by slowing
the disease. A scientist involved in the study called it "the
best example" of ex-vivo expanded T cells for cancer therapy.
involves attacking tumor cells' ability to sense nutrients. Imitating
a bacterium's natural weapon against fungi, several independent
teams of researchers are designing drugs to fool tumor cells into
thinking they're starving, and provoking them to shut their metabolic
In a related
development, one of the first studies of senescence in human cancer
supports the theory that chemotherapy may fail because tumor cells
under cytotoxic attack become passive-aggressive. They stop growing,
but they do not die, continuing to send "grow" messages
the holy grail of curing cancer is the goal of early, reliable,
easy detection. Several important talks revealed advances that may
lead to earlier detection, better diagnosis, or early warnings of
two groups of researchers discussed the development of proteomics-based
blood tests for ovarian cancer saying the advance could be critical,
as there is no good noninvasive test at present.
A new approach
to locating cancer-risk genes has identified a novel low-risk gene
apparently involved in breast cancer. Adding this information to
analyses that include the known BrCA genes generates a normal risk
curve that, unlike the one predicted using the two BrCA genes alone,
resembles the real epidemiological situation.
have also identified a mutation that may be linked to the progression
of head and neck squamous cell carcinoma. While the mutation is
not responsible for the cancer, it may explain why the disease accelerates
rapidly in some patients, but not in others.
the fruits of research into the genome were very evident. Because
as much as 80% of the human genome is composed of ancestral blocks
of DNA that have remained intact over time, using such data on genetic
variation and single nucelotide polymorphisms could improve the
power of SNP association studies, experts said.
Also, a preliminary
study of the effects of the antidepressant bupropion on smoking
cessation may help identify which smokers are genetically inclined
to be responsive to drug therapy in helping them kick the habit,
epidemiologist Caryn Lerman reported.
At the same
time, ethicists cautioned, progress in gene identification is outpacing
our ability to construct sound social policy about genetic testing.
unveiled new technologies and new insights into important molecular
mechanisms. Improved mouse cancer models, most notably 'knock-in'
mice genetically engineered to be tumor-prone, may be more relevant
to the human condition than traditional mouse models of cancer,
oncologist David Tuveson reported.
are also developing a deeper understanding of how cells control
the transitions between active, transiently inactive, and stably
inactive chromatin, and testing new drugs that may help control
the mechanical details of DNA repair, researchers now find that
two complexes, not one, provide the specificity and sensitivity
required - challenging a dogma in the field.
Reaper, a Drosophila
protein that promotes apoptosis, works by destabilizing Inhibitors
of apoptosis proteins and by blocking protein synthesis, researchers
found. In an unexpected twist, they discovered Reaper-related proteins
in several encephalitis-causing viruses, and speculate that the
Reaper-like protein functions contribute to disease pathology.
ban on new stem-cell lines in the US represents a threat to further
progress in the field, speakers cautioned. Stanford University researcher
Irving Weissman lamented that the limited number of stem cell lines
currently available to researchers in the US in insufficient to
fulfill their promise. The existing cell lines have a limited lifespan,
and using them may also create misleading results, he warned.
controversy reared its head at the meeting. One month after the
publication of two high-profile papers linking the simian virus
SV40 to human lymphomas, there was heated discussion of accusations
that SV40-contaminated polio vaccine stocks are to blame for certain
But the meeting
ended on a high note in one of its last sessions. The audience erupted
with enthusiasm after the premiere of the first-ever film showing
cancer cells metastasizing through normal tissue, at a session that
featured metastasis experts including AACR award-winner Lynn Matrisian.