Annual Meeting Proceedings Part 1 - American Society of Clinical ...

672s Tumor Biology
10566 General Poster Session (Board #45G), Mon, 1:15 PM-5:15 PM
Comparative analysis of myeloid-derived suppressor cell (MDSC) subsets in
patients with gastrointestinal (GI) malignancies. Presenting Author: Austin G.
Duffy, National Cancer Institute/National Institutes of Health, Bethesda, MD
Background: Immunotherapy represents a potential new treatment option for
patients with cancer. Myeloid derived suppressor cells (MDSCs) constitute a
heterogenous cell population, which inhibit the host anti-tumor immune
response, limiting the effectiveness of both immune and non-immune treatments.
MDSC are known to be increased in patients with GI cancer. Characterization
of MDSC in humans has been difficult with heterogeneous phenotype
classification. Differences in processing are also potentially important. The aim
of this study was to perform a comparative analysis of MDSC subsets in patients
with GI cancer. Methods: Fluorescence activated cell sorting (FACS) analysis was
performed on PBMC and whole blood (WB) from healthy adults (N�44) and
patients with GI cancer (N�41). MDSC subsets were enumerated using the
following antibodies: anti-CD14; anti-CD15; anti-HLA-DR; anti-CD33; anti-
CD11b; 7-AAD. Suppressor function of MDSC subsets was tested using FACS
sorted MDSC subpopulations co-cultured with CD3/CD28-stimulated autologous
effector cells. Proliferation and IFN-g were measured. Results: The frequencies
of Monocytic (Def: CD14 � , HLA-DR -/low ) and Granulocytic (Def: CD15 � ,CD14 -
CD33 � CD11b � ) MDSC are shown in the table below. Monocytic MDSC were
increased in the blood of patients (vs control; P�.0001) and frozen (vs fresh
PBMC; P�.05). While CD15� cells were increased in cancer patients we did not
find an increase in granulocytic MDSC. Functional studies will also be presented.
Conclusions: Monocytic MDSC are more frequent in patients with advanced GI
cancer compared to healthy volunteers. An increase in this population was also
found in WB and frozen PBMC compared to fresh PBMC reflecting the need for
homogenous preparation in studies evaluating this population in humans. While
CD15�CD14- cells were also increased in cancer patients we did not find an
increase in CD14-CD15�CD33�CD11b� cells.
CD14�ve, HLA-DR -/low* CD15�ve,CD14-veCD33�CD11b�*
Patient PBMC 5.5 3.1
Healthy PBMC 1.2 4.55
Frozen PBMC (healthy) 4.16 3.3
Frozen PBMC (patient) 10 1.36
Patient WB 2.5 15
Healthy WB
* Rel frequency.
0.8 17.65
10568 General Poster Session (Board #46A), Mon, 1:15 PM-5:15 PM
Extracellular matrix and breast cancer cells’ response to trastuzumab: The
role of glycosaminoglycans, heparanases, and syndecan-1. Presenting
Author: Maria Aparecida Silva Pinhal, Universidade Federal de São Paulo,
Sao Paulo, Brazil
Background: Trastuzumab is an antibody anti-epidermal growth factor 2
receptor (HER2), which improves disease-free and overall survival in HER2
positive breast cancer. Nevertheless, many patients become resistant to
this treatment. Heparanase (HPSE) is an enzyme that is responsible for
removal of heparan sulfate (HS) chains from proteoglycans, generating free
oligosaccharides that modulate many physiopathological functions, including
tumor developing. We have analyzed whether some extracellular matrix
components influence trastuzumab efficacy. Methods: Heparanase-1
(HPSE-1) overexpression effect was analyzed using MCF7 cells stable
transfected with HPSE-1 cDNA (MCF7-HPSE-1). HPSE-1, HPSE-2, Syndecan-1
(Syn-1) and HER2 expression, HPSE-1 activity and cell viability were
evaluated in different breast cancer cells treated or not with trastuzumab.
The glycosaminoglycans synthesis and shedding were also evaluated.
Trastuzumab and HS binding were analyzed by confocal microscopy and
Fluorescence Resonance Energy Transfer (FRET). Results: MCF7 transfected
with HPSE-1 cDNA becomes completely resistant to trastuzumab.
HS affinity by Trastuzumab was then tested, showing that they bind in high
levels and this binding is necessary to antibody activity. In MCF7 cells,
trastuzumab decreases HPSE-1, HPSE-2, HER2 and Syn-1 mRNA expression,
while in MCF7-HPSE-1 the antibody increases the expression of these
molecules. Conclusions: Our results have demonstrated that an ideal
concentration of HS in cell surface, regulated by trastuzumab, is necessary
to its action, beyond HER2 high levels. High HS concentration at cell
surface enhances the antibody amount disposable to interact with HER2 in
cell surface, determining breast cancer cells susceptibility to trastuzumab.
These new insights could be useful when devising strategies for overcoming
trastuzumab resistance in HER2 positive cancers. Supported by FAPESP,
CNPq, CAPES.
10567 General Poster Session (Board #45H), Mon, 1:15 PM-5:15 PM
Correlation of the maximum standardized uptake value for f-18 fluorodeoxyglucose
with molecular subtype and survival in advanced breast cancer.
Presenting Author: Zhen Jia, Fudan University Cancer Center, Shanghai,
China
Background: Tumor glucose metabolism correlates with tumor biology and
clinical outcome of breast cancer patients. This prospective cohort study
was to explore correlations of 18F-FDG uptake, a surrogate for glucose
metabolism, with molecular subtypes in women with advanced breast
cancer. Methods: Patients diagnosed as advanced breast cancer were
enrolled in the study. PET/CT was performed and the Maximum Standardized
Uptake Value (SUVmax) of each lesion was documented as baseline,
so was clinical and treatment information. Diagnosis of malignant nature of
a lesion was confirmed by pathology or further follow-up. Patients who had
got a progressive disease in the efficacy assessment were assigned new
treatments as per-institutional guidelines. Results: 244 patients met the
criteria and were all put into this analysis. Independent factors for
influencing SUVmax value included luminal subtype (p� 0.002), triplenegative
subtype (p�0.001), ER status (p� 0.028), Her-2 status
(p�0.001), and CEA level (p�0.001). A higher SUVmax was significantly
associated with poorer median PFS (6.9 vs. 8.1 months, p�0.040) and OS
(13.8 vs. 16.9 months, p�0.003). Cox Regression analysis showed that
SUVmax value, previous treatments, subsequent treatments and treatment
efficacy were four independent prognostic factors for PFS, while age,
menopausal status, disease free interval, 4 subtypes, previous treatments,
number of metastatic sites, SUVmax value and subsequent treatment
efficacy were independent prognostic factors for OS. Conclusions: 18F-FDG uptake correlates with molecular subtypes in women with advanced breast
cancer. Baseline SUVmax is an independent prognostic factor for survival
of patients with advanced breast cancer, especially those with luminal
subtypes.
10569 General Poster Session (Board #46B), Mon, 1:15 PM-5:15 PM
Detection of EML4-ALK in serum RNA from lung cancer patients using
MassARRAY platform. Presenting Author: Keita Kudo, Thoracic Oncology
Center, Cancer Institute Hospital, Japanese Foundation for Cancer Research,
Tokyo, Japan
Background: The presence of the transforming fusion gene EML4-ALK in
non–small cell lung cancer (NSCLC) is a predictive marker for the efficacy
of ALK kinase inhibitors. The break apart fluorescence in situ hybridization
(FISH) assay has served as the standard test for identification of NSCLC
patients with ALK gene rearrangement. Circulating RNA in plasma/serum is
an emerging field for noninvasive molecular diagnosis. We previously
developed a MassARRAY assay to detect nine types of EML4-ALK fusion
gene (variants 1, 2, 3a, 3b, 4, 5a, 5b, 6, and 7). The assay is based upon
region-specific PCR followed by specific single-base primer extension
reactions; the extended products are resolved using MALDI-TOF mass
spectrometry. In this study, we evaluated whether EML4-ALK fusion RNA
could be detected in serum obtained from NSCLC patients. Methods: The
RNA was extracted from serum obtained from 12 lung cancer patients with
ALK rearrangements by FISH analysis. The extracted RNA was reverse
transcribed into cDNA, and the resultant cDNA was amplified by nested
PCR. The PCR product was subjected to MassARRAY assay to identify
EML4-ALK variants. Results: The EML4-ALK RNA (variant 1 and 3) was
detected in serum from 2 of 12 patients. These are confirmed by
subcloning and sequencing. Conclusions: The detection of EML4-ALK in
serum RNA samples by MassARRAY assay is feasible. This noninvasive
assay will be useful in patients with insufficient or unavailable tumor
specimens. Additional experiments will reveal the sensitivity and specificity
of this detection system.
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