Journal Thoracic Oncology

Abstracts Journal of Thoracic Oncology • Volume 12 Issue S1 January 2017
MAPK pathways resulted in the opposite regulation of these genes. Inhibition
of MMP1 via siRNAs or pharmacological inhibitors prevented FGF2-induced
scattering and invasiveness. In unsupervised clustering, the gene expression
profiles of solvent- or cytokine-treated cells were associated with those of
epithelioid and sarcomatoid MPM, respectively. Immunohistochemistry
showed an association of MMP1 as well as phospho-ERK with the sarcomatoid
part of tissue specimens from biphasic tumors. Pathway enrichment analysis
of differentially expressed genes as well as the targets of altered microRNAs
after FGF2 treatment showed that the regulated genes are assigned to
categories important for cell growth and aggressive behavior. Conclusion:
Our data characterize FGFR-mediated signals as important players in
MPM aggressiveness and the morphological and behavioral plasticity of
mesothelioma cells, leading to a better understanding of the link between the
MPM histological subtypes and their influence on patient outcome.
Keywords: Epidermal Mesenchymal Transition, Mesothelioma, Fibroblast
Growth Factors
POSTER SESSION 3 – P3.03: MESOTHELIOMA/THYMIC MALIGNANCIES/ESOPHAGEAL
CANCER/OTHER THORACIC
MESOTHELIOMA TRANSITIONAL –
WEDNESDAY, DECEMBER 7, 2016
P3.03-003 MESOTHELIUM COVERING PLEURAL PLAQUE IS NOT
PRIMARILY INVOLVED IN ASBESTOS-INDUCED MESOTHELIAL
CARCINOGENESIS IN HUMAN
Yuichi Koda, Kozo Kuribayashi, Shingo Kanemura, Eisuke Shibata, Taiichiro
Otsuki, Koji Mikami, Takashi Nakano
Respiratory, Nishinomiya/Japan
Background: Malignant pleural mesothelioma (MPM) initially arises not
from the visceral pleura but parietal pleural mesothelial cells in the thoracic
cavity. MPM has a close relationship to asbestos exposure in etiology. The
carcinogenic potential of asbestos fibers has been linked to their geometry,
size, and chemical composition. Long respirable fibers(length>5μm,
diameter5% membranous staining regardless of intensity and
high positive as >50%. Genomic DNA was obtained from tumour cores of a
representative subset (100 patients) and used for genome-wide copy number
analysis. Percent genome aberrated (PGA) was computed for each sample
as the total number of base pairs within altered regions, divided by the total
number of base pairs in each region included in the array. Correlations of PGA,
CNA profile and individual aberration (loss/gain) frequency with parameters
including PD-L1 expression and survival were explored. Results: Amongst
329 patients evaluated, the median age was 67 years and most were male
274(83.2%). Epithelioid histology (N=203; 62.9%) was the commonest. PD-L1
positivity was seen in 41.7% with high positivity in 9.6%. PD-L1+ correlated
with non–epitheloid histology (P=