96. Jahrestagung der Deutschen Gesellschaft für Pathologie e. V ...

Abstracts
detect alterations in histopathological inconspicuous urothelium. Gene
expression profiling, TMA technology, promoter methylation analysis,
qRT-PCR, aCGH and in vitro studies were performed for the identification
and functional characterization of progression-related candidate
genes in BC. A comprehensive molecular, immunohistochemical and
clinicopathological analysis of a large collection of plasmacytoid BC
samples was performed.
Results. Deletions on chromosomes 9 and 8p were detected in approx.
10% of normal urothelial samples from BC patients. The most common
deleted region was on chromosome 9q33.3. Deletions of chromosome 8p
were identified as progression markers for papillary BC. Loss of sFRP1
expression (located on 8p11.21) was found in 35% of BC cases and was
caused by gene copy loss and/or promoter methylation. Functional studies
revealed an influence of sFRP1 on proliferation, cell viability and
migration in papillary BC. Patients with papillary BC and sFRP1 loss
showed a significant decreased overall survival which was not relevant
in patients with solid tumors. Plasmacytoid BC displayed molecular alterations
of advanced, aggressive BC. A complete loss of membranous
E-Cadherin underlined the high malignant and metastatic potential of
this BC variant.
Conclusions. BC is not affecting the complete urothelium. Molecular alterations
in the normal urothelium could be origins of multifocal tumor
growth and argue for the “field cancerization” theory. Deletions on chromosome
8p and expression loss of sFRP1 might act as entity-specific progression
markers for papillary BC. The profile of molecular alterations in
plasmacytoid BC might help to find the suitable therapeutic intervention
for patients with this highly aggressive BC variant.
FR-017
Novel approaches to progressive renal diseases
P . Boor1 1RWTH Aachen University, Aachen
Aims. Essentially all chronic renal diseases but also repeated or serious
acute insults inevitably lead to chronic kidney disease and renal fibrosis.
We currently lack effective treatment options for renal fibrosis; the
development of an effective therapy would be invaluable virtually for all
renal patients.
Methods. We have used various in vivo and in vitro models of renal fibrosis.
Results. We have identified PDGF-CC, PDGF-DD, C5a and PPAR-α as
novel treatment targets in renal fibrosis. By identifying these targets as
crucial components of renal tubulointerstitial fibrosis we also uncovered
the mechanisms relevant for their actions, including mitogenic effect
of PDGF-DD and proinflammatory effects of PDGF-CC on interstitial
fibroblasts and effects of C5a/C5aR and PPAR-α on tubular epithelial
cells resulting in reduced profibrotic paracrine signaling to interstitial
fibroblasts. We verified all of the targets using tools used in, tested for or
developed for clinical use. These studies lay an important experimental
basis for translating these targets to clinical practice. In this regard, we
also showed that serum PDGF-DD is specifically increased in patients
with mesangioproliferative but not other types of glomerulonephritis. In
further studies on renal fibrosis we showed that irrelevant IgG has antifibrotic
effects in a model of progressive mesangioproliferative glomerulonephritis
resulting in improved survival. We also documented that the
renal profibrotic effects of cyclosporine A are mediated by Y-box binding
protein-1 (YB-1) and that mesenchymal stem cells might maldifferentiate
and induce local fibrotic response in progressive glomerulonephritis in
rats. We also pointed out that simple non-pharmacological approaches
in diabetic rats, e.g. regular moderate exercise, reduced renal fibrosis in a
very early stage when no functional changes were yet observed. The mechanism
seemed to be via improving metabolism and interfering with an
important pathogenic pathway in diabetes, the advanced glycation. We
have also identified environmental factors, which led to renal but also
cardiac fibrosis in healthy rats, i.e. passive smoking and industrial dust
52 | Der Pathologe · Supplement 1 · 2012
particles amozite. These environmental risk factors are external, modifiable
and could lead to better monitoring of patients with such (occupational)
risk.
Conclusions. Still much is to be learned about renal fibrosis. We hope to
have uncovered some pieces of this immense puzzle and surely aim to
continue to put it together in the future.
FR-018
Using genome-wide molecular screening for the identification of
new marker and target genes of human hepatocellular carcinoma
T . Longerich1 1University Hospital Heidelberg/Institute of Pathology, Heidelberg
Aims. To identify new diagnostic and prognostic markers that may be
used as therapeutic targets and to develop an oncogenetic progression
model of human hepatocellular carcinoma (HCC).
Methods. A well-characterized human HCC collection was used for
systematic genome-wide screening. Identified potential candidate genes
were validated via expression analysis and selected candidates were further
characterized in vitro using suitable HCC cell lines.
Results. Using a meta-analysis of classical comparative genomic hybridisation
(CGH) analysis (24 dysplastic nodules, 871 HCCs) a genomic
progression model of tumour dedifferentiation (1q – 8q – 4q – 16q – 13q)
was generated. Array-based CGH analysis revealed recurrent chromosomal
gains at 1q, 6p, 8q, 17q, 19p, and 20q, while genomic losses were
observed at 1p, 4q, 8p, 13q, 16q, and 17p. The mouse double minute homolog
4 (MDM4) that functions as a negative p53 regulator could be identified
as a target gene of 1q gains in human HCC. Aetiology-dependent
copy number gains and MYC overexpression was detected in viral and
alcohol-related HCCs. In contrast, cryptogenic HCCs showed neither
8q24 gains, nor MYC overexpression, nor target gene activation. The
role of Polo-like kinase family (PLK) members was analyzed in human
HCC. PLK1 levels were upregulated in human HCC, reaching the highest
expression in tumours with poorer outcome. PLK1 overexpression
resulted from activation of the Ha-Ras/FOXM1/PLK1-axis. In contrast
PLK2, PLK3, and PLK4 expression were downregulated in HCC, with
the lowest levels being detected in HCC with shorter survival. PLK2-4
down-regulation was paralleled by promoter hypermethylation and/or
loss of heterozygosity. Immunohistological analysis revealed that a diffuse
sinusoidal expression of Annexin A2 has diagnostic value for the
biopsy diagnosis of highly-differentiated HCC and may increase the accuracy
of the established diagnostic marker panel (GPC3, GS, HSP70)
for HCC detection.
Conclusions. Five genomic aberrations allow the generation of a robust
progression model of human hepatocarcinogenesis. MDM4 upregulation
may result in functional p53-inactivation in HCCs that may allow
p53-reactivation as a therapeutic strategy. Differential oncogenic and tumour
suppressive roles of Polo-like kinases could be identified in human
HCC. Systematic genome-wide screening analysis were used to identify
new diagnostic marker and potential oncogenic and tumorsuppressive
factors that may be promising future therapeutic targets.
FR-019
In situ hybridization in clinical pathology
T . Gaiser1 1Philipps-University Marburg, Institute of Pathology, Marburg
Aims. Over the last decade in situ hybridization (ISH) has emerged as a
powerful clinical and research tool for the assessment of target DNA dosages
within interphase and metaphase nuclei. HER2 detection is the widest
application for ISH in routine pathology but EGFR ISH or the newly
introduced melanoma FISH are further possible applications, which can
be additionally improved by computer based analysis systems.