ABSTRACTS OF THE 21st ANNUAL MEETING OF THE ITALIAN ...

Abstracts of the 21st Annual Meeting of the Italian Society of Uro-Oncology (SIUrO), 22-24 June, 2011, Naples, Italy
environmental carcinogenic exposure. Two isoforms of Nacetyltransferase,
NAT1 and NAT2, are involved in the
detoxification of arylamine contained in cigarette smoke and
certain foods. The inactivation of arylamine by NAT2 must be
rapid to prevent the formation of an electrophylic compound
that on binding to DNA may cause mutations which can lead
to tumorigenesis. Gene polymorphism produces a ‘slow
acetylator’ phenotype with a reduced capacity to inactivate
carcinogens. The purpose of this study was to verify the
presence of NAT2 gene polymorphism in patients with bladder
carcinoma and in healthy individuals exposed to risk factors.
Materials and Methods: Analysis of NAT2 gene polymorphism
was studied on DNA extracted from peripheral blood. The
NAT2 gene was amplified by PCR. DNA bands were
visualized by restriction fragment-length polymorphism
(RFLP) analysis. Finally, an allele-specific amplification of
NAT2*5 was carried out. A volume of 50 μg of protein from
each lysate was run on 10% SDS-PAGE and subsequently
transferred to PVDF membrane. The membranes were blocked
with 5% non-fat dry milk in TPBS and then incubated with
the NAT2 antibody. Samples from 160 individuals were
analyzed (48 female and 112 male), of whom 80 were bladder
cancer patients (71 smokers and 20 exposed to environmental
carcinogens) and 80 were healthy individuals (27 smokers and
24 exposed to environmental carcinogens). Results: In the 80
patients, NAT2*5 polymorphism consisted of T341C specific
nucleotide substitution for this allele. Independently of
histological grade (G3 n=57, G2 n=15, G1 n=8) and stage (Ta
n=21, T1 n=37, T2 n=10. T3 n=7, T4 n=5), all bladder cancer
patients had NAT2 polymorphism. Moreover, nearly all healthy
individuals at risk of bladder cancer had NAT2 gene
polymorphism. In patients with carcinoma, the NAT2*5 allele
was associated with a significant reduction or absence of
protein expression compared with healthy individuals
(p=0.001). Conclusion: NAT polymorphism characterization
may help to identify people who are not at risk of developing
bladder cancer even if exposed to environmental carcinogens.
The mechanism responsible for reduction of protein
expression in bladder cancer is under investigation.
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RENAL CELL CARCINOMA: DOES
TRANSCRIPTIONAL DEREGULATION OF
ADULT RENAL STEM/PROGENITOR
CELLS LEAD TO ONCOGENESIS?
Vanessa Galleggiante1 , Monica Rutigliano1 , Fabio Sallustio2 ,
Giuseppe Lucarelli1 , Carlo Bettocchi1 , Pasquale Ditonno1 ,
Antonio Vavallo1 and Michele Battaglia1 1Department of Emergency and Organ Transplantation
(DETO) University of Bari, Section of Urology, Andrology
and Kidney Transplantation, Bari, Italy;
2Section of Nephrology and Kidney Transplant, University
of Bari, Italy
Background: Cancer stem cells (CSCs) are a subset of
undifferentiated cells responsible for tumor initiation,
maintenance and progression. They possess an unlimited
potential for proliferation, self-renewal ability and generation
of differentiated progeny cells that become the most important
cell population of the tumor. Recently, in an experimental
model of severe combined immunodeficient mice, a
population of CD133 + stem cells isolated from human renal
cell carcinoma (RCC) and which was able to initiate tumor
growth was detected. Aim: The aim of this study was the
isolation and characterization of CD133 + cells derived from
human clear cell RCC in order to study the features of the
progenitor/stem cells, including the ability for self-renewal.
Patients and Methods: Fresh human renal cortical tissue was
harvested from 15 patients diagnosed with RCC. Tissue
fractions of both healthy and tumorous renal tissue were used
for the isolation of progenitor/stem cells. Two healthy cell
populations were isolated: one resident in the renal tubules and
the other in the glomeruli. The same procedure was also used
for the pathological tissue, but in this case it was impossible to
distinguish tubules and glomeruli since this portion appeared
deprived of a compartmentalized structure. The isolated cells
were purified for stem cell marker CD133. The CD133 + -
derived clones were purified for CD24. This marker allowed
us to distinguish resident renal stem cells from hematopoietic
ones. The expression of classic markers of stemness (CD133,
PAX-2, CD24, BMI-I, OCT-4) and tumorigenicity (NCAM,
CD10 and VEGFR/KDR) was assessed by cytofluorimetric
analysis. Therefore, lysate protein from CD133 + /CD24 + cells
was used to perform a protein array including 16 stem cell
markers (OCT3/4, NANOG, SOX2, E-cadherin, α-fetoprotein,
GATA4, HNF-3β/FOX A2, PDX-1/IPF1, SOX17, OTX2,
TP63/TP73L, Gosecoid, SNAIL, VEGF R2/KDR/FLK1, and
HCG). Results: We isolated viable renal stem cells
(CD133+/24+) from healthy and neoplastic renal tissue. By
cytofluorimetric analysis, we confirmed the expression of the
following markers in CSCs: CD133, CD24, PAX-2, BMI-I,
and OCT-4. Only a small percentage of this population was
NCAM + . The quantitative analysis of cellular proteins
obtained from the array confirmed the stemness of
CD133 + /24 + CSCs and the increased expression of particular
proteins NANOG, OCT3/4, SOX2, SOX 17, OTX2 and
SNAIL versus the normal stem cells isolated from the same
patient. Discussion and Conclusion: Taken together, these
results showed that stem cells are present in clear cell RCC
and that they are more undifferentiated than normal stem cells
due to their expression of embryogenesis-derived markers. It is
conceivable, therefore, that only the eradication of CSCs or,
alternatively, the induction of differentiation in cells without
self-renewal potential, is able to lead to effective treatment of
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