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Immunohistochemical expression
of superoxide dismutase (MnSOD) anti-oxidant enzyme in invasive
breast carcinoma
E. Tsanou1, E. Ioachim, E. Briasoulis2,
K. Damala1, A. Charchanti1, V. Karavasilis2, N. Pavlidis2 and
N.J. Agnantis1
1Department of Pathology, Medical School,
University of Ioannina, Ioannina, Greece and 2Department of Medical
Oncology, Medical School, University of Ioannina, Ioannina, Greece
Offprint requests to: Professor N.J. Agnantis MD, PhD, FRCPATH,
Department of Pathology, Medical School, University of Ioannina,
45110 Ioannina, Greece. Fax: +32 651 99212. e-mail: etsanu@cc.uoi.gr
Summary. The
most important cellular protective mechanisms against oxidative
stress are antioxidant enzymes. Their action is based on decomposal
of reactive oxygen species (ROS) and their transformation to
H2O2. Within the mitochondria manganese superoxide dismutase
(MnSOD) affords the major defense against ROS.
In this study we investigated tissue sections from 101 breast
carcinomas for the immunohistochemical expression of MnSOD protein
and these results were assessed in relation to various clinicopathological
parameters, in order to clarify the prognostic value of this
enzyme. The possible relationship to hormone receptor content,
anti-apoptotic protein bcl-2, p53 and cell proliferation was
also estimated.
High expression levels were observed, as 79/101 (78,2%) cases
expressed strong immunoreactivity. In this study MnSOD increased
in a direct relationship with tumor grade and is therefore inversely
correlated with differentiation (p=0.0004). Furthermore, there
was a strong positive correlation between MnSOD expression and
p53 protein immunoreactivity (p=0.0029). The prognostic impact
of MnSOD expression in determining the risk of recurrence and
overall survival with both univariate (long-rang test) and multivariate
(Cox regression) methods of analysis was statistically not significant.
These results indicate that neoplastic cells in breast carcinomas
retain their capability to produce MnSOD and thus protected from
the possible cellular damage provoked by reactive oxygen species.
In addition, MnSOD content varies according to the degree of
differentiation of breast carcinoma. Histol. Histopathol.
19, 807-813 (2004)
Key words: MnSOD,
Breast cancer, Oxidative stress
DOI: 10.14670/HH-19.807
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