The central nervous system cancer represents 2% of all malignancies in
the world population and 23% of cases of childhood cancer. In Brazil, an estimated
4,820 cases of cancer in men and women in 4450 to the year 2012. Gliomas are
tumors of the central nervous system formed from glial cells, making up over 70% of
brain tumors. The most important property of gliomas is the ability of immune
evasion. Age, ethnicity, gender and occupation may be considered risk factors for the
development of gliomas, and are twice as common in African-Americans. The
astrocytoma is the most common glial tumor, constituting about 75% of cases of
gliomas. These tumors are classified into four levels according to the World Health
Organization. Mitochondrial DNA is related to the development and progression of
various types of tumors. Mitochondrion is responsible for cellular energy balance and
is involved in triggering apoptosis responding to oxidative stress. Mutations in DLOOP
can change DNA replication rates and increase the developing cancer risk.
We analyzed 29 samples astrocytoma classified according to the WHO. Our data
suggest that low-grade astrocytomas may be related to genetic inheritance, making
some patients with specific mutations or polymorphisms more susceptible to the risk
of developing the disease, and high grade may be related to prolonged exposure to
carcinogenics. Polymorphisms and mutations have been identified which correlate
with some risk of developing astrocytomas and disease progression. The insertion of
two or more nucleotides at microsatellite regions may cause instability and contribute
to the cancer onset. Deletion at the site 16132 may be a high-grade astrocytoma
marker, as well as insertion of two or more cytosines to the site 16190 can be an
astrocytoma specific marker. Heteroplasmy may be decisive for the emergence and /
or progression of high-grade astrocytomas.
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