Plenary Lecture
Promoter Methylation and Protein Expression of the (APC,
E-cadherin, MGMT, p15, and p16) Genes in the
Clinical Estimation of Oral Cavity Cancer
Professor Dor Mohammad Kordi Tamandani
Co-authors: K. Moazeni, A. Torkamanzahi, MA. Rigi Ladize,
M. Hashemi, N. Sharifi
Department of Biology, Sistan and Baluchestan University
Zahedan, Iran
E-mail:
dor_kordi@yahoo.com
Abstract:
Nowadays, almost all of the genes in the human genome
have been sequenced. The challenge now is to understand
the molecular mechanisms that allow these genes to be
selectively expressed. Although all genes are
transcribed in an organism at some stage of its life
cycle, a more restricted number are required for the
differentiation of a specialized cell type. Remarkably,
it is essential to select not only the correct genes to
turn on, but also those that need to be inactivated.
Failure to repress genes appropriately has been
connected to many human diseases, including
neurodevelopmental disorders and cancer. Notable among
the mechanisms that stably inactivate genes in a
heritable manner is DNA methylation and the associated
assembly of repressive hetrochromatine. DNA methylation
in mammalian cells occurs at the 5-position of cytosine
within the CpG dinucleotide..Although CpG islands
account for only about 1% of the genome and for 15% of
the total genomic CpG sites, these regions contain over
50% of the unmethylated CpG dinucleotides. There are
about 45,000 CpG islands, most of which reside within or
near the promoters or first exons of genes and are
unmethylated in normal cells,with the exception of CpG
islands on the inactive X chromosome in general. Oral
cancer continues to be a significant health problem that
more people die from oral cancer than melanoma,
cervical, and ovarian cancer combined. Early diagnosis
significantly improves tumor control and survival. The
five-year survival for patients with stage I or II oral
cancer is 70 percent to 80 percent. In contrast,
patients with stage III or IV oral cancer have a
survival rate of only 40 percent to 50 percent. Dental
health care professionals are commonly required to
evaluate patients with potentially malignant oral
lesions. Methylation is one of the earliest events in
oral carcinogenesis, preceding changes in protein
expression level. These advantages make promoter
hypermethylation a very attractive diagnostic marker for
the early detection of oral cancer. The hypothesis of
this project is that the presence of oral cancer leads
to changes in promoter hyper methylation. Therefore, is
to quantitatively analyze promoter hypermethylation of
five genes (APC, E-cadherin, MGMT, p15(INK4B), and
p16(INK4A)) in patients and healthy groups. Current
studies with tissue DNA reveal these genes are most
often inactivated by promoter hypermethylation, allowing
for the progression of oral cancer.
Brief Biography of the Speaker:
Upon completion of my doctorate in Biotechnology at the
University of Panjab, Chandigarh, India in 2008, I
joined as faculty at Department of Biology, University
of Sistan and Baluchistan ,Zahedan -Iran. So, My study
will provide help in finding any diagnostic biomarkers
in deferent population which can use as targets that
finally lead to the development of molecular technique
for early diagnosis of cancer patients and susceptible
individual. Currently, I have focused on effect of
Methylation on oral cavity cancer. Till now I had
published many international papers in this regard.
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