Seyedeh niloofar ashrafzadeh - M.SC. Thesis. Department of biology. Islamic Azad University, East Tehran Branch

BCancer is the first and second cause of death, in developed and developing countries respectivly. Stomach cancer is the fourth most common cancer and the second leading cause of cancer death in the world .pten gene is tumor suppressor gene.PTEN gene is 200 kb and is located on chromosome 10q23.3 containing 9 exons and 8 introns and codes 403 amino acids. It is part of a suppressor pathway in gastric cancer. Recent study suggest that PTEN gene controls cells proliferation, apoptosis, migration, adhesion and balance by regulating a variety of cellular signaling pathway. Mutation in pten gene is detected in multiple malignancies. In this investigation ,we are studied the expression and common polymorphisms of PTEN gene in blood samples of Iranian patients with gastric cancer using REAL TIME PCR and RFLP PCR technics. 45 blood samples (36 document cancer patients and 9 control)were studied with REAL TIME PCR method for evaluation of gene expression,and RFLP PCR method for detection of gene expression,and RFLP PCR method for detection of mutation and polymorphisms. Reduce PTEN gene expression was detected in most of cancer patient s blood sample. Better result needs more advanced molecular techniques and more sample size for investigation. Understanding of the genetic basis of gastric cancer,can expand our insight for prevention ,early detection,progression and treatment of this multifactorial disease.

Gastric cancer, PTEN, gene expression, polymorphism