genetics
nasser pouladi; mohammadali hosseinpourfeizi
Volume 25, Issue 3 , July and August 2018, , Pages 399-407
Abstract
Background: Thyroid cancer is the most common malignant endocrine tumor, and the incidence was rising worldwide over the last three decades. TP53 is one of the most important tumor suppressor genes in the genome, and its mutations are found in approximately 50% of human cancers. It plays pivotal roles ...
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Background: Thyroid cancer is the most common malignant endocrine tumor, and the incidence was rising worldwide over the last three decades. TP53 is one of the most important tumor suppressor genes in the genome, and its mutations are found in approximately 50% of human cancers. It plays pivotal roles in the regulation of cell cycle arrest and apoptosis. The aim of this study was to analyze TP53 gene mutations among thyroid cancer patients in East- Azerbaijan. Material and Methods: 40 tumor samples have been collected from thyroid cancer patients from Tabriz hospitals between 2007-2009. DNA was extracted by Proteinase K – Iso propanol method and then the mutations in p53 gene from exon5 to exon8, were detected by Polymarase Chain Reactions (PCR) and direct sequencing techniques.Results: Alterations in the p53 gene were detected in 12.5% of the patients, including single nucleotide polymorphisms and mutations, including codon216 (GTG>GTA), codon215 (AGT>ATT) and codon273 (CGT>CAT) mutations (each mutation in one of the cases) and two linked polymorphisms 14181C>T and 14201T>G (in two cases).Conclusion: This result helps us to clarify p53 mutation status among Azerbaijani thyroid cancer patients.
Ahmad Hamta; Narges Sharif
Abstract
Backgrounds Breast cancer is the most common cancer in females worldwide. Phosphatidylinositol 3-kinases (PI3Ks) evolve from lipid kinase that regulates the diverse cellular signaling pathways and are often altered in human cancers. Mutations in the gene encoding the p110α catalytic subunit PI3K ...
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Backgrounds Breast cancer is the most common cancer in females worldwide. Phosphatidylinositol 3-kinases (PI3Ks) evolve from lipid kinase that regulates the diverse cellular signaling pathways and are often altered in human cancers. Mutations in the gene encoding the p110α catalytic subunit PI3K (PIK3CA) can increase the enzyme activity and cause uncontrolled growth in cells. Previous studies indicated high frequency of mutation in PIK3CA gene in breast cancer. The current study aimed at determining the activating mutations of PI3K gene that can treat breast cancer using kinase activity of the enzyme inhibitors.Methods & Materials In the current study, due to the high rate of breast cancer in Markazi province, mutations of PIK3CA gene in 45 patient samples and 20 controls were investigated by the means of single-strand conformational polymorphism (SSCP) and direct DNA sequencing. In addition, the correlation between PIK3CA mutations and clinicopathological factors including age at diagnosis, lymph node metastases, subtype histology, tumor size, and histological grade were investigated by the Pearson Chisquare (X2) test.Results Among the 26.6% PIK3CA gene mutations in the study, 75% were identified in the exon 9; and accordingly, in addition to hotspot mutation [G1624A (E542K)], another mutation [G1634C (E545A)] was also detected. The current study showed no significant correlation between PIK3CA mutations and clinicopathological factors. Conclusion Mutations in PI3K gene, a proto-oncogene, showed the importance of this pathway for therapeutic purposes to prevent and cease the growth of breast cancer
M NIKBAKHT; R GOLMOHAMMADI
Volume 13, Issue 1 , March and April 2006, , Pages 7-13
Abstract
Background and purpose: Colorectal cancer is one of the most important common cancers all over the world. Its prevalence varies with geographical distribution. Its multifactorial cause may include environmental, genetic and dietary origins. P53 is the most important tumor suppressive gene. P53 exon 6 ...
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Background and purpose: Colorectal cancer is one of the most important common cancers all over the world. Its prevalence varies with geographical distribution. Its multifactorial cause may include environmental, genetic and dietary origins. P53 is the most important tumor suppressive gene. P53 exon 6 mutation with protein overexpression is reported in different areas. This study is intended to determine the relationship between P53 exon 6 mutation with protein overxpression and prognosis in colorectal cancer.
Methods and Materials: This study was conducted on 80 cases of Colorectal cancers, admitted to Isfahan hospitals in Isfahan, Iran from 1382 (2003) to 1385(2006). DNA was extracted by phenol chloroform isoamil alcohol at the Genetic Department of the faculty of Medicine. Exon 6 of the P53 gene was amplified using primers in a PCR assay. After gel electrophoresis by SSCP method, exon 6 mutations were determined. P53 protein overexpression was determined in cases by immunohistochemistry. Chi-square test was used for data analysis.
Results: Mutations were observed in 12 cases (15%); in 10 cases, mutations demonstrated protein overexpression as well. No significant relationship was observed between P53 exon 6 mutation and its overexpression (p>0.05).
Conclusion: The study revealed that not all P53 exon 6 mutations were accompanied by P53 overexpression. Therefore, besides immuno histochemistry, we need PCR-SSCP or sequencing for diagnosis.