Cloning and characterisation of the Schizosaccharomyces pombe rad32 gene: A gene required for repair of double strand break and recombination

A new Schizosaccharomyces pombe mutant (rad32) which is sensitive to gamma and UV irradiation is described. Pulsed field gel electrophoresis of DNA from irradiated cells indicates that the rad32 mutant, in comparison to wild type cells, has decreased ability to repair DNA double strand breaks. The mutant also undergoes decreased meiotic recombination and displays reduced stability of minichromosomes. The rad32 gene has been cloned by complementation of the UV sensitive phenotype. The gene, which is not essential for cell viability and is expressed at a moderate level in mitotically dividing cells, has significant homology to the meiotic recombination gene MRE11 of Saccharomyces cerevisiae. Epistasis analysis indicates that rad32 functions in a pathway which includes the rhp51 gene (the S. pombe homologue to S. cerevisiae RAD51) and that cells deleted for the rad32 gene in conjunction with either the rad3 deletion (a G2 checkpoint mutation) or the rad2 deletion (a chromosome stability and potential nucleotide excision repair mutation) are not viable

Association between the polymorphism of CA dinucleotide repeat in intron 1 of NFκB1 gene and risk of breast cancer

زمینه و هدف: ژن NFκB1 زیر واحد اتصالی به DNA در کمپلکس NF-κB را کد می‌کند. تزاید بیان این ژن در برخی سرطان‌ها از جمله سرطان پستان گزارش ‌شده ‌است. در این مطالعه، وجود پلی‌مورفیسم تکرار CA در اینترون یک ژنNFκB1 و ارتباط آن با خطر ابتلا به سرطان پستان در جمعیت اصفهان مورد بررسی قرار گرفت. روش بررسی: این مطالعه‌ی مورد- شاهد، بر روی 115 زن مبتلا به سرطان پستان و 115 زن سالم صورت گرفت. پس از استخراج DNA از نمونه‌های خون افراد مورد مطالعه، توالی مورد نظر توسط واکنش زنجیره‌ای پلیمراز تکثیر گردید. در نهایت پلی‌مورفیسم تکرار CA توسط الکتروفورز قطعات تکثیر شده بر روی ژل پلی‌اکریل‌آمید و تعیین توالی مشخص شد. یافته ها: بر طبق نتایج حاصل از این مطالعه، نه الل مختلف تکرار CA در محدوده‌ی 14 تا 23 تکرار در اینترون یک این ژن مشخص شد. بیشترین فراوانی اللی در هر دو گروه بیمار (27) و کنترل (28/69) متعلق به الل 16(CA) بود. با توجه به فراوانی الل کوتاه 14(CA) در افراد بیمار (3/04) و کنترل (0)، زنان حامل الل 14(CA) ژنNFκB1 به طور قابل توجهی در معرض خطر بالاتری برای ابتلا به سرطان پستان قرار دارند. نتیجه گیری: از آنجا که الل‌ 14 تکرار CA تنها در افراد بیمار مشاهده شد و با توجه به نسبت افزاینده بزرگتر از هشت، ممکن است این تکرار اللی بتواند به عنوان یک مارکر پیش‌آگاهی سرطان پستان مورد استفاده قرار گیرد

Association of the length of CA Dinucleotide repeat in the epidermal growth factor receptor with risk and age of breast cancer onset in Isfahan

Background: The epidermal growth factor receptor (EGFR) also known as HER1 or ErbB1 is a prominent member of the erbB proto-oncogene family, which encodes a receptor tyrosine kinase with a pivotal role in the regulation of cell growth and differentiation. The aim of this research was to study the CA repeat polymorphism in intron I of EGFR among the patients with breast cancer and healthy controls. We have also evaluated risks for breast cancer, age of onset and grade of tumor associated with the CA repeat polymorphism. Methods: In the

The study of TAAAA polymorphism in p53 gene and its association with colorectal cancer

زمینه و هدف: تغییرات ژنتیکی در ژن p53 با تومورزایی به­خصوص تومورهای جامد مانند کولون، ریه و پستان در ارتباط می باشند. تاکنون مطالعه ای در مورد ارتباط تعداد تکرارهای TAAAA واقع در اینترون 1 ژن p53 و سرطان کولورکتال صورت نگرفته است. هدف این پژوهش، بررسی پلی مورفیسم TAAAA واقع در اینترون 1 ژن p53 در بین مبتلایان به سرطان کولورکتال و افراد سالم و ارتباط آن با سرطان کولورکتال می باشد. روش بررسی: در این پژوهش، نمونه خون 151 فرد مبتلا به سرطان کولورکتال و 180 فرد سالم جمع آوری و بررسی شد. پس از استخراج DNA ژنومی از خون محیطی و تکثیر توالی مورد نظر، تعداد تکرار و توالی TAAAA به­وسیله الکتروفورز بر روی ژل پلی آکریل آمید و تعیین توالی به­دست آمد. یافته ها: در این مطالعه، 5 آلل متفاوت از تکرار TAAAA بین 6 تا 10 تکرار و 13 ترکیب آللی (ژنوتیپ) مختلف در بین افراد شاهد و مورد مشاهده شد. بیشترین فراوانی آللی در میان افراد مورد و شاهد مربوط به آلل 8 تکرار بود. تعداد ژنوتیپ های هموزیگوت مساوی یا کوچک تر از 8 در افراد شاهد بیشتر از بیمار می باشد. بر عکس تعداد ژنوتیپ های مساوی و بزرگ تر از 9 (9/9 و 1/9) در افراد بیمار بیشتر است. به­علت تعداد کم نمونه ها محاسبات آماری ارتباط معنی داری را نشان نمی دهد. هیچ ارتباطی بین این ژنوتیپ ها با متاستاز و سن فرد مشاهده نشد. نتیجه گیری: مطالعات ما ارتباط معنی داری را بین پلی مورفیسم تکرار TAAAA در ژن p53 و خطر ابتلا به سرطان کولورکتال نشان نداد

Improvement of SCP production and BOD removal of whey with mixed yeast culture

This research emphasizes on single cell protein (SCP) production and Biochemical Oxygen Demand (BOD) removal from whey with mixed yeast culture. For this purpose, 11 yeast strains were isolated from dairy products (M1-M11) and the strains were identified by morphological and physiological properties. These yeast strains were tested for their ability to reduce the BOD and to produce SCP from whey. Among these strains, K. lactis (M2) had the most SCP production from whey with the yield of 11.79 g/l. Ammonium sulphate as nitrogen source had an increasing effect on biomass yield. The mixed culture of the isolated yeast strains with Saccharomyces cerevisiae was used in order to increase the biomass yield and BOD removal. The highest biomass yield (22.38 g/l) and reduction of initial BOD from 30000 to 3450 mg/l were obtained with the mixed culture of K. lactis (M2) and S. cerevisiae

Association between the length of a CA dinucleotide repeat in the EGFR and risk of breast cancer.

We studied the association of breast cancer with the polymorphic CA repeat in 108 cases of breast cancer and 108 matched controls from Isfahan city of Iran. The most common genotype in controls and patients was homozygous with allele length of 16. Our findings demonstrate that Women with two short CA repeat (< 19) are at a significantly higher risk of breast cancer, at an estimated odds ratio of 1.86. We have also found that women with short alleles (< 19) had much greater risk of developing cancer before the age of 55 (OR, 3.36)

Evaluation of rs62527607 [GT] single nucleotide polymorphism located in BAALC gene in children with acute leukemia using mismatch PCR-RFLP

Acute leukemia is the most common cancer in children and involves several factors that contribute to the development of multidrug resistance and treatment failure. According to our recent studies, the BAALC gene is identified to have high mRNA expression levels in childhood acute lymphoblastic leukemia (ALL) and those with multidrug resistance. Several polymorphisms are associated with the expression of this gene. To date, there has been no study on the rs62527607 [GT] single nucleotide polymorphism (SNP) of BAALC gene and its link with childhood acute lymphoblastic and myeloid leukemia (AML). The purpose of this study is to evaluate the prevalence of this polymorphism in pediatric acute leukemia, as well as its relationship with prognosis. DNA samples were extracted from bone marrow slides of 129 children with ALL and 16 children with AML. The rs62527607 [GT] SNP was evaluated using mismatch polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-based analysis. The association between the SNP alleles and patient disease-free survival was then assessed. The prevalence of the T-allele of rs62527607 [GT] SNP in childhood T-ALL and pre-B-ALL was 28.3% and 11.2%, respectively. In the pre-B-ALL patients, 3 year disease free survival was associated with the GG genotype. Results showed a robust association between the rs62527607 SNP and the risk of relapse in ALL, but not AML, patients. T-ALL patients with the GT genotype had an 8.75 fold higher risk of relapse. The current study demonstrates a significant association between the genotype GT and the polymorphic allele G424T, and introduces this SNP as a negative prognostic factor in children with ALL