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Background. Astrocytomas are diffusible infiltrative and aggressive brain tumors that are extensive and heterogeneous clusters of neoplastic growths in the central nervous system (CNS). Meningioma tumors are commonly benign but may demonstrate an invasive pattern with frequent recurrences. Human telomerase reverse transcriptase (hTERT) is an unfavorable prognostic factor for several types of cancers, and there are controversies about its role. Objectives. In the present study, we investigated the relative expression of hTERT splice variants in 2 groups of brain tumors compared to non-tumor samples. Material and methods. The mRNA of 40 brain tumor samples and 4 control samples was extracted; mRNA expression of hTERT a-deletion and ß-deletion variants, as well as the wild type isoform, was quantified using quantitative reverse transcription polymerase chain reaction (RT-qPCR). Results. The a-deletion variant was significantly expressed in primary benign meningeal tumors (p = 0.01). The results indicate a positive correlation between the relative expression of hTERT mRNA transcript and a-deletion and ß-deletion variants in both groups of tumors (meningiomas and astrocytomas). A strong association between the expression of the full-length splice variant and the ß-deletion variant was observed in astrocytoma tumors (p = 0.045). The most significant correlations were found between the hTERT fulllength and ß-deletion variants in high-grade meningiomas (p = 0.018, correlation coefficient (CC) = 0.964) and grade II astrocytomas (p = 0.015; CC = 0.580. In addition, in low grades of both types of tumors, the hTERT full-length variant and especially the a-deletion variant were the predominant isoforms. The overexpression of hTERT and ß-deletion variants in high grades of these tumors was statistically significant. Our findings indicate that a-deletion and ß-deletion isoforms are associated with high levels of full-length hTERT mRNA in both groups of brain tumor patients. Conclusions. Changes in the splicing pattern of hTERT splice variants in brain tumors and their correlation with pathological alterations in cells could be applied as diagnostic or prognostic biomarkers, or possibly as targets for cancer therapy. However, the function and biological role of hTERT splice variants remain to be clarified. [ABSTRACT FROM AUTHOR]

Background: Acute leukemia is a common pediatric cancer. Novel strategies for treatment of acute leukemia have been developed, but treatment resistance is remained as the most problematic issue. It is hypothesized that the HO-1 gene up-regulation is responsible for tumor resistance to chemotherapy or radiotherapyinduced apoptosis. The levels of HO-1 expression are related to (GT)n microsatellite polymorphisms in the location of its promoter. This study designed to compare allelic frequencies of (GT)n microsatellite polymorphisms in HO-1 gene between acute leukemia patients and healthy controls. Indeed, 3-year diseasefree survival was also evaluated. Methods: Sixty-three patients with acute leukemia and seventy healthy infants were included in this study. We used the medical records of patients to collect information about survival after chemotherapy. The number of GT repeats in HO-1 promoter was determined by an ABI 3100 sequencer. Results: The HO-1 GT repeats ranged from 14 to 34 with peaks at 27 repeats in both cases and controls. Children with longer alleles ((GT)n ≥ 27) had enhanced 3-year survival rate after treatment with chemotherapy or radiotherapy (P<0.05). Conclusion: Although no significant differences were observed between leukemia patients and controls regarding allelic frequency, we found elevated frequency of "LL" genotype in leukemia patients with good prognosis and 3-years surveillance. Radiotherapy and chemotherapy might elevate the expression levels of HO-1 with subsequent increased resistance of leukemia patients to therapy. [ABSTRACT FROM AUTHOR]

Background and objective: Approximately 50 million people worldwide (1% of the world's population) suffer from epilepsy. Among 700 thousand people with epilepsy in Iran, 20% have refractory epilepsy. Accumulation of leukocytes in patients' brain parenchyma is thought to be related to different types of epilepsy. Recent clinical observations suggest that therapeutic strategies that interfere with leukocytes or cause them to migrate may have therapeutic efficacy in epilepsy. The aim of this study was to identify treatment-resistant patients, and investigate the association between polymorphism rs1024611 in CCL2 gene and drug resistance in patients with epilepsy in Isfahan, Iran. Methods: Blood samples were taken from 50 patients with intractable epilepsy (case group) and 50 drug-responsive patients with epilepsy (control group). Genomic DNA was extracted from peripheral blood by salting out method. Specific primers were designed by Oligo 7 software to investigate polymorphism rs1024611 using PCR-RFLP. The preliminary results for a number of samples were confirmed by sequencing. Results: The results of this study showed that there was a significant relationship between intractable epilepsy and presence of C allele. Conclusion: Similar to previous study, we found a significant association between CCL2 gene polymorphism and drug-resistant epilepsy. [ABSTRACT FROM AUTHOR]

Viral hepatitis, as an international public health concern, seriously affects communities and health system. In recent years, great strides have been taken for development of new potential tools against viral hepatitis. Among these efforts, a valuable strategy introduced new molecules called "aptamers". Aptamers as potential alternatives for antibodies could be directed against any protein in infected cells and any components of viral particles. In this review, we will focus on recent advances in the diagnosis and treatment of viral hepatitis based on aptamer technology. In recent years, various types of aptamers including RNA and DNA were introduced against viral hepatitis. Some of these aptamers can be utilized for early and precise diagnosis of hepatitis infections and other group selected as therapeutic tools against viral targets. Designing diagnostic and therapeutic platforms based on aptamer technology is a promising approach in viral infections. The obtained aptamers in the recent years showed obvious potential for use as diagnostic and therapeutic tools against viral hepatitis. Although some modifications to increase the biostability and half-life of aptamers are underway, it seems these molecules will be a favorable substitute for monoclonal antibody in near future. [ABSTRACT FROM AUTHOR]

Hepatitis B virus (HBV) is considered as a global health concern and hepatitis B surface antigen (HBsAg) is the most immunogenic protein of HBV. The purpose of this study was to evaluate the expression of HBsAg on the cell surface of human embryonic kidney cell line (HEK293T). After transformation of expression vector pcDNA/HBsAg to E.coli TOP10F', plasmid was extracted and digested with BglII. Afterwards, the linearized vector was transfected to cells and treated with hygromycin B for 5 weeks to expand the resulted clonies. The permanent expression of HBsAg followed by flow cytometry uptill now about one year. Genomic DNA was extracted from transfected cells and the existence of HBsAg gene was assessed by PCR. Real-time RT-PCR was utilized to measure the expression at the RNA level and flow cytometery was carried out to assess protein expression. Insertion of HBsAg cDNA in HEK293T genome was confirmed by PCR. The results of real-time RT-PCR illustrated that each cell expresses 2275 copies of mRNA molecule. Flow cytometry showed that compared with negative control cells, 99.9% of transfected cells express HBsAg on their surface. In conclusion, stable expression of hepatitis B surface antigen on the membrane of HEK293T provides an accurate post-translational modification, proper structure, and native folding in contrast with purified protein from prokaryotic expression systems. Therefore, these exposing HBsAg cells are practical in therapeutic, pharmaceutical, and biological sets of research. [ABSTRACT FROM AUTHOR]

Objective: To design and evaluate a noninvasive protocol for prenatal diagnosis (PND) of β-thalassemia, using cell free fetal DNA (cff-DNA) in maternal circulation. Traditional current PND which is mainly based on chorionic villous sampling (CVS), amplification refractory mutation system and sequencing holds as gold standard. Methods: Ten thalassemia trait couples with distinct mutations for the husband and wife were included in this study. The mutations in carrier fathers were IVSI-1, IVSI-5, FR8/9 and CD44. After maternal plasma isolation and free DNA extraction, all samples subjected to designed protocol including DNA size separation on agarose gel, elution of DNA from the gel slices using a simple and efficient manual purification method, with or without whole genome amplification and the detection method was allele-specific real-time PCR. Results: Presence or absence of the paternal mutant allele was correctly determined in all of cases and the accuracy of designed protocol was determined 100%. Conclusions: The protocol described here is very simple, inexpensive and easy to perform, but with satisfactory accuracy in detection of paternal mutations in cff-DNA. Due to the risk of fetal loss with current invasive sampling for PND, a noninvasive alternative is highly demanded in clinical setting. [ABSTRACT FROM AUTHOR]