Iranian Biomedical Journal
Volume:14 Issue: 3, Jul 2010

Impaired DNA repair mechanism is one of the main causes of tumor genesis. Study of intrinsic radiosensitivity of cancer patients in a non-target tissue (e.g. peripheral blood) might show the extent of DNA repair deficiency of cells in affected individuals and might be used a predictor of cancer predisposition. Initial radiation-induced DNA damage (ratio of Tail DNA/Head DNA), dose-response curves and kinetics of DNA repair in leukocytes from healthy volunteers and prostate cancer patients were assessed using alkaline comet assay after exposure to 60Co gamma rays. Results showed that higher levels of baseline and gamma rays induced DNA damage in leukocytes of prostate cancer cases than in controls. Asimilar dose response was obtained for both groups. After a repair time of 24 h following in vitro irradiation,samples from the healthy individuals showed no residual DNA damage in their leukocytes, whereas prostate cancer patients revealed more than 20%. Although similar initial radiosensitivity was observed for both groups, the repair kinetics of radiation induced DNA damage of leukocytes from prostate cancer cases and healthy subjects were statistically different. These results support the hypothesis that men affected by prostate cancer may have a constitutional genomic instability.

The ectopic expression of receptor tyrosine kinase Ror1 has been reported in patients with hematological malignancies such as chronic lymphocytic leukemia and acute lymphoblastic leukemia. Here we report, for the first time, expression of ROR1 gene in both tumor tissues and peripheral blood mononuclear cells (PBMC) from patients with renal cancer (RC). In the current study, the expression of ROR1 gene was semi-quantitatively measured in PBMC and tumor tissues from 16 RC patients as well as PBMCfrom 22 healthy individuals relative to the expression of the housekeeping gene phosphoglucomutase 1 by RT-PCR. Our results showed that ROR1 was expressed at gene level in 81.3% of renal tumor tissues (13 out of 16) whereas it was expressed in 94% of PBMC from RC patients (15 out of 16). A weak expression of ROR1 was observed in PBMC of 4 out of 22 healthy individual. A significant expression of ROR1 was observed in PBMC from RC patients when compared to that in PBMC from normal healthy individuals (P<0.001). The expression of ROR1 in PBMC may reflect a shedding of tumor cells into blood stream. We conclude that detection of a high level of ROR1 expression in blood cells might assist inearly detection of renal malignancies, providing taking into consideration the clinical symptoms of the disease.

Herpes simplex virus type-1 (HSV-1) establishes a lifelong latent infection in neuron following primary infection. The existence of latent HSV-1 DNA in the trigeminal ganglia of infected BALB/c mice was examined using a direct in situ PCR technique, based on Digoxigenin-11-dUTP detection system with anti-digoxigenin-peroxidase and 3,3'-diaminobenzidine (DAB) substrate. Eight-weekold male BALB/c mice were inoculated via the eye by 104 plaque forming unit of wild type Iranian isolates of HSV-1. After establishment of latency, trigeminal ganglia were removed and examined using in situ PCR to detect HSV-1 genome. Finally, the results of in situ PCR were verified by a two-round PCR method, usingamplification cocktail of in situ reaction, as a template for a conventional gel base PCR. Results and The results suggest that a direct in situ PCR method using a peroxidase and DAB detectionsystem is a useful means for detection of latent HSV-1 DNA in the latently infected ganglia.

One third of epileptic patients are resistant to several anti-epileptic drugs (AED). Pglycoprotein (P-gp) is an efflux transporter encoded by ATP-binding cassette subfamily B membe 1 (ABCB1) gene that excludes drugs from the cells and plays a significant role in AEDs resistace. Overexpression of P-gp could be a result of polymorphisms in ABCB1 gene. We studied the association of T129C and T1236C single-nucleotide polymorphisms (SNP) of ABCB1 gene with drug-resistant epilepsy in Iranianepileptics. DNA samples were obtained from 200 healthy controls and 332 epileptic patients, of whom 200 were drug responsive and 132 drug resistant. The frequencies of the genotypes of the two SNP were determined by polymerase chain reaction followed by restriction fragment length polymorphism. No significant association was found between T129C and T1236C genotypes and drug-resistant epilepsy neither in adults nor in children. However, the risk of drug resistance was higher in female patient with 1236CC (P = 0.02) or CT (P = 0.008) genotype than in those with TT genotype. The risk of drugresistance was also higher in patients with symptomatic epilepsies with 1236CC (P = 0.02) or CT (P = 0.004)genotype than in those with TT genotype. The risk of drug resistance was lower in patients with idiopathicepilepsies with 129TT genotype (P = 0.001) than in those with CT genotype. Our results indicatethat T1236C polymorphism is associated with drug resistance in Iranian female epileptic patients. Replicationstudies with large sample sizes are needed to confirm our results.

Currently, there are no effective vaccines against leishmaniasis, and treatment using pentavalent antimonial drugs is occasionally effective and often toxic for patients. The PTR1 enzyme, which causes antifolate drug resistance in Leishmania parasites encoded by gene pteridine reductase 1 (ptr1). Since Leishmania lacks pteridine and folate metabolism, it cannot synthesize the pteridine moiety from guanine triphosphate. Therefore, it must produce pteridine using PTR1, an essential part of the salvage pathway that reduces oxidized pteridines. Thus, PTR1 is a good drug-target candidate for anti-Leismania chemotherapy.The aim of this study was the cloning, expression, and enzymatic assay of the ptr1 gene from Iranian lizard Leishmania as a model for further studies on Leishmania. Promastigote DNA was extracted from the Iranian lizard Leishmania, and the ptr1 gene was amplified using specific primers. The PCR product wascloned, transformed into Escherichia coli strain JM109, and expressed. The recombinant protein (PTR1 enzyme) was then purified and assayed. ptr1 gene was successfully amplified and cloned into expression vector. Recombinant protein (PTR1 enzyme) was purified using affinity chromatography andconfirmed by Western-blot and dot blot using anti-Leishmania major PTR1 antibody and anti-T7 tagmonoclonal antibody, respectively. The enzymatic assay was confirmed as PTR1 witch performed using 6-biopterin as a substrate and nicotinamide adenine dinucleotide phosphate as a coenzyme. Iranianlizard Leishmania ptr1 was expressed and enzymatic assay was performed successfully.

The ovariectomized animals are good models to evaluate the effect of different steroid hormone treatments on implantation events and the pattern of integrin expression. Therefore, this study was performed to compare the expression of integrins and osteopontin (OPN) in correlation with pinopode development in ovariectomized mice endometrium which was subjected to steroid hormones. Ovariectomized mice were subjected to estrogen, progesterone and estrogen-progesterone hormones. Their uterine horns were evaluated for integrin expression by immunohistochemistry and real-time RT-PCR and for pinopodedevelopment by transmission and scanning electron microscopic studies. No immunostaining for integrin and OPN molecules were detected in the endometrium of non-ovariectomized mice except inmetestrus phase. The α4 and β1 integrin genes were expressed in all phases of estrous cycle. In ovariectomized mice, no reaction was detected in the endometrium of control, sham and estrogen-treatedgroups, but in both progesterone-treated groups, all examined genes were expressed. There was not anycorrelation between pinopodes and integrin expression in ovariectomized mice. The progesterone is more effective on endometrial integrin expression than estrogen and differences in the expression pattern of integrins reflect their important and different roles in embryo implantation. The pinopodes may have minoreffect in mice implantation or have some delay in their expressions in ovariectomized mice which were subjected to exogenous hormones.

The leaves of Eucalyptus globulus (eucalyptus) are used for treatment of diabetes mellitus in traditional medicine. The aim of this study was to evaluate the effects of eucalyptus in treatment of established systemic infection with Candida albicans in normal and streptozotocin-induced diabetic rats. Sixty normoglycemic male Wistar rats, weighing 200-250 g, were selected and randomly divided into six groups (n= 10): normal control, control + C. albicans, control + eucalyptus + C. albicans, diabetic control, diabetic + C. albicans, diabetic + eucalyptus + C. albicans. Diabetes was induced after a single intraperitoneal injection of streptozotocin (60 mg/kg body weight) and eucalyptus was added to the diet (62.5 g/kg) and drinking water (2.5 g/L) of treated animals for 4 weeks. The concerned groups were inoculated with C. albicans 15 days after diabetes induction. At the end of one month experiment, fasted rats were killed by cervical decapitation.Blood was collected from neck vein for estimation of glucose. C. albicans concentrations were estimated in liver and kidneys using serial dilution culture of tissue homogenates. Eucalyptus administration significantly improved the hyperglycemia, polydipsia, polyphagia, and it also compensated weight loss of diabetic rats (P<0.05). Moreover, eucalyptus caused a significant reduction in C. albicans concentration inliver and kidney homogenates (P<0.01). The results revealed that eucalyptus improves Candidiainfection in normal and diabetic rats that in some ways validates the traditional use of this plant in treatment of diabetic patients.