Association of PDCD1 gene markers with susceptibility to thyroid cancer.

PURPOSE: PD-1 receptor is a co-signaling molecule with an important role in regulation of T-lymphocyte activity. Correlation between PD-1 gene (PDCD1) polymorphisms and some immune-related diseases has been reported before. In current study, we aimed to investigate the association of PD-1 polymorphisms at positions +7146 G/A (PD-1.3) and +7785 C/T (PD-1.5), as well as the emerged haplotypes with susceptibility to thyroid carcinoma. METHODS: One hundred five patients with confirmed thyroid cancer and 160 healthy individuals as control group were enrolled. Genotypes were identified using PCR-RFLP and nested PCR-RFLP methods. Results were analyzed by Arlequin and SPSS software packages. RESULTS: Analysis revealed a significant increase in the frequency of PD-1.5 mutant T allele and heterozygous CT genotype in patients with thyroid cancer in comparison with controls [79 (37.7%) vs. 71 (22.2%), and 51 (48.6%) vs. 51 (31.9%), p = 0.0001 and p = 0.009, receptively]. CC genotype at this position observed to be significantly higher among controls than the patients [99 (61.9%) vs. 40 (38.1%), p = 0.0002]. There were no significant differences in the frequencies of genotypes and alleles at locus PD-1.3 between patients and control group. Despite this, GT haplotype emerged from both positions (PD-1.3 G and PD-1.5 T) has also been observed with significant increased frequency between patients and controls [70 (36.8%) vs. 71 (22.2%), p = 0.0005]. CONCLUSION: As the first study to investigate two mentioned polymorphisms in thyroid cancer, current study confirmed the association of PD-1.5 C/T polymorphism and a haplotype resulted from both loci, PD-1.3 and PD-1.5, with susceptibility of Iranians to thyroid cancer.

Helper and cytotoxic T-cell subsets (Th1, Th2, Tc1, and Tc2) in benign and malignant salivary gland tumors.

OBJECTIVE: The objective of this study was to explore the prevalence of T helper type 1 (Th1; CD4(+) IFN-γ (+) ) and Th2 (CD4(+) IL-4(+) ) cells, as well as cytotoxic T cell type 1 (Tc1; CD8(+) IFN-γ(+) ) and Tc2 cells (CD8(+) IL-4(+) ) in peripheral blood of the patients with salivary gland tumors (SGTs). SUBJECTS AND METHODS: Thirty new patients with SGTs and 15 healthy controls were recruited. After intracellular cytokine staining, data acquisition and analysis were performed by flow cytometry. RESULTS: The mean percentages of Th1 and Tc1 cells, as well as the ratios of Th1/Th2 and Tc1/Tc2, were observed to be significantly lower in patients with malignant SGTs in comparison with controls. Furthermore, the geometric mean fluorescent intensity (geometric MFI, representing the cytokine expression intensity) for IL-4 production by Th2 and Tc2 lymphocytes was significantly higher in patients with malignant tumors than controls. Positive correlations were observed between the mean percentage of Tc2 cells with Th2 cells, and with the tumor size in patients with benign and malignant tumors, respectively. CONCLUSION: The findings suggest that the imbalance of Th1/Th2 and Tc1/Tc2 ratios, as well as the increase in the expression of IL-4 by Th2 and Tc2 lymphocytes, may contribute to the pathogenesis of SGTs, especially in malignant cases.

Serum levels of interleukin-7 and interleukin-8 in head and neck squamous cell carcinoma.

Background: The aim of this study was to investigate the association of head and neck squamous cell carcinoma (HNSCC) with serum levels of interleukin-7 (IL-7) and IL-8, the two cytokines whose associations with HNSCC need more clarifications. Materials and Methods: Commercial enzyme-linked immunosorbent assay kits were used for the quantification of the cytokines. Sera were collected from 48 untreated patients (36 men and 12 women; mean age: 52.7 ± 9.8 years) and 34 healthy donors (26 men and 8 women; mean age: 53.1 ± 9.0 years). Results: Serum IL-8 level was neither significantly different between HNSCC patients and control individuals nor associated with smoking status, gender, age, tumor location, tumor grade, and stage of the patients (P > 0.05). Regarding IL-7, all control individuals had serum levels below the sensitivity of the kit (3 pg/ml), but nine patients had detectable levels, and that the mean serum IL-7 was significantly higher in the patients compared to the controls (P = 0.008). Conclusions: Serum IL-8 level is not significantly associated with HNSCC. With the sensitivity of the kit we employed, it seems that serum IL-7 levels are specifically elevated in HNSCC patients compared to healthy individuals. Data from other independent studies are required to clarify the possible employment of IL-7 as an HNSCC biomarker.

Elevated PD-1 expression and decreased telomerase activity in memory T cells of patients with symptomatic Herpes Zoster infection.

We investigated PD-1 levels on VZV-specific CD8+ T-cells of patients with zoster and the effect of PD-1 on the telomerase activity. CD3, CD8, CD137 and PD-1 expressions were analyzed on PBMCs from 9 symptomatic and 5 asymptomatic individuals. The effect of PD-1 blockade at the time of stimulation on the telomerase activity of non-senescent CD57-CD45RO+CD8+CD3+ memory T-cells was evaluated. PD-1 was elevated on CD8+ T-cells in patients. The frequency of PD-1+ and CD137- cells in total CD3+CD8+ T cells of patients was elevated compared to controls. Telomerase activity of non-senescent memory T-cells was lower than that of controls. Blockade of PD-1 at the time of stimulation increased telomerase activity of non-senescent memory T-cells, accompanied by increased CD137 expression. Low telomerase activity of the patients with reactivated zoster could be partially overcome by blocking PD-1 pathway.

Knowledge and attitude of dental faculty members towards evidence-based dentistry in Iran.

INTRODUCTION: Educating dental practitioners is a major component in obtaining evidence-based approach to oral health care, but there is no evidence about knowledge and attitude of dental faculty members towards evidence-based dentistry (EBD) in Iran. MATERIALS AND METHODS: A cross-sectional study was conducted using self-administered questionnaires on dental school faculties in Iran to assess their knowledge and attitude towards basic principles and methods of EBD. A total of eight dental schools were randomly selected of 17 public and two existing private schools. Validated questionnaire with an appropriate reliability (Cronbach's alpha 0.67 - 0.87) was conducted on (n = 505) available dental instructors. The covered dimensions were perceived knowledge on critical appraisal, actual knowledge of EBD concepts, evidence-accessing methods and attitudes about EBD. Correlations were assessed between background characteristics and four main parts of the questionnaire, and multiple linear regression analysis was also used. RESULTS: A total of 377 of 505 dental instructors returned completed questionnaires (response rate 74.65%). The mean perceived knowledge score was 15.32 ± 4.69 on a range of 6-36, and mean actual knowledge was 7.98 ± 2.0 on a range of 0-11 for all respondents with an overall positive attitude towards EBD. CONCLUSIONS: This study suggests that the level of actual knowledge of dental faculties about basic principles of EBD was moderate in Iran. However, faculties' overall interest and positive attitude towards learning EBD is encouraging. Therefore, it is highly recommended that degree/certificate continuing educational programmes be planned by the organising committees.

Preparation and assessment of chitosan-coated superparamagnetic Fe3O4 nanoparticles for controlled delivery of methotrexate.

In this study, Fe3O4 superparamagnetic nanoparticles were synthesized and stabilized by chitosan. Then the nanoparticles were characterized by Fourier transform infrared spectroscopy and transmission electron microscopy (TEM). Particle size distribution and Zeta potential of the particles also was assessed using Malvern Zetasizer. The paramagnetic behaviors of the uncoated and chitosan coated nanoparticles were measured using vibrating scanning magnetometry Particles morphology and size ranges of uncoated iron oxide nanoparticles were evaluated by TEM, showing uniform and narrow size distribution about 10 nm. After coating nanoparticles with chitosan and loading of methotrexate (MTX), the change in size was assessed using Zetasizer. Considerable increase in size was observed following the coating of the particles with chitosan and loading with MTX (the average size was 152 nm). Paramagnetic properties of the uncoated and chitosan-coated particles were assessed showing significant decrease in paramagnetic behavior after coating with chitosan, but it was enough to respond to the magnetic field. Finally loading efficiency, release rate and cytotoxicity of MTX were assessed indicating slow release behavior with the same levels of cell toxicity in SK-BR-3 cell lines, suggesting this formulation as a good candidate for the controlled delivery of MTX.

CTLA4 exon 1 and promoter polymorphisms in patients with multiple sclerosis.

OBJECTIVE: The polymorphisms of exon 1 (+49 A/G) and promoter regions (-1722 T/C, -1661 A/G and -318 C/T)of cytotoxic T lymphocyte antigen 4 (CTLA4) and also haplotypes constructed from mentioned loci were investigated amongst 153 Iranian patients with definite multiple sclerosis (MS) and 190 healthy controls. METHODS: The polymorphisms were genotyped by PCR-restriction fragment length polymorphisms and PCR-amplification refractory mutation system. The 4-locus haplotypes were estimated by Arlequin software (University of Berne, Berne, Switzerland). RESULTS: Preliminary results showed significant increase of +49 G allele and -1661 AG genotype, as well as TGCA haplotype among patients than controls (P < 0.036, P = 0.009 and P < 0.010, respectively). The distribution of -1722 T/C, -1661 A/G, -318 C/T and +49 A/G (TACA) haplotype, from the contrary, was observed to be significantly increased among controls (P < 0.001). CONCLUSIONS: After Bonferroni correction, the results provide preliminary evidence that CTLA4 genetic variation at -1661 locus may render Iranian individuals to be more susceptible to MS, whereas harboring TACA haplotype might be protective.

Association of CTLA-4 gene promoter polymorphisms with systemic sclerosis in Iranian population.

In a recent study, we were unable to show any association between CTLA-4 exon-1 polymorphism and systemic sclerosis (SSc) in Iranian population. In order to further explore the role of this immune inhibitory gene in SSc development, in the present study, the polymorphisms in the CTLA-4 promoter region (-1,722 T/C, -1,661 A/G and -318 C/T) were investigated in 83 SSc patients and 166 healthy controls. All genotypes and allele frequencies in patients were significantly different from the control group (P=0.022 for -1,722 T/C, P=0.03 for -1,661 A/G and P=0.014 for -318 C/T genotypes). The -1,722C, -1,661G and -318T alleles contributed to SSc with P=0.012, odds ratio (OR) 2.16, P=0.031, OR 1.82 and P=0.023, OR 2.45, respectively. A significant difference was observed in the frequency homozygous 'genotype combination' -1,722TT/-1,661AA/-318CC of these three polymorphisms (P(c)=0.003). The frequency of this genotype combination was significantly higher in the control group than in patients. Results of this investigation indicate that -1,722C, -1,661G and -318T alleles of CTLA-4 gene promoter appear to be associated with SSc, and individuals carrying these alleles may be more susceptible to this disease.

Cytotoxic T lymphocyte antigen-4 promoter variants in breast cancer.

CTLA4 is a coinhibitory molecule expressed mainly on activated T lymphocytes. To test the putative involvement of CTLA-4 in inhibitory state of immunity to breast cancer, we genotyped 283 patients and 245 healthy control subjects for -1722 T/C, -1661 A/G, and -318 C/T single nucleotide polymorphisms in the promoter region of the CTLA4 gene. There were no significant differences in genotype, allele, or haplotype frequencies in all three loci between patients and healthy controls. Moreover, the incidence of the most frequent haplotype combination (TAC/TAC, T -1722, A -1661, C -318) was only slightly higher among healthy controls than patients (68.4 vs. 64.8%, P = 0.2). This haplotype combination was associated with lower stages of the disease (P = 0.0007), however, and higher estrogen receptor (ER) expression in patients (P = 0.006). Association with tumor prognostic or predictive factors was also observed with certain genotypes: the -1661 AA genotype was associated with lesser lymph node (LN) involvement (P = 0.017) and higher ER expression (P = 0.004), and the -318 CC genotype with lesser LN involvement (P = 0.007). These results suggest that CTLA4 promoter variants participate in the progression of breast cancer rather than in its initial development.