Possible Role of GADD45γ Methylation in Diffuse Large B-Cell Lymphoma: Does It Affect the Progression and Tissue Involvement?

OBJECTIVE: Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma among adults and is characterized by heterogeneous clinical, immunophenotypic, and genetic features. Different mechanisms deregulating cell cycle and apoptosis play a role in the pathogenesis of DLBCL. Growth arrest DNA damage-inducible 45 (GADD45γ) is an important gene family involved in these mechanisms. The aims of this study are to determine the frequency of GADD45γ methylation, to evaluate the correlation between GADD45γ methylation and protein expression, and to investigate the relation between methylation status and clinicopathologic parameters in DLBCL tissues and reactive lymphoid node tissues from patients with reactive lymphoid hyperplasia. MATERIALS AND METHODS: Thirty-six tissue samples of DLBCL and 40 nonmalignant reactive lymphoid node tissues were analyzed in this study. Methylation-sensitive high-resolution melting analysis was used for the determination of GADD45γ methylation status. The GADD45γ protein expression was determined by immunohistochemistry. RESULTS: GADD45γ methylation was frequent (50.0%) in DLBCL. It was also significantly higher in advanced-stage tumors compared with early-stage (p=0.041). In contrast, unmethylated GADD45γ was associated with nodal involvement as the primary anatomical site (p=0.040). CONCLUSION: The results of this study show that, in contrast to solid tumors, the frequency of GADD45γ methylation is higher and this epigenetic alteration of GADD45γ may be associated with progression in DLBCL. In addition, nodal involvement is more likely to be present in patients with unmethylated GADD45γ.

HIF1A as a major vascular endothelial growth factor regulator: do its polymorphisms have an association with age-related macular degeneration?

BACKGROUND: To investigate the association between age-related macular degeneration (AMD) and the polymorphisms of HIF1A, a major vascular epithelial growth factor regulator under hypoxic conditions. The associations of AMD and polymorphisms of genes CFH, SKIV2L and MYRIP were also studied. DESIGN: Prospective study. PARTICIPANTS: Eighty-seven AMD patients and 80 healthy subjects admitted to the Department of Ophthalmology at Pamukkale University Hospital, Denizli, Turkey, were included: 45 (52%) had wet type AMD, and 42 (48%) had dry type AMD. METHODS: Polymorphisms rs1061170 (CFH), rs429608 (SKIV2L), rs2679798 (MYRIP) and both rs11549465 and rs11549467 (HIF1A) were investigated in DNA isolated from peripheral blood samples of the cases and controls by dye-termination DNA sequencing. MAIN OUTCOME MEASURES: Genotype distribution of rs1061170 (CFH), rs429608 (SKIV2L), rs2679798 (MYRIP) and both rs11549465 and rs11549467 (HIF1A) in AMD cases and healthy controls; association between genotypes and AMD subtypes. RESULTS: Given the significant difference between the mean age of case and control groups (72.13 ± 5.77 vs. 62.80 ± 5.22, respectively) (P = .000), subsequent analyses were adjusted for age. We found that having at least one C allele for polymorphism rs1061170 increases AMD risk independent of age (OR = 2.42, 95% confidence interval [CI], 1.22-4.81). The ancestral T allele for polymorphism rs1061170 has a protective effect for AMD (OR = 0.53, 95% CI, 0.34-0.83). No statistically significant difference for distributions of other single nucleotide polymorphisms (SNPs) emerged between patients and healthy subjects. CONCLUSIONS: No associations appeared between HIF1A SNPs and AMD, which were studied here for the first time; however, polymorphism rs1061170 of the CFH gene is associated with AMD in our population.

The mRNA expression of cytochrome P450 isoforms in human gastric tissue.

BACKGROUND/AIMS: Human Cytochrome P450 (CYP) comprises a multigene family of microsomal enzymes that metabolize a wide variety of xenobiotics, including drugs and carcinogens. Although the a number of CYP enzymes were also detected in epithelial cells along the gastrointestinal tract, little is known about the expression of CYP genes in gastric tissue. METHODOLOGY: In this study, the expression patterns of CYP isoforms was investigated in a total of 14 antral biopsy tissues obtained from the patients with either chronic gastritis (n = 6) or cancer (n = 8) by gene-specific real-time reverse transcriptase -PCR analyses. We employed primer sets specific for CYPs -1A1, -1A2, -2A6, -2B6, -2C, -2D6, -2E1, and -3A5. RESULTS: Among the isoforms CYP1A1, CYP2C and CYP2D6 gave rise to detectable mRNAs in all 14 gastric tissues while the mRNAs for the other CYPs were detected in some of the tissues. The expression patterns were compared to clinical parameters. There were no significant differences in the parameters between the two groups; however the mRNA expression of CYP2A6 was significantly higher in women than man (p < 0.05). CONCLUSIONS: Our data suggests that the CYP isoforms were independently expressed with respect to the pathological status in human gastric tissue.

Progressive autosomal dominant optic atrophy and sensorineural hearing loss in a Turkish family.

PURPOSE: To describe the clinical features, mode of inheritance, and linkage analysis of ten affected members of a three-generation family with progressive optic atrophy and progressive hearing loss. MATERIALS AND METHODS: The proband, a 10-year-old boy, presented with progressive visual failure. Ten other members in his family, including his mother, half-sister, aunt, two uncles, grandfather, and some of the cousins, also had progressive visual loss and hearing loss. Six affected and four unaffected cases were examined in detail. Blood samples were drawn from 16 members for DNA extraction. Two loci previously described for optic atrophy were tested for linkage in the present family. RESULTS: The mode of inheritance was clearly autosomal dominant. Six members of the family were found to have progressive optic atrophy and hearing loss, both starting in the first decade of life. Total or red-green color blindness was detected in some patients. None of the members of this family showed evidence of other systemic disorders; however, four had blepharochalasis. No other cause could be found for the hearing or the visual loss. Linkage analysis excluded OPA1 and OPA2. CONCLUSION: The present Turkish family belongs to the group of individuals with autosomal dominantly inherited optic atrophies with hearing loss. Linkage analysis excluded OPA1 and OPA2, indicating that a novel gene defect underlies the disease in this family. Further genome-wide linkage analysis and identification of the disease-associated gene will help define the pathophysiology of this syndrome.