An enhanced risk of basal cell carcinoma is associated with particular polymorphisms in the VDR and MTHFR genes.

BACKGROUND: Vitamin D and folate are influenced by ultraviolet radiation (UVR), and both are implicated in skin carcinogenesis. Polymorphisms in the genes involved in the metabolism of these two compounds may alter the risk of basal cell carcinoma (BCC). OBJECTIVE: To assess the frequency of four polymorphisms in the gene encoding the vitamin D receptor (VDR) (FokI, BsmI, TaqI and ApaI) and two in the gene encoding methylenetetrahydrofolate reductase (MTHFR) (677C/T and 1286A/C) in 142 patients of Polish origin with BCC and the same number of controls. The expression of VDR and MTHFR proteins in the skin, and the vitamin D status of a subset of patients and controls were also measured. PATIENTS/METHODS: The polymorphisms were assayed by PCR-RFLP, the VDR and MTHFR proteins by immunoblotting and vitamin D status as 25-hydroxyvitamin D (25(OH)D) level in the serum by RIA. RESULTS: The presence of the TT genotype in the FokI VDR polymorphism resulted in a >10-fold higher risk of BCC development. The CT genotype in 677C/T MTHFR polymorphism and CC genotype in 1286A/C MTHFR polymorphism also significantly increased the risk of BCC development. The expression of the VDR and MTHFR proteins was significantly higher in BCCs of the patients than in the healthy skin of the controls. The median serum level of 25(OH)D was significantly higher in the control group compared with the patients with BCC. CONCLUSIONS: Certain VDR and MTHFR gene polymorphisms increase the risk of BCC development in individuals of Polish origin.

Cytosolic phospholipase A2 group IVA influence on GM-CSF expression in human lung cells: a pilot study.

BACKGROUND: Granulocyte-macrophage colony-stimulating factor (GM-CSF) is an important mediator in the differentiation, maturation, and survival of inflammatory cells. It might play a significant role in the pathogenesis of asthma. We have shown previously that cytosolic phospholipase A2 group IV A (cPLA2alpha) is able to activate gene expression, through peroxisome proliferator-activated receptor (PPAR)-gamma response elements (PPRE). In the promoter regions of GM-CSF gene (CSF2), we have found potential PPRE. The goal of the current study was to investigate the influence of cPLA2 overexpression and activation on CSF2 gene expression in human lung cells. MATERIAL/METHODS: Subconfluent A549 cells were transfected with GM-CSF reporter gene and cPLA2alpha overexpression vector. Transfected cells were treated with or without calcium ionophore, A23187, or epidermal growth factor (EGF). Cell lysates were collected and assayed for dual luciferase activity. Some cultures were preincubated with a potent cPLA2alpha inhibitor, methyl arachidonyl fluorophosphonate (MAFP); a secretory phospholipase A2 inhibitor, thioetheramide-PC; a calcium-independent phospholipase A2 inhibitor, bromoenol lactone (BEL); or vehicle. After preincubation, cells were treated with A23187. Expression of GM-CSF messenger RNA (mRNA) was measured using real-time polymerase chain reaction mRNA quantification. RESULTS: Overexpression of cPLA2alpha or activation of endogenous cPLA2alpha by calcium ionophore or EGF caused a significant increase in GM-CSF relative luciferase activity. Calcium ionophore significantly increased GM-CSF mRNA in A549 human lung cells. These effects were at least in part inhibited by MAFP treatment, but not by BEL or thioetheramide-PC. CONCLUSIONS: These preliminary data might suggest an influence of cPLA2alpha on GM-CSF gene expression in human lung cells, which could play a role in the pathogenesis of asthma and other inflammatory diseases.

Variable expression of cysteinyl leukotriene type I receptor splice variants in asthmatic females with different promoter haplotypes.

BACKGROUND: Cysteinyl leukotrienes are potent inflammatory mediators implicated in the pathogenesis of asthma. Human cysteinyl leukotriene receptor 1 (CYSLTR1) gene contains five exons that are variably spliced. Within its promoter few polymorphisms were described. To date, there has been no evidence about the expression of different splice variants of CysLT1 in asthma and their association with CYSLTR1 promoter polymorphisms.The goal of our study was to investigate CysLT1 alternative transcripts expression in asthmatic patients with different CYSLTR1 promoter haplotypes.The study groups consisted of 44 patients with asthma, diagnosed according to GINA 2008 criteria and 18 healthy subjects. Genomic DNA and total RNA was extracted from peripheral blood mononuclear cells. Real-time PCR was performed with specific primers for transcript I [GenBank:DQ131799] and II [GenBank:DQ131800]. Fragments of the CYSLTR1 promoter were amplified by PCR and sequenced directly to identify four single nucleotide polymorphisms: C/T [SNP:rs321029], A/C [SNP:rs2637204], A/G [SNP:rs2806489] and C/T [SNP:rs7066737]. RESULTS: The expression of CysLT1 transcript I and II in asthma did not differ from its expression in healthy control group. However, in major alleles homozygotic CAAC/CAAC women with asthma we found significantly higher expression of transcript I as compared to heterozygous CAAC/TCGC women in that loci. CysLT1 transcript I expression tended to negative correlation with episodes of acute respiratory infection in our asthmatic population. Moreover, expression of CysLT1 transcript II in CAAC/CAAC homozygotic women with asthma was significantly lower than in CAAC/CAAC healthy control females. CONCLUSIONS: Genetic variants of CYSLTR1 promoter might be associated with gender specific expression of CysLT1 alternative transcripts in patients with asthma. CysLT1 splice variants expression might also correlate with the susceptibility to infection in asthmatic population.

[Cysteinyl leukotrienes and their receptors]. / Leukotrieny cysteinylowe i ich recepto.

Cysteinyl leukotrienes (LTC4, LTD4, LTE4) have a proinflamation effect, such as contraction of blood vessels smooth muscle and the respiratory tract, chemotaxis of proinflammatory cells increased endothelium cells permeability and mucus secretion. They are lipid mediators playing an important part in the pathophysiology of bronchial asthma, allergic rhinitis, atopic dermatitis, urticaria, cardiovascular system disorders and tumors. They act through at least four receptors from the rhodopsin gene family, lying in the area of GPCR genes superfamily--CYSLTR1, CYSLTR2, GPR17 and receptor for LTE4 (CYSLT(E)R). Their location, apart from small exceptions, is differentiated and typical for tissues. The highest CYSLTR1 expression was stated in the spleen, peripheral blood leucocytes, interstitial lung macrophage and smooth muscle cells. CYSLTR2 shows highest expression in the hearth, adrenal glands, placenta, spleen and peripheral blood leucocytes, and somewhat smaller in the brain. Biochemical and pharmacological study and the analysis of sequences have shown that all three types of receptors belong to the group of 7-transmembrane receptors--GPCR. The CYSLTR1 excitation power is distributed: LTD4>LTC4>LTF4, and CYSLTR2 LTC4=LTD4>LTE4. Cysteinyl leukotrienes receptors are coupled with the G(q/11) proteins and signal path leading to phosphatidylinositol hydrolysis (PI) and mobilization of intracellular calcium. These receptors are in vivo coupled with the PTX-sensitive G(q/11) protein or both G proteins. CYSLTR1 increases the metabolism of PI and intracellular calcium, activates MAPK kinases, induces differentiation and proliferation of cells, chemotaxis, actin reorganization, release of inflammation mediators and regulation of hematopoietic stem cells. CYSLTR2 also increases the concentration of intracellular calcium, stimulates the release of IL-8 and increases expression of early genes. It is connected to thrombosis, vessel damage, inflammation process and cell death. The existence of new, nuclear, localization of CYSLTR and coexistence with other membrane receptors is postulated. It is probable that they can crate homo- or heterodimers. This indicates the existence of new, previously not know actions of, cysteinyl leukotrienes and their receptors.