Adrenal carcinoma tumor progression and penultimate cell surface oligosaccharides.

Many previous studies have implicated cell surface saccharides, and sialylglycoconjugates in particular, as important mediators of tumor cell metastasis. In this report, we have used three different specific sialidases and a highly sensitive high-performance liquid chromatographic sialic acid assay to probe the cell surfaces of several murine adrenal carcinoma variants. In contrast to several earlier studies on other metastatic variants, we find no significant differences in the overall levels of cell surface or total cellular sialic acid among three Y1 murine adrenal carcinoma variants with widely different metastatic phenotypes. However, using highly purified, linkage-specific sialyltransferases, in conjunction with V. cholerae sialidase, to probe the cell surface saccharide topography of specific penultimate oligosaccharides, we do find striking differences in oligosaccharide structures underlying the sialic acid moieties. Two tumorigenic and metastatic variants (F2 and F4) contain about 6-fold more penultimate Gal beta 1----4GlcNAc sialylation sites than a related tumorigenic but nonmetastatic variant (HSR) when CMP-[3H]-N-acetylneuraminic acid and the Gal beta 1----4GlcNAc alpha 2,6 sialyltransferase are used to probe the adrenal carcinoma cell surfaces. The metastatic variants also are found to contain 4- to 4.5-fold more Gal beta 1----3GalNAc sialylation sites than the nonmetastatic variant when the Gal beta 1----3GalNAc alpha 2,3 sialyltransferase is used as a cell surface probe. Earlier work, which used the same sialyltransferase probes on sialidase-treated murine melanoma variants (A. Passaniti and G. W. Hart, J. Biol. Chem., 263: 7591-7603, 1988), also showed similar quantitative differences in penultimate structures between metastatic variants. However, in contrast to the adrenal carcinoma cells, the highly metastatic melanoma cells have severalfold lower levels of sialylatable penultimate Gal beta 1----4GlcNAc and Gal beta 1----3GalNAc saccharides compared to their nonmetastatic counterparts. Thus, while the precise structural alterations or surface accessibilities of penultimate saccharides appear to be cell type dependent, these results suggest that pronounced changes in penultimate cell surface sialo-oligosaccharide moieties occur during progression to a malignant phenotype in two widely different tumor systems. These types of alterations in the underlying penultimate oligosaccharide structures of cell surface sialoglycoconjugates may be a common feature of highly metastatic cells arising from very different tumor cell types.     

Expression and activity of CYP2E1 in circulating lymphocytes are not altered in diabetic individuals

Cytochrome P4502E1 (CYP2E1) plays an important role in ROS production thus favouring accelerated membrane lipid peroxidation. This isoform is strongly expressed in the liver but it can be also found in lymphocytes. As such, lymphocyte may provide a non-invasive accessible pool for screening CYP2E1 expression in man. We have, therefore, analysed CYP2E1 expression and activity in lymphocyte microsomes from 12 healthy controls, 11 type 1 and 12 type 2 diabetic subjects by using Western blot and enzymatic activities. Immunoblotting did not show difference among CYP2E1 protein bands in controls, type 1 and type 2 diabetics. To assess CYP2E1 activity we used the 7-ethoxy-4-trifluoromethylcoumarin (7-EFC), as a fluorescent substrate. The rate of deethylation of 7-EFC from controls did not differ from type 1 and type 2 diabetic subjects. The lack of any difference in CYP2E1 activity also was confirmed by the NADPH-dependent microsomal lipid peroxidation CCL4-induced assay showing similar peroxidation rates among controls and diabetic subjects. The results show that CYP2E1 expression/activity in lymphocytes is not enhanced in diabetes.     

Expression of RANK‐ligand in prostate cancer cell lines

The molecular mediators of bone remodelling, receptor activator of nuclear factor‐kappaB ligand (RANKL), receptor activator of nuclear factor‐kappaB (RANK) and osteoprotegerine (OPG), are believed to be involved in the cellular mechanisms by which tumours metastasize to bone. RANKL is a potent stimulator of osteoclastic bone resorption and is expressed in a variety of tumour cells. We have investigated if the membrane bound form of RANKL is expressed in prostate cancer cell lines, and whether this expression might be regulated by the presence of human osteoblasts. Three prostate cancer cell lines were co‐cultured with human osteoblast‐like cells (hOB) and RANKL expression on cell surface was measured by FACS. We found basal expression of RANKL on the cell surface, and in co‐culture with hOBs the number of cells expressing RANKL was increased between 2.5 and 4 times. These data suggest a signalling mechanism between bone cells and prostate cancer cells that might increase bone resorption and thereby promote bone metastases.     

Effects of low-dose oral contraceptives on sugar metabolism

The effects on carbohydrate metabolism by four low-dose oral contraceptives were evaluated in four low-dose oral contraceptives were evaluated-66 young women randomly divided in four groups. In the various preparations there were a different dosage of estrogen (ethinylestradiol) together different doses and types of progestogen (desogestrel, gestodene, cyproterone acetate). After six months of treatment, in all groups a slight increase of glycemic and insulinemic responses during OGTT was observed; the significance was achieved with the preparation containing cyproterone acetate alone. Glycated hemoglobin did not change. Our results suggest that these new low-dose oral contraceptives induced negligible metabolic side effects.     

PCR analysis of nasal polyps,chronic sinusitis,and hypertrophied turbinates for DNA encoding bacterial 16S rRNA

BACKGROUND: Nasal polyps are considered to result from chronic inflammation, but the initial or persisting stimulus for the inflammation is not known. A variety of bacteria and fungi have been cultured from nasal polyps, but approximately 35% have sterile cultures. Previously, Mycoplasma pneumoniae-specific DNA was detected in human nasal polyps using polymerase chain reaction (PCR) techniques, suggesting M. pneumoniae as a causative agent in the etiology of nasal polyps. METHODS: In this study, we tested for the presence of bacterial DNA in nasal polyps resected from 40 patients, in nasal mucosa membrane from 9 patients undergoing turbinectomy for hypertrophy, and in sinus mucosa membrane from 6 patients undergoing endoscopic surgery for chronic sinusitis. Tissue DNA was extracted and analyzed by PCR using M. pneumoniae specific primers for DNA that encode the 16S rRNA gene in 41 specimens (31 polyps, 6 turbinates, and 4 sinus), and by consensus sequence-based PCR using broad range primers for most eubacterial DNA encoding the 16S rRNA gene in 38 specimens (26 polyps, 7 turbinates, and 5 sinuses). RESULTS: Only two samples were positive for bacterial DNA encoding 16S rRNA: Streptococcus sp. DNA was isolatedfrom one polyp specimen and Pseudomonas aeruginosa DNA was isolated in one maxillary sinusitis specimen. No evidence of M. pneumoniae-specific DNA encoding 16S rRNA was found in any of the tissues. CONCLUSIONS: This study suggests that chronic bacterial infection is not a major component of nasal polyp etiology.     

Cytochrome P450 2J2 Polymorphism in Healthy Caucasians and those with Diabetes Mellitus

Objective: Cytochrome P450 (CYP) 2J2 plays an important role in the biosynthesis of the biologically active cis-epoxyeicosatrienoic acids. An allelic variant named CYP2J2*6, which encodes an enzyme that is almost inactive in the metabolism of arachidonic acid, has recently been described. We investigated the frequency of the CYP2J2*6 variant in a Caucasian population and the relationship between this polymorphism and the development of micro- and macrovascular complications and hypertension in patients with type 1 or type 2 diabetes mellitus. Methods: Genomic DNA was extracted from peripheral blood cells and the fragment containing the A/T single nucleotide polymorphism at position 25 661 in exon 8 of the CYP2J2 gene was amplified. The 532 bp amplified product was subsequently digested with Tsp509I and analyzed on 12% polyacrylamide gel electrophoresis. Results: In the whole population, the frequency of the CYP2J2*6 allele was 0.0064 and the frequency of the CYP2J2*1 allele was 0.9936. Genotype distribution did not show significant differences between controls and patients with type 1 or type 2 diabetes. No homozygotes for CYP2J2*6 allele were found. No association was found between this allele and complications or hypertension in either type of diabetes. Conclusion: The CYP2J2*6 allele is rare in the Caucasian population, and no association is inferred between this allelic variant and diabetic complications.