Dextran-catechin conjugate: a potential treatment against the pancreatic ductal adenocarcinoma.

PURPOSE: A polysaccharide-flavonoid conjugate was developend and proposed for the treatment of pancreatic ductal adenocarcinoma (PDAC). METHODS: The conjugate was synthesized by free radical grafting reaction between catechin and dextran. The chemical characterization of the conjugate was obtained by UV-Vis, 1H-NMR, FT-IR and GPC analyses, while the functionalization degree was determined by the Folin-Ciocalteu assay. The biological activity of the catechin-dextran conjugate was tested on two different cell lines derived from human pancreatic cancer (MIA PaCa-2 and PL45 cells), and the toxicity towards human pancreatic nestin-expressing cells evaluated. RESULTS: Both the cancer cell lines are killed when exposed to the conjugate, and undergo apoptosis after the incubation with catechin-dextran which resulted more effective in killing pancreatic tumor cells compared to the catechin alone. Moreover, our experimental data indicate that the conjugate was less cytotoxic to human pancreatic nestin-expressing cells which are considered a good model of non-neoplastic pancreatic cells. CONCLUSION: The suitability of newly synthesized Dextran-Catechin conjugate in the treatment of PDAC was proved confirming the high potential application of the proposed macromolecula system in the cancer therapy.

A novel breast cancer-associated BRIP1 (FANCJ/BACH1) germ-line mutation impairs protein stability and function.

PURPOSE: BRCA1-interacting protein 1 (BRIP1; FANCJ/BACH1), which encodes a DNA helicase that interacts with BRCA1, has been suggested to be a low-penetrance breast cancer predisposing gene. We aimed to assess whether BRIP1 mutations contribute to breast cancer susceptibility in our population and, if so, to investigate the effect of such mutation(s) on BRIP1 function. EXPERIMENTAL DESIGN: A series of 49 breast/ovarian cancer families, devoid of a BRCA1/BRCA2 mutation, were screened for BRIP1 mutations. Functional analyses, including coimmunoprecipitation and stability assays, were employed to further characterize a previously unreported variant. RESULTS: Five sequence alterations were identified, of which four had been already described. Herein, we report a novel BRIP1 germ-line mutation identified in a woman with early-onset breast cancer. The mutation consists of a 4-nucleotide deletion (c.2992-2995delAAGA) in BRIP1 exon 20 that causes a shift in the reading frame, disrupts the BRCA1-binding domain of BRIP1, and creates a premature stop codon. Functional analysis of the recombinant mutant protein in transfected cells showed that the truncation interferes with the stability of the protein and with its ability to interact with BRCA1. Loss of the wild-type BRIP1 allele with retention of the mutated one was observed in the patient's breast tumor tissue. CONCLUSIONS: These results, by showing that the newly identified BRIP1 c.2992-2995delAAGA mutation is associated with instability and functional impairment of the encoded protein, provide further evidence of a breast cancer-related role for BRIP1.

Hypnotizability and Catechol-O-Methyltransferase (COMT) polymorphysms in Italians.

Higher brain dopamine content depending on lower activity of Catechol-O-Methyltransferase (COMT) in subjects with high hypnotizability scores (highs) has been considered responsible for their attentional characteristics. However, the results of the previous genetic studies on association between hypnotizability and the COMT single nucleotide polymorphism (SNP) rs4680 (Val(158)Met) were inconsistent. Here, we used a selective genotyping approach to re-evaluate the association between hypnotizability and COMT in the context of a two-SNP haplotype analysis, considering not only the Val(158)Met polymorphism, but also the closely located rs4818 SNP. An Italian sample of 53 highs, 49 low hypnotizable subjects (lows), and 57 controls, were genotyped for a segment of 805 bp of the COMT gene, including Val(158)Met and the closely located rs4818 SNP. Our selective genotyping approach had 97.1% power to detect the previously reported strongest association at the significance level of 5%. We found no evidence of association at the SNP, haplotype, and diplotype levels. Thus, our results challenge the dopamine-based theory of hypnosis and indirectly support recent neuropsychological and neurophysiological findings reporting the lack of any association between hypnotizability and focused attention abilities.

Association of donor-specific microchimerism with graft dysfunction in kidney transplant patients.

The biological significance of donor-specific microchimerism (DSM) in solid organ transplantation is unresolved. It has been reported both as a favourable feature, which may facilitate induction and maintenance of tolerance, and as a sign of graft-vs-host disease. Here, we applied a quantitative real-time PCR assay (qRT-PCR) to a selected series of kidney transplant recipients to measure the level of microchimerism in relation to allograft function and survival. DSM level was assessed by scoring the HLA-DRB1 locus in 54 patients (42 males, 12 females) with more than 2 years of follow-up after transplantation; 38 patients were considered to have stable renal function (SRF) and 16 had allograft dysfunction (AD). Among patients with AD, 12 (75%) showed detectable level of microchimerism, compared to 11 (29%) SRF patients (Odds Ratio 7.36, 95% CI 1.7-35.2; p<0.01). In addition, AD patients showed a higher mean donor genome equivalents (6.5×10(-5) vs. 2.4×10(-5); p<0.001). SRF patients were re-evaluated two years later; 2 out of 27 DSM negative vs. 2 out of 11 DSM positive had lost their transplanted organ. In conclusion, qRT-PCR applied to peripheral blood shows significant association between DSM and allograft dysfunction in kidney transplant patients.

Cancer transmissibility across HLA barriers between immunocompetent individuals: rare but not impossible.

The axiom of human leukocyte incompatibility (HLA) incompatibility has always led scientists to consider cancer transmission between HLA-different individuals impossible. In fact, cancer transmission between individuals represents a frightening possibility in animal populations with limited HLA diversity or for rare cancers exploiting downregulation of HLA expression. We review here evidence from nonhuman models and settings for interhuman transmission.

Real-time quantitative polymerase chain reaction analysis of patients with refractory chronic periodontitis.

BACKGROUND: Periodontitis is a complex multifactorial disease and is typically polygenic in origin. Genes play a fundamental part in each biologic process forming complex networks of interactions. However, only some genes have a high number of interactions with other genes in the network and may, therefore, be considered to play an important role. In a preliminary bioinformatic analysis, five genes that showed a higher number of interactions were identified and termed leader genes. In the present study, we use real-time quantitative polymerase chain reaction (PCR) technology to evaluate the expression levels of leader genes in the leukocytes of 10 patients with refractory chronic periodontitis and compare the expression levels with those of the same genes in 24 healthy patients. METHODS: Blood was collected from 24 healthy human subjects and 10 patients with refractory chronic periodontitis and placed into heparinized blood collection tubes by personnel trained in phlebotomy using a sterile technique. Blood leukocyte cells were immediately lysed by using a kit for total RNA purification from human whole blood. Complementary DNA (cDNA) synthesis was obtained from total RNA and then real-time quantitative PCR was performed. PCR efficiencies were calculated with a relative standard curve derived from a five cDNA dilution series in triplicate that gave regression coefficients >0.98 and efficiencies >96%. The standard curves were obtained using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and growth factor receptor binding protein 2 (GRB2), casitas B-lineage lymphoma (CBL), nuclear factor-KB1 (NFKB1), and REL-A (gene for transcription factor p65) gene primers and amplified with 1.6, 8, 40, 200, and 1,000 ng/µL total cDNA. Curves obtained for each sample showed a linear relationship between RNA concentrations and the cycle threshold value of real-time quantitative PCR for all genes. Data were expressed as mean ± SE (SEM). The groups were compared to the analysis of variance. A probability value <0.01 was considered statistically significant. RESULTS: The present study agrees with the preliminary bioinformatics analysis. In our experiments, the association of pathology with the genes was statistically significant for GRB2 and CBL (P <0.01), and it was not statistically significant for REL-A and NFKB1. CONCLUSION: This article lends support to our preliminary hypothesis that assigned an important role in refractory aggressive periodontitis to leader genes.

Human leptin tissue distribution, but not weight loss-dependent change in expression, is associated with methylation of its promoter.

Leptin is a master regulator of energy homeostasis. Its expression, prevalently localized in adipocytes, is positively related to adipose mass. Epigenetics is emerging as an important contributor to the changes in gene expression undergone by adipose tissue during obesity. We herein investigated the involvement of methylation-dependent mechanisms in leptin regulation in humans. We studied the methylation profile of a 305 bp region in the leptin promoter and analyzed the correspondent leptin expression in visceral adipocyte fraction (AF) and stromal vascular fraction (SVF) of white adipose tissue (WAT) and liver. We found an inverse relationship between methylation and leptin expression with AF displaying a lower methylation density (8%) than SVF and liver (18%, 21%). We evidenced a hot spot region, which mostly differentiates AF versus liver. This includes C15 and 21, which are within the recognition sequences for the transcription factors Sp1 and C/EBP, and C22-23/24, flanking a TATA box. In vitro studies demonstrated that demethylation (by decitabine) increase or de novo activate leptin expression in primary fibroblasts and HeLa cells, respectively. A longitudinal study carried out in patients analyzed before and after bariatric surgery-induced weight loss indicated that in this case decrease in WAT leptin expression (about 50%) does not correspond to changes in promoter methylation density. In conclusion, methylation density in the leptin promoter constitutes one control level for cell type specific leptin expression, whereas weight-loss induced changes in leptin expression does not seem to be methylation-dependent.

Promoter polymorphisms of the NOS3 gene are associated with hypnotizability-dependent vascular response to nociceptive stimulation.

Hypnotizability is associated with a few physiological characteristics also in the normal awake state. Differences in flow-mediated dilation (FMD) have been observed in subjects with high (Highs) or low (Lows) hypnotizability during nociceptive stimulation. FMD is largely due to the nitric oxide (NO) produced by vascular endothelium through the activity of NO synthase (eNOS). Endothelial NOS is encoded by the NOS3 locus. Aim of this pilot study was to investigate the association between genetic polymorphisms of NOS3 involved in NO blood levels and hypnotizability. Nine single nucleotide polymorphisms (SNPs) of the NOS3 gene were analyzed in the DNA of 24 Highs, 22 Lows, and 61 newborns. Two SNPs, rs1800783 (-1474 T/A) and rs2070744 (-786 T/C), located in the upstream and promoter region of the gene, respectively, showed significant differences between Highs and Lows in allele frequency. Haplotype analysis showed that the newborns were in linkage equilibrium for these SNPs, whereas both Highs and Lows showed linkage disequilibrium. The A-C haplotype (associated with lower NO availability in the general population) was more frequent in Highs, and the T-T haplotype was more frequent in Lows. Thus, the lower FMD reduction observed in Highs during nociceptive stimulation, which is indicative of higher NO availability, should be due to greater efficacy of shear stress-related transcriptional factors and/or to lower effects of NOS inhibitory controls. A consequent theoretical proposal concerns the possible role of NO in the brain vessels where, in stimulation conditions, NO diffusion to the extracellular compartment might be involved in hypnotic responding.