Synthesis, Characterization, and Antiproliferative Properties of New Bio-Inspired Xanthylium Derivatives.

Xanthylium derivatives are curcumin analogs showing photochromic properties. Similarly, to anthocyanins, they follow the same multistate network of chemical species that are reversibly interconverted by external stimuli. In the present work, two new asymmetric monocarbonyl analogues of curcumin, 4-(4-hydroxy-3-metoxybenzylidene)-1,2,3,4-tetrahydroxanthylium chloride (compound 3) and 4-(4-hydroxybenzylidene)-6-methoxy-1,2,3,4-tetrahydroxanthylium chloride (compound 4) were synthesized, and their photochromic and biological properties were investigated. The UV-Vis spectroscopy and the direct and reverse pH-jumps studies confirmed the halochromic properties and the existence of different molecular species. A network of chemical reactions of these species was proposed. Furthermore, the antiproliferative properties of both compounds were evaluated using P19 murine embryocarcinoma cells and compared with each other. The results demonstrate that both new xanthylium derivatives modify the progression through the cell cycle of P19 cells, which translates into a significant antiproliferative effect. The effect of the methoxy group position is discussed and several checkpoint proteins are advanced as putative targets.

Gene network analysis of the transcriptome impact of methylated microRNAs on oral squamous cell carcinoma.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is one of the most common head and neck squamous cell tumors. MicroRNAs and DNA methylation, as epigenetic mechanisms, regulate the expression of oncogenes and tumor suppressor genes, contributing to the carcinogenic development. However, the current knowledge on the genetic and epigenetic landscape of OSCC is still limited. OBJECTIVES: To assess the transcriptomic impact of microRNAs found to be methylated through Infinium genome-wide methylation profiling of archived OSCC tissues, and to analyze their biological role using gene network analysis. MATERIAL AND METHODS: We used the Infinium array-based methylation assay to assess the genome-wide methylation status at the single-CpG-site level of DNA purified from archived OSCC tissue samples. After quality control, filtering out poorly performing probes and normalization of data, we identified the differentially methylated microRNA loci. We performed a literature-based analysis of OSCC transcriptomic data to identify the predicted target genes for each microRNA, followed by individual network and pathway enrichment analyses. RESULTS: The analysis of Infinium methylation array data revealed 1469 differentially hypomethylated loci, 4 of which were of interest, namely hsa-microRNA-124-3, hsa-microRNA-24-1, hsa-microRNA-769, and hsa-microRNA-4500. Network and pathway enrichment analyses revealed multiple pathways modulated through DNA methylation-microRNA expression axes. CONCLUSIONS: We describe the transcriptomic impact of 4 differentially methylated microRNAs in OSCC tissues samples and discuss their role in the pathology of OSCC. These results may contribute to a better understanding of how epigenetic mechanisms such as DNA methylation and microRNAs cooperate to impact the development of OSCC.

Changes in global DNA methylation and hydroxymethylation in oral mucosa according to tobacco smoke exposure.

OBJECTIVE: This prospective clinical study comparatively investigated the effects of tobacco smoking on global methylation and hydroxymethylation in oral epithelial cells. METHODS: Buccal cells from the inside of the cheeks were collected from 47 individuals, including smokers, former smokers, and never smokers. DNA was extracted using dedicated kits. Methylated and hydroxymethylated DNA fractions were measured using assays similar to enzyme-linked immunosorbent assays. The levels of methylation and hydroxymethylation were compared among groups using unpaired two-tailed t-tests or the Mann-Whitney U test; P < 0.05 was considered statistically significant. RESULTS: There was no statistically significant difference in the average number of cigarettes between smoker and former smoker groups. Although methylation levels were lower for smokers (3.1%) and former smokers (2.16%), compared with never smokers (4.16%), these differences were not statistically significant. There was a two-fold increase in hydroxymethylation level in never smokers, compared with smokers. CONCLUSIONS: Our findings suggest that smoking leads to global reductions in both methylation and hydroxymethylation levels in oral epithelial cells in a manner influenced by the intensity and length of exposure to tobacco smoke.

A pilot study on the expression of microRNAs resident on chromosome 21 in laser microdissected FFPE prostate adenocarcinoma samples.

The tremendous research effort of the last decades added a new, epigenetic layer of complexity to the already complex image of prostate cancer pathogenesis. Here we use quantitative real-time polymerase chain reaction (qRT-PCR) to investigate the expression of the microRNAs resident on chromosome 21 (miR-ch21) in laser capture microdissected (LCM) tissues from formalin-fixed paraffin-embedded (FFPE) archived, prostate adenocarcinoma samples. We show a strong, specific down-regulation of miR-ch21 in tumoral epithelia and stromae as compared to normal counterparts, results at odd with the current paradigm on the involvement of these microRNAs in prostate oncogenesis. By comparing this result with the expression of two well-known pluripotency associated microRNA, hsa-miR-372 and miR-373, we suggest that miR-ch21 down-regulation might be the result of specific silencing of miR genes mapped to chromosome 21. Further studies, of larger sample size are needed to confirm our preliminary data.

Safety of vascular endothelial and hepatocyte growth factor gene therapy in patients with critical limb ischemia.

UNLABELLED: The present clinical trial analyzed the safety of gene therapy using plasmidial constructs expressing vascular endothelial and hepatocyte growth factors in patients with critical limb ischemia. The study included 43 patients: 29 in the treatment group and 14 allocated to the placebo group. The primary end points were the rate of major amputations and the clinical safety of the method. Secondary end points were improvement of pain at rest, walking ability and the ankle/brachial pressure index. The overall major amputation rate was 31.04% in the treatment group and 71.42% in the placebo group (p = 0.029). Pain at rest was improved in 65% of patients in the gene therapy group and in 7% in the placebo group (p = 0.0006). There were no significant adverse effects in the treatment group. CONCLUSION: Gene therapy with vascular endothelial and hepatocyte growth factors is therapeutically safe and reduces the rate of major amputations and relieves pain at rest in patients with critical limb ischemia.