Elena Marchesi

Sex hormone receptor levels in laryngeal carcinoma: a comparison between protein and RNA evaluations

The larynx is a secondary sex organ, and the hormone dependence of laryngeal carcinomas is considered an interesting matter of speculation. However, while tumors of other secondary sex organs, including the prostate, breast, and endometrium, have been recognized as hormone-dependent cancers, the laryngeal carcinomas are still subject to controversy. In this study, samples from 15 laryngeal carcinomas obtained at the time of surgery were assayed for specific estrogen alpha, progesterone, and androgen receptor expression, both at mRNA and protein levels. Detectable levels of specific estrogen and progesterone receptors, 53.3 and 73.3%, respectively, were found in the tumors. This positive detection by immunohistochemical analysis was higher in tumors than in normal mucosa adjacent to the tumor areas and was correlated with the absence of metastatic lymph nodes. No androgen receptor protein was detected in any sample analyzed, even if quantitative RT-PCR revealed high mRNA levels specific for this receptor. A strict correspondence between protein and mRNA hormone receptor levels was not found. This is in agreement with the transcriptional and protein synthesis mechanisms, and it is also compatible with the complex larynx tumorigenesis.

Persistent Dystrophin Protein Restoration 90 Days after a Course of Intraperitoneally Administered Naked 2′OMePS AON and ZM2 NP-AON Complexes in mdx Mice

In Duchenne muscular dystrophy, the exon-skipping approach has obtained proof of concept in animal models, myogenic cell cultures, and following local and systemic administration in Duchenne patients. Indeed, we have previously demonstrated that low doses (7.5 mg/Kg/week) of 2′-O-methyl-phosphorothioate antisense oligoribonucleotides (AONs) adsorbed onto ZM2 nanoparticles provoke widespread dystrophin restoration 7 days after intraperitoneal treatment in mdx mice. In this study, we went on to test whether this dystrophin restoration was still measurable 90 days from the end of the same treatment. Interestingly, we found that both western blot and immunohistochemical analysis (up to 7% positive fibres) were still able to detect dystrophin protein in the skeletal muscles of ZM2-AON-treated mice at this time, and the level of exon-23 skipping could still be assessed by RT real-time PCR (up to 10% of skipping percentage). In contrast, the protein was undetectable by western blot analysis in the skeletal muscles of mdx mice treated with an identical dose of naked AON, and the percentage of dystrophin-positive fibres and exon-23 skipping were reminiscent of those of untreated mdx mice. Our data therefore demonstrate the long-term residual efficacy of this systemic low-dose treatment and confirm the protective effect nanoparticles exert on AON molecules.

Synthesis, characterization of strontium-bile acid salts and their bioactivity vs. the anti-osteoporosis drug strontium ranelate

The strontium salts Sr(cholate)2, (Compound 1), Sr(dehydrocholate)2, (Compound 2) and Sr3(3-dehydrocholanoyliden-L-tartrate)2, (Compound 3) have been prepared and characterized. The potential anti-osteoporotic activity of these compounds was tested on human primary osteoblasts (hOBs) and human primary osteoclasts (hOCs) in comparison with the bioactivity of strontium ranelate, previously registered as drug in the treatment of post-menopausal osteoporosis. Our results led to the hypothesis that the tested compounds, particularly Compound 2, may have requirements for modulating skeletal tissue regeneration or at least down regulating the loss of bone mass. In fact, all tested compounds have been shown to induce maturation in human primary osteoblasts (hOBs) and apoptosis of human primary osteoclasts (hOCs) at the same time.

Synthesis and in vitro cytotoxicity of deoxyadenosine–bile acid conjugates linked with 1,2,3-triazole

We report herein the synthesis and biological evaluation of novel deoxynucleoside–bile acid conjugates linked through a 1,2,3-triazole ring. The conjugates were synthesized via Cu(I) mediated 1,3-dipolar cycloaddition reaction (‘click’ chemistry) of 3-azidobile acid derivatives and terminal alkyne moieties linked to the C-8 position of deoxyadenosine. All novel molecules were evaluated in vitro for their anti-proliferative activity against four human cell lines (i.e., leukemic T Jurkat and K562; colon carcinoma HCT116; and ovarian cancer A2780) and their cytotoxicity toward human fibroblast cells. Several conjugates exhibited strong anti-proliferative activity against human leukemia T cells. The best cytotoxicity was observed for HdA-CDC on both leukemia cell lines with IC50 up to 8.51 μM. The apoptotic activity of several conjugates was also established.

Rational Design of Nucleoside–Bile Acid Conjugates Incorporating a Triazole Moiety for Anticancer Evaluation and SAR Exploration

Herein we report a study on the synthesis and biological evaluation of a library of nucleoside-bile acid conjugates prepared by combining 2′-deoxyadenosine, 2′-deoxyguanosine, 2′-deoxyuridine as well as adenosine and guanosine derivatives with cheno-, urso-, nor-cheno-, nor-urso- and taurourso-desoxycholic acid derivatives by means of the click reaction. The new nucleoside-bile acid conjugates incorporating a triazole moiety were tested in vitro against leukemic K562 and HCT116 colon carcinoma, as well as on normal fibroblast cells. Six compounds displayed interesting anti-proliferative activity against the selected cancer lines and no cytotoxic effects against normal fibroblasts. A possible structure activity relationship was also investigated.

UDP‐GlcNAc Analogues as Inhibitors of O‐GlcNAc Transferase (OGT): Spectroscopic, Computational, and Biological Studies

A series of glycomimetics of UDP-GlcNAc, in which the β-phosphate has been replaced by either an alkyl chain or a triazolyl ring and the sugar moiety has been replaced by a pyrrolidine ring, has been synthesized by the application of different click-chemistry procedures. Their affinities for human O-GlcNAc transferase (hOGT) have been evaluated and studied both spectroscopically and computationally. The binding epitopes of the best ligands have been determined in solution by means of saturation transfer difference (STD) NMR spectroscopy. Experimental, spectroscopic, and computational results are in agreement, pointing out the essential role of the binding of β-phosphate. We have found that the loss of interactions from the β-phosphate can be counterbalanced by the presence of hydrophobic groups at a pyrroline ring acting as a surrogate of the carbohydrate unit. Two of the prepared glycomimetics show inhibition at a micromolar level.

Conjugated Oligonucleotides for Biochemical Applications

In the last 30 years oligonucleotides i.e., relatively short polymers (usually 12-24 units long) based on DNA structure, have found a widespread use in biochemical studies and as biochemical probes and chemotherapeutic agents for the downregulation of genetic expression or for exon skipping. Here we present a short review of studies from our laboratories on the synthesis and applications of different kind of conjugates to address some of these techniques. Preparation of conjugates with small alkyl groups, intercalators, fluorescent oligothiophenes, and lipophilic bile-acids will be discussed.