Communication of prostate cancer cells with bone cells via extracellular vesicle RNA; a potential mechanism of metastasis.

The role of extracellular vesicles (EVs) as vehicles for cell-to-cell communication between a tumour and its environment is a relatively new concept. The hypothesis that EVs may be critical in co-opting tissues by tumours to generate distant metastatic niches is particularly pertinent to prostate cancer (PCa), where metastatic-tropism to bone predominates over other tissue types. The potential role of EVs as a means of communication between PCa cells and cells of the bone stroma such as osteoblasts, is yet to be fully explored. In this study, we demonstrate that PCa cell EVs both enhance osteoblast viability and produce a significantly more supportive growth environment for PCa cells when grown in co-culture with EV-treated osteoblasts (p < 0.005). Characterisation of the RNA cargo of EVs produced by the bone-metastatic PCa cell line PC3, highlights the EV-RNA cargo is significantly enriched in genes relating to cell surface signalling, cell-cell interaction, and protein translation (p < 0.01). Using novel techniques to track RNA, we demonstrate the delivery of a set of PCa-RNAs to osteoblast via PCa-EVs and show the effect on osteoblast endogenous transcript abundance. Taken together, by using proof-of-concept studies we demonstrate for the first time the contribution of the RNA element of the PCa EV cargo, providing evidence to support PCa EV communication via RNA molecules as a potential novel route to mediate bone metastasis. We propose targeting PCa EVs could offer a potentially important preventative therapy for men at risk of metastatic PCa.

Is it possible docking and scoring new ligands with few experimental data? Preliminary results on estrogen receptor as a case study.

Estrogens are steroid hormones playing critical roles in several physiological processes, which bind the estrogen receptors ERalpha and ERbeta. Aim of this work is to analyze, by different docking experiments, the behavior of a set of compounds, mimicking estrogens activity, in order to understand the relationship between ERalpha and such new ligands. Main goal is to verify, using a widely tested scoring software procedure applied on a set of 10 compounds, the possibility to produce new lead candidate molecules in lack of, or with few experimental data. Our preliminary results reveal the significance of HINT software as a scoring function in docking methodology and specifically, as a mean for assessing the consistency of docking solutions.

A novel PTPN11 mutation in LEOPARD syndrome.

PTPN11 gene mutations are common to both patients with Noonan (NS) and LEOPARD syndrome (LS). So far only two recurrent mutations have been identified in LS patients by different research groups, i.e., Tyr279Cys and Thr468Met. In this work we describe the third PTPN11 mutation that has been found in a single LS patient. The mutation (c.1517A>C) substitutes a proline for a glutamine at amino acid 506 (Gln506Pro) in the phosphatase domain (PTP) of the PTPN11 peptide SHP2. This region is a mutation hotspot. Changes at amino acids 501 to 504 cause NS. Gln506Pro is predicted, by modeling analysis, to seriously disrupt the normal contacts between the regulating N-SH2 and the active PTP domains, leading to hyperactivity of the phosphatase. This report demonstrates that rarer mutations other than Tyr279Cys and Thr468Met can be found in LS patients and the need of screening the whole gene in those negative for the commonest mutations.

A novel system to quantitate nuclear-cytoplasmic flux in vivo: kinetics of signal-dependent nuclear protein export.

Compared to signal-mediated nuclear protein import, there is a paucity of kinetic information with respect to signal-mediated nuclear protein export. In this study we use the novel approach of simultaneous nuclear/cytoplasmic microinjection of beta-galactosidase fusion proteins to examine nuclear import and export conferred by the leucine-rich nuclear export signals (NESs) of HIV-1 Rev and the cAMP-dependent protein kinase inhibitor PKI, comparing results to those for either a fusion protein containing a conventional nuclear localization sequence (NLS) or beta-galactosidase itself. We also analyze nuclear transport of the proteins in vitro. Both the Rev and PKI NESs confer nuclear export, in contrast to the NLS or mutated inactive NESs; steady state was achieved within 40-45min although not all NES-containing protein hadbeen exported from the nucleus at this time point. Interestingly, the Rev and PKI NES fusion proteins, in stark contrast to beta-galactosidase itself, exhibited nuclear entry in vivo and nuclear accumulation to levels about twofold those in the cytoplasm in vitro. We conclude that NESs, rather than exclusively conferring nuclear export, may be able to mediate shuttling between the nuclear and cytoplasmic compartments.