Silencing of CCDC6 reduces the expression of 14-3-3σ in colorectal carcinoma cells.

Coiled-coil domain containing 6 (CCDC6) is frequently rearranged in papillary thyroid carcinomas participating in the formation of RET/PTC1 oncogene. Other rearrangements involving CCDC6 have also been identified demonstrating its high susceptibility to chromosomal recombination. Malignancies bearing CCDC6 fusion genes are developed in a background where CCDC6 is either lost or deregulated. Our aim was to identify interacting proteins which are affected by the silencing of CCDC6 expression and could possibly link CCDC6 deregulation to cancer causality. Therefore, a proteomic approach was adopted using a human cancer cell-line (HCT116) where CCDC6 expression was silenced by lentiviral shRNA constructs. 14-3-3σ down-regulation in the absence of CCDC6 was revealed and verified by western blot analysis and confocal microscopy. Only the levels and not the topology of CCDC6 were altered. The down-regulation of 14-3-3σ in the absence of CCDC6 demonstrated their direct association and supports the notion that CCDC6 contributes to cancer development, possibly through malignant pathways involving 14-3-3σ.

The proteome of normal human chorionic villus sampling cells.

Chorionic villi samples are widely used for prenatal diagnosis of various fetal disorders. Although, our knowledge regarding the molecular level of these disorders is extensive, little is known about the implicated proteins. In the present study, two dimensional electrophoresis (2-DE) followed by mass spectrometry (MS) was applied to reveal the proteomic profile of the CV cells. This proteomic technique was previously used successfully in the cases of amniotic fluid, follicular fluid and maternal blood, but has not yet been applied to CV. Therefore, 2-DE was combined with matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF/MS) to characterise the proteome of normal CV cultured cells. Two hundred eighty two-individual gene products were identified including cytoplasmic and nuclear proteins. Although the majority of the proteins were enzymes, structural, signalling and carrier molecules were also isolated. 2D protein map elucidates 282 protein molecules expressed in the CV cells that can be used as a reference for future comparison to various pathological conditions.

A two-dimensional proteomic profile of Tetrahymena thermophila whole cell lysate.

Tetrahymena thermophila is a unicellular eukaryotic model organism used for a variety of biochemical, molecular and biological studies. According to its macronucleus genome sequence, it is expected to contain more than 27,000 protein-coding genes, although only a small proportion of them have information published specifically about them. Here, we present a reference map for whole cell lysate of T. thermophila obtained using two-dimensional gel electrophoresis (2-DE) combined with mass spectrometry. Although (2-DE) is one of the most efficient techniques for resolving complex protein mixtures and revealing the relative high-abundance proteins, it has not yet been applied generally to ciliates. In order to obtain qualitative protein samples for analysis, an appropriate homogenization method is required. Optimization of the homogenization method led to the analysis of nearly 4500 protein spots, the final identification of 375 different proteins using Mascot software and an additional 258 gene products using a newly developed web service, called Peptide Finder, resulting in a total of 631 different gene products that are considered to constitute the proteomic profile of the whole cell lysate of T. thermophila.