Comparative proteome analysis of human epithelial ovarian cancer

<p>Abstract</p> <p>Background</p> <p>Epithelial ovarian cancer is a devastating disease associated with low survival prognosis mainly because of the lack of early detection markers and the asymptomatic nature of the cancer until late stage. Using two complementary proteomics approaches, a differential protein expression profile was carried out between low and highly transformed epithelial ovarian cancer cell lines which realistically mimic the phenotypic changes observed during evolution of a tumour metastasis. This investigation was aimed at a better understanding of the molecular mechanisms underlying differentiation, proliferation and neoplastic progression of ovarian cancer.</p> <p>Results</p> <p>The quantitative profiling of epithelial ovarian cancer model cell lines TOV-81D and TOV-112D generated using iTRAQ analysis and two-dimensional electrophoresis coupled to liquid chromatography tandem mass spectrometry revealed some proteins with altered expression levels. Several of these proteins have been the object of interest in cancer research but others were unrecognized as differentially expressed in a context of ovarian cancer. Among these, series of proteins involved in transcriptional activity, cellular metabolism, cell adhesion or motility and cytoskeleton organization were identified, suggesting their possible role in the emergence of oncogenic pathways leading to aggressive cellular behavior.</p> <p>Conclusion</p> <p>The differential protein expression profile generated by the two proteomics approaches combined to complementary characterizations studies will open the way to more exhaustive and systematic representation of the disease and will provide valuable information that may be helpful to uncover the molecular mechanisms related to epithelial ovarian cancer.</p

Western blot validation of selected proteins identified by iTRAQ and/or 2DE analysis

<p><b>Copyright information:</b></p><p>Taken from "Comparative proteome analysis of human epithelial ovarian cancer"</p><p>http://www.proteomesci.com/content/5/1/16</p><p>Proteome Science 2007;5():16-16.</p><p>Published online 24 Sep 2007</p><p>PMCID:PMC2072939.</p><p></p> Equal amounts, 25 μg, of protein extracts from TOV-112D and TOV-81D cell lines were loaded onto a 12 % SDS-PAGE and processed for Western blotting with the indicated antibodies. Protein expression differences were quantified using a Chemilmager 4000 imaging system and AlphaEase software 3.3 (Alpha Innotech Corporation). The data are expressed as relative integrated density value (IDV). Each point represents the mean +/- SE from three independent experiments. Data were analysed by Student's unpaired test. Representative blots for each analysis are depicted

Poly(ADP-ribose) glycohydrolase is a component of the FMRP-associated messenger ribonucleoparticles

PARG [poly(ADP-ribose) glycohydrolase] is the only known enzyme that catalyses the hydrolysis of poly(ADP-ribose), a branched polymer that is synthesized by the poly(ADP-ribose) polymerase family of enzymes. Poly(ADP-ribosyl)ation is a transient post-translational modification that alters the functions of the acceptor proteins. It has mostly been studied in the context of DNA-damage signalling or DNA transaction events, such as replication and transcription reactions. Growing evidence now suggests that poly(ADP-ribosyl)ation could have a much broader impact on cellular functions. To elucidate the roles that could be played by PARG, we performed a proteomic identification of PARG-interacting proteins by mass spectrometric analysis of PARG pulled-down proteins. In the present paper, we report that PARG is resident in FMRP (Fragile-X mental retardation protein)-associated messenger ribonucleoparticles complexes. The localization of PARG in these complexes, which are components of the translation machinery, was confirmed by sedimentation and microscopy analysis. A functional link between poly(ADP-ribosyl)ation modulation and FMRP-associated ribonucleoparticle complexes are discussed in a context of translational regulation

Zoomed sections from TOV-112D and TOV-81D gels demonstrating differential expression of proteins listed in Table 2

<p><b>Copyright information:</b></p><p>Taken from "Comparative proteome analysis of human epithelial ovarian cancer"</p><p>http://www.proteomesci.com/content/5/1/16</p><p>Proteome Science 2007;5():16-16.</p><p>Published online 24 Sep 2007</p><p>PMCID:PMC2072939.</p><p></p> (A) Selected TOV-112D spots with undetectable TOV-81D matching spots. (B) Selected TOV-81D spots with undetectable TOV-112D matching spots. (C) Selected spots differentially expressed with a minimum deregulation ratio of 2.0