Expression of oncofetal RNA-binding protein CRD-BP/IMP1 predicts clinical outcome in colon cancer

Embryonic expression of Drosophila IMP in the developing CNS and PNS

Drosophila IMP (dIMP) is related to the vertebrate RNA-binding proteins IMP1-3, ZBP1, Vg1RBP and CRD-BP, which are involved in RNA regulatory processes such as translational repression, localization and stabilization. The proteins are expressed in many fetal tissues, including the developing nervous system, and IMP up-regulation in solid tumors correlates with a high metastatic potential and poor prognosis. In this study, we used immunohistochemistry and live-imaging of an endogenous promoter-driven GFP-dIMP fusion protein to reveal the expression pattern of dIMP protein throughout embryogenesis. In the cellular blastoderm, immunoreactivity was seen in the entire cell-layer, where it was localized apically to the nucleus, and in the pole cells. Later, the GFP-dIMP fusion protein appeared in the developing central nervous system, both in the brain and in the ventral nerve cord. In the peripheral nervous system, immunoreactivity was detected in both neurons and accessory cells of chordotonal and external sensory organs.

Mechanisms and cellular roles of local protein synthesis in mammalian cells

After the export from the nucleus it turns out that all mRNAs are not treated equally. Not only is mRNA subject to translation, but also through RNA-binding proteins and other trans-acting factors, eukaryotic cells interpret codes for spatial sorting within the mRNA sequence. These codes instruct the cytoskeleton and translation apparatus to make decisions about where to transport and when to translate the intended protein product. Signaling pathways decode extra-cellular cues and can modify transport and translation factors in the appropriate cytoplasmic space to achieve translation locally. Identifying regulatory sites on transport factors as well as novel physiological functions for well-known translation factors has provided significant advances in how spatially controlled translation impacts cell function.

Comparative proteome analysis of human epithelial ovarian cancer

Background

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.

Results

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.

Conclusion

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.