A comprehensive in silico expression analysis of RNA binding proteins in normal and tumor tissue: Identification of potential players in tumor formation.

RNA binding proteins (RBPs) are involved in several post-transcriptional stages of gene expression and dictate the quality and quantity of the cellular proteome. When aberrantly expressed, they can lead to disease states as well as cancers. A basic requirement to understand their role in normal tissue development and cancer is the build of comprehensive gene expression maps. In this direction, we generated a list with 383 human RBPs based on the NCBI and EMSEMBL databases. SAGE and MPSS were then used to verify their levels of expression in normal tissues while SAGE and microarray datasets were used to perform comparisons between normal and tumor tissues. As main outcomes of our studies, we identified clusters of co-expressed or co-regulated genes that could act together in the development and maintenance of specific tissues; we also obtained a high confidence list of RBPs aberrantly expressed in several tumor types. This later list contains potential candidates to be explored as diagnostic and prognostic markers as well as putative targets for cancer therapy approaches.

Bone formation during forelimb regeneration: a microtomography (microCT) analysis.

In our study of bone regeneration in the forelimbs of mature newts (Notophthalmus viridescens), we used noninvasive X-ray microtomography (microCT) to image regenerating limbs from 37 to 85 days and matching (contralateral) controls. We compared the patterns of regenerated and existing (nonregenerated) bone, investigating in particular the onset of mineralization of specific bones, the level of mineral present, and the lengths of the different bones. Overall, we find that the missing limb skeletal elements are restored in a proximal-to-distal direction, which reiterates the developmental patterning program. However, in contrast to this proximal-distal sequence, the portion of the humerus distal to the amputation site fails to ossify in synchrony with the regenerating radius and ulna. This finding suggests that the replacement of cartilage with mineralized bone close to the amputation site is delayed with respect to other regenerating skeletal elements.