Isaac S Kohane from Children's Hospital Boston and Harvard University, US, led a team of researchers who performed a comprehensive comparison of genes expressed in early developmental stages of various human tissues and those expressed in different cancers affecting these tissues. He says, "Our study reveals potentially clinically relevant differences in the gene expression of different cancer types and represents a reference framework for interpretation of smaller-scale functional studies".

One of the three described groups of cancers has an early developmental phenotype and expresses genes that are characteristic of stem cells. From a developmental perspective, this group presents very homogeneously. A second, more heterogeneous group tends to be more similar to late development and is characterized by an inflammatory signature. The third is a small group of cancers that present as a transition phenotype between these two extremes and displays both characteristics.

According to Kohane, "This segregation of tumors into three groups with distinct expression patterns is surprising. Clearly, the developmental trajectory provides a meaningful background for capturing large-scale differences in gene expression across diverse conditions".

The study's results will lead towards a better understanding of human disease from a 'macrobiological' approach to analyzing high-throughput data. According to the authors, "Shifting our focus from single sets of genes or processes to the biology of aggregates on the order of the entire transcriptome is likely to be useful in establishing highly robust molecular correlations between seemingly unrelated disease phenotypes".

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Members of the Washburn lab have been developing synthetic alternatives to demineralized bone matrix. In the work being presented today, they created a flexible hydrogel using biologically active and degradable hyaluronic acid. Hydrogels, which are considered to be the state-of-the-art in tissue design, are made from polymers that swell in water to form a gel-like material. They interact with growth factors much like demineralized bone matrix does, providing scaffolding for bone cells to proliferate and form new tissue. The researchers found that, in vitro, the hydrogels promoted cell proliferation, differentiation and mineralization of pre-osteoblast cells.

Further research by the group has created a hybrid hydrogel that incorporates a nanogel structure. This new hydrogel promotes the differentiation of cells, much like the hyaluronic acid gel while also releasing nanogels in a controlled and targeted manner. The researchers hope that this structure could be used to partner tissue engineering with gene therapy.

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