Osteosarcoma progression is associated with increased nuclear levels and transcriptional activity of activated ß-Catenin.

Osteosarcoma (OS) is an aggressive primary bone malignancy that has peak incidence in children and young adults <25 years of age. Despite current multimodal treatments, no significant change in patient outcome has been observed in two decades. Presently, there is a lack of established, reliable baseline prognostic markers for aggressive OS, other than extent and site of disease involvement. The canonical Wnt/ß-catenin pathway controls multiple cellular processes, and is known to be a critical pathway in OS progression. This pathway regulates cellular levels of ß-catenin, which is a significant player in the oncogenesis and progression of many cancers. We investigated the relationship between ß-catenin, more specifically, the transcriptionally active form of ß-catenin, Activated ß-Catenin (ABC), and OS progression. Using an in vitro model, we observed that cellular/nuclear ABC levels, but not cellular/nuclear ß-catenin levels, increase with the degree of aggressiveness in OS. Our results demonstrate a strong association between nuclear-ABC levels and aggressive OS in vitro. Furthermore, we observed significant correlation between positive nuclear-ABC and patient age and tumor stage. Our results support the potential use of ABC as a predictive marker for risk stratification in OS.

Chromatin Immunoprecipitation (ChIP) Protocols for the Cancer and Developmental Biology Laboratory.

Chromatin immunoprecipitation assays permit the isolation and subsequent identification of genomic DNA (gDNA) fragments bound directly or indirectly to proteins of interest, including transcription factors, co-factors, or chromatin remodeling proteins. These isolated DNA fragments may include gene regulatory regions from enhancers, super-enhancers, promoters, and/or insulators. Cells of interest can be obtained from embryonic tissues at various developmental time points or cancer cells from patients or derived from model systems, including patient-derived xenotransplants and primary cancer stem cells and cell lines. ChIP variants include ChIP-reChIP to identify targets bound to different transcription factors or members of protein complexes or, alternatively, to characterize the histone modifications accompanying occupation of specific regulatory regions by the protein of interest, such as a transcription factor. Subsequent analysis of ChIP experiments includes standard PCR, quantitative PCR (qPCR), and ChIPseq.

Hirschsprung's disease: clinical dysmorphology, genes, micro-RNAs, and future perspectives.

On the occasion of the 100th anniversary of Dr. Harald Hirschsprung's death, there is a worldwide significant research effort toward identifying and understanding the role of genes and biochemical pathways involved in the pathogenesis as well as the use of new therapies for the disease harboring his name (Hirschsprung disease, HSCR). HSCR (aganglionic megacolon) is a frequent diagnostic and clinical challenge in perinatology and pediatric surgery, and a major cause of neonatal intestinal obstruction. HSCR is characterized by the absence of ganglia of the enteric nervous system, mostly in the distal gastrointestinal tract. This review focuses on current understanding of genes and pathways associated with HSCR and summarizes recent knowledge related to micro RNAs (miRNAs) and HSCR pathogenesis. While commonly sporadic, Mendelian patterns of inheritance have been described in syndromic cases with HSCR. Although only half of the patients with HSCR have mutations in specific genes related to early embryonic development, recent pathway-based analysis suggests that gene modules with common functions may be associated with HSCR in different populations. This comprehensive profile of functional gene modules may serve as a useful resource for future developmental, biochemical, and genetic studies providing insights into the complex nature of HSCR.