Asthma now affects one child in seven in the United Kingdom. Most cases (95%) of childhood asthma are associated with atopy, the immunoglobulin E (IgE)-mediated familial syndrome of allergic asthma, eczema and rhinitis. Segregation analysis has consistently suggested the presence of major genes influencing atopy and IgE levels, with the expectation that these genes may be identified by positional cloning or the examination of candidate genes. Here we report the results of a genome-wide search for linkage to one qualitative and four quantitative traits associated with allergic (atopic) asthma. We have identified six potential linkages (P<0.001), five of which are to quantitative traits. Monte Carlo simulations show that 1.6 false-positive linkages at this level of significance would be expected from the data. One linkage, to chromosome 11q13, has been established previously. Three of the new loci show evidence of linkage to a second panel of families, in which maternal effects and pleiotropy of linked phenotypes are seen. The results demonstrate the extent and the complexity of the genetic predisposition to asthma.

Bone is a common site of cancer metastasis. Breast, prostate, and lung cancers show a predilection to metastasize to bone. Recently, we reported that the chemokine interleukin 8 (IL-8) stimulates both human osteoclast formation and bone resorption. IL-8 mRNA expression was surveyed in a panel of human breast cancer lines MDA-MET, MDA-MB-231, MDA-MB-435, MCF-7, T47D, and ZR-75, and the human lung adenocarcinoma cell line A549. IL-8 mRNA expression was higher in cell lines with higher osteolytic potential in vivo. Human osteoclast formation was increased by MDA-MET or A549 cell-conditioned medium, but not by MDA-MB-231. Pharmacologic doses of receptor activator of nuclear factor-KB (RANK)-Fc or osteoprotogerin had no effect on the pro-osteoclastogenic activity of the conditioned medium; however, osteoclast formation stimulated by conditioned medium was inhibited 60% by an IL-8-specific neutralizing antibody. The data support a model in which tumor cells cause osteolytic bone destruction independently of the RANK ligand (RANKL) pathway. Tumorproduced IL-8 is a major contributor to this process. The role of secreted IL-8 isoforms was examined by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry, which detected distinct IL-8 isoforms secreted by MDA-MET and MDA-231 cells, suggesting different pro-osteoclastogenic activities of the two IL-8-derived peptides. These data indicate that (a) osteoclast formation induced by MDA-MET breast cancer cells and A549 adenocarcinoma cells is primarily mediated by IL-8, (b) cell-specific isoforms of IL-8 with distinct osteoclastogenic activities are produced by tumor cells, and (c) tumor cells that support osteoclast formation independent of RANKL secrete other pro-osteoclastogenic factors in addition to IL-8. (Cancer Res 2005; 65(23): 11001-9)

Although the control of bone metastasis has been the focus of intensive investigation, relatively little is known about the molecular mechanisms that regulate or predict the process, even though widespread skeletal dissemination is an important step in the progression of many tumors. As a result, understanding the complex interactions contributing to the metastatic behavior of tumor cells is essential for the development of effective therapies. Using a state-of-the-art combination of gene expression profiling and functional annotation of human tumor cells, and surfaceenhanced laser desorption/ionization time-of-flight mass spectrometry of patient serum, we have shown that changes in tumor biochemistry correlate with disease progression and help to define the aggressive tumor phenotype. Based on these approaches, it is apparent that the metastatic phenotype of tumor cells is extremely complex. The identification of the phenotype of tumor cells has benefited greatly from the application of gene expression profiling (microarray analysis). This technology has been used by many investigators to identify changes in gene expression and cytokine and growth factor elaboration (such as interleukin 8). The tumor phenotype(s) presumably also include changes in the cell surface carbohydrate profile (via altered glycosyltransferase expression) and heparan sulfate expression (via increased heparanase activity), to name but a few. These specific alterations in gene expression, identified by functional annotation of accumulated microarray data, have been validated using a variety of approaches. Collectively, the data described here suggest that each of these activities is associated with distinct aspects of the aggressive tumor cell phenotype. Collectively, the data suggest that multiple factors constitute the complex phenotype of metastatic tumor cells. In particular, the differences observed in gene expression profiles and serum protein biomarkers play a critical role in defining the mechanisms responsible for bone-specific colonization and growth of tumors in bone. Future studies will identify the mechanisms that participate in the formation of secondary tumor growths of cancers in bone.