Remodeling of the stromal extracellular matrix and elevated expression of specific

Remodeling of the stromal extracellular matrix and elevated expression of specific proto-oncogenes within the adjacent epithelium represent cardinal features of breast cancer, yet how these events become integrated is not fully understood. a novel quantitative image analysis tool with 3-D organotypic cultures, demonstrate that stromal changes associated with breast cancer can control proto-oncogene function. Most contemporary experimental and clinical breast cancer research studies have focused on the gain or loss of function of specific oncogenes or tumor suppressor genes, respectively, as primary transforming events within the mammary epithelium.1 Equally compelling evidence, however, demonstrates that the biochemical and -physical nature of the stromal BIX 02189 extracellular matrix (ECM) microenvironment surrounding the epithelium also contributes to breast homeostasis and tumorigenesis.2,3,4 For example, when cultured within a laminin-enriched compliant ECM, normal breast epithelial cells produce an endogenous basement membrane (BM), which directs the formation of polarized, spherical, multicellular acini, each of which contains a single centrally-located lumen.5 On the other hand, blocking exuberrant 1 integrin signaling between malignant human breast cancer cells and their BM microenvironment induces phenotypic reversion and functional normalization of mammary acini.6 Mouse monoclonal to CD48.COB48 reacts with blast-1, a 45 kDa GPI linked cell surface molecule. CD48 is expressed on peripheral blood lymphocytes, monocytes, or macrophages, but not on granulocytes and platelets nor on non-hematopoietic cells. CD48 binds to CD2 and plays a role as an accessory molecule in g/d T cell recognition and a/b T cell antigen recognition In addition, changes within the mammary ECM, such as those associated with postlactational involution, lead to altered signals to normal and malignant epithelium, failing to support duct development in the former while promoting metastasis BIX 02189 in the latter.7 Increases in the biophysical stiffness of the normal mammary stromal ECM have also been shown to result in malignant behavior.3 Collectively, these and other studies reinforce the notion BIX 02189 that tissue phenotype, specified by the ECM, can exert a dominant effect over gene expression in adjacent epithelial cells. Three-dimensional (3-D) laminin-based cultures have allowed investigators to elucidate the effects of specific oncogenes on mammary epithelial tissue form and function in an appropriate coordinates. Here, s(is the index for a slice number (corresponding to a specific confocal image slice at a particular discrete points, typically in the order of 200. The active contour was constrained to be a cylinder by setting s(Ppositions of the active surface S to volumetric data V, the equatorial section was manually traced in an approximate fashion. The equatorial slice was the only slice manually traced, which was subsequently optimized using the procedure described below. Briefly, all of BIX 02189 the remaining slices above and below the equatorial plane were sequentially and independently fit using the previous slice fit as the starting point. Active contour optimization was restricted in the axis as previously described because of limited resolution in the dimension.20 For any particular section, the contour was optimized using an iterative procedure to minimize the energy function, = = ?was used to set the relative importance of low-level image features. The dx, dy maps referred to below represent BIX 02189 this gradient. High-level shape properties were defined by equal spacing of surface points in each section = (was minimized by calculating a vector for each point directed toward the nearest point on the bisector of the two neighboring points.21 This approach resulted in = 0 when all points were equally spaced. By decreasing the value of in was increased, resulting in smoother fits. A sequential technique for fitting the surface to the acinar surface was used. Initially, the entire surface was fitted using a larger Gaussian blur of the immunostaining intensity (typically = 6 pixels), which had the effect of smoothing over extraneous debris, and producing a good.