Quantitative analysis of three-dimensional human mammary epithelial tissue architecture reveals a role for tenascin-C in regulating c-met function.
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. To address this question, we focused on tenascin-C (TN-C), a stromal extracellular matrix glycoprotein whose expression increases with disease severity. Initially, nonmalignant human mammary epithelial cells (MCF-10A) were cultured within a reconstituted basement membrane (BM) where they formed three-dimensional (3-D) polarized, growth-attenuated, multicellular acini, enveloped by a continuous endogenous BM. In the presence of TN-C, however, acini failed to generate a normal BM, and net epithelial cell proliferation increased. To quantify how TN-C alters 3-D tissue architecture and function, we developed a computational image analysis algorithm, which showed that although TN-C disrupted acinar surface structure, it had no effect on their volume. Thus, TN-C promoted epithelial cell proliferation leading to luminal filling, a process that we hypothesized involved c-met, a proto-oncogene amplified in breast tumors that promotes intraluminal filling. Indeed, TN-C increased epithelial c-met expression and promoted luminal filling, whereas blockade of c-met function reversed this phenotype, resulting in normal BM deposition, proper lumen formation, and decreased cell proliferation. Collectively, these studies, combining a novel quantitative image analysis tool with 3-D organotypic cultures, demonstrate that stromal changes associated with breast cancer can control proto-oncogene function.
Taraseviciute
Agne
A
Department of Cell Biology, Stem Cells, and Development, University of Colorado Denver, Aurora, Colorado, USA.
Vincent
Benjamin T
BT
Schedin
Pepper
P
Jones
Peter Lloyd
PL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D044584:Carcinoma, Ductal / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D048429:Cell Size; D002478:Cells, Cultured; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D021621:Imaging, Three-Dimensional; D042361:Mammary Glands, Human / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D008875:Middle Aged; D008954:Models, Biological; D000090063:Proto-Oncogene Mas; D019859:Proto-Oncogene Proteins c-met / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D019063:Tenascin / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D055815:Young Adult
C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D019063:Tenascin; D019859:Proto-Oncogene Proteins c-met