Calcium phosphate deposits in domes of human pancreatic adenocarcinoma (Capan‐1) cell cultures

Abstract

Human pancreatic cells of the Capan-1 line form domes in culture during the stationary growth stage. The domes are thought to be a result of the transport of water and electrolytes by the Capan-1 cells. In older Capan-1 cultures, the epithelial sheets formed thickenings from several layers of cells of which the outermost ones were joined by tight type junctions. In the intracellular space, deposits of insoluble calcium salts were observed. Culture of Capan-1 cells in the presence of fibroblasts prolonged survival of the cultures with intact domes for more than 80 days. The Capan-1 cells proliferated forming multilayers and closed cavities which we called super-domes. X-ray spectrometry and electron diffraction analysis showed that the abundant deposits inside these cavities consisted of calcium phosphate in an apatite structure. The number of these deposits increased with time in culture, and they appeared to be formed at the sites of contact with an extracellular matrix consisting of cell debris. Deposits were not observed within the culture medium. Cells from domes were stained cytochemically for ATPases and alkaline phosphatases and examined by light and electron microscopy. The Capan-1 cells surrounding the domes were differentiated, polarized cells containing placental type alkaline phosphatases on their apical membranes and Ca2(+)-ATPases on their basolateral membranes. These enzymes were thought to play a role in the accumulation of phosphate and Ca2+ ions in the dome cavities, which then formed crystals in the presence of organic compounds produced by lysis of cells of the deepest layers of the super-domes. The crystals of hydroxyapatite observed in standard Capan-1 cell cultures and those cocultured with fibroblasts were assumed to be a result of transepithelial transport of Ca2+ and phosphate ions by these cells.

Rotavirus NSP4: Cell type-dependent transport kinetics to the exofacial plasma membrane and release from intact infected cells

“…To evaluate the directional transport of NSP4 in the polarized kidney and intestinal cell lines, the cells were seeded at a density of 1 × 10 5 cells/cm 2 on Transwell permeable membrane supports (Corning Costar, Acton, MA) and separately on plastic at the same density to monitor confluency and the formation of domes, which are indicative of directional transepithelial water and electrolyte transport [58,59]. Transepithelial resistance (TER) was monitored prior to, during and post RV infection using a Millicel-ERS volt-ohmmeter according to the manufacturer's instructions (Millipore, Billerica, MA).…”

Response of Vicia faba L. to metal toxicity on mine tailing substrate: Geochemical and morphological changes in leaf and root

“…They were found as clusters of needle-like crystals surrounded by amorphous material. EDX and electronic diffraction analysis showed that they were Ca-P crystals close to apatite composition (Table 5), which have already been described generally in pathological cases of animal tissues (Hering et al, 1987;Hollande et al, 1990;Cantet et al, 2001). To our knowledge, calcium phosphate crystals have not yet been described in plants.…”

Cytological characterization of apatitic calcium phosphate structures in bronchial epithelial tissue cultured from a child with cystic fibrosis (ΔF508)

“…The crystalline structures observed in CF tissues [10,16,24,25,29,32] may well have been calcium phosphate in an apatite-like structure. It is likely that such crystals form at a late stage of cystic fibrosis as has been observed in other diseases [1,17,32]. The crystalline aggregates in bronchial segments and alveoli that we observed could be accounted for by the fact that the tissue came from a child with an advanced stage of the disease.…”