H-ras-transformed NRK-52E renal epithelial cells have altered growth, morphology, and cytoskeletal structure that correlates with renal cell carcinoma in vivo.

We studied the effect of the ras oncogene on the growth kinetics, morphology, cytoskeletal structure, and tumorigenicity of the widely used NRK-52E rat kidney epithelial cell line and two H-ras oncogene-transformed cell lines, H/1.2-NRK-52E (H/1.2) and H/6.

TGF-beta1 resistance is not associated with alterations in TGF-beta type II receptors in immortalized human lung epithelial cells.

A frequent cause of TGF-beta resistance is decreased expression or mutation of TGF-beta receptor Type II (TGFbetaRII) protein. We previously isolated two isogeneic subclones of the human bronchial epithelial cell line BEAS-2B that are respectively resistant (R.1) or sensitive (S.

Transforming growth factor beta modulation of the epidermal growth factor Ca2+ signal and c-Fos oncoprotein levels in A431 human epidermoid carcinoma cells.

Transforming growth factor beta (TGF beta) was examined regarding its regulation of the mitogen EGF. A431 human epidermoid carcinoma cells were treated with TGF beta and epidermal growth factor (EGF) (10 ng/ml each) to determine if TGF beta modulates EGF-induced Ca2+ signaling and c-Fos oncoprotein levels. Changes in [Ca2+]i were determined by digital imaging analysis or photon counting.

Cytosolic Ca2+ elevation and calpain inhibitors in HgCl2 injury to rat kidney proximal tubule epithelial cells.

This study assessed HgCl2 injury to proximal tubule epithelial cells as it relates to the concentration of ionized cytosolic Ca2+ ([Ca2+]i) elevation and activation of calpains. Experiments in high and low extracellular Ca2+ concentration ([Ca2+]e) were performed using the calpain inhibitors antipain and leupeptin, and also trypsin inhibitor, methylamine, chloroquine, and ryanodine. Cell killing was time/dose dependent and greater with high [Ca2+]e.

Primary cultures of normal rat kidney proximal tubule epithelial cells for studies of renal cell injury.

Normal rat kidney proximal tubule epithelial cell cultures were obtained by collagenase digestion of cortex and studied for 10 days. To assess the purity of the seeding suspension, we histochemically demonstrated gamma-glutamyltranspeptidase in greater than 95% of the starting material. To identify cell types in cultures, we investigated several markers.

HgCl2-induced alteration of actin filaments in cultured primary rat proximal tubule epithelial cells labelled with fluorescein phalloidin.

When proximal tubule epithelial cells are exposed to HgCl2, cytoplasmic blebs are formed. These represent an early, potentially reversible response to injury. These blebs are accompanied by reorganization of cytoskeletal proteins, and presumably by alternations in cytoskeletal-plasma membrane interactions.

Nephrotoxicity in vitro: Role of ion deregulation in signal transduction following injury-Studies utilizing digital imaging fluorescence microscopy.

Over the years, many approaches have been utilized for studying in vitro toxicity in the kidney. These have included the use of isolated perfused kidneys, renal slices, isolated nephron explants and cultured tubular epithelium. Currently, in vitro systems of either primary cultures or cell lines make it possible to use newly developed fluorescent probes and digital imaging fluorescence microscopy coupled with image analysis to quantify various ions (e.

Relation between toxicity and carcinogenesis in the kidney: an heuristic hypothesis.

Cellular toxicity and cellular carcinogenesis are closely linked. In the kidney, this relationship has been emphasized by the recent discovery of a number of putatively non-mutagenic chemicals that result in acute and chronic toxicity and ultimately in carcinogenesis, especially in the male rat. Many, but not all such compounds, result in renal PTE phagolysosomal overload.

Long-term culture of human esophageal explants and cells.

Human esophageal epithelium obtained from intermediate autopsies (less than 12 h) was maintained as cell and explant cultures. In order to develop a serum-free, defined media culture model, several medias and additives were evaluated. The viability and differentiation of the epithelial cells cultured with serum-free, Keratinocyte Growth Media (KGM, Clonetics Co.

The relationship between cellular ion deregulation and acute and chronic toxicity.

Cell injury proceeds through a predictable series of stages as it progresses from reversible to irreversible injury (or "point of no return") and ends eventually in cell death. Ion deregulation is strongly implicated in this process and, in particular, the deregulation of cytosolic Ca2+ ([Ca2+]i) which is thought by most to be a critical step in the transition from reversible to irreversible injury. [Ca2+]i is normally maintained at approximately 100 microM, a level 10,000 times lower than for extracellular Ca2+ [( Ca2+]e).