bromochloroacetic-acid and ethylphenylpropiolate

Topics: Alkynes; Animals; Cell Differentiation; Cytoplasmic Granules; Epidermis; Hair; Hyperplasia; Keratins; Phorbol Esters; Phorbols; Protein Biosynthesis; Tetradecanoylphorbol Acetate; Time Factors; Tretinoin

The effects of four different hyperplastic agents and of the carcinogen DMBA on cytokeratin expression in hamster cheek pouch epithelia were compared. Reversible hyperplasia was produced by the application of either oil of turpentine, vitamin A or TPA. No hyperplastic changes were produced by application of EPP. Apart from the transient appearance of a 45 kDa cytokeratin in one group treated with vitamin A, the immunohistochemical staining patterns and immunoblot profiles of cytokeratins from cheek pouches treated with each of the hyperplastic agents were identical to controls. Following application of DMBA, the cytokeratins stained with increased intensity in the spinous and granular cell layers. This was associated with increased amounts of 42-56 kDa cytokeratins and decreased production of 62-75 kDa cytokeratins. Monoclonal antibody AE1 detected a 45 kDa cytokeratin in extracts of DMBA-treated epithelia that was not detected in untreated epithelial extracts. Monoclonal antibody AE3 detected an additional 54 kDa cytokeratin band in extracts of DMBA-treated epithelia. These cytokeratin changes were present in preneoplastic epithelia and maintained in neoplastic epithelia.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Alkynes; Animals; Cricetinae; Diterpenes; Epithelium; Gene Expression Regulation, Neoplastic; Hyperplasia; Immunoblotting; Immunohistochemistry; Keratins; Male; Molecular Weight; Mouth Mucosa; Mouth Neoplasms; Precancerous Conditions; Retinyl Esters; Tetradecanoylphorbol Acetate; Turpentine; Vitamin A

Hyperplasia in the hamster cheek pouch was examined using 4 different hyperplastic agents: oil of turpentine 50% v/v in liquid paraffin; vitamin A palmitate 10% w/v in liquid paraffin; 12-O-tetradeconyl-phorbol-13-acetate 16nM in acetone; and ethylphenylpropiolate 0.04mM in acetone. Acetone, paraffin and untreated control groups were also examined. Cheek pouches were painted 3 times a week for up to 4 weeks with each solution. Samples were removed and prepared for light microscopy 24 hours after 2 weeks of painting and 24 hours, 6, 12 and 18 weeks after 4 weeks of painting. Hyperplasia was produced by application of turpentine, vitamin A and TPA after 2 weeks of application. Further increases in epithelial width occurred after 4 weeks of painting in the turpentine and vitamin A groups but a decrease was seen in the TPA group. Six weeks (vitamin A and TPA groups) or 12 weeks (turpentine group) after the completion of treatment the epithelium had a normal histological appearance. No differences between the control or EPP treated cheek pouch mucosa could be detected. Turpentine and vitamin A can be used as models of reversible hyperplasia in the hamster cheek pouch.

Topics: Alkynes; Animals; Cell Nucleus; Connective Tissue; Cricetinae; Cytoplasmic Granules; Diterpenes; Epithelium; Hyalin; Hyperplasia; Keratins; Male; Mouth Mucosa; Retinyl Esters; Tetradecanoylphorbol Acetate; Time Factors; Turpentine; Vitamin A

We have studied the effects of the potent tumour promoter phorbol, 12-myristate, 13-acetate (PMA) and two non-promoting hyperplasiogenic compounds ethyl phenylpropriolate (EPP) and the divalent cation ionophore A23187 on the terminal differentiation of normal and transformed human keratinocytes using the loss of cloning efficiency and the formation of cornified envelopes as markers of the differentiated state. PMA induced terminal differentiation in a far greater proportion of normal keratinocytes than it did in the squamous cell carcinoma line SCC-27 but EPP and the calcium ionophores A23187 and Br-X537A had no such differential effect, possibly explaining the poor promoting ability of the last three compounds.

Topics: Alkynes; Calcimycin; Carcinoma, Squamous Cell; Cell Differentiation; Cell Line; Cell Transformation, Neoplastic; Cells, Cultured; Clone Cells; Humans; Hyperplasia; Keratins; Phorbols; Skin; Tetradecanoylphorbol Acetate

Topics: Alkynes; Anthralin; Calcimycin; Carcinogens; Diterpenes; Epidermal Cells; Epidermis; Hyperplasia; Keratins; Phorbol Esters; Terpenes; Tetradecanoylphorbol Acetate