Biomedical subjects

R H Rice

Publications and source records attributed to R H Rice.

At least 73 records · Page 4Linked to original sources

PubMed1985

Keratinocyte-specific transglutaminase of cultured human epidermal cells: relation to cross-linked envelope formation and terminal differentiation.

The predominant form of the cross-linking enzyme, transglutaminase, in cultured normal human epidermal keratinocytes, is found in cell particulate material and can be solubilized by nonionic detergent. It elutes as a single peak upon either anion-exchange or gel-filtration chromatography. Monoclonal antibodies raised to the particulate enzyme cross-react with one of two transglutaminases in the cell cytosol. The second cytosolic transglutaminase, which has distinct kinetic and physical properties from the first, does not cross-react and is not essential for formation of the keratinocyte cross-linked envelope in vitro. The anti-transglutaminase antibodies stain the more differentiated layers of epidermis in a pattern similar to that given by anti-involucrin antiserum. These observations support the hypothesis that the transglutaminase so identified is involved in cross-linked envelope formation in vivo.

Acyltransferases↗

PubMed1985

Retinoid suppression of transglutaminase activity and envelope competence in cultured human epidermal carcinoma cells. Hydrocortisone is a potent antagonist or retinyl acetate but not retinoic acid.

Growth of SCC-13 squamous carcinoma cultures in the presence of retinoids considerably reduced the expression of two differentiation markers, the cellular capability to form cross-linked envelopes, and the enzyme transglutaminase required for cross-linking. A limited survey of retinoids showed that all-trans retinoic acid, 13-cis retinoic acid, and arotinoid Ro 13-6298 were highly effective in the absence of hydrocortisone and were only slightly antagonized by its presence in the medium. In contrast, retinyl acetate, retinol, and retinol bound to its plasma binding protein were quite active in the absence of hydrocortisone but were essentially inactive in its presence. Dexamethasone was also highly effective in antagonizing the suppressive action of retinyl acetate on envelope formation, while the corticosteroid antagonists cortexolone and progesterone were inactive. These results suggest that there are separate pathways, which are differentially regulated by hydrocortisone, for either the metabolism or action of retinol and retinoic acid in SCC-13 cells.

Acyltransferases↗

PubMed1985

Immuno-ultrastructural localization of involucrin in squamous epithelium and cultured keratinocytes.

Involucrin immunoreactivity was localized ultrastructurally with protein A--gold in epidermis and cultured keratinocytes embedded in Lowicryl K4M. In the skin, immunoreactivity was found predominantly in cells of the granular layer and inner stratum corneum. The label was associated primarily with amorphous cytoplasmic material and especially keratohyaline granules. Some labeling was observed at the cell periphery, but little with keratin filaments. Tissue samples examined without aldehyde fixation showed relatively greater labeling in the outer stratum corneum than fixed tissue. In cultured cells, the labeling was also associated primarily with cytoplasmic granular material and to a lesser extent with the cell periphery. Upon treatment with the ionophore X537A, keratin filaments were found in aggregated arrays and the plasma membranes became convoluted. That involucrin immunoreactivity persisted in the cytoplasm in cultured cells and in vivo after cross-linking occurs could account for considerable isopeptide bonding detected in epidermal keratin fractions and indicates that not all the involucrin participates in envelope formation.

Cells, Cultured↗

PubMed1984

Melittin-stimulated arachidonic acid metabolism by cultured malignant human epidermal keratinocytes.

Upon melittin stimulation, cultured SCC-13 keratinocytes release prostaglandins E2, F2 alpha, 6-keto-F1 alpha, thromboxane B2, leukotriene B4, and 6-sulfido-peptide-containing leukotrienes (SRS) into serum free medium. Release of prostaglandins E2, F2 alpha, and SRS, normalized to cell protein, is 3- to 10-fold higher from rapidly growing than confluent cultures. Cells growing with hydrocortisone in the medium produce approximately twice the level of the cyclooxygenase-mediated metabolites PGE2 and PGF2 alpha as those without hydrocortisone, but similar levels of the lipoxygenase-mediated metabolite SRS. The results demonstrate the potential utility of squamous carcinoma lines for investigating biochemical pathways of arachidonic acid metabolism in keratinocytes.

Arachidonic Acid↗

PubMed1984

Involucrin in laryngeal dysplasia. A marker for differentiation.

Involucrin is a major structural subunit of the cross-linked protein envelope that encases keratin in maturing squamous cells. Intracytoplasmic involucrin is identifiable via immunoperoxidase techniques as these cells migrate from the basal layer to the more superficial layers of the stratified epithelium. Normal squamous epithelia and mildly dysplastic epithelia show uniform staining in the suprabasal and superficial layers of the mucosa but show no staining in the basal layer. Moderate to severe dysplasias and invasive carcinomas demonstrate irregular or focal staining in all three layers. Thirty-three microscopic samples from 27 glottic laryngeal biopsy specimens were reviewed. The histochemically abnormal differentiation identified via involucrin staining correlated with accepted histologic criteria for dysplasia. Involucrin staining may provide objective information to assist the pathologist in differentiating degrees of dysplasia in laryngeal biopsy specimens.

Biopsy↗

PubMed1984

Opposing effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and hydrocortisone on growth and differentiation of cultured malignant human keratinocytes.

The human keratinocyte line SCC-13, derived from a squamous cell carcinoma of epidermis, was examined for effects on growth and differentiation upon treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Inhibition of growth was observable at 0.1 nM and maximal in the concentration range of 1-100 nM TCDD, but was completely antagonized by addition of hydrocortisone to the growth medium. TCDD was found to inhibit several aspects of keratinocyte differentiation that are stimulated by hydrocortisone. In confluent cultures, accumulation of keratin protein and transglutaminase activity were suppressed as well as spontaneous envelope formation and envelope competence. This phenomenon occurred without significant effect of TCDD on depletion of hydrocortisone from the medium. We conclude that the response of SCC-13 cells to TCDD depends upon hormonal conditions in culture and that this agent can interfere with cellular responses to normal physiological conditions, thereby altering the differentiation program ordinarily observed.

Acyltransferases↗

PubMed1984

Papillomavirus infection of the cervix. III: Relationship of the presence of viral structural proteins to the expression of involucrin.

Forty-two cervical biopsies with cervical intraepithelial neoplasia were compared with respect to the expression of human papillomavirus (HPV) structural proteins and the expression of the cellular structural protein involucrin, a marker of suprabasal squamous differentiation. HPV structural protein and involucrin expression displayed an inverse correlation with the severity of dysplasia. Both of these proteins were detected in 11 of 28 cases (39%) of mild and moderate dysplasia, but in only two of 14 (14%) cases of severe dysplasia. This difference was statistically significant (p less than 0.001). The presence of HPV was also associated with expression of involucrin in the full thickness of the epithelium, including the basal layer, and an altered staining pattern in the more superficial cells, particularly the koilocytotic cells. These findings support the hypothesis that squamous differentiation is required for the expression of viral structural proteins and that HPV infection begins in the basal epithelium. The study also demonstrates the utility of involucrin staining in differentiating virus-induced cytologic atypia from true neoplasia.

Adult↗

PubMed1984

Evaluation of squamous epithelium in adenoacanthoma and adenosquamous carcinoma of the endometrium: immunoperoxidase analysis of involucrin and keratin localization.

A study was undertaken to determine whether immunoperoxidase stains for keratin and involucrin, the latter a protein present in cells of stratified squamous epithelium that have differentiated beyond the basal stage, distinguish any differences in squamous cells present in the adenoacanthoma from those in the adenosquamous carcinoma of the uterine corpus. Forty-eight tumors were studied, of which 33 were adenoacanthomas and 15 adenosquamous carcinomas. The patients with adenoacanthomas were slightly younger (mean 61.5 vs. 64.5 years) and had tumors that were generally better differentiated than the adenosquamous carcinomas. The squamous epithelium in every tumor, regardless of histologic type, stained positively for keratin. There were no obvious differences in staining when tumors were stratified for histologic type, grade, or location within the tumor. The glandular portion of both tumor types stained irregularly, but nonetheless positively, for keratin in 71% of the cases. Involucrin was detected in 57% of adenoacanthomas and 87% of adenosquamous carcinomas. The deeper or more central portion of the squamous morules stained only if the more superficial or peripheral areas were positive. The extent of the involucrin staining was less in the adenosquamous carcinomas than in the adenoacanthomas. The glandular component of the tumors did not stain for involucrin. It is concluded that no qualitative differences in the staining reactions with respect to keratin and involucrin distinguish the adenoacanthomas from the adenoaquamous carcinoma. These findings support the argument that the adenoacanthoma and adenosquamous carcinoma represent a spectrum of squamous differentiation in a single tumor type.

Adenocarcinoma↗

PubMed1984

Involucrin expression in normal and neoplastic human skin: a marker for keratinocyte differentiation.

Involucrin is a recently recognized structural component of mature squamous epithelial cells. We examined involucrin expression using an immunoperoxidase technique in normal skin and in a variety of epidermal hyperplasias and neoplasms to determine whether distinctive staining patterns existed within these lesions. Four patterns of reactivity were observed: diffuse intracellular staining typical of keratinocytes of the upper third of normal epidermis and epidermal hyperplasias and benign neoplasms; staining at cell borders, seen principally in benign epidermal neoplasms; patchy staining characteristic of squamous cell carcinoma in situ; and absence of staining in benign and neoplastic basaloid epithelium. Invasive nests of squamous cell carcinomas were negative for involucrin reactivity, whereas pseudoinvasive tongues of epithelium at the bases of keratoacanthomas were focally positive. These results suggest that immunoperoxidase staining for involucrin may be useful in distinguishing certain benign from malignant epidermal neoplasms as well as in understanding the altered maturation and kinetics of proliferative processes afflicting keratinocytes.

Cell Differentiation↗

PubMed1983

Complete amino acid sequence of a mouse epidermal keratin subunit and implications for the structure of intermediate filaments.

We have determined the complete primary structure of an intermediate filament subunit, the 59,000 molecular weight subunit of mouse epidermal keratin, from the nucleotide sequence of cDNA clones. The central portion of the sequence forms extended tracts of a coiled-coil alpha-helical conformation. This is flanked at both termini by similar non-alpha-helical sequences that are extremely rich in glycine residues, frequently configured in tandem peptide repeats. Limited chymotryptic digestion of keratin filaments containing this protein suggests a structural organization whereby the terminal glycine-rich sequences protrude from a conserved core structure into which the coiled-coil alpha-helical segments are packed.

Amino Acid Sequence↗

PubMed1983

Rat esophageal and epidermal keratinocytes: intrinsic differences in culture and derivation of continuous lines.

Serially cultivated with 3T3 feeder layer support as colonies of stratified squamous epithelium, rat epidermal and esophageal epithelial cells were readily distinguishable by three criteria. First, the epidermal colonies, exhibiting extensive piling up of squames in the centers, were more stratified than esophageal colonies. Second, in sparse culture 70 to 90% of the esophageal cells but as few as 1 to 5% of the epidermal cells were competent in cross-linked envelope formation upon treatment with the ionophore X537A. After reaching confluence, up to 90% of the cells of both types formed envelopes upon ionophore treatment. Third, epidermal cells in suspension culture reached maximal levels of spontaneously cross-linked envelopes in 1 day or less, while esophageal cells required about 4 days in suspension to reach maximal levels. A reproducible finding with both cell types was that initial colony-forming efficiencies of less than 1% increased to about 40% upon serial passage with consequent derivation of continuous lines. Sparse cultures of esophageal cells with high colony-forming ability retained a high degree of envelope competence (70 to 90%), indicating these two properties are not mutually exclusive. The derived lines exhibited reduced dependence upon feeder layer support at clonal density, but in suspension culture the cells did not grow and lost colony-forming ability with a half-time of several hours. We conclude that cells from these keratinized rat epithelia exhibit intrinsic differences in culture and become continuous lines expressing characteristic regulation of envelope competence and loss of germinative capability in suspension.

Animals↗

PubMed1983

Interactions of heme proteins with hydrogen peroxide: protein crosslinking and covalent binding of benzo[a]pyrene and 17 beta-estradiol.

This work reveals two biochemical effects of hydrogen peroxide treatment on hemoglobin, myoglobin, and cytochrome c. First, these heme proteins rapidly formed covalently crosslinked dimers and polymers detectable by detergent gel electrophoresis. Second, when treated in the presence of radioactive benzo[a]pyrene or 17 beta-estradiol, the heme proteins became covalently labeled. Nonheme proteins exhibited both cross-linking and radioactive labeling upon peroxide treatment in the presence but not the absence of heme protein or free hemin. Benzoyl peroxide or glucose and glucose oxidase effectively replaced direct addition of hydrogen peroxide. These results indicate that adventitious peroxidase activity expressed by oxygen carrying and electron transport proteins yields active oxygen species that can damage these heme proteins and nearby macromolecules, a possible biochemical mechanism for the lethal and other deleterious intracellular effects of peroxide.

Animals↗

PubMed1983

Convergent differentiation in cultured rat cells from nonkeratinized epithelia: keratinocyte character and intrinsic differences.

Epithelial cells derived from a variety of glandular and other nonkeratinized rat tissues (pituitary, thyroid, bladder, endometrium, trachea, seminal vesicle, prostate, and mammary epithelium) were serially cultivated using a feeder layer of lethally irradiated 3T3 cells. The epithelial cells grew as progressively expanding colonies, in some cases stratified, and were shown to form cornified envelopes upon ionophore-induced activation of cross-linking. Cultures derived from each tissue were distinguishable from the others by characteristic cellular appearance and colony morphology. Those examined in greater detail could be distinguished biochemically in three ways. (a) A majority of cells in sparse cultures of bladder, tracheal, endometrial, and vaginal epithelial cells were capable of envelope formation, whereas those from pituitary, thyroid, seminal vesicle, and mammary epithelia did not attain maximal envelope forming ability until after confluence. (b) Bladder, thyroid, and pituitary cells exhibited different electrophoretic profiles of keratins, which accounted for 20-50% of the cellular protein. (c) Bladder cells were distinguished from thyroid and pituitary cells by a greater suppression of envelope-forming ability by vitamin A. These observations showed that cells from many epithelia have the potential to express properties of keratinocytes in culture while maintaining morphological and physiological differences. Serial passage of these cells generated continuous lines.

Acyltransferases↗

PubMed1983

Mutually antagonistic effects of hydrocortisone and retinyl acetate on envelope competence in cultured malignant human keratinocytes.

Serially propagated SCC-13 keratinocytes, derived from a human squamous cell carcinoma, are greatly influenced by culture conditions in their ability to form ionophore-inducible cross-linked envelopes. Supplementation of the growth medium with fetal bovine serum at concentrations ranging from 0.5 to 20 percent had little effect on competence to form envelopes in confluent cultures. At each serum concentration, however, addition of hydrocortisone to the medium led to an increase in competence of almost fourfold, from approximately 20 to nearly 80 percent. With the serum supplementation held at 5 percent, addition of retinyl acetate to the medium suppressed competence in a concentration-dependent manner over the range of 1 to 100 ng/ml. At the highest concentration employed, competence was reduced over fourfold in the presence of hydrocortisone and virtually eliminated in its absence. When the cells were grown using serum depleted of endogenous vitamin A, a majority were competent in the absence of hydrocortisone. Under this condition, retinyl acetate suppressed competence over fivefold in the absence of hydrocortisone, but not at all in its presence. We conclude that hydrocortisone stimulates envelope competence primarily by antagonizing the suppressive effect of vitamin A. The SCC-13 cell line may prove valuable in studying mechanisms of retinoid and corticosteroid therapeutic action on diseased human keratinocytes.

Carcinoma, Squamous Cell↗

PubMed1983

Modulation of involucrin and envelope competence in human keratinocytes by hydrocortisone, retinyl acetate, and growth arrest.

Involucrin accumulation and ionophore-assisted envelope formation, markers of keratinocyte differentiation, were found to be highly dependent on culture conditions in the malignant epidermal keratinocyte line, SCC-13, derived from a human squamous cell carcinoma. In confluent cultures, approximately one-half of the cells were competent to form envelopes when grown in medium without hydrocortisone or retinyl acetate supplementation. Addition of hydrocortisone to the medium during growth resulted in up to 90% competence, while addition of retinyl acetate instead resulted in as low as 10% competence. Hydrocortisone partially antagonized the effect of retinyl acetate when both agents were added together. Involucrin levels, measured by radioimmunoassay, were modulated essentially in parallel with envelope competence under the various conditions tested. When the cells were grown in medium supplemented with hydrocortisone, the levels shortly after confluence were over 50-fold higher than in sparse cultures. Regardless of hydrocortisone or retinyl acetate addition, less than 1% of the cells were competent in sparse cultures of growing cells, but up to 90% exhibited this property after growth arrest in serum-free medium containing hydrocortisone. High levels of competence were correlated with cessation of cell division but not with loss of colony-forming efficiency; under optimal conditions, two-thirds of the cells were capable of both envelope formation and colony initiation. Normal human epidermal cells showed a 4- to 5-fold increase in envelope competence from sparse to confluent culture but were insensitive to the suppressive effect of retinyl acetate. The results suggest that some potential differentiated character of malignant keratinocytes may be suppressed in vivo by physiological agents such as vitamin A.

Carcinoma, Squamous Cell↗

PubMed1983

Polycyclic aromatic hydrocarbon toxicity and induction of metabolism in cultivated esophageal and epidermal keratinocytes.

Serially cultivated keratinocytes of human and rat epidermis and esophagus were compared with respect to their sensitivity to toxic effects of 3-methylcholanthrene and ability to metabolize benzo(a)pyrene. 3-Methylcholanthrene was highly toxic to the human keratinocytes and to early-passage rat epidermal keratinocytes, as evidenced by markedly reduced growth upon continuous exposure or reduced colony-forming ability after 1-day exposure to concentrations of 0.4 to 40 microM in the culture medium. Rat esophageal and late-passage rat epidermal cells appeared insensitive to 3-methylcholanthrene by these criteria. All the cell types except late-passage rat epidermal cells metabolized benzo(a)pyrene at comparable rates, and expressed aryl hydrocarbon hydroxylase maximally inducible by similar concentrations of 3-methylcholanthrene. Biotransformation in the human cells was greatly inhibited by alpha-naphthoflavone, a specific inhibitor of aryl hydrocarbon hydroxylase. The lack of toxicity of 3-methylcholanthrene toward late-passage rat epidermal cells can be attributed to the low constitutive rate of biotransformation these cells exhibit. The insensitivity of rat esophageal cells despite substantial metabolic activity reflects the importance of intrinsic differences among keratinocytes derived from different epithelia and species in determining toxic response. Human cervical and monkey esophageal keratinocyte cultures also actively metabolized benzo(a)pyrene, illustrating further the utility of the culture system for exploring differences among species and epithelial cell types.

Animals↗

PubMed1982

Immunoperoxidase staining for involucrin: a potential diagnostic aid in cervicovaginal pathology.

Involucrin, a protein subunit of keratinocyte cross-linked envelopes, is a distinctive marker for suprabasal differentiation in stratified squamous epithelium. Immunoperoxidase staining for involucrin was used to evaluate paraffin sections of tissue obtained by colposcopically directed biopsies of infectious, metaplastic, and dysplastic lesions of the cervix and vagina. Areas of normal squamous epithelium, papillary and flat condyloma acuminatum, and mature and immature squamous metaplasia showed positive staining in 99 per cent of samples lacking significant inflammation and in 60 per cent of those with moderate or severe inflammation. In contrast, only 19 per cent of the squamous cell dysplasias, even those without much inflammation, showed positive staining, and no area with moderate or severe inflammation showed positive staining. These findings indicate that expression of involucrin is modulated by cellular pathologic features and microenvironment. We suggest that immunoperoxidase staining for involucrin may be useful in distinguishing mild dysplasia from immature metaplasia and flat condyloma in some biopsy specimens in which routine histologic examination yields an indeterminate diagnosis.

Carcinoma, Squamous Cell↗

PubMed1980

The primary structure of myoglobin from yellowfin tuna (Thunnus albacares).

The amino acid sequence of myoglobin from yellowfin tuna (Thunnus albacares) has been determined. The globin is an aminoacetylated chain containing 146 residues and having deletions, with respect to mammalian and avian myoglobins, at the NH2 terminus and two internal locations. From 79 to 85 amino acid substitutions are observed between this myoglobin and those of mammals, birds, and shark. Two external regions containing 6 and 7 residues, which are highly conserved in mammalian and avian myoglobins, are greatly or totally altered in the tuna sequence. Significant differences are apparent in the extent of electrostatic bonding in the myoglobins of fish and in those of mammals or birds.

Amino Acid Sequence↗