Glucocorticoid-induced alterations of morphology and growth of fibrosarcoma cells derived from 7,12-dimethylbenz(a)anthracene rat mammary tumor.

Cloned cell strains with adverse patterns of differentiation obtained from 7,12-dimethylbenz(a)anthracene-induced rat mammary tumor tissue were used to study the effects of glucocorticoid hormones on morphology and proliferation. HH-16 clone 2/1 cells apparently reflecting mesenchymal cells of the stromal part of the mammary gland grow as elongated, mostly bipolar fibroblasts in criss-cross patterns. When cultured in the presence of glucocorticoids, the cells flattened, lost bipolarity, extended in size, and showed arrest of growth at confluence, possibly due to contact inhibition. Immunocytochemical examination of dexamethasone-treated cells revealed actin cables which were absent in untreated cells. The hormone-treated cells expressed Mr 50,000-67,000 cytokeratins, and the extracellular matrix proteins fibronectin and laminin were increased. The in vitro effects on morphology and growth were reversible 3-4 days after withdrawal of the glucocorticoids. In dexamethasone-treated animals the growth of fibrosarcomas produced by inoculation of newborn rats with HH-16 clone 2/1 cells was reduced, and the survival time of the tumor-bearing animals was extended. Apparently, morphology and growth of HH-16 clone 2/1 fibrosarcoma cells can be controlled by glucocorticoids. In comparison, epithelioid HH-16 clone 4 cells established simultaneously from 7,12-dimethylbenz(a)anthracene-induced rat mammary tumor were unresponsive to glucocorticoids.

Elevated expression of v-mos is correlated with altered differentiation of carcinoma cells.

Permanent alterations of the epithelial differentiation pattern were investigated after infection of HH-16 cl. 4 adenocarcinoma cells with Moloney murine sarcoma virus (MoMuSV). Transformed cell clones with fibroblastoid morphology were isolated and compared with clones of unchanged epithelioid phenotype. Southern blot analyses showed intact MoMuSV proviral genomes in copy numbers between 4 and 9 in the DNA of the morphologically transformed cell clones as well as in the clones with unaltered morphology. The fibroblastoid cells produced sarcomas after inoculation of newborn rats, whereas MoMuSV-infected cell clones with unaltered epithelioid morphology yielded adenocarcinomas. Immunocytochemical analyses revealed that morphological transformation into the fibroblastoid phenotype was accompanied by loss of cytokeratin expression and appearance of the mesenchymal marker protein vimentin. Proviral DNA was transcribed in the infected cell clones irrespective of their phenotype; however, transcription was significantly higher in cells with fibroblastoid morphology than in epithelioid cells.

IFN-gamma-induced change in microtubule organization and alpha-tubulin expression during growth inhibition of lung squamous carcinoma cells.

In cultures of KNS-62 cells derived from a human lung squamous cell carcinoma, the initial growth arrest in the continuous presence of interferon-gamma (IFN-gamma) turned to cytopathic effects after 2 days of treatment. The remaining viable cells showed grossly distorted morphology, with enlargement and extensions up to 5 cell diameters. The presence of apoptotic cells was shown 3 days after treatment with IFN-gamma. Immunocytochemically, the microtubular structures appeared augmented and highly aggregated. The level of alpha-tubulin-specific mRNA was distinctly increased after administration of IFN-gamma, and the amount of extractable alpha-tubulin protein was reduced. In parallel kinetics experiments, growth arrest by serum depletion or by contact inhibition during confluence resulted in reduced levels of alpha-tubulin-specific mRNA and in slightly elevated alpha-tubulin protein. The IFN-gamma-induced effects suggest interference with assembly or maintenance of the tubulin cable network, presumably associated with cell deformation and cytotoxicity.

Motility factors identified in supernatants of human cholangiocarcinoma cell lines.

Motility factors, e.g. SF/HGF (scatter factor/hepatocyte growth factor) or AMF (autocrine motility factor) can influence the migration of tumor cells in vitro and may facilitate invasive growth and metastases in vivo. The production of motility factors was studied in cell lines derived from human cholangiocarcinomas. Culture supernatants from 5 different cholangiocarcinoma cell lines (EGI-1, RPMI 7451, MZ CHA-1, MZ CHA-2 and MZ CHA-3) were analyzed in scatter assays with NRK and MDCK cells as indicator cells which react with cellular migration in the presence of motility factors. Culture supernatants from 4 of the 5 cell lines investigated induced migration of the indicator cells thus demonstrating the production of motility factors. Three of the cell lines (MZ CHA-1, MZ CHA-2, RPMI 7451) produced a factor with a molecular weight ranging between 50 and 100 kDa, EGI-1 cells secreted a factor with a molecular weight >100 kDa. None of the factors was identical to HGF as demonstrated by the lacking reactivity in a HGF specific ELISA and by the inability to induce scattering of HPAF indicator cells like HGF. Similar to SF/HGF, the activity of the EGI-1 factor was inhibited by the proteoglycan heparin and stimulated the chemotactic cell migration, but in contrast to SF/HGF it could not induce invasive growth of NRK cells. The production of scatter factors could be involved in tumor progression and formation of metastases of cholangiocarcinomas.

In vivo assessment of the efficacy of an innovative face care system in subjects with mild acne vulgaris.

The purpose of our studies was to verify efficacy and skin compatibility of a medical face care system containing 2% lactic acid (LA) as active ingredient in a specially designed vehicle (Follicle Targeting System) in adult subjects with mild acne vulgaris. The first study (46 patients) demonstrated superiority of 2% LA in comparison to 2% salicylic acid with respect to number of comedones and inflammatory lesions. The second study evaluated 90 patients receiving distinct combinations of face care products (Eucerin) Impure Skin, Hamburg, Germany), i.e. cleansing gel, facial tonic (2% LA) and cream gel (2% LA). All treatments were performed twice daily over a 12 weeks period. Lesion counts, cyanoacrylate biopsies and determination of quality of life by questionnaires were performed at different timepoints. A reduction of comedones by 56% corresponding to an 46% increase of quality of life index was demonstrated in patients applying cleansing gel, facial tonic and cream gel. For the first time we were able to show a significant improvement concerning the quality of life after using a new face care line. Especially adults with mild forms of acne may benefit from this effective skin care regimen.

Skin-lightening effects of a new face care product in patients with melasma.

BACKGROUND: Melasma is a common pigmentation disorder having considerable effect on patients' emotional and psychological well-being. OBJECTIVE: Assessment of efficacy and tolerability of a new face care product for the targeted spot treatment of darker pigmented areas in subjects with melasma and evaluation of effects on patients' quality of life. METHODS: Twenty subjects with melasma were enrolled in this study. Data of 19 participants were available for analysis. Melasma severity was evaluated at baseline, after 4 weeks, and after 8 weeks by using the Melasma Area and Severity Index (MASI). Furthermore, chromametry and digital image analysis of videomicroscopic photographs were performed, and quality of life was measured using the Melasma Quality of Life Scale. RESULTS: The application of the product resulted in a significant lightening of melasma in comparison with baseline and to untreated control areas. The MASI score dropped by more than 40% after 8 weeks. Measurement of skin color by chromametry revealed lightening of pigmented areas and a significant decrease in contrast between melasma and normal-pigmented surrounding skin. These results were confirmed by digital image analysis. Tolerability of the product was rated to be excellent, and patients experienced a significant gain in quality of life. CONCLUSION: The data demonstrate that the new face care product is effective and highly skin tolerable and clearly improves quality of life of patients with melasma.

[Interaction of retroviruses and oncogenes with the cellular genome. 1]. / Interaktion von Retroviren und Onkogenen mit dem Zellgenom. 1. Mitteilung.

Due to the peculiar type of replication and genome structure, retroviruses (RNA tumor viruses) are characterized by an intensive interaction with the genome of the infected cell. For replication, transcription of the viral RNA genome into double-stranded DNA and subsequent integration of the viral information into the cellular genome are requisite. The recombinatory events with the cellular DNA provide ample opportunities to generate new viral genome structures with altered information and to influence the expression of cellular genes. The lack of specificity of the integration process may lead to inactivation of cellular genes by insertion mutagenesis. The enhancer and promoter sequences of the proviral LTR (long terminal repeat) regions are able to activate the expression of cellular genes in the neighborhood of integration sites. Transforming retroviruses have acquired cellular genes as oncogenes the transcriptional products of which may trans-activate other genes of the host cell. Retroviral infection may result in malignant transformation and alteration of the differentiation pattern of the invaded cell. Depending on the cell type, a loss of expression of cellular functions (dedifferentiation) or an induction of differentiation processes is noticeable. The demonstration of cellular oncogenes (proto-oncogenes) and their activation by retroviruses has initiated new perspectives in understanding the regulation of cell growth and differentiation as well as the formation of tumors at the molecular level.

Transcriptionally active genome regions are preferred targets for retrovirus integration.

We have analyzed the transcriptional activity of cellular target sequences for Moloney murine leukemia virus integration in mouse fibroblasts. At least five of the nine random, unselected integration target sequences studied showed direct evidence for transcriptional activity by hybridization to nuclear run-on transcripts prepared from uninfected cells. At least four of the sequences contained multiple recognition sites for several restriction enzymes that cut preferentially in CpG-rich islands, indicating integration into 5' or 3' ends or flanking regions of genes. Assuming that only a minor fraction (less than 20%) of the genome is transcribed in mammalian cells, we calculated the probability that this association of retroviral integration sites with transcribed sequences is due to chance to be very low (1.6 x 10(-2]. Thus, our results strongly suggest that transcriptionally active genome regions are preferred targets for retrovirus integration.

Karyotype instability and altered differentiation of rat sarcoma cells after retroviral infection.

The karyotypic and phenotypic stability of cultured rat fibrosarcoma cells was challenged by infection with Moloney murine sarcoma virus (MoMuSV). After transformation, the spindle-like morphology of the parental HH-16 cl.2/1 cells had altered to a rounded phenotype, which was maintained in tumors produced by inoculating transformed cells into congenic animals. In contrast to the parental cells, transformed cells lacked cables of cytokeratins 14-16 and 19 and showed reduction of the mesenchymal marker protein vimentin. Additionally, the morphologically altered cell clones tf-1 to tf-3 had lost growth arrest in the presence of dexamethasone. The DNA of the transformed cells contained between four and six randomly integrated proviral copies. Karyotypic alterations were manifested by reduction of morphologically intact chromosomes in the MoMuSV-transformed cells together with increase of structural aberrations. Three additional markers were identified in the virus-transformed cell clones. Karyotypic instability induced by MoMuSV infection appeared closely related to reduction of the cellular differentiation status, although only cells of clone tf-1 had increased metastatic potential.