Fibroblasts potentiate melanoma cells in vitro invasiveness induced by UV-irradiated keratinocytes.

Melanoma represents a malignant disease with steadily increasing incidence. UV-irradiation is a recognized key factor in melanoma initiation. Therefore, the efficient prevention of UV tissue damage bears a critical potential for melanoma prevention. In this study, we tested the effect of UV irradiation of normal keratinocytes and their consequent interaction with normal and cancer-associated fibroblasts isolated from melanoma, respectively. Using this model of UV influenced microenvironment, we measured melanoma cell migration in 3-D collagen gels. These interactions were studied using DNA microarray technology, immunofluorescence staining, single cell electrophoresis assay, viability (dead/life) cell detection methods, and migration analysis. We observed that three 10 mJ/cm2 fractions at equal intervals over 72 h applied on keratinocytes lead to a 50% increase (p < 0.05) in in vitro invasion of melanoma cells. The introduction cancer-associated fibroblasts to such model further significantly stimulated melanoma cells in vitro invasiveness to a higher extent than normal fibroblasts. A panel of candidate gene products responsible for facilitation of melanoma cells invasion was defined with emphasis on IL-6, IL-8, and CXCL-1. In conclusion, this study demonstrates a synergistic effect between cancer microenvironment and UV irradiation in melanoma invasiveness under in vitro condition.

Detection of Distinct Changes in Gene-expression Profiles in Specimens of Tumors and Transition Zones of Tenascin-positive/-negative Head and Neck Squamous Cell Carcinoma.

BACKGROUND/AIM: Having previously initiated genome-wide expression profiling in head and neck squamous cell carcinoma (HNSCC) for regions of the tumor, the margin of surgical resecate (MSR) and normal mucosa (NM), we here proceed with respective analysis of cases after stratification according to the expression status of tenascin (Ten). MATERIALS AND METHODS: Tissue specimens of each anatomical site were analyzed by immunofluorescent detection of Ten, fibronectin (Fn) and galectin-1 (Gal-1) as well as by microarrays. RESULTS: Histopathological examination demonstrated that Ten+Fn+Gal-1+ co-expression occurs more frequently in samples of HNSCC (55%) than in NM (9%; p<0.01). Contrary, the Ten-Fn+Gal-1- (45%) and Ten-Fn-Gal-1- (39%) status occurred with significantly (p<0.01) higher frequency than in HNSCC (3% and 4%, respectively). In MSRs, different immunophenotypes were distributed rather equally (Ten+Fn+Gal-1+=24%; Ten-Fn+Gal-1-=36%; Ten-Fn-Gal-1-=33%), differing to the results in tumors (p<0.05). Absence/presence of Ten was used for stratification of patients into cohorts without a difference in prognosis, to comparatively examine gene-activity signatures. Microarray analysis revealed i) expression of several tumor progression-associated genes in Ten+ HNSCC tumors and ii) a strong up-regulation of gene expression assigned to lipid metabolism in MSRs of Ten- tumors, while NM profiles remained similar. CONCLUSION: The presented data reveal marked and specific changes in tumors and MSR specimens of HNSCC without a separation based on prognosis.

Genome-wide Expression Profiling (with Focus on the Galectin Network) in Tumor, Transition Zone and Normal Tissue of Head and Neck Cancer: Marked Differences Between Individual Patients and the Site of Specimen Origin.

BACKGROUND/AIM: Expression profiling was performed to delineate and characterize the impact of malignancy by comparing tissues from three sites of head and neck cancer of each patient, also determining interindividual variability. MATERIALS AND METHODS: Genome-wide analysis was carried out covering the expression of 25,832 genes with quantification for each site of seven patients with tonsillar or oropharyngeal squamous cell carcinoma. Immunohistochemical analysis was performed for adhesion/growth-regulatory galectins, three pro-inflammatory chemo- and cytokines and keratins. RESULTS: Up- and down-regulation was found for 281 (tumor vs. normal) and 276 genes (transition zone vs. normal), respectively. The profile of the transition zone had its own features, with similarity to the tumor. Galectins were affected in a network manner, with differential regulation and interindividual variability between patients, also true for keratins and the chemo- and cytokines. CONCLUSION: These results underline special features at each site of specimen origin as well as the importance of analyzing galectins as a network and of defining the expression status of the individual patient prior to reaching clinically relevant conclusions.

Analysis of dermal fibroblasts isolated from neonatal and child cleft lip and adult skin: Developmental implications on reconstructive surgery.

The nonsyndromic cleft is one of the most frequent congenital defects in humans. Clinical data demonstrated improved and almost scarless neonatal healing of reparative surgery. Based on our previous results on crosstalk between neonatal fibroblasts and adult keratinocytes, the present study focused on characterization of fibroblasts prepared from cleft lip tissue samples of neonates and older children, and compared them with samples isolated from normal adult skin (face and breast) and scars. Although subtle variances in expression profiles of children and neonates were observed, the two groups differed significantly from adult cells. Compared with adult cells, differences were observed in nestin and smooth muscle actin (SMA) expression at the protein and transcript level. Furthermore, fibroblast to myofibroblast differentiation drives effective wound healing and is largely regulated by the cytokine, transforming growth factor-ß1 (TGF-ß1). Dysregulation of the TGF-ß signalling pathway, including low expression of the TGF-ß receptor II, may contribute to reducing scarring in neonates. Fibroblasts of facial origin also exhibited age independent differences from the cells prepared from the breast, reflecting the origin of the facial cells from neural crest-based ectomesenchyme.

Functional differences between neonatal and adult fibroblasts and keratinocytes: Donor age affects epithelial-mesenchymal crosstalk in vitro.

Clinical evidence suggests that healing is faster and almost scarless at an early neonatal age in comparison with that in adults. In this study, the phenotypes of neonatal and adult dermal fibroblasts and keratinocytes (nestin, smooth muscle actin, keratin types 8, 14 and 19, and fibronectin) were compared. Furthermore, functional assays (proliferation, migration, scratch wound closure) including mutual epithelial­mesenchymal interactions were also performed to complete the series of experiments. Positivity for nestin and α smooth muscle actin was higher in neonatal fibroblasts (NFs) when compared with their adult counterparts (adult fibroblasts; AFs). Although the proliferation of NFs and AFs was similar, they significantly differed in their migration potential. The keratinocyte experiments revealed small, poorly differentiated cells (positive for keratins 8, 14 and 19) in primary cultures isolated from neonatal tissues. Moreover, the neonatal keratinocytes exhibited significantly faster rates of healing the experimentally induced in vitro defects in comparison with adult cells. Notably, the epithelial/mesenchymal interaction studies showed that NFs in co-culture with adult keratinocytes significantly stimulated the adult epithelial cells to acquire the phenotype of small, non-confluent cells expressing markers of poor differentiation. These results indicate the important differences between neonatal and adult cells that may be associated with improved wound healing during the early neonatal period.