Leaf anatomy of Protium ovatum and its antiproliferative potential in cervical cells

ABSTRACT The aim of this study was to analyze the morphology and anatomy of the leaves of Protium ovatum Engl., Burseraceae, and verify the antiproliferative activity in cervical cells. For anatomical analysis, the leaf samples were fixed in formol, acetic acid, alcohol 70, dehydrated, included in hydroxyethyl methacrylate and sectioned at a thickness of 5-10 µm in rotative microtome. The samples were stained with toluidine blue and blades mounted with synthetic resin "Entellan". Histochemical tests and scanning electron microscopy were also performed. To investigate the antiproliferative effect we used the cells strain of human cervix carcinoma and normal keratinocytes. The anatomical analysis demonstrated that the leaf is hypostomatic and the epidermal cells walls were slightly undulate on both faces. The palisade parenchyma occupies most part of leaf mesophyll. The spongy parenchyma is organized into 3-4 layers of cells. Vascular bundles of smaller diameter and secretory cavities are distributed along the leaf mesophyll. The midrib region was formed by a single vascular bundle with xylem in the center surrounded by phloem. Secretory cavities are distributed along the phloem. The histochemical tests revealed the presence of lipids in the secretory cavities and phenolic compounds in almost cell of mesophyll. Scanning electron microscopy analysis showed the smooth leaf cuticle ornamentation with some striated areas. It was observed antiproliferative effect on human cervix carcinoma cell comparing with normal cells.

Genomics and proteomics approaches to the study of cancer-stroma interactions.

BACKGROUND: The development and progression of cancer depend on its genetic characteristics as well as on the interactions with its microenvironment. Understanding these interactions may contribute to diagnostic and prognostic evaluations and to the development of new cancer therapies. Aiming to investigate potential mechanisms by which the tumor microenvironment might contribute to a cancer phenotype, we evaluated soluble paracrine factors produced by stromal and neoplastic cells which may influence proliferation and gene and protein expression. METHODS: The study was carried out on the epithelial cancer cell line (Hep-2) and fibroblasts isolated from a primary oral cancer. We combined a conditioned-medium technique with subtraction hybridization approach, quantitative PCR and proteomics, in order to evaluate gene and protein expression influenced by soluble paracrine factors produced by stromal and neoplastic cells. RESULTS: We observed that conditioned medium from fibroblast cultures (FCM) inhibited proliferation and induced apoptosis in Hep-2 cells. In neoplastic cells, 41 genes and 5 proteins exhibited changes in expression levels in response to FCM and, in fibroblasts, 17 genes and 2 proteins showed down-regulation in response to conditioned medium from Hep-2 cells (HCM). Nine genes were selected and the expression results of 6 down-regulated genes (ARID4A, CALR, GNB2L1, RNF10, SQSTM1, USP9X) were validated by real time PCR. CONCLUSIONS: A significant and common denominator in the results was the potential induction of signaling changes associated with immune or inflammatory response in the absence of a specific protein.

Annexin 1: differential expression in tumor and mast cells in human larynx cancer.

Annexin 1 protein (ANXA1) expression was evaluated in tumor and mast cells in human larynx cancer and control epithelium. The effect of the exogenous ANXA1 (peptide Ac 2-26) was also examined during the cellular growth of the Hep-2 human larynx epidermoid carcinoma cell line. This peptide inhibited the proliferation of the Hep-2 cells within 144 hr. In surgical tissue specimens from 20 patients with larynx cancer, ultrastructural immunocytochemistry analysis showed in vivo down-regulation of ANXA1 expression in the tumor and increased in mast cells and Hep-2 cells treated with peptide Ac2-26. Combined in vivo and in vitro analysis demonstrated that ANXA1 plays a regulatory role in laryngeal cancer cell growth. We believe that a better understanding of the regulatory mechanisms of ANXA1 in tumor and mast cells may lead to future biological targets for the therapeutic intervention of human larynx cancer.