Inhibitory effects of p-dodecylaminophenol on the invasiveness of human fibrosarcoma cell line HT1080

Three dimensional reconstruction of skin with melanoma: A model for study of invasion in vitro

Melanoma is a type of tumor skin with high metastatic potential. Reconstructed human skin, development for pre-clinic assay, are make using primary human cells, but with same limitations. The aim this study was to characterize a cell culture model, with structure similar to human skin containing melanoma cells entirely from cell lines. Reconstructed skin with melanoma were development using human fibroblasts (MRC5), human epidermal keratinocytes (HaCat), and human melanoma (SK-MEL-28) embedded in collagen type I. The structure was characterized by hematoxylin-eosin stained, as well as points of melanoma cell invasion, which was associated with activity of MMPs (MMP-2 and MMP-9) by zymographic method. Then, the gene expression of the target molecular mechanisms involved in melanoma progression were evaluated. Here, the model development showed a region epidermis organized and separated from the dermis, with fibroblast cells confined and melanoma cells form delimited area invasion. MMP-2 and MMP-9 were identified during of cell culture and gene expression of BRAF, NRAS, and Vimentin was confirmed. The proposed model provides one more opportunity to study in vitro tumor biology of melanoma and also to allows the study of new drugs with more reliable results then whats we would find in vivo.

[Prevention and Treatment of Cancer with Vitamin A and Its Derivatives: Cell Differentiation and Proliferation]

Normal differentiation and proliferation of cells are essential for maintaining homeostasis. Following the successful completion of whole genome sequencing, protein modification has been attracted increasing attention in order to understand the roles of protein diversification in protein function and to elucidate molecular targets in mechanisms of signal transduction. Vitamin A is an essential nutrient for health maintenance. It is present as β-carotene in green and yellow vegetables and retinyl ester in animal products and absorbed into the body from the intestines. After ingestion, it is converted to retinol and oxidized in target cells to retinal, which plays critical roles in vision. It is then further oxidized to retinoic acid (RA), which exhibits a number of effects prior to being metabolized by cytochrome P450 and excreted from the body. Since RA exhibits cell differentiation-inducing actions, it is used as a therapeutic agent for patients with acute promyelocytic leukemia. The current paper describes: (1) HL60 cell differentiation and cell differentiation induction therapy by RA; (2) roles played by RA and retinal and their mechanisms of action; (3) retinoylation, post-translational protein-modified by RA, a novel non-genomic RA mechanism of action without RA receptor; (4) new actions of β-carotene and retinol in vivo and (5) potent anticancer effects of p-dodecylaminophenol (p-DDAP), a novel vitamin A derivative created from the RA derivative fenretinide. We propose that nutritional management of vitamin A can be effective at preventing and treating diseases, and that p-DDAP is a promising anticancer drug.

Vitamin A in health care: Suppression of growth and induction of differentiation in cancer cells by vitamin A and its derivatives and their mechanisms of action

Vitamin A is an important micro-essential nutrient, whose primary dietary source is retinyl esters. In addition, β-carotene (pro-vitamin A) is a precursor of vitamin A contained in green and yellow vegetables that is converted to retinol in the body after ingestion. Retinol is oxidized to produce visual retinal, which is further oxidized to retinoic acid (RA), which is used as a therapeutic agent for patients with promyelocytic leukemia. Thus, the effects of retinal and RA are well known. In this paper, we will introduce (1) vitamin A circulation in the body, (2) the actions and mechanisms of retinal and RA, (3) retinoylation: another RA mechanism not depending on RA receptors, (4) the relationship between cancer and actions of retinol or β-carotene, whose roles in vivo are still unknown, and (5) anti-cancer actions of vitamin A derivatives derived from fenretinide (4-HPR). We propose that vitamin A nutritional management is effective in the prevention of cancer.

22β-hydroxytingenone reduces proliferation and invasion of human melanoma cells

Melanoma is a skin cancer with high invasive potential and high lethality. Considering that quinonemethide triterpenes are described as promising anticancer agents, the aim of this study was to evaluate the effect of 22β-hydroxytingenone (22-HTG) against human melanoma cells. Alamar blue assay was performed in order to evaluate its cytotoxic effect. Thus, subtoxic concentrations (1.0, 2.0, and 2.5 μM) were used to evaluate the effect of this compound on proliferation, migration, metabolism, and invasion. IC₅₀ value against SK-MEL-28 cell line was 4.35, 3.72, and 3.29 μM after 24, 48, and 72 h of incubation, respectively. 22-HTG reduced proliferation, migration and invasion by melanoma cells, with decreased activity of metalloproteinases (MMP-2 and MMP-9). Futhermore, 22-HTG decreased expression of lactate dehydrogenase (LDHA), an enzyme associated with cell metabolism. Howerver, the small reduction in LDHA enzyme activity must have occurred by the cytotoxic effect of 22-HTG. According to the results, 22-HTG interferes with important characteristics of cancer, with anti-proliferative, and anti-invasive effect against melanoma cells. The data suggest that 22-HTG is an effective substance against melanoma cells and it should be considered as a potential anticancer agent.