Although, arsenic trioxide has been the subject of toxicological research, in vitro cytotoxicity and genotoxicity studies using relevant cell models and uniform methodology are not well elucidated. Hence, the aim of the present study was to evaluate the cytotoxicity and genotoxicity induced by arsenic trioxide in human keratinocytes (HaCaT) using the MTT [3-(4, 5-dimethylthiazol-2-yl)2,5-diphen...

Previous studies addressing functional aspects of nuclear factor KB (NF-KB) activation in normal and transformed keratinocytes revealed complex and seemingly contradictory roles of this transcription factor in this cell type. In normal skin, NF-KB signaling seems to inhibit squamous cell carcinoma development whereas, in squamous cell carcinoma themselves, deregulated NF-KB expression and/or si...

The deleterious effects of ultraviolet radiation on human skin are via inducing inflammation, immunosuppression, premature skin aging and carcinogenesis. As the most energetic component of ultraviolet radiation reaching the earth’s surface, UVB radiation induces DNA damage and is a critical carcinogenic factor in skin carcinogenesis. However, UVB irradiation may trigger apoptosis and/or cell de...

Photodynamic therapy (PDT) using photosensitizer can induce diverse cellular responses, including apoptosis. Recently, it has been reported that PDT using methylaminolaevulinate may be effective in basal cell carcinoma. However, it is largely unknown whether PDT using a natural product such as curcumin can induce apoptosis in skin cancer. In this study, to confirm the photodynamic effect of cur...

The present study is to investigate which kinds of solvent extracts of Inulae Flos inhibit the chemokine productions in HaCaT cell and whether the inhibitory capacity of Inulae Flos is related with constitutional compounds. The 70% methanol extract showed comparatively higher inhibition of thymus and activation-regulated chemokine (TARC/CCL17) in HaCaT cells, therefore this extract was further ...

Quercetin and phenylpropanoids are well known chemoprotective compounds identified in many plants. This study was aimed at determining their effects on activation of Nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant response element (Nrf2-ARE) signalling pathway and expression of its important downstream effector phase II detoxification enzyme glutathione-S-transferase P1 (GSTP1) i...

Thapsigargin is a specific inhibitor of the sarco/endoplasmic reticulum Ca ATPase of the endoplasmic reticulum. Here, we show that stimulation of human HaCaT keratinocytes with nanomolar concentrations of thapsigargin triggers expression of activating transcription factor (ATF) 3, a basic-region leucin zipper transcription factor. ATF3 expression was also up-regulated in thapsigargin-stimulated...

PURPOSE The aim of this study was to compare levels of apoptosis, necrosis, mitotic cell death and senescence after treatment with both direct radiation and irradiated cell conditioned medium. MATERIALS AND METHODS Human keratinocytes (HaCaT cell line) were irradiated (0.005, 0.05 and 0.5 Gy) using a cobalt 60 teletherapy unit. For bystander experiments, the medium was harvested from donor Ha...

Excessive ultraviolet B (UVB) irradiation causes apoptotic cell death or induction of tumors in skin. Melatonin is a promising antioxidant and direct radical scavenger. Recently, it was reported that melatonin increases the survival of ultraviolet-B (UVB)-irradiated HaCaT keratinocyte cell lines. However, the precise molecular mechanisms underlying protective effect of melatonin on UVB damage a...

In this study we sought to develop a computational modeling paradigm in order to describe the influence of calcium on normal and transformed keratinocyte proliferation and differentiation. Keratinocytes and HaCat cells were grown in monolayer cultures with low and physiologic calcium concentrations, and levels of proliferation and involucrin expression were assessed. Both types of cells grew as...