The interaction of epidermal growth factor (EGF) with specific cell surface receptors initiates biochemical events in target cells which result in cellular proliferation and differentiation. In this report the regulation of extracellular-associated plasminogen activator (PA) production by EGF in human squamous cell carcinomas and its influence on tumor cell-mediated degradation of extracellular...

When human A431 cells, which carry high numbers of epidermal growth factor (EGF) receptors, are exposed to EGF, the total content of phosphotyrosine in cell protein is increased, the EGF receptor becomes phosphorylated at tyrosine, and new phosphotyrosine-containing 36,000- and 81,000-dalton proteins are detected. We examined the properties of A431 cells infected with Snyder-Theilen feline sarc...

Ultraviolet C (UVC) is a DNA damage inducer, and 20 J/m(2) of UVC irradiation caused cell growth inhibition and induced cell death after exposure for 24-36 h. The growth of NIH 3T3 cells was significantly suppressed at 24 h after UVC irradiation whereas the proliferation of A431 cells was inhibited until 36 h after UVC irradiation. UVC irradiation increased COX-2 expression and such up-regulati...

AIM To explore the function ofTSPAN1 in squamous cell skin carcinoma by means of TSPAN1-specific siRNA and antisense oligonucleotide techniques. METHODS pU6H1-GFP-siRNA TSPAN1 and pcDNA3.1 antisense TSPAN1 were constructed and transfected into squamous cell skin carcinoma cell line A431 cells to knock down TSPAN1 gene expression. The levels of TSPAN1 mRNA and protein expression were detected ...

The aim of the present study was to investigate the effect of resveratrol on cell apoptosis, ability of telomerase and the human telomerase reverse transcriptase (hTERT) protein expression in human A431 epidermoid carcinoma cells. A431 cells were treated with different concentrations of resveratrol, and the cell appearance was then observed under a microscope. In addition, the cell proliferatio...

Zinc is a trace element that requires for more than 2000 transcription factors regulating cell development, differentiation, and growth of many types including cancer cells. Prior studies reported zinc induced apoptosis in cells, such as glioma, bladder, prostate, breast, melanoma. The effects cutaneous squamous carcinoma (SCC) have not been formally assessed. Two SCC lines (A431 HSC-5) were cu...

Although there is increasing evidence that human bone marrow mesenchymal stem cells (hBM-MSCs) play an important role in cancer progression, the underlying mechanisms are poorly understood. Transforming growth factor β (TGF-β) is an important pro-metastatic cytokine. We have previously shown that CD109, a glycosylphosphatidylinositol-anchored protein, is a TGF-β co-receptor and a strong inhibit...

Transforming growth factor beta (TGF-beta) increased the phosphorylation of the epidermal growth factor (EGF) receptor and inhibited the growth of A431 cells. Incubation with TGF-beta induced maximal EGF receptor phosphorylation to levels 1.5-fold higher than controls. Phosphorylation increased more prominently (4-5-fold) on tyrosine residues as determined by phosphoamino acid analysis and anti...

Brazilian green propolis (BGP) is noted for its impressive antitumor effects and has been used as a folk medicine in various cultures for many years. It has been demonstrated that BGP could enhance the cytotoxic effect of cytostatic drugs on tumor cells. Photodynamic therapy (PDT) is a therapeutic approach used against malignant cells. To assess the synergistic effect of BGP extract on protopor...