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...

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...

The role of epidermal growth factor in the regulation of the proteolytic and RBC cytolytic activity of the A431 cancer cell line has been evaluated using our previously described gelatin/polyacrylamide electrophoretic assay and tumor-induced RBC cytolysis assay, respectively. A431 cells maintained in 10% fetal bovine serum were actively cytolytic for RBC (release index, 53.0 +/- 2.9%), whereas ...

Activation of phospholipase C (PLC)-mediated signaling pathways in nonexcitable cells causes the release of Ca2+ from intracellular Ca2+ stores and activation of Ca2+ influx across the plasma membrane. Two types of Ca2+ channels, highly Ca2+-selective ICRAC and moderately Ca2+-selective ISOC, support store-operated Ca2+ entry process. In previous patch-clamp experiments with a human carcinoma A...

Purpose: Raltitrexed, pemetrexed, lometrexol, and ZD9331 are antifolate drugs transported into cells via the ubiquitously expressed reduced-folate carrier. They display also high affinity for the -folate receptor ( -FR), a low capacity folate transporter that is highly overexpressed in some epithelial tumors. The role of -FR in the activity of the antifolates has been evaluated in two -FR-overe...

Treatment of cells with tumor-promoting phorbol diesters, which causes activation of protein kinase C, leads to phosphorylation of the epidermal growth factor (EGF) receptor at threonine-654. Addition of phorbol diesters to intact cells causes inhibition of the EGF-induced tyrosine-protein kinase activity of the EGF receptor and it has been suggested that this effect of phorbol diesters is medi...

12-Hydroxyeicosatetraenoic acid (12-HETE) is formed from arachidonic acid either by 12-lipoxygenase or by a cytochrome P450 monooxygenase. 12-Lipoxygenase is generally localized in the soluble cytosolic fraction, and the cytochrome P450 monooxygenase is a microsomal enzyme. In this study, 12-HETE biosynthesis and the regulation of 12-HETE biosynthesis by epidermal growth factor (EGF) in A431 ce...

BACKGROUND Time-dependence of cisplatin (CDDP) and oxaliplatin (L-OHP) cytotoxic effects in A431 and A431/Pt cells (sensitive and CDDP-resistant human cervical tumor cells) were investigated. MATERIALS AND METHODS The drug application modes were pulse (12.5, 25 or 50 microM up to 72 h) and pulse-plus-chase (50 microM for 2, 4 or 6 h, followed by washing and 72 h-incubation in drug-free medium...

To explore bidirectional regulatory interactions between interferons and autocrine polypeptide factors, we examined the modulation of expression of transforming growth factor-a and 2’,5’-oligoadenylate synthetase activity in A431 epidermoid carcinoma cells after treatment with interferon-y and transforming growth factor-a. Treatment of A431 cells with interferon-y increased steady state levels ...

Anti-VEGF therapies benefit several cancer types, but drug resistance that limits therapeutic response can emerge. We generated cell lines from anti-VEGF-resistant tumor xenografts to investigate the mechanisms by which resistance develops. Of all tumor cells tested, only A431 (A431-V) epidermoid carcinoma cells developed partial resistance to the VEGF inhibitor aflibercept. Compared with the p...