scholarly journals Prolonged induction of p21Cip1/WAF1/CDK2/PCNA complex by epidermal growth factor receptor activation mediates ligand-induced A431 cell growth inhibition.

1995 ◽  
Vol 131 (1) ◽  
pp. 235-242 ◽  
Author(s):  
Z Fan ◽  
Y Lu ◽  
X Wu ◽  
A DeBlasio ◽  
A Koff ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Tyrosine Kinase ◽  
Growth Inhibition ◽  
Receptor Tyrosine Kinase ◽  
G1 Arrest ◽  
A431 Cells ◽  
Cdk2 Activity ◽  
F Cells ◽  
Epidermal Growth

Proliferation of some cultured human tumor cell lines bearing high numbers of epidermal growth factor (EGF) receptors is paradoxically inhibited by EGF in nanomolar concentrations. In the present study, we have investigated the biochemical mechanism of growth inhibition in A431 human squamous carcinoma cells exposed to exogenous EGF. In parallel, we studied a selected subpopulation, A431-F, which is resistant to EGF-mediated growth inhibition. We observed a marked reduction in cyclin-dependent kinase-2 (CDK2) activity when A431 and A431-F cells were cultured with 20 nM EGF for 4 h. After further continuous exposure of A431 cells to EGF, the CDK2 activity remained at a low level and was accompanied by persistent G1 arrest. In contrast, the early reduced CDK2 activity and G1 accumulation in A431-F cells was only transient. We found that, at early time points (4-8 h), EGF induces p21Cip1/WAF1 mRNA and protein expression in both EGF-sensitive A431 cells and EGF-resistant A431-F cells. But only in A431 cells, was p21Cip1/WAF1 expression sustained at a significantly increased level for up to 5 d after addition of EGF. Induction of p21Cip1/WAF1 by EGF could be inhibited by a specific EGF receptor tyrosine kinase inhibitor, tyrphostin AG1478, suggesting that p21Cip1/WAF1 induction was a consequence of receptor tyrosine kinase activation by EGF. We also demonstrated that the increased p21Cip1/WAF1 was associated with both CDK2 and proliferating cell nuclear antigen (PCNA). Taken together, our results demonstrate that p21Cip1/WAF1 is an important mediator of EGF-induced G1 arrest and growth inhibition in A431 cells.

scholarly journals Rapid uptake of tyrphostin into A431 human epidermoid cells is followed by delayed inhibition of epidermal growth factor (EGF)-stimulated EGF receptor tyrosine kinase activity.

1991 ◽  
Vol 11 (5) ◽  
pp. 2697-2703 ◽  
Author(s):  
C A Faaland ◽  
F H Mermelstein ◽  
J Hayashi ◽  
J D Laskin
Keyword(s):  
Cell Cycle ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Kinase Activity ◽  
Egf Receptor ◽  
Tyrosine Kinase Activity ◽  
A431 Cells ◽  
Epidermal Growth

Treatment of A431 human epidermoid cells with epidermal growth factor (EGF; 20 nM) results in decreased proliferation. This is associated with blockage of the cells in the S and/or G2 phases of the cell cycle. We found that tyrphostin, a putative tyrosine kinase inhibitor, in the range of 50 to 100 microM, partially reversed the growth-inhibitory and cell cycle changes induced by EGF. By using high-pressure liquid chromatography with electrochemical detection, we found that tyrphostin was readily incorporated into A431 cells, reaching maximal levels within 1 h. Although tyrphostin (50 to 100 microM) had no effect on high-affinity binding of EGF to its receptor in A431 cells for up to 24 h, the compound partially inhibited EGF-stimulated EGF receptor tyrosine kinase activity. However, this effect was evident only after prolonged treatment of the cells (4 to 24 h) with the drug. When the peak intracellular concentration of tyrphostin occurred (1 h), no inhibition of tyrosine kinase activity was observed. After both 1 and 24 h, tyrphostin was a less effective inhibitor of tyrosine kinase activity than the potent tumor promoter 12-O-tetradecanoyl phorbol-13-acetate, which almost completely blocked EGF receptor autophosphorylation. On the basis of our data, we hypothesize that tyrphostin is not a competitive inhibitor of the EGF receptor tyrosine kinase in intact cells and that it functions by an indirect mechanism.

Rapid uptake of tyrphostin into A431 human epidermoid cells is followed by delayed inhibition of epidermal growth factor (EGF)-stimulated EGF receptor tyrosine kinase activity

1991 ◽  
Vol 11 (5) ◽  
pp. 2697-2703
Author(s):  
C A Faaland ◽  
F H Mermelstein ◽  
J Hayashi ◽  
J D Laskin
Keyword(s):  
Cell Cycle ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Kinase Activity ◽  
Egf Receptor ◽  
Tyrosine Kinase Activity ◽  
A431 Cells ◽  
Epidermal Growth

Treatment of A431 human epidermoid cells with epidermal growth factor (EGF; 20 nM) results in decreased proliferation. This is associated with blockage of the cells in the S and/or G2 phases of the cell cycle. We found that tyrphostin, a putative tyrosine kinase inhibitor, in the range of 50 to 100 microM, partially reversed the growth-inhibitory and cell cycle changes induced by EGF. By using high-pressure liquid chromatography with electrochemical detection, we found that tyrphostin was readily incorporated into A431 cells, reaching maximal levels within 1 h. Although tyrphostin (50 to 100 microM) had no effect on high-affinity binding of EGF to its receptor in A431 cells for up to 24 h, the compound partially inhibited EGF-stimulated EGF receptor tyrosine kinase activity. However, this effect was evident only after prolonged treatment of the cells (4 to 24 h) with the drug. When the peak intracellular concentration of tyrphostin occurred (1 h), no inhibition of tyrosine kinase activity was observed. After both 1 and 24 h, tyrphostin was a less effective inhibitor of tyrosine kinase activity than the potent tumor promoter 12-O-tetradecanoyl phorbol-13-acetate, which almost completely blocked EGF receptor autophosphorylation. On the basis of our data, we hypothesize that tyrphostin is not a competitive inhibitor of the EGF receptor tyrosine kinase in intact cells and that it functions by an indirect mechanism.

Successful retreatment with erlotinib after erlotinib-related interstitial lung disease

2021 ◽  
pp. 030089162110200
Author(s):  
Haci M. Turk ◽  
Mustafa Adli ◽  
Melih Simsek ◽  
Altay Aliyev ◽  
Mehmet Besiroglu
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Interstitial Lung Disease ◽  
Epidermal Growth Factor ◽  
Tyrosine Kinase ◽  
Lung Disease ◽  
Receptor Tyrosine Kinase ◽  
Kinase Inhibitors ◽  
Growth Factor Receptor ◽  
Epidermal Growth

Background: Epidermal growth factor receptor tyrosine kinase inhibitors are effectively being used in the treatment of non-small cell lung cancer. Although most of their adverse effects are mild to moderate, they occasionally can cause life-threatening interstitial lung disease. We aimed to present a case of lung adenocarcinoma successfully re-treated with erlotinib after recovery with effective treatment of erlotinib-induced interstitial lung disease. Case description: A 54-year-old nonsmoking woman was diagnosed with metastatic adenocarcinoma of the lung. After progression with first-line chemotherapy, erlotinib 150 mg daily was initiated. On the 45th day of erlotinib treatment, interstitial lung disease occurred and erlotinib was discontinued. Clinical improvement was achieved with dexamethasone treatment and erlotinib was re-initiated. Ten weeks after re-initiation of erlotinib, 100 mg daily partial response was observed. Conclusions: Incidence of interstitial lung disease is higher in men, smokers, and patients with pulmonary fibrosis. Interstitial lung disease radiologically causes ground-glass opacity and consolidation. The physician should quickly evaluate new respiratory symptoms in patients treated with epidermal growth factor receptor tyrosine kinase inhibitors, discontinue the epidermal growth factor receptor tyrosine kinase inhibitor treatment, and initiate corticosteroids if clinical diagnosis is interstitial lung disease.

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