Lidocaine Inhibits Tyrosine Kinase Activity of the Epidermal Growth Factor Receptor and Suppresses Proliferation of Corneal Epithelial Cells

2004 ◽  
Vol 100 (5) ◽  
pp. 1206-1210 ◽  
Author(s):  
Masashi Hirata ◽  
Masahiro Sakaguchi ◽  
Chikako Mochida ◽  
Chie Sotozono ◽  
Kyoko Kageyama ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Growth Factor ◽  
Epithelial Cell ◽  
Tyrosine Kinase ◽  
Kinase Activity ◽  
Epithelial Cell Proliferation ◽  
Tyrosine Kinase Activity ◽  
Corneal Epithelial Cells ◽  
Corneal Epithelial ◽  
Epidermal Growth

Background Although lidocaine is recognized as an excellent topical corneal analgesic, its toxic effect on corneal epithelial cells limits its use during corneal epithelial wound healing. Mechanism of the impairment of corneal reepithelialization with lidocaine, however, has not been evaluated. The authors' previous study revealed that lidocaine inhibits the activity of tyrosine kinase receptors through the interaction with specific amino acid sequences around autophosphorylation sites, including acidic, basic, and aromatic amino acids. Epidermal growth factor receptor (EGFR), a tyrosine kinase receptor with an important role in epithelial cell proliferation after corneal wounding, also possesses these amino acids sequences around autophosphorylation sites. The authors hypothesized that lidocaine would suppress tyrosine kinase activity of EGFR and would impair corneal epithelial cell proliferation. Methods To investigate the effect of lidocaine (4 microM-40 mM) on epidermal growth factor (EGF)-stimulated autophosphorylation of EGFR, the authors studied purified EGFR in microtubes. They cultured human corneal epithelial cells (HCECs) with EGF and lidocaine to investigate the effect of lidocaine on cell proliferation and on autophosphorylation of EGFR in HCECs. Results Lidocaine (> or =400 microM) significantly suppressed EGF-stimulated autophosphorylation of the purified EGFR. In the HCEC study, EGF alone stimulated cell proliferation and increased autophosphorylation of EGFR in HCECs. Lidocaine (> or = 400 microM) significantly suppressed both the proliferation of HCECs promoted by EGF and EGF-stimulated autophosphorylation of EGFR. Conclusion Lidocaine directly inhibits tyrosine kinase activity of EGFR and suppresses the corneal epithelial cell proliferation.

scholarly journals Localization and significance of pp55, a gastric mucosal membrane protein with tyrosine kinase activity

1998 ◽  
Vol 274 (5) ◽  
pp. G863-G870 ◽  
Author(s):  
Adhip P. N. Majumdar ◽  
James R. Goldenring
Keyword(s):  
Cell Proliferation ◽  
Growth Factor ◽  
Tyrosine Kinase ◽  
Kinase Activity ◽  
Mucosal Cell ◽  
Mucous Cells ◽  
Tyrosine Kinase Activity ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Mucosal Cell Proliferation

In Fischer 344 rats, induction of gastric mucosal proliferative activity, whether the result of aging or injury or occurring after administration of epidermal growth factor, gastrin, or bombesin, is associated with a rise in tyrosine kinase activity and tyrosine phosphorylation of several mucosal proteins, including a protein with a molecular mass of 53–55 kDa. We hypothesized that this phosphotyrosine membrane protein (referred to as pp55) may play a role in regulating gastric mucosal cell proliferation and differentiation. Purification and subsequent immunoprecipitation studies now show that pp55 is a tyrosine kinase. In addition, the enzyme activity in the gastric mucosa is found to be fourfold higher in aged rats than in young rats. Incubation of gastric mucosal membranes with transforming growth factor-α (2 × 10−8 M) stimulates tyrosine kinase activity of pp55. Immuolocalization studies reveal that pp55 immunoreactivity is predominantly present in mucous cells that are located just above the proliferative zone and spasmolytic peptide-immunoreactive mucous neck cells. Tyrosine kinase activity as well as expression of pp55 are also greatly increased in the gastric mucosa after hypertonic saline-induced injury, a condition that results in stimulation of surface mucosal cell proliferation and differentiation. Our current data suggest that pp55 is a tyrosine kinase, likely localized to pre-surface cells. The presence of pp55 in pre-surface mucous cells and the expression and tyrosine kinase activity of this protein, which can be stimulated during mucosal cell proliferation and differentiation, strongly suggest a role for pp55 in differentiation of gastric surface mucous 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.

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