PT  - JOURNAL ARTICLE
AU  - H. Ben-Bassat
AU  - S. Rosenbaum-Mitrani
AU  - Z. Hartzstark
AU  - R. Levitzki
AU  - M. Chaouat
AU  - Z. Shlomai
AU  - B. Y. Klein
AU  - N. Kleinberger-Doron
AU  - A. Gazit
AU  - R. Tsvieli
AU  - A. Levitzki
TI  - Tyrphostins That Suppress the Growth of Human Papilloma Virus 16-Immortalized Human Keratinocytes
DP  - 1999 Sep 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 1442--1457
VI  - 290
IP  - 3
4099  - http://jpet.aspetjournals.org/content/290/3/1442.short
4100  - http://jpet.aspetjournals.org/content/290/3/1442.full
SO  - J Pharmacol Exp Ther1999 Sep 01; 290
AB  - Human papilloma virus 16 (HPV16) is considered to be the causative agent for cervical cancer, which ranks second to breast cancer in women’s malignancies. In an attempt to develop drugs that inhibit the malignant transformation of HPV16-immortalized epithelial cells, we examined the effect of tyrphostins on such cells. We examined the effect of tyrphostins from four different families on the growth of HPV16-immortalized human keratinocytes (HF-1) cells. We found that they alter their cell cycle distribution, their morphology, and induce cell death by apoptosis. The effects of tyrphostins on HF-1 cells are different from their effects on normal keratinocytes. Growth suppression by AG555 and AG1478 is accompanied by 30% apoptosis in HF-1 cells, but this is not observed in normal keratinocytes. Tyrphostin treatment produces distinctive morphological changes in HF-1 cells and in normal keratinocytes; however, the culture organization of normal keratinocytes is less disrupted. These differential effects of the tyrphostins on HPV16-immortalized keratinocytes compared with their effects on normal keratinocytes suggests that these compounds are suitable candidates for the treatment of papilloma. Previous and present results indicate that group 1 tyrphostins, which inhibit Cdk2 activation, and group 2 tyrphostins, represented by AG1478, a potent epidermal growth factor receptor kinase inhibitor, induce cell cycle arrest; and, in the case of HF-1 cells, apoptosis and differentiation. Cells accumulate in the G1 phase of the cell cycle at the expense of S and G2 + M. These compounds block the growth of normal keratinocytes without inducing apoptosis or differentiation, causing them to accumulate in G1. AG17, which belongs to group 4, exerts its antiproliferative effect mainly by increasing the fractions of cells in G1 with a concomitant decrease in the fraction of cells in S and G2 + M. The American Society for Pharmacology and Experimental Therapeutics