@article{oai:nagoya.repo.nii.ac.jp:00015492,
 author = {CHEN, FAN and GOTO, SETSUKO and NAWA, AKIHIRO and OKAMOTO, TOMOMITSU and TOMODA, YUTAKA},
 issue = {1-4},
 journal = {Nagoya Journal of Medical Science},
 month = {Mar},
 note = {Binding of epidermal growth factor (EGF) to its receptor was evaluated in the four cultured choriocarcinoma cell lines BeWo, NaUCC-1, NaUCC-2. and NaUCC-3. Also, the effect of the anti-tumor drugs actinomycin-D (Act-D) and methotrexate (MTX) on the EGF receptor binding was investigated in these cell lines. Incubation of these cells with [125I]EGF at 37°C resulted in a higher binding than that at 22°C or at 4°C. These bindings were saturable during 30- to 60-min incubation, and were specific and reversible. Scatchard analysis showed that the maximal number of receptor binding sites was 2.89 x 10^3/cell in BeWo cells, 2.04 x 10^3/cell in NaUCC-1 cells, 1.84 x 10^3/cell in NaUCC-2 cells, and 1.01 x 10^3/cell in NaUCC-3 cells. Preincubation with Act-D or MTX for 24 hr decreased the number of receptor binding sites (26 %-53 %) and slightly increased the receptor binding affinities. Combination of the two drugs resulted in a further diminution of EGF receptor binding sites in BeWo, NaUCC-1, and NaUCC-3 cells, respectively, but reversed the Act-D effect in NaUCC-2 cells. These results indicated that choriocarcinoma tissue is rich in EGF receptors, that the anti-tumor drugs Act-D and MTX diminish the receptor binding sites in the tissue. and suggest that MTX might induce a drug resistance to Act-D in some choriocarcinoma tissue.},
 pages = {5--11},
 title = {Receptor Binding of Epidermal Growth Factor in Cultured Human Choriocarcinoma Cell Lines: Effects of Actinomycin-D and Methotrexate},
 volume = {52},
 year = {1990}
}