Dichloro-[1-(hydroxyphenyl)-2-phenylethylenediamine]platinum(II) complexes: testing on the human ovarian cancer cell lines NIH: OVCAR3 and SK OV 3

The diastereoisomeric dichloro-[1-(2-, 3- and 4-hydroxyphenyl)-2-phenylethylenediamine]platinum(II) complexes were tested on two human ovarian cancer cell lines NIH: OVCAR-3 and SK-OV-3, both resistant against cisplatin. Dichloro-[threo-1-(3-hydroxyphenyl)-2-phenylethylenediamine]platinum(II) (threo-5-PtCl2) proved to be the most active representative of the new series, producing cytocidal effects at a concentration range of 2.5 to 5.0 microM on the NIH: OVCAR-3 cell line. On the more resistant SK-OV-3 cell line, threo-5-PtCl2 was only moderately active, while in combination with BSO, a GSH level lowering compound, threo-5-PtCl2 showed a strong synergistic effect

Standardized kinetic microassay to quantify differential chemosensitivity on the basis of proliferative activity

Conventionally in vitro cytotoxicity assays are performed as single-end-point determinations. To compensate for the diversity of growth rates among different cell lines in this report we describe a computerized kinetic chemosensitivity assay based on quantification of biomass by staining cells with crystal violet. As a prerequisite four human breast cancer cell lines (MDA-MB-231, MCF-7, T-47-D and ZR-75-1) were characterized with regard to oestrogen and progesterone receptor content, modal chromosome number and proliferation kinetics depending on the number of passages in culture. With prolonged time in culture for ZR-75-1 exposed to various concentrations of cisplatinum a dose-related increase in drug effect was observed. Owing to a correction of the T/C values for the initial cell mass (at the time when drug is added) a sharp distinction between cytostatic and cytocidal drug effects becomes obvious in plots of corrected T/C values versus time of incubation. The influence of the untreated control on the corrected T/C values and possible time courses of theoretical inhibition profiles (reflecting cytostatic, transient cytotoxic or cytocidal drug effects as well as development of resistance) and their relationship to the corresponding growth curves of drug-treated cells are discussed. Chemosensitivity assays with diethylstilbestrol dipropionate, tamoxifen, melphalan, cisplatinum, vinblastine, Adriamycin and 5-fluorouracil prove the theoretical considerations to be true for MDA-MB-231, MCF-7, T-47-D and ZR-75-1 human breast cancer cell lines in practice

Chemosensitivity of human MCF-7 breast cancer cells to diastereoisomeric diaqua(1,2-diphenylethylenediamine) platinum(II) sulfates and specific platinum accumulation

Cisplatin, raceme-diaqua[1,2-bis(4-fluorophenyl)ethylenediamine]platinu m(II) sulfate (compound I), meso-diaqua[1,2-bis(4-fluorophenyl)ethylenediamine]-platinum(II) sulfate (compound II), and meso-diaqua[1,2-bis(2,6-dichloro-4- hydroxyphenyl)ethylenediamine]platinum(II) sulfate (compound III) were compared with regard to their effect on the MCF-7 breast cancer cell line in vitro. At equimolar concentrations (5 microM), cisplatin, compound I, and compound II were equiactive after 231 h drug exposure, whereas compound III was ineffective. Although compounds I and II showed markedly greater inactivation than did cisplatin after 6 h incubation with culture medium, compound I (but not compound II) exhibited antitumor activity equivalent to that of cisplatin when cells were exposed to the drugs for 6 h. Platinum measurements by neutron-activation analysis revealed that compound I was selectively and rapidly accumulated by MCF-7 cells, resulting in a high degree of DNA platination within the first few hours of drug exposure. However, when the drug-exposure period was long enough, platinum enrichment was not reflected in an overall difference in the cytotoxicity of compound I vs cisplatin. Nevertheless, compound I should be superior to cisplatin in vivo, provided that effective plasma levels can be maintained for about 6 h

Tumor inhibiting [1,2-bis(fluorophenyl)ethylenediamine]platinum(II) complexes, III: Evaluation of the mammary tumor inhibiting properties

Diastereomeric diaqua[1,2-bis(4-fluorophenyl)ethylenediamine]platinum(II) sulfates and nitrates produce a strong inhibition of the hormone-dependent MXT-M 3.2 mammary carcinoma of the B6D2F1 mouse. Besides an interference in the DNA synthesis in analogy to cisplatin a lowering of the estrogen level due to an interference in steroid biosynthesis is suggested as the mode of action. In contrast to the R,R/S,S configurated diaqua[1,2-bis(4-fluorophenyl)ethylenediamine]platinum(II) salts the corresponding R,S configurated compounds are also markedly active on the hormone-independent MXT-Ovex mammary carcinoma of the B6D2F1 mouse

Tumor inhibiting [1,2-bis(fluorophenylethylenediamine]platinum(II) complexes. Part I. Synthesis

DL- And meso-NHCH(ClH4X)CH(C6H4X)NH2 (L; X = 2-, 3-, 4-F) were prepd. from meso-1,2-bis(2-hydroxyphenyl)ethylenediamine and XC6H4CHO by a diaza Cope-rearrangement. K2PtX4 (X = Ce, I) reacted with L to give PtX2. PtLI2 reacted with Ag2SO4 or AgNO3 to give [PtL(H2O)2]SO4 (X = 2-, 3-, 4-F) and PtL(NO3)2 (X = 4-F), resp

Tumor-inhibiting [1,2-bis(fluorophenyl)ethylenediamine]platinum(II) complexes. V. Synthesis and evaluation of enantiomeric [1,2-bis-(4-fluorophenyl)ethylenediamine]dichloroplatinum(II) complexes

The enantiomeric [1,2-bis(4-fluorophenyl)ethylenediamine]dichloroplatinum(II) complexes were synthesized and tested on the hormone-sensitive human MCF7 breast cancer cell line and on the P388 leukemia of the mouse. They showed a strong and comparable activity on both tumor models

New antagonists of bombesin gastrin-releasing Peptide with C-terminal leu-psi-(ch2n)tac-nh2.

Several new pseudononapeptide bombesin/GRP analogs containing C-terminal Leu Psi(CH2N)Tac-NH2 with variations at the N-terminus, corresponding to position 6 of bombesin, have been synthesized in order to develop more potent Bn antagonists for the hormonal therapy of cancers. The biological activities of the new compounds were evaluated in vitro by investigating their ability to inhibit the binding of [I-125-Tyr(4)]Bn and to suppress the GRP(14-27)-stimulated DNA synthesis in quiescent Swiss 3T3 cells. All compounds investigated inhibited the binding of [I-125-Tyr(4)]Bn, suppressed the GRP(14-27)-induced proliferation of Swiss 3T3 cells in a dose-dependent manner and proved to act as Bn antagonists without agonistic activity. Two of the newly synthesized pseudononapeptides [Hca(6), Leu(13)Psi(CH2N)-Tac(14)]Bn(6-14) (RC-3940-II) and [D-Nal(6), Leu(13)Psi (CH2N)Tac(14)]Bn(6-14) (RC-3965-II) exhibited higher binding affinities to Swiss 3T3 cells than the Bn/GRP antagonist RC-3095 and the recently developed compound [D-Phe(6), Leu(13)Psi(CH2N) Tac(14)]Bn(6-14) (RC-3950-II). RC-3940-II caused 50% inhibition of the specific binding of [I-125-Tyr(4)]Bn to Swiss 3T3 cells at concentrations less than 1 pM and suppressed by 50% the GRP(14-27)-induced proliferation of Swiss 3T3 cells at doses one order of magnitude lower than RC-3095. This study demonstrates the importance of the nature of the N-terminus in addition to the C-terminal Leu Psi(CH2N)Tac-NH. The elimination of the free amino group in the aromatic residue in position 6 appears to increase the antagonistic activity. These findings suggest the merit of further investigations of this class of Bn/GRP antagonists for their antitumor activities in various cancers

NAA of platinated DNA after treatment of cancer cells with new platinum complexes

In MCF-7 cells treated with Pt complexes, which differed from cis-(NH3)2PtCl3 by substitution of the NH3-groups with bidentate ligands, the correlation between the degree of DNA platination and the antitumor effect of complexes was examd