estramustine and Ovarian-Neoplasms

Microtubules are one of the major filament of the cytoskelton and play a role in various biological functions such as mitosis, cell motility and intracellular transport. Therefore, microtubules are considered one of the most important molecular targets for cancer chemotherapy. Tubulin is one of the major microtubular components, and its polymerization and depolymerization regulate microtubular dynamics. Other microtubular components such as microtubule-associated protein (MAPs), actin, and intermediate and microfilaments have also been demonstrated to be involved in microtubular dynamics. Recent studies provide evidence that the functions of MAPs and filaments in microtubule assembly are regulated by phosphorylation, which is catalyzed by mitogenactivated protein kinase (MAP kinase) and cdc2 kinase. Antimitotic agents that disrupt microtubules can be classified in two categories according to the mechanism of action, vinca alkaloids and taxanes. Vinca alkoloids, estramustine, rhizoxin, and E7010 inhibit microtubule polymerization. In contrast, taxanes such as paclitaxel and docetaxel promote polymerization of microtubules and enhance microtubule stability. We have demonstrated that paclitaxel inhibits the catalytic activity of MAP kinase and cdc2 kinase in lung cancer cell lines. This biological effect may be responsible for the increased affinity between MAP2 and tubulins, resulting in promotion of microtubule assembly. Factors that contribute to the resistance to antimitotic agents include intracellular accumulation of the drugs, genetic or functional alternations in tubulin, and alternations in MAP kinase cascade. Antimitotic agents showed a broad spectrum of preclinical antitumor activity. Clinical trials of taxanes revealed that they were effective for several cancers which were advanced or resistant against other anticancer drugs, especially for breast cancers, ovarian cancers and non-small cell lung cancers.

Topics: Animals; Antineoplastic Agents; Antineoplastic Agents, Alkylating; Antineoplastic Agents, Phytogenic; Breast Neoplasms; Calcium-Calmodulin-Dependent Protein Kinases; Carcinoma, Small Cell; Drosophila Proteins; Estramustine; Extracellular Signal-Regulated MAP Kinases; Female; Humans; Lung Neoplasms; Mice; Microtubules; Ovarian Neoplasms; Paclitaxel; Vinca Alkaloids

Estramustine phosphate (EMP) is thought to form a chemical link between estradiol and non-nitrogen mustard. An estramustine-binding protein has been isolated in prostate, breast, and brain cancers as well as in malignant melanoma cells. Estramustine phosphate's ability to bind to microtubular-associated proteins and to interfere with mdr-mediated drug efflux are thought to result in its enhancement of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) activity in cell lines and in its ability to affect hormone-resistant prostate cancer. This phase I study administered combined paclitaxel and EMP to 25 women with ovarian, breast, and other tumors and assessed efficacy and toxicity. Estramustine phosphate was administered at two dose levels, 900 or 1,200 mg/m2 daily on days 1, 2, and 3 in 3-week cycles. On day 3, paclitaxel (150, 180, 210, or 225 mg/m2) was given concomitantly by 3-hour infusion. Therapeutic effects were noted in all patients. Partial responses were noted in three of eight patients with breast cancer who had failed to improve on paclitaxel alone. Three other patients experienced prolonged stable disease. Only moderate toxicities were noted until EMP levels of 1,200 mg/m2 were reached. At these dose levels, gastrointestinal toxicities became more prominent. The addition of EMP to paclitaxel allowed patients to receive paclitaxel for longer periods, and may have enhanced the therapeutic effects of paclitaxel. If so, the mechanisms of such enhancement warrant investigation. The two drugs may work on different aspects of microtubular function, for example, or may reduce efflux of paclitaxel in P-glycoprotein overexpressed tumors.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Estramustine; Fatigue; Female; Humans; Middle Aged; Nausea; Ovarian Neoplasms; Paclitaxel; Treatment Outcome; Vomiting

This study was conducted to evaluate whether estramustine (estrogen mustard [EM]) is a promising alternative in the treatment of patients with epithelial ovarian carcinoma (OVCA). EM is a microtubule-associated protein (MAP) specific antimicrotubule agent with low toxicity.. The authors investigated the ability of EM to induce apoptosis and suppress colony formation of OVCA cells. Paclitaxel was used as a positive control. DNA electrophoresis and terminal deoxynucleotidyl dUTP-X nick end labeling (TUNEL) assays were used to detect internucleosomal DNA fragmentation. Flow cytometry was used to identify apoptotic cells and disturbance of the cell cycle of EM-treated OVCA cells further. Quantitation of detached cultured cells also provided a relative estimate of the apoptotic response of OVCA cells to treatment with EM. The colony formation assay was used to evaluate the effects of EM on clonogenicity.. The effects of EM on four OVCA cell lines in culture were highly similar to those of paclitaxel in causing apoptosis and inhibiting clonogenicity. DNA electrophoresis and TUNEL assays showed that EM induced internucleosomal DNA fragmentation in OVCA cells. Flow cytometry showed changes typical of apoptotic changes and cell cycle block and synchronization at the G2/M-phase. Counting of detached cells showed a log-dose response to EM treatment. The colony formation assay also showed a log-dose response suppression of OVCA cell clonogenicity after treatment with EM.. EM may be a promising candidate in the clinical treatment of patients with OVCA. The lower toxicity and MAP specific action of EM is a novel chemotherapy for OVCA.

Topics: Antineoplastic Agents, Alkylating; Apoptosis; Carcinoma; Estramustine; Female; Humans; In Situ Nick-End Labeling; Ovarian Neoplasms; Paclitaxel; Tumor Cells, Cultured; Tumor Stem Cell Assay

Topics: Antineoplastic Agents, Hormonal; Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Docetaxel; Drug Synergism; Estramustine; Female; Humans; Neoplasms; Ovarian Neoplasms; Paclitaxel; Taxoids

An estramustine-resistant human ovarian carcinoma cell line, SKEM, was generated to explore resistance mechanisms associated with this agent. Cytogenetic analysis revealed that SKEM cells have a homogeneously staining region (hsr) at chromosome 9q34. Microdissection of the hsr, followed by fluorescence in situ hybridization to SKEM and normal metaphase spreads, confirmed that the amplified region was derived from sequences from 9q34. In situ hybridization with a probe specific for ABC2, a gene located at 9q34 that encodes an ATP-binding cassette 2 (ABC2) transporter, indicated that this gene is amplified approximately 6-fold in the estramustine-resistant cells. Southern analysis confirmed that ABC2 was amplified in SKEM, and Northern analysis indicated that the ABC2 transcript was overexpressed approximately 5-fold. The ABC1 gene located at 9q22-31 was not amplified in the resistant cells, and mRNA levels of several other ABC transporter genes were unaltered. Consistent with the concept that increased ABC2 expression contributes to the resistant phenotype, we observed that the rate of efflux of dansylated estramustine was increased in SKEM compared with control cells. In addition, antisense treatment directed toward ABC2 mRNA sensitized the resistant cells to estramustine. Together, these results suggest that amplification and overexpression of ABC2 contributes to estramustine resistance and provides the first indication of a potential cellular function for this product.

Topics: Antineoplastic Agents, Hormonal; ATP-Binding Cassette Transporters; Carcinoma; Chromosomes, Human, Pair 9; Down-Regulation; Drug Resistance, Neoplasm; Estramustine; Female; Gene Amplification; Gene Expression Regulation, Neoplastic; Humans; In Situ Hybridization, Fluorescence; Oligonucleotides, Antisense; Ovarian Neoplasms; Polymerase Chain Reaction; RNA, Messenger; Transcription, Genetic; Tumor Cells, Cultured

Topics: ATP Binding Cassette Transporter, Subfamily B, Member 1; Carrier Proteins; Drug Resistance; Estramustine; Female; Humans; Membrane Glycoproteins; Neoplasm Proteins; Ovarian Neoplasms; Tumor Cells, Cultured

Previous preclinical studies of combinations of estramustine and vinblastine or paclitaxel (Taxol) have shown that it is possible to achieve a greater than additive cytotoxicity with these antimicrotubule drug combinations. Phase II studies in hormone-refractory prostate cancer have demonstrated clinical antitumor activity of sufficient magnitude to stimulate further laboratory and clinical studies of these drugs combinations.. Our purpose was to characterize the interactions of estramustine with P-glycoprotein and to determine its effects.. Standard laboratory techniques were used to study the effects of estramustine on intracellular drug concentrations, cytotoxicity, and induction of messenger RNA (mRNA) for the MDR1 (also known as PGY1) gene. Using a photoaffinity analogue of estramustine 17-0-[[2-[3-(4-azido-3-[125I]-iodophenyl) propionamido]ethyl]-carbamyl]estradiol-3-N-bis(2-chloroethyl)ca rba mate ([125I]AIPP-estramustine), binding to the membrane proteins of human ovarian (SKOV3) and their multidrug-resistant counterpart SKVLB1 cells was studied. Southern-blot analysis was performed on DNA extracted from human prostate carcinoma wild-type DU145, estramustine-resistant cell line (E4), and SKVLB1 cells.. Membrane fractions from SKOV3 and SKVLB1 cells were analyzed for proteins that could be photoaffinity labeled with [125I]AIPP-estramustine. Competitive inhibition of this binding was achieved with excess concentrations of (in order of efficacy) estramustine, vinblastine, verapamil, progesterone, and to a lesser degree, by paclitaxel but not with estramustine phosphate, estradiol, and estriol. SKVLB1 cells accumulated much less [3H]vinblastine and [3H]paclitaxel than did SKOV3 cells. Estramustine caused a concentration-dependent enhancement of drug accumulation in the SKVLB1 cells to a maximum of approximately 12-fold. No effect of estramustine was apparent for the wild-type SKOV3 cells. In comparison with verapamil, estramustine was less effective as a modulator; however estramustine demonstrated good chemosensitizing activity in combination with actinomycin D and vinblastine. Neither short-term, low-dose no longer-term, higher concentration were found to produce measurable transcript (mRNA for the MDR1 gene levels. Such data suggest that, at least levels. Such data suggest that, at least for two distinct human cell line (SKOV3 and DU145), estramustine does not induce the overexpression of the MDR1 gene.. It is apparent from the P-glycoprotein data that estramustine interacts with this efflux pump, altering intracellular drug accumulation. Overall, the nonempiric basis for including estramustine in clinical protocols that contain other multidrug-resistant drugs is strengthened by the present data.

Topics: ATP Binding Cassette Transporter, Subfamily B, Member 1; Carrier Proteins; Drug Resistance; Estramustine; Female; Gene Expression; Humans; Membrane Glycoproteins; Neoplasm Proteins; Ovarian Neoplasms; Phenotype; Protein Binding; RNA, Messenger; Tumor Cells, Cultured

After having succeeded in imaging the prostate with 131I-Estracyt in our former experiments we tried to use the same method for scanning gynecological tumors. In about fifty per cent of the patients (34 cases) there was a convenient accumulation of the labeled estrogen, first of all the adenoid tumors, myomas of uteri and carcinomas can take up this radiopharmacon. Though the number of cases is rather low it is to be concluded that tumors of hormonal dependence can be scanned using estrogen hormon. Further investigations are in progress.

Topics: Estramustine; Female; Genital Neoplasms, Female; Humans; Iodine Radioisotopes; Nitrogen Mustard Compounds; Ovarian Neoplasms; Radionuclide Imaging; Uterine Neoplasms