Estramustine Research Articles

Microtubule depolymerization induces ferroptosis in neuroblastoma cells.

Estramustine (EM), a clinically successful hormone-refractory anti-prostate cancer drug, exhibited potent anti-proliferative activity, depolymerized microtubules, blocked cells at mitosis, and induced cell death in different cancer cells. Altered iron metabolism is a feature of cancer cells. Using EM, we examined the plausible relationship between microtubule depolymerization and induction of ferroptosis in human neuroblastoma (SH-SY5Y and IMR-32) cells. EM reduced glutathione (GSH) levels and induced reactive oxygen species (ROS) generation. The pre-treatment of neuroblastoma cells with ROS scavengers (N-acetyl cysteine and dithiothreitol) reduced the anti-proliferative effects of EM. EM treatment increased labile iron pool (LIP), depleted glutathione peroxidase 4 (GPX4) levels, and lipid peroxidation, hallmark features of ferroptosis, highlighting ferroptosis induction. Ferroptosis inhibitors (deferoxamine mesylate and liproxstatin-1) abrogated the cytotoxic effects of EM, further confirming ferroptosis induction. Vinblastine and nocodazole also increased LIP and induced lipid peroxidation in neuroblastoma cells. This study provides evidence for the coupling of microtubule integrity to ferroptosis. The results also suggest that microtubule-depolymerizing agents may be considered for developing pro-ferroptosis chemotherapeutics.

Expanding the Arsenal of PtIV Anticancer Agents: Multi‐action PtIV Anticancer Agents with Bioactive Ligands Possessing a Hydroxy Functional Group

AbstractMost multi‐action PtIV prodrugs have bioactive ligands containing carboxylates. This is probably due to the ease of carboxylating the OH axial ligands and because following reduction, the active drug is released. A major challenge is to expand the arsenal of bioactive ligands to include those without carboxylates. We describe a general approach for synthesis of PtIV prodrugs that release drugs with OH groups. We linked the OH groups of gemcitabine (Gem), paclitaxel (Tax), and estramustine (EM) to the PtIV derivative of cisplatin by a carbonate bridge. Following reduction, the axial ligands lost CO2, rapidly generating the active drugs. In contrast, succinate‐linked drugs did not readily release the free drugs. The carbonate‐bridged ctc‐[Pt(NH3)2(PhB)(Gem‐Carb)Cl2] was significantly more cytotoxic than the succinate‐bridged ctc‐[Pt(NH3)2(PhB)(Gem‐Suc)Cl2], and more potent and less toxic than gemcitabine, cisplatin, and co‐administration of cisplatin and gemcitabine.

Expanding the Arsenal of PtIV Anticancer Agents: Multi-action PtIV Anticancer Agents with Bioactive Ligands Possessing a Hydroxy Functional Group.

Most multi-action PtIV prodrugs have bioactive ligands containing carboxylates. This is probably due to the ease of carboxylating the OH axial ligands and because following reduction, the active drug is released. A major challenge is to expand the arsenal of bioactive ligands to include those without carboxylates. We describe a general approach for synthesis of PtIV prodrugs that release drugs with OH groups. We linked the OH groups of gemcitabine (Gem), paclitaxel (Tax), and estramustine (EM) to the PtIV derivative of cisplatin by a carbonate bridge. Following reduction, the axial ligands lost CO2 , rapidly generating the active drugs. In contrast, succinate-linked drugs did not readily release the free drugs. The carbonate-bridged ctc-[Pt(NH3 )2 (PhB)(Gem-Carb)Cl2 ] was significantly more cytotoxic than the succinate-bridged ctc-[Pt(NH3 )2 (PhB)(Gem-Suc)Cl2 ], and more potent and less toxic than gemcitabine, cisplatin, and co-administration of cisplatin and gemcitabine.

Re-expression of microRNA-4319 inhibits growth of prostate cancer via Her-2 suppression.

Her-2 is an epidermal growth factor receptor expressed in some prostate cancers (PC) associated with outgrowth of the tumor. Dysregulation of some microRNAs is involved in the regulation of PC pathogenesis, whereas the role of miR-4319 in PC is unknown and addressed in the current study. The levels of miR-4319 in PC tissues were determined by RT-qPCR and their association with patient survival was studied by Kaplan-Meier analysis. Targeted genes for miR-4319 were predicted by a bioinformatics algorithm and confirmed by a dual-luciferase reporter assay. Growth of cells of overexpression or inhibition of miR-4319 or Her-2 was analyzed by an MTT assay. Cell survival in response to a chemotherapeutic drug, estramustine (EM), was analyzed by CCK-8 assay. Cell apoptosis was evaluated by TUNEL assay and Western blotting for apoptosis-associated proteins. MiR-4319 levels were decreased in PC specimens, compared to corresponding normal prostate tissue. Lower levels of miR-4319 were correlated with poorer overall patients' survival. In vitro, the cell survival mediated with Her-2 against chemotherapy was inhibited by overexpression of miR-4319 and was enhanced by depletion of miR-4319. Depletion of miR-4319 in primary prostate epithelial cells increased Her-2-dependent cell growth, while re-expression of miR-4319 in PC cells inhibited Her-2-dependent cell growth and Her-2-dependent resistance to EM-induced apoptosis. The growth and chemo-resistance of PC cells may be suppressed via re-expression of miR-4319 that inhibits Her-2 signaling.

Estramustine phosphate induces prostate cancer cell line PC3 apoptosis by down-regulating miR-31 levels.

Estramustine phosphate induces prostate cancer cell line PC3 apoptosis by down-regulating miR-31 levels.

Comparative study of microtubule inhibitors – Estramustine and natural podophyllotoxin conjugated PAMAM dendrimer on glioma cell proliferation

The synthetic estramustine (EM) and natural podophyllotoxin (PODO) anti-mitotic agents that inhibit tubulin polymerization are known anticancer agents. As low bioavailability limits their anticancer properties, we investigated whether conjugation with PAMAM dendrimer (D) could enhance the activity of D-EM and D-PODO by altering their release pattern. Release kinetics indicated synthesized conjugates to be stable against hydrolytic cleavage and showed sustained release characteristics. However, release of D-EM was slow compared to D-PODO conjugate. Antitumor effect of these conjugates on glioma cells revealed (i) increased cell death and cell cycle arrest (ii) decreased migration and (iii) increased tubulin depolymerization as compared to free drug. Importantly, the effects of natural PODO conjugate on glioma cell survival and migration is more pronounced than D-EM.

Treatment patterns of castration-resistant prostate cancer: A retrospective claims database analysis.

198 Background: Prostate cancer is the most commonly diagnosed malignancy among men in the US; mortality rates are highest among those with castration-resistant prostate cancer (CRPC). Observational data on CRPC are limited. This study examined CRPC treatment patterns relative to NCCN guidelines in a large US health plan. Methods: This was a retrospective claims database analysis of commercial and Medicare Advantage enrollees with evidence of prostate cancer (ICD-9: 185.xx) between 07/01/06 – 03/31/11. CRPC patients were then identified based on prostate-specific antigen (PSA) progression (≥2 PSA increases based on ≥3 PSA values) and/or use of chemotherapy: docetaxel (DOC), mitoxantrone (MIT), estramustine (EST), or cabazitaxel (CAB). The CRPC index date was the first date of PSA progression or chemotherapy. Patients were continuously enrolled for 6 months before (baseline) and ≥6 months after the index date until 09/30/2011 or until death, if sooner (follow-up). Results: A total of 1651 patients met the CRPC selection criteria. Mean (SD) age was 70 ± 9 years, 1085 (66%) received DOC on the index date, and 467 (28%) died during follow-up. A third of patients with DOC received additional CRPC therapy during follow-up: 160 (15%) received MIT, EST, or CAB, and 239 (22%) received a secondary hormonal therapy (SHT: antiandrogens, aminoglutethimide, GnRH/LHRH antagonists, estrogen, or abiraterone acetate). Among 566 patients without DOC, 99 (17%) received a different chemotherapy (MIT = 45; EST = 52; CAB = 2), and 178 (31%) received a SHT. More than half 311 (55%) without DOC did not receive any other CRPC therapy during follow-up, of which 40 (13%) received bone-directed therapy (BDT: denosumab = 0; bisphosphonates = 27; radiation = 13). Conclusions: Consistent with NCCN guidelines, DOC was the most commonly used therapy. However, two-thirds of patients with DOC and over half of patients without DOC did not receive additional CRPC therapy after the index date. In addition, only 13% of patients with no CRPC therapy received any follow-up BDT. Additional research is warranted to understand whether clinical rationale, patient preference, or access to care may have resulted in patients not receiving additional therapy.

Oncological outcome of docetaxel-based chemotherapy for Japanese men with metastatic castration-resistant prostate cancer

ObjectivesTo retrospectively review the oncologic outcomes of docetaxel-based chemotherapy in Japanese men with metastatic castration-resistant prostate cancer (mCRPC). Materials and methodsThis study included 257 consecutive Japanese patients with mCRPC who were treated with docetaxel-based chemotherapy between April 2007 and March 2010. The prognostic significance of several clinicopathologic factors in these patients was analyzed. ResultsIn these 257 patients, the median age and serum value of prostate-specific antigen (PSA) prior to docetaxel-based chemotherapy were 72 years and 43.0 ng/ml, respectively. Of these patients, 64 (24.9%) and 193 (75.1%) received docetaxel as a weekly (30 mg/m2) and 3-weekly (70–75 mg/m2) regimen, respectively, and estramustine (EM) was administered in combination with docetaxel in 137 (53.3%). PSA decline was observed in 205 patients (79.8%), including 143 (55.6%) achieving PSA decline ≥ 50%. The median progression-free survival and overall survival (OS) were 4.3 and 25.4 months, respectively. Of several factors examined, univariate analysis identified performance status (PS), PSA value, significant clinical pain, bone metastasis, prior treatment with EM, treatment cycle, and PSA response as significant predictors of OS, of which only PS, significant clinical pain, prior treatment with EM, treatment cycle, and PSA response appeared to be independently related to OS on multivariate analysis. Furthermore, there were significant differences in OS according to positive numbers of these 5 independent risk factors. ConclusionsOncologic outcomes in Japanese mCRPC patients receiving docetaxel-based chemotherapy is generally favorable, and the risk stratification presented in this study may contribute to precisely predicting the prognosis of such patients.

Prognosis of the metastatic prostatic carcinoma and analyze the relative factors

Objective To discuss the prognosis of the metastatic prostatic carcinoma and analyze the relative factors. Methods From 2001 to 2002, 32 cases of matastatic prostatic carcinoma were admitted to our hospital, the ages ranging from 54 to 87, with the mean age of 71 years. All the diagnosis was proved by the six cores transrectal biopsy of the prostate. The serum PSA ranged from 63 to 2000 ng/ml. Two cases had the Gleason score of 2 - 6, 19 cases had the Gleason score of 7 and 11 cases had the Gleason score of 8 - 10. Preoperative routine examinations included serum testosterone, pelvic CT or MRI scan, CXR and bone scan. Twenty-seven cases were found to have osseous metastasis, among them 8 cases combined with lymph nodes metastasis, and 5 cases with lymph nodes metastasis only. All of them were treated with gonadectomy and the blockade of the androgen receptor (with Bicalutamide 50 mg/d or Flutamide 250 mg/d). It lasted 7 - 48 months with first endocrine therapy,and mid last time 23 months. After first line endocrine therapy failure, Diethylstilbestrol and Estramustine were used in the androgen-independent stage. Thirteen cases were not effective, and second therapy had effect to 19 cases and it lasted for 3 - 15 months. Results The follow-up periods ranged from 13 to 98 months, with the mean period of 33 months. Twenty-eight cases died, 4 cases survived. The median survial period was 37 months, 1-year survival rate was 100% (32/32), 3-year survival rate was 53%(17/32) , 5-year survival rate was 19%(6/23). As to the survival period, there were negative correlaions between survival and the level of PSA (r= -0. 262, P=0. 045) and the Gl-eason score (r=- 0. 624, P=0. 001). There were positive correlations between survival and the level of testosterone (r=0. 514, P=0. 008) and the age (r=0. 311, P = 0. 032). And there was no correlation between survival and the number of the positive cores of the biopsy (r=0. 211, F = 0. 158) and the clinical stage (r=0. 211, P = 0. 352). Conclusions As to the metastatic prostatic carcinoma, there are correlations between the survival and the levels of testosterone before treatment, age, the Gl-eason score and the level of PSA. There is no relationship between the survival period of the metastatic prostatic carcinoma and the number of the positive cores of the biopsy and the clinical stage. Key words: Prostatic neoplasms; Carcinoma; Metastatic; Prognosis

Ultraselective internal iliac artery chemotherapy and embolism for hormone-refractory prostate cancer

Objective To assess the application of ultraselective internal iliac artery chemotherapy and embolism for hormone-refractory prostate cancer. Methods Forty-eight patients with hormone-refractory prostate cancer were randomly divided into 2 groups: treatment group (8 cases of stage Ⅲ, 17 cases of stage Ⅳ, 10 cases with bone metastases) and control group (7 cases of stage Ⅲ, 16 cases of stage Ⅳ, 9 cases with bone metastases). Ultraselective internal iliac artery chemotherapy and embolism was performed for the treatment group with cyclophosphamidum 100 mg, pirarubicin 30mg, hydroxycamptothecin 20 mg and gel-foam as embolization material. It was carried out once per mouth for 3 times and then once every 3-6 months. Estramustine phosphate (280 mg twice per day) was administrated as well. Patients of the control group were given estramustine phosphate 280 mg twice per day alone. All the patients with bone mastatases were given 6 mg ibandronic acid per month. Results The pre-treatment prostate volume was (71.4±4.6) ml in treatment group and (72.3±3.2)ml in control group; The prostate volume was (50.2±4.1)ml and (64.2±4.5)ml, respectively, after two week treatment. The pre-treatment maximum uroflow rate (Q ) in treatment group and control group was (10.8±1.1)ml/s and (11.2±1.2) ml/s, respectively; Two weeks after treatment, the Q was (16.7±1.8)ml/s in treatment group and (13.8±1.5)ml/s in control group. The pre-treatment PSA of the patients was (64.34±5.32)ng/ml in treatment group and (65.02±6.16)ng/ml in control group; Two weeks after treatment, PSA was (23.56±4.26)ng/ml in treatment group and (56.43±4.76)ng/ml in control group. For above parameters, the difference in treatment group was significant (P 0.05) ; The difference between treat-ment group and control group was not significant before treatment (P>0.05), but was significant after treatment (P 0.05). Conclusian The ultraselective internal iliac artery chemotherapy and embolism is effective for the quality of life improvement and symptom relieving in the patients with hormone-refractory prostate cancer. Key words: Prostatic neoplasms; Carcinoma; Chemotherapy; Embolism; Estramustine phosphate

Intermittent docetaxel therapy with estramustine for hormone-refractory prostate cancer in Japanese patients

We evaluated the efficacy and toxicity of intermittent docetaxel (DCT) with estramustine (EM) for hormone-refractory prostate cancer (HRPC). Fifteen patients were enrolled. They received injected DCT (70 mg/m2 body surface) on day 1 in association with oral EM 560 mg/day (days 1-5). Treatments were repeated every 3 weeks. Serum prostate-specific antigen (PSA) levels were categorized based on the first three courses. Patients exhibiting either a response or stable disease (SD) could have a holiday from treatment (intermittent schedule). The holiday continued until elevation of the PSA level from the nadir baseline level occurred three times. All patients were evaluated for toxicity and quality of life (QOL). Survival curves were established using Kaplan-Meier graphs. The median number of courses of DCT/EM therapy was five (range, 3-12 courses). The response rate of the first cycle was 53%: 3 patients with complete response (CR), 5 patients with partial response (PR), 4 patients with SD, and 3 patients with disease progression. Eight patients were able to begin the second re-entry cycle. No patients showed a CR, 2 patients exhibited PR, 4 patients had SD, and the overall response rate was 25%. The survival rates were 93% at 1 year, and 26.1% at 2 years Grade 3-4 anemia was observed in 2 patients (13.3%), neutropenia in 11 (73.3%), and thrombocytopenia in 2 (13.3%). The QOL scale showed good QOL after 6 months, with improvement in the score for nausea and vomiting. Intermittent DCT/EM therapy was well tolerated, and has the potential to prolong survival, with a high QOL, in patients with HRPC.

Combining Docetaxel With Estramustine: Back to the Future?

Combining Docetaxel With Estramustine: Back to the Future?

Androgen-Deprivation Therapy With or Without Chemotherapy

Before results of phase III trials leading to FDA approval of docetaxel for castrate-progressive prostate cancer were published (N Engl J Med 2004; 351:1502 and N Engl J Med 2004; 351:1513), various treatments were used to manage the disease. These included conventional androgen-deprivation therapy (ADT) as well as a popular regimen consisting of ketoconazole and doxorubicin alternating weekly with vinblastine and estramustine (KA/VE). To test whether the addition of KA/VE …

The ATP-binding cassette transporter ABCA2 as a mediator of intracellular trafficking

ATP-binding cassette (ABC) transporters are a family of proteins that translocate molecules across cellular membranes. Substrates can include lipids, cholesterol and drugs. Mutations in ABC transporter genes can cause human pathologies and drug resistance phenotypes in cancer cells. ABCA2, the second member the A sub-family to be identified, was found at high levels in ovarian carcinoma cells resistant to the anti-cancer agent, estramustine (EM). In vitro models with elevated levels of ABCA2 are resistant to a variety of compounds, including estradiol, mitoxantrone and a free radical initiator, 2,2′-azobis-(2-amidinopropane) (AAPH). ABCA2 is most abundant in the central nervous system (CNS), ovary and macrophages. Enhanced expression of ABCA2 and related proteins, including ABCA1, ABCA4 and ABCA7, is found in human macrophages upon bolus cholesterol treatment. ABCA2 also plays a role in the trafficking of low-density lipoprotein (LDL)-derived free cholesterol and is coordinately expressed with genes involved in cholesterol homeostasis. Additionally, ABCA2 expression has been linked with gene cluster patterns consistent with pathologies including Alzheimer's disease (AD). A single-nucleotide polymorphism (SNP) in exon 14 of the ABCA2 gene was shown to be linked to early onset AD in humans, supporting the observation that ABCA2 expression influences levels of β-amyloid peptide (Aβ), the primary component of senile plaques. ABCA2 may play a role in cholesterol transport and affect a cellular phenotype conducive to the pathogenesis of a variety of human diseases including AD, atherosclerosis and cancer.

Combination chemotherapy with estramustine phosphate, ifosfamide and cisplatin for hormone-refractory prostate cancer.

We evaluated the efficiency and toxicity of estramustine phosphate (ECT), ifosfamide (IFM) and cisplatin (CDDP) combination chemotherapy in twenty-one patients with hormone-refractory prostate cancer (HRPC), for which there is currently no effective treatment. Patients received a daily dose of 560 mg ECT in combination with 1.2 g/m2 IFM on days 1 to 5 and 70 mg/m2 CDDP on day 1. This combination therapy was given every 3 to 4 weeks. An objective response of more than 50% reduction in prostate-specific antigen was observed in 9 of 18 patients (50%), and a more than 50% reduction in bi-dimensionally measurable soft-tissue lesions was observed in 2 of 7 patients (29%). The median duration of response among the cases showing partial response was 40 weeks, while the median duration of response of overall partial-response plus stable cases was 30 weeks. The median survival duration of all cases was 47 weeks. Toxicity was modest and acceptable. In conclusion, the ECT, IFM and CDDP combination chemotherapy regimen is a viable treatment option for HRPC. However, in comparison with our previous chemotherapy regimen of IFM and CDDP, no additional long-lasting effects resulting from the inclusion of ECT could be affirmed.

Combination chemotherapy with docetaxel, estramustine and suramin for hormone refractory prostate cancer

Purpose To investigate more effective chemotherapy against hormone refractory prostate cancer (HRPC) with the combination of estramustine (EM), docetaxel, and suramin. Patients and methods A total of 42 patients with symptomatic, progressive HRPC were included in this study. We evaluated the activity of the following schedule: EM 10 mg/kg orally daily on Days 1 to 21 every 28 days, docetaxel 70 mg/m 2 IV on Day 2 every 28 days and a total doses of 2150 mg of suramin in every cycle. Treatment was continued until disease progression or excessive toxicity. Results Median follow-up was 23.4 months. A median of 8.8 consecutive cycles was administered per patient. In the 25 patients with lymphadenopathy, there were three (12%) complete and 18 (72%) partial responses for a measurable disease response rate of 84%. Levels of prostatic specific antigen (PSA) decreased by greater than 50% in 100% of patients and by greater than 90% in 76.2%. The median time to progression was 57 weeks and median overall survival was 132 weeks. A decline in PSA of ≥50% lasting ≥30 days was significantly associated with a prolonged median time to progression and median overall survival. Tumor volume reduction and/or antitumor treatment effects were observed in 88% of patients. A significant decrease in mean pain score from 7.8 (range, 6–10) to 2.2 (range, 0–4) ( P < 0.001) was achieved in 78%. Of patients with bone metastasis, 30.5% demonstrated a partial response. The mean Eastern Cooperative Oncology Group (ECOG) performance score improved from 2.8 to 1.5 at the end of treatment period. There was no therapy-related death. The predominant toxicities were Grade 3 or 4 leukopenia in 33.3%, anemia in 21%, thrombocytopenia in 21.4%, cardiac ischemia in 4.7%, and rash in 4.7%. Conclusion The combination of docetaxel, EM, and suramin is a highly effective regimen for HRPC. Although hematologic and gastrointestinal toxicities were modest, these were easily managed medically.

Synthesis of estromustine, estramustine and estramustine phosphate labelled with deuterium

AbstractThe preparation of estromustine (EoM), estramustine (EaM) and estramustine phosphate (EMP) specifically labelled with deuterium is reported. A two‐step, one‐pot procedure based on the reaction of N,N‐bis(2‐chloroethyl)carbamoyl chloride with the commercially available [2,4,16,16‐2H4]estrone (1) or [2,4,16,16,17‐2H5]estradiol (2) afforded [2,4,16,16‐2H4]estromustine (3) and [2,4,16,16,17‐2H5]estramustine (4), respectively. The phosphorylation of 4 followed by hydrolysis gave [2,4,16,16,17‐2H5]estramustine phosphate (5) in 65% chemical yield from 2. Copyright © 2004 John Wiley &amp; Sons, Ltd.

Phase I Clinical and Pharmacologic Trial of Intravenous Estramustine Phosphate

PURPOSE: To determine the dose-limiting toxicities, maximum-tolerated dose, and pharmacokinetics of intravenous estramustine phosphate (IV EMP). PATIENTS AND METHODS: A total of 31 patients with hormone-refractory prostate cancer received IV EMP as a 30- to 90-minute infusion weekly (n = 28) or for 3 consecutive days followed by a single weekly dose (n = 3). IV EMP dose was escalated from 500 to 3,000 mg/m2. Pharmacokinetics of EMP and the metabolites estramustine (EaM), estromustine (EoM), estradiol, and estrone were assessed after weeks 1 and 4 of treatment. RESULTS: The initial IV EMP infusion caused perineal discomfort that was ameliorated by lengthening the infusion time. Other common toxicities were grade 1 to 2 hepatotoxicity, nausea or vomiting, and fatigue or malaise. Lower-extremity thrombosis occurred in one patient, and two others developed upper-extremity thrombosis associated with venous infusion catheters. Dose-limiting fatigue and hypotension occurred at 3,000 mg/m2, and cumulative fatigue...

Results of a Phase II Study Using Estramustine Phosphate and Vinblastine in Combination with High‐Dose Three Dimensional Conformal Radiotherapy for Patients with Locally Advanced Prostate Cancer.

Results of a Phase II Study Using Estramustine Phosphate and Vinblastine in Combination with High‐Dose Three Dimensional Conformal Radiotherapy for Patients with Locally Advanced Prostate Cancer.

Detection of chromosome loss and gain induced by griseofulvin, estramustine, and vanadate in binucleated lymphocytes using FISH analysis

Cytochalasin B-blocked binucleated human lymphocytes from a healthy male donor were used to detect micronucleus induction and other aneuploidy events (chromosome loss and gain) after treatment with griseofulvin (GF), estramustine (EM), and sodium orthovanadate (Na(3)VO(4)). A two-color FISH was performed by using centromeric probes for chromosome 2 (FITC labeled) and the X chromosome (TRITC labeled) to measure chromosome loss and gain events in binucleated cells. GF induced mainly aneuploid binucleates involving the X chromosome, but this was not associated with preferential loss of one of the two chromosomes. EM preferentially induced aneuploidy of chromosome 2, and Na(3)VO(4) of the X chromosome. Our results indicate that chromosome malsegregation events (chromosome loss and/or gain) are probably not randomly induced, suggesting that different mechanisms leading to aneuploidy may be either chromosome-dependent or compound- and dose- related.