Home > Treatments > Chemotherapy > Drugs > Epirubicin


"An anthracycline which is the 4'-epi-isomer of doxorubicin. The compound exerts its antitumor effects by interference with the synthesis and function of DNA." (MeSH 2013)

Found this page useful?

Web Resources: Epirubicin
Latest Research Publications

Web Resources: Epirubicin (6 links)

Latest Research Publications

This list of publications is regularly updated (Source: PubMed).

Juang V, Lee HP, Lin AM, Lo YL
Cationic PEGylated liposomes incorporating an antimicrobial peptide tilapia hepcidin 2-3: an adjuvant of epirubicin to overcome multidrug resistance in cervical cancer cells.
Int J Nanomedicine. 2016; 11:6047-6064 [PubMed] Free Access to Full Article Related Publications
Antimicrobial peptides (AMPs) have been recently evaluated as a new generation of adjuvants in cancer chemotherapy. In this study, we designed PEGylated liposomes encapsulating epirubicin as an antineoplastic agent and tilapia hepcidin 2-3, an AMP, as a multidrug resistance (MDR) transporter suppressor and an apoptosis/autophagy modulator in human cervical cancer HeLa cells. Cotreatment of HeLa cells with PEGylated liposomal formulation of epirubicin and hepcidin 2-3 significantly increased the cytotoxicity of epirubicin. The liposomal formulations of epirubicin and/or hepcidin 2-3 were found to noticeably escalate the intracellular H2O2 and O2(-) levels of cancer cells. Furthermore, these treatments considerably reduced the mRNA expressions of MDR protein 1, MDR-associated protein (MRP) 1, and MRP2. The addition of hepcidin 2-3 in liposomes was shown to markedly enhance the intracellular epirubicin uptake and mainly localized into the nucleus. Moreover, this formulation was also found to trigger apoptosis and autophagy in HeLa cells, as validated by significant increases in the expressions of cleaved poly ADP ribose polymerase, caspase-3, caspase-9, and light chain 3 (LC3)-II, as well as a decrease in mitochondrial membrane potential. The apoptosis induction was also confirmed by the rise in sub-G1 phase of cell cycle assay and apoptosis percentage of annexin V/propidium iodide assay. We found that liposomal epirubicin and hepcidin 2-3 augmented the accumulation of GFP-LC3 puncta as amplified by chloroquine, implying the involvement of autophagy. Interestingly, the partial inhibition of necroptosis and the epithelial-mesenchymal transition by this combination was also verified. Altogether, our results provide evidence that coincubation with PEGylated liposomes of hepcidin 2-3 and epirubicin caused programmed cell death in cervical cancer cells through modulation of multiple signaling pathways, including MDR transporters, apoptosis, autophagy, and/or necroptosis. Thus, this formulation may provide a new platform for the combined treatment of traditional chemotherapy and hepcidin 2-3 as a new adjuvant for effective MDR reversal.

Sun F, Shi J, Geng C
Dexrazoxane improves cardiac autonomic function in epirubicin-treated breast cancer patients with type 2 diabetes.
Medicine (Baltimore). 2016; 95(44):e5228 [PubMed] Related Publications
OBJECTIVE: The study objective was to investigate the protective effects of dexrazoxane (DRZ) on the cardiac autonomic nervous system (ANS) activity in anthracycline-treated breast cancer patients with diabetes.
METHODS: A total of 110 early stage breast cancer patients with type 2 diabetes were divided randomly into 2 even groups: chemotherapy alone (Chemo) and chemotherapy + DRZ (Chemo + DRZ). All patients underwent adjuvant chemotherapy (80 mg/m epirubicin and 500 mg/m cyclophosphamide) for a total of 6 cycles with 21 days/cycle. The Chemo + DRZ group patients were treated intravenously with 800 mg/m DRZ 30 minutes prior to the administration of epirubicin, while the Chemo group patients were given saline. The cardiac ANS function was evaluated for each patient before and after 6 cycles of chemotherapy by resting heart rate (RHR) and heart rate variability (HRV), which was evaluated by both time and frequency domains.
RESULTS: Before and after chemotherapy, patients in both groups showed significant decreases in HRV indices and increases in RHR and the low-frequency/high-frequency ratio. There were no significant differences between Chemo and Chemo + DRZ groups in terms of RHR and HRV indices before chemotherapy; however, after chemotherapy, patients in the Chemo group had a higher average RHR and lower HRV indices compared with patients in the Chemo + DRZ group.
CONCLUSION: DRZ protects the cardiac ANS in epirubicin-treated early stage breast cancer patients with diabetes.

Wu J, Xue X, Zhang B, et al.
Enhanced antitumor activity and attenuated cardiotoxicity of Epirubicin combined with Paeonol against breast cancer.
Tumour Biol. 2016; 37(9):12301-12313 [PubMed] Related Publications
Epirubicin is widely used for the therapy of various breast cancers. However, it has serious adverse side effects, particularly cardiotoxicity, which can cause irreversible damage in patients. Paeonol, an active component from Moutan Cortex, enhances antitumor activity of antineoplastics and reduces toxicities induced by chemotherapeutics. In this study, we investigated the anticancer activity of Paeonol in combination with Epirubicin against breast cancer and the alleviated effect of Paeonol on cardiotoxicity induced by Epirubicin. The apoptosis results and the coefficient of drug interaction values suggested significantly synergistic in combination of Paeonol and Epirubicin to 4T1 and MCF-7 cells. We further examined antitumor activities of Paeonol or/and Epirubicin in vivo in BALB/c mice and found that co-treatment of Paeonol and Epirubicin had a synergistic inhibitory effect on tumor growth and enhanced apoptosis in tumors in vivo compared with Epirubicin alone. Increased apoptosis was associated with the activation of apoptosis-related proteins including PARP, Bax, caspase 3, and inhibition of p38/JNK/ERK MAPKs. Moreover, Paeonol exhibited a mitigative effect on Epirubicin-induced cardiotoxicity through suppressing NF-kB pathway. In conclusion, Paeonol (a) enhanced the antitumor activity of Epirubicin in a synergistic manner against breast cancer cells via inhibiting p38/JNK/ERK MAPKs and (b) alleviated Epirubicin-induced cardiotoxicity by suppressing NF-kB pathway. These findings suggest that combination of Paeonol and Epirubicin is potentially applicable for breast cancer treatment.

Evangelatov A, Skrobanska R, Mladenov N, et al.
Epirubicin loading in poly(butyl cyanoacrylate) nanoparticles manifests via altered intracellular localization and cellular response in cervical carcinoma (HeLa) cells.
Drug Deliv. 2016; 23(7):2235-2244 [PubMed] Related Publications
OBJECTIVE: Drug loading into nanocarriers is used to facilitate drug delivery to target cells and organs. We have previously reported a change in cellular localization of epirubicin after loading to poly(butyl cyanoacrylate) (PBCA) nanoparticles. We aimed to further investigate the altered cellular localization and cellular responses to the described drug formulation.
MATERIALS AND METHODS: HeLa cells were treated with epirubicin-loaded PBCA nanoparticles prepared by the pre-polymerization method. A systematic study was performed to evaluate the formulation cytotoxicity. Cellular localization and uptake of the formulation as well as cellular response to the treatment were evaluated.
RESULTS: Our studies revealed decreased cytotoxicity of the nanoparticle-formulated epirubicin compared to the free drug as well as a noticeable change in the drug's intracellular localization. Epirubicin-loaded nanoparticles were internalized via endocytosis, accumulated inside endosomal vesicles and induced a two-fold stronger pro-apoptotic signal when compared to the free drug. The level of the tumor suppressor protein p53 in HeLa cells increased significantly upon treatment with free epirubicin, but remained relatively unchanged when cells were treated with equivalent dose of nanoparticle-loaded drug, suggesting a possible shift from p53-dependent DNA/RNA intercalation-based induction of cytotoxicity by free epirubicin to a caspase 3-induced cell death by the epirubicin-loaded PBCA formulation.

Guo W, Wang Y, Wang Z, et al.
Inhibiting autophagy increases epirubicin's cytotoxicity in breast cancer cells.
Cancer Sci. 2016; 107(11):1610-1621 [PubMed] Free Access to Full Article Related Publications
Chemotherapy, radiotherapy, and endocrinotherapy are documented to induce autophagy among breast cancer cells, but the role of autophagy in this disease has been attributed as cytoprotective as well as tumor-suppressing. Thus we studied MDA-MB-231 and SK-BR-3 breast cancer cell lines treated with epirubicin (EPI) to assess autophagy and apoptosis. We found out that EPI induced apoptosis and autophagy in both cell lines. The lysosomal inhibitor bafilomycin A1 inhibited cellular autophagy and enhanced EPI-triggered apoptosis, perhaps due to inhibition of autolysosome formation, which then inhibited autophagic effects of engulfing and clearing damaged mitochondria. This inhibition increased mitochondrial cytochrome C release which augmented epirubicin-induced caspase-dependent apoptosis and cytotoxicity. In addition, the lysosomal neutralizing agent ammonia chloride (AC), and Atg7 knockdown by siRNA, could inhibit epirubicin-triggered autophagy, enhance cytotoxicity, and increase caspase-9- and caspase-3-dependent apoptosis. Thus, autophagy plays a prosurvival role in EPI-treated MDA-MB-231 and SK-BR-3 cells, and autophagy inhibition can potentially reverse this effect and increase the cytotoxicity of EPI.

Paszel-Jaworska A, Totoń E, Dettlaff K, et al.
Increased proapoptotic activity of electron beam irradiated doxorubicin and epirubicin in multidrug-resistant human leukemic cells.
Chem Biol Interact. 2016; 258:69-78 [PubMed] Related Publications
This study evaluated the effect of electron beam irradiation on the cytotoxic activity of anthracycline antibiotics such as doxorubicin (DOX), epirubicin (EPI), and dunorubicin (DAU) in human acute lymphoblastic leukemia cell line CCRF-CEM and its multidrug-resistant variant CCRF-VCR1000 cell line characterized by the overexpression of ABCB1 gene. Drugs were irradiated at doses of 10 and 25 kGy. Data from EPR studies proved that the highest concentration of free radicals was found in DOX and that the number of stable free radicals is always greater after irradiation. In in vitro studies, a higher cytotoxic activity of irradiated DOX and EPI in multidrug-resistant CCRF-VCR1000 cells was observed. This tendency was maintained during the storage at 4 °C for 90 days. Changes in CCRF-CEM cells' viability were not dependent on the irradiation status and its dose and were only drug-concentration dependent in all measurement time points. It was proved that increased potency of 25 kGy e-beam irradiated drugs results from their enhanced proapoptotic activity. Apoptotic cell death observed in CCRF-VCR1000 cells treated with irradiated drugs was caspase-8, -9, and -3 dependent and related to the increased Bax/Bcl-2 ratio. No significant differences in the effects of irradiated and non-irradiated drugs on p53 and NFκB transcription factor level and their translocation to the nucleus were noted. Increased activity of the irradiated drugs was not dependent on ABCB1 level.

Cainap C, Nagy V, Seicean A, et al.
Results of third-generation epirubicin/cisplatin/xeloda adjuvant chemotherapy in patients with radically resected gastric cancer.
J BUON. 2016 Mar-Apr; 21(2):349-59 [PubMed] Related Publications
PURPOSE: The purpose of this study was to evaluate the efficacy and toxicity of a third-generation chemotherapy regimen in the adjuvant setting to radically operated patients with gastric cancer. This proposed new adjuvant regimen was also compared with a consecutive retrospective cohort of patients treated with the classic McDonald regimen.
METHODS: Starting in 2006, a non-randomized prospective phase II study was conducted at the Institute of Oncology of Cluj-Napoca on 40 patients with stage IB-IV radically resected gastric adenocarcinoma. These patients were administered a chemotherapy regimen already considered to be standard treatment in the metastatic setting: ECX (epirubicin, cisplatin, xeloda) and were compared to a retrospective control group consisting of 54 patients, treated between 2001 and 2006 according to McDonald's trial.
RESULTS: In a previous paper, we reported toxicities and the possible predictive factors for these toxicities; in the present article, we report on the results concerning predictive factors on overall survival (OS) and disease free survival (DFS). The proposed ECX treatment was not less effective than the standard suggested by McDonald's trial. Age was an independent prognostic factor in multivariate analysis. N3 stage was an independent prognostic factor for OS and DFS. N ratio >70% was an independent predictive factor for OS and locoregional disease control. The resection margins were independent prognostic factors for OS and DFS.
CONCLUSION: The proposed treatment is not less effective compared with the McDonald's trial. Age was an independent prognostic factor in multivariate analysis. N3 stage represented an independent prognostic factor and N ratio >70% was a predictive factor for OS and DFS. The resection margins were proven to be independent prognostic factors for OS and DFS.

Petrioli R, Roviello G, Zanotti L, et al.
Epirubicin-based compared with docetaxel-based chemotherapy for advanced gastric carcinoma: A systematic review and meta-analysis.
Crit Rev Oncol Hematol. 2016; 102:82-8 [PubMed] Related Publications
Docetaxel or Epirubicin-based regimens are both approved for the treatment of metastatic gastric cancer. We perform a systemic review with metanalysis to evaluate the efficacy and toxicities of docetaxel-based chemotherapy compared with epirubicin-containing regimens. A metaanalysis of randomized studies in accordance with the preference guidelines for reported items in systematic reviews and meta-analyses is performed in which the databases of PubMed, the Cochrane Library, and the ASCO University Meeting were searched for relevant publications. The primary outcome was efficacy, the secondary toxicities. A total of 553 cases were included in the meta-analysis; 278 received epirubicin-based treatment and 313 received docetaxel. The pooled risk ratio to achieve an objective response and a disease control rate were 1.08 (95% CI 0.85-1.37; P=0.52) and 0.90 (95% CI 0.75-1.08; P=0.27) respectively. EPI arm showed a decrease in the risk of neutropenia, anemia, fatigue, asthenia and diarrhea, paraesthesia; docetaxel arm showed a decrease in the risk of leucopenia, thrombocytopenia, anorexia, nausea, nausea-vomiting, stomatitis and neutropenic fever. The results of our study suggest a similar activity of docetaxel and epirubicin-based chemotherapeutic regimens in metastatic gastric cancer. Other parameters as, comorbidity, concomitant diseases and prior therapies should be taken into account to address the clinician's choice in selecting the best therapeutical approach for any single patient.

Zhang L, Li G, Gao M, et al.
RGD-peptide conjugated inulin-ibuprofen nanoparticles for targeted delivery of Epirubicin.
Colloids Surf B Biointerfaces. 2016; 144:81-9 [PubMed] Related Publications
Recently, chemotherapy-based polymeric nanoparticles have been extensively investigated for solid tumor treatment. Tumor targeted nanoparticles demonstrated great potential for improved accumulation in the tumor tissue, superior anticancer activity and reduced side effects. Thus, inulin-ibuprofen polymer was synthesized by esterification between inulin and ibuprofen, and RGD targeted epirubicin (EPB) loaded nanoparticles were prepared by the self-assembly of inulin-ibuprofen polymer and in situ encapsulation of EPB. RGD conjugated EPB loaded nanoparticles were characterized by dynamic light scattering (DLS) and transmission electron microscope (TEM). The EPB release from the nanoparticles showed pH-dependent profile and accelerated by the decreased pH value, which would favor the effective drug delivery in vivo. Intracellular uptake analysis suggested that RGD conjugated nanoparticles could be easily internalized by the cancer cells. In vitro cytotoxicity revealed that RGD conjugated EPB loaded nanoparticles exhibited the better antitumor efficacy compared with non-conjugated nanoparticles. More importantly, RGD conjugated EPB loaded nanoparticles showed superior anticancer effects and reduced toxicity than free EPB and non-conjugated nanoparticles by in vivo antitumor activity, EPB biodistribution and histology analysis.

Gu X, Xue JQ, Han SJ, et al.
Circulating microRNA-451 as a predictor of resistance to neoadjuvant chemotherapy in breast cancer.
Cancer Biomark. 2016; 16(3):395-403 [PubMed] Related Publications
OBJECTIVE: We aimed to explore the potential application of circulating microRNA-451 (miR-451) in serum in predicting the resistance to neoadjuvant chemotherapy (NACT) in breast cancer (BC).
METHODS: Eighty-two BC patients who underwent NACT were recruited in our study, including 41 NACT-sensitive patients (NACT-sensitive group) and 41 NACT-resistant patients (NACT-resistant group). Additionally, 60 healthy subjects were selected as normal controls. Epirubicin-resistant MCF-7 BC cell line (MCF-7/EPI) and docetaxel-resistant MCF-7 BC cell line (MCF-7/DOC) were cultured in our study. MTT assay was applied to calculate the survival rates of MCF-7 cells, MCF-7/DOC cells and MCF-7/EPI cells. The expression levels of miR-451 in normal controls, NACT-sensitive group, NACT-resistant group, MCF-7 cells, MCF-7/DOC cells and MCF-7/EPI cells were measured by qRT-PCR method.
RESULTS: The proliferation rates of both the MCF-7/DOC and MCF-7/EPI cells were significantly restrained at the drug concentration of 10 ng/ml, 50 ng/ml, 100 ng/ml and 200 ng/ml. However, the proliferation rates of MCF-7/DOC and MCF-7/EPI cells both increased significantly at the drug concentration of 500ng/ml. Furthermore, the IC50 of MCF-7/DOC cells was 23.603 ng/ml and the IC50 of MCF-7/EPI cells was 3.209 ng/ml. The relative expression of miR-451 was significantly lower in both the NACT-resistant group and the NACT-sensitive group than the normal control group. We also found that the relative expression level of miR-451 was significantly lower in the NACT-resistant group than that in the NACT-sensitive group. The expression of miR-451 in the MCF-7/EPI and the MCF-7/DOC cell lines was significantly lower than that in the MCF-7 cell lines.
CONCLUSION: We supported the view that the relative expression level of miR-451 was lower in the NACT-resistant BC patients, suggesting the circulating miR-451 may have a functional significance in predicting the resistance to NACT in BC patients. We laid a foundation for further research on the resistance to NACT in BC treatment.

Hénin E, Meille C, Barbolosi D, et al.
Revisiting dosing regimen using PK/PD modeling: the MODEL1 phase I/II trial of docetaxel plus epirubicin in metastatic breast cancer patients.
Breast Cancer Res Treat. 2016; 156(2):331-41 [PubMed] Related Publications
The MODEL1 trial is the first model-driven phase I/II dose-escalation study of densified docetaxel plus epirubicin administration in metastatic breast cancer patients, a regimen previously known to induce unacceptable life-threatening toxicities. The primary objective was to determine the maximum tolerated dose of this densified regimen. Study of the efficacy was a secondary objective. Her2-negative, hormone-resistant metastatic breast cancer patients were treated with escalating doses of docetaxel plus epirubicin every 2 weeks for six cycles with granulocyte colony stimulating factor support. A total of 16 patients were treated with total doses ranging from 85 to 110 mg of docetaxel plus epirubicin per cycle. Dose escalation was controlled by a non-hematological toxicity model. Dose densification was guided by a model of neutrophil kinetics, able to optimize docetaxel plus epirubicin dosing with respect to pre-defined acceptable levels of hematological toxicity while ensuring maximal efficacy. The densified treatment was safe since hematological toxicity was much lower compared to previous findings, and other adverse events were consistent with those observed with this regimen. The maximal tolerated dose was 100 mg given every 2 weeks. The response rate was 45 %; median progression-free survival was 10.4 months, whereas 54.6 months of median overall survival was achieved. The optimized docetaxel plus epirubicin dosing regimen led to fewer toxicities associated with higher efficacy as compared with standard or empirical densified dosing. This study suggests that model-driven dosage adjustment can lead to improved efficacy-toxicity balance in patients with cancer when several anticancer drugs are combined.

Dong H, Yao L, Bi W, et al.
Combination of survivin siRNA with neoadjuvant chemotherapy enhances apoptosis and reverses drug resistance in breast cancer MCF-7 cells.
J Cancer Res Ther. 2015 Oct-Dec; 11(4):717-22 [PubMed] Related Publications
BACKGROUND: Chemotherapeutic resistance is a main problem in clinical breast cancer therapy. The purpose of our study is to investigate whether the combination of neoadjuvant chemotherapy and survivin siRNA treatment could enhance the therapeutic effect of neoadjuvant chemotherapy using paclitaxel or epirubicin.
MATERIALS AND METHODS: The molecular cloning technique was applied to construct the expression vector of siRNA against survivin. Effectene Transfection Reagent was used to transfect plasmids to MCF-7 cells. Survivin expressions were detected by quantitative real-time PCR (qRT-PCR) and Western blot methods. The effect of paclitaxel or epirubicin, with or without the combination of survivin siRNA treatment, on drug susceptibility of MCF-7 cells was detected by CCK-8 assay. MCF-7 cell apoptosis was detected by Flow Cytometry.
RESULTS: Survivin siRNA effectively inhibited the expression of Survivin RNA and protein levels (P < 0.05). Both paclitaxel and epirubicin can suppress the proliferation of MCF-7 cells and induce apoptosis to a certain degree respectively. The combination of survivin siRNA with the two chemotherapy drugs significantly enhanced both effects of the two chemotherapeutics respectively (P < 0.05).
CONCLUSION: Survivin siRNA combined with the neoadjuvant chemotherapy can significantly enhance the sensitivity of MCF-7 cells to chemotherapeutics and cell apoptosis. This technology has important potential value in the therapeutic study of breast cancer.

Tarpgaard LS, Qvortrup C, Nygård SB, et al.
A phase II study of Epirubicin in oxaliplatin-resistant patients with metastatic colorectal cancer and TOP2A gene amplification.
BMC Cancer. 2016; 16:91 [PubMed] Free Access to Full Article Related Publications
UNLABELLED: The overall purpose of this study is to provide proof of concept for introducing the anthracycline epirubicin as an effective, biomarker-guided treatment for metastatic colorectal cancer (mCRC) patients who are refractory to treatment with oxaliplatin-based chemotherapy and have TOP2A gene amplification in their tumor cells.
BACKGROUND: Epirubicin is an anthracycline that targets DNA topoisomerase 2-α enzyme encoded by the TOP2A gene. It is used for treatment of several malignancies, but currently not in CRC. TOP2A gene amplifications predict improved efficacy of epirubicin in patients with breast cancer and thus could be an alternative option for patients with CRC and amplified TOP2A gene. We have previously analysed the frequency of TOP2A gene aberrations in CRC and found that 46.6% of these tumors had TOP2A copy gain and 2.0% had loss of TOP2A when compared to adjacent normal tissue. The TOP2A gene is located on chromosome 17 and when the TOP2A/CEN-17 ratio was applied to identify tumors with gene loss or amplifications, 10.5% had a ratio ≥ 1.5 consistent with gene amplification and 2.6% had a ratio ≤ 0.8 suggesting gene deletions. Based on these observations and the knowledge gained from treatment of breast cancer patients, we have initiated a prospective clinical, phase II protocol using epirubicin (90 mg/m2 iv q 3 weeks) in mCRC patients, who are refractory to treatment with oxaliplatin.
METHODS/DESIGN: The study is an open label, single arm, phase II study, investigating the efficacy of epirubicin in patients with oxaliplatin refractory mCRC and with a cancer cell TOP2A/CEN-17 ratio ≥ 1.5. TOP2A gene amplification measured by fluorescence in situ hybridization. A total of 25 evaluable patients (15 + 10 in two steps) will be included (Simon's two-stage minimax design). Every nine weeks, response is measured by computed tomography imaging and evaluated according to RECIST 1.1. The primary end-point of the study is progression-free survival.
TRIAL REGISTRATION: Eudract no. 2013-001648-79.

Zhang LH, Yang AJ, Wang M, et al.
Enhanced autophagy reveals vulnerability of P-gp mediated epirubicin resistance in triple negative breast cancer cells.
Apoptosis. 2016; 21(4):473-88 [PubMed] Article available free on PMC after 01/04/2017 Related Publications
Epirubicin (EPI) is widely used for triple negative breast cancer (TNBC), but a substantial number of patients develop EPI resistance that is associated with poor outcome. The underlying mechanism for EPI resistance remains poorly understood. We have developed and characterized an EPI-resistant (EPI-R) cell line from parental MDA-MB-231 cells. These EPI-R cells reached stable growth in the medium containing 8 μg/ml of EPI. They overexpressed P-glycoprotein (P-gp) and contained numerous autophagic vacuoles. The suppression of P-gp overexpression and/or autophagy restored the sensitivity of these EPI-R cells to EPI. We further show that autophagy conferred resistance to EPI on MDA cells by blocking the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-mediated pro-apoptotic signals. Together, these results reveal a synergistic role of P-gp, autophagy, and NF-κB pathways in the development of EPI resistance in TNBC cells. They also suggest that blocking the P-gp overexpression and autophagy may be an effective means of reducing EPI resistance.

Di-Wen S, Pan GZ, Hao L, et al.
Improved antitumor activity of epirubicin-loaded CXCR4-targeted polymeric nanoparticles in liver cancers.
Int J Pharm. 2016; 500(1-2):54-61 [PubMed] Related Publications
A liver-targeted drug delivery system (CX-EPNP) composed of PLGA/TPGS was prepared and characterized. The surface of nanoparticle was conjugated with LFC131 peptide to increase the specific interaction of carrier with CXCR4 overexpressing liver cancers to enhance the Epirubicin (EPI) delivery to tumors. The particles were nanosized with size than 150 nm and portrayed a sustained release kinetics suggesting its suitability for cancer targeting. The in vitro cell uptake results showed that the introduction of LFC131 to the nanoparticles could increase significantly the affinity to human hepatic carcinoma cells (HepG2) with approximately a 3-fold improvement in cellular uptake than non-targeted one. A specific receptor-mediated uptake was observed by confocal laser scanning microscopy. In addition, CX-EPNP showed remarkable cytotoxicity towards HepG2 cells, and could effectively inhibit tumor growth. The more significant EPI accumulation from CX-EPNP in the cancer cells gave rise to the enhanced EPI cytotoxicity and cell apoptosis. The CX-EPNP distributed mostly in the xenograft tumor after intravenous administration to mice and adequately remained in the blood for at least 24h. It seemed that CX-EPNP upon intravenous injection avoided rapid recognition by Kupffer cells and adequately remained in the blood. These findings suggest that CX-EPNP could effectively inhibit the growth of liver tumors in situ and could potentially reduce the systemic side effects. However, extensive investigation is still needed to assess the possible applications of the CX-EPNP in humans.

Tang H, Feng X, Zhang T, et al.
Stability, Pharmacokinetics, Biodistribution and Safety Assessment of Folate-Conjugated Pullulan Acetate Nanoparticles as Cervical Cancer Targeted Drug Carriers.
J Nanosci Nanotechnol. 2015; 15(9):6405-12 [PubMed] Related Publications
It is recognized that the stability and journey in the body of nanoparticles are important issues for drug formulations. In this study, we prepared folate-conjugated pullulan acetate nanoparticles (FPANs) and epirubicin loaded FPANs (FPA/EPI) using dialysis method. The storage stability of FPANs and FPA/EPI at 4 degrees C could be up to 3 months. Using folate receptor overexpressed Hela cells, dose dependent cellular uptake and receptor-mediated endocytosis of FPA/EPI were confirmed. From the in vivo pharmacokinetics test, compared to free EPI, half-life time (t½) of FPA/EPI was extended 1.57 times and the area under-the-curve (AUC) increased 3.95 times as well. In addition, biodistribution data showed that, EPI concentration in tumor in FPA/EPI group was 2.01 times higher than that in free EPI group after 96 h; The concentration of drug in liver treated by FPA/EPI was 5.7-11.6 times, while in heart, kidney, especially in stomach and intestine were much lower than those in free EPI group from 24 to 96 h. Furthermore, blank FPANs showed no apparent acute toxicity at dose up to 125 mg/kg. All results suggested that FPA/EPI showed a promising potential on treating cervical carcinoma and its metastatic hepatocellular carcinoma in future because of the high stability, less toxicity and tumor targeting.

Framarino-dei-Malatesta M, Perrone G, Giancotti A, et al.
Epirubicin: a new entry in the list of fetal cardiotoxic drugs? Intrauterine death of one fetus in a twin pregnancy. Case report and review of literature.
BMC Cancer. 2015; 15:951 [PubMed] Article available free on PMC after 01/04/2017 Related Publications
BACKGROUND: Current knowledge indicate that epirubicin administration in late pregnancy is almost devoid of any fetal cardiotoxicity. We report a twin pregnancy complicated by breast cancer in which epirubicin administration was causatively linked to the death of one twin who was small for gestational age (SGA) and in a condition of oligohydramnios and determined the onset of a transient cardiotoxicity of the surviving fetus/newborn.
CASE PRESENTATION: A 38-year-old caucasic woman with a dichorionic twin pregnancy was referred to our center at 20 and 1/7 weeks for a suspected breast cancer, later confirmed by the histopathology report. At 31 and 3/7 weeks, after the second chemotherapy cycle, ultrasound examination evidenced the demise of one twin while cardiac examination revealed a monophasic diastolic ventricular filling, i.e. a diastolic dysfunction of the surviving fetus who was delivered the following day due to the occurrence of grade II placental abruption. The role of epirubicin cardiotoxicity in the death of the first twin was supported by post-mortem cardiac and placental examination and by the absence of structural or genomic abnormalities that may indicate an alternative etiology of fetal demise. The occurrence of epirubicin cardiotoxicity in the surviving newborn was confirmed by the report of high levels of troponin and transient left ventricular septal hypokinesia.
CONCLUSION: Based on our findings we suggest that epirubicin administration in pregnancy should be preceded by the screening of some fetal conditions like SGA and oligohydramnios that may increase its cardiotoxicity and that, during treatment, the diastolic function of the fetal right ventricle should be specifically monitored by a pediatric cardiologist; also, epirubicin and desamethasone for lung maturation should not be closely administered since placental effects of glucocorticoids may increase epirubicin toxicity.

Chen H, Xie LQ, Qin J, et al.
Surface modification of PLGA nanoparticles with biotinylated chitosan for the sustained in vitro release and the enhanced cytotoxicity of epirubicin.
Colloids Surf B Biointerfaces. 2016; 138:1-9 [PubMed] Related Publications
In this study, poly(d,l-lactide-co-glycolide) nanoparticles (PLGA NPs) with biotinylated chitosan (Bio-CS)-surface modification were prepared to be usded as a tumor-targeted and prolonged delivery system for anticancer drugs. Epirubicin (EPB), as a model drug, was encapsulated into Bio-CS surface modified PLGA (Bio-CS-PLGA) NPs with a drug encapsulation efficiency of 84.1 ± 3.4%. EPB-loaded Bio-CS-PLGA NPs were spherical shaped, and had a larger size and higher positive zeta potential compared to the unmodfied EPB-loaded PLGA NPs. The in vitro drug releases showed that EPB-loaded Bio-CS-PLGA NPs exhibited relatively constant drug release kinetics during the first 48 h and the drug burst release significantly decreased in comparison to the unmodified PLGA NPs. The results of MTS assays showed that Bio-CS-PLGA NPs markedly increased the cytotoxicity of EPB, compared to both the unmodified PLGA NPs and the CS-PLGA NPs. The uptakes of NPs in human breast cancer MCF-7 cells were evaluated by the flow cytometry and the confocal microscope. The results revealed that Bio-CS-PLGA NPs exhibited a greater extent of cellular uptake than the unmodified PLGA NPs and CS-PLGA NPs. Moreover, the cellular uptake of Bio-CS-PLGA NPs was evidently inhibited by the endocytic inhibitors and the receptor ligand, indicating that biotin receptor-mediated endocytosis was perhaps involved in the cell entry of Bio-CS-PLGA NPs. In MCF-7 tumor-bearing nude mice, EPB-loaded Bio-CS-PLGA NPs were efficiently accumulated in the tumors. In summary, Bio-CS-PLGA NPs displayed great potential for application as the carriers of anticancer drugs.

Yan B, Wang J, Liu L
Chemotherapy promotes tumour cell hybridization in vivo.
Tumour Biol. 2016; 37(4):5025-30 [PubMed] Article available free on PMC after 01/04/2017 Related Publications
Spontaneous cell-cell fusion has been recognized to be an important mechanism for tissue and organ development and repair. In cancer, cell fusion is critically involved in tumourigenesis, metastasis and drug resistance, as illustrated by in vitro experiments. However, there has been no direct detection of tumour cell fusion or hybridization in an in vivo tumour environment, and the features of hybridized cells under selective pressures, such as chemotherapy, are unknown. Here, we expressed two fluorescent marker proteins in the human breast cancer cell line SKBR3 to detect tumour cell hybridization in vivo and performed a xenograft chemotherapy experiment in mice to evaluate the chemotherapeutic response of the hybrids. The mice treated by epirubicin showed that chemotherapy promoted tumour cell hybridization in vivo, which elicited the production of more hybrids in the outer section of the tumour. These results provide the first in vivo evidence of tumour cell fusion and indicate that chemotherapy may contribute to a poor prognosis by enriching for fused cells, which are more malignant. It is therefore necessary to reassess chemotherapy strategies.

Pan XW, Li L, Huang Y, et al.
Icaritin acts synergistically with epirubicin to suppress bladder cancer growth through inhibition of autophagy.
Oncol Rep. 2016; 35(1):334-42 [PubMed] Related Publications
Bladder cancer is one of the most commonly diagnosed urological malignancies. Acquired resistance to chemotherapy is a great barrier for achieving successful treatment of bladder cancer. In the present study, we investigated the effect and mechanisms of icaritin, a flavonol glycoside derived from genus Epimedium, against human bladder cancer cells. It was found that despite the low cytotoxicity in normal human HEK293 cells, icaritin significantly inhibited the proliferation and colony formation of BT5637 and T24 bladder cancer cells time- and dose-dependently compared to the DMSO vehicle control. Moreover, cell viability monitored through mitochondrial membrane potential was inhibited markedly after icaritin treatment. Further investigation indicated that icaritin may inhibit epirubicin (EPI)-induced autophagy, and acted synergistically with EPI to suppress the proliferation of BT5637 and T24 cells. These findings suggest that icaritin may prove to be a novel potent therapeutic agent for the treatment of bladder cancer.

Zhang CX, Zhao WY, Liu L, et al.
A nanostructure of functional targeting epirubicin liposomes dually modified with aminophenyl glucose and cyclic pentapeptide used for brain glioblastoma treatment.
Oncotarget. 2015; 6(32):32681-700 [PubMed] Article available free on PMC after 01/04/2017 Related Publications
The objectives of the present study were to develop functional targeting epirubicin liposomes for transferring drugs across the blood-brain barrier (BBB), treating glioblastoma, and disabling neovascularization. The studies were performed on glioblastoma cells in vitro and on glioblastoma-bearing mice. The results showed that the constructed liposomes had a high encapsulation efficiency for drugs (>95%), suitable particle size (109 nm), and less leakage in the blood component-containing system; were significantly able to be transported across the BBB; and exhibited efficacies in killing glioblastoma cells and in destroying glioblastoma neovasculature in vitro and in glioblastoma-bearing mice. The action mechanisms of functional targeting epirubicin liposomes correlated with the following features: the long circulation in the blood system, the ability to be transported across the BBB via glucose transporter-1, and the targeting effects on glioblastoma cells and on the endothelial cells of the glioblastoma neovasculature via the integrin β3 receptor. In conclusion, functional targeting epirubicin liposomes could be used as a potential therapy for treating brain glioblastoma and disabling neovascularization in brain glioblastomas.

Yang J, Zhang R, Radford DC, Kopeček J
FRET-trackable biodegradable HPMA copolymer-epirubicin conjugates for ovarian carcinoma therapy.
J Control Release. 2015; 218:36-44 [PubMed] Article available free on PMC after 01/04/2017 Related Publications
To develop a biodegradable polymeric drug delivery system for the treatment of ovarian cancer with the capacity for non-invasive fate monitoring, we designed and synthesized N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-epirubicin (EPI) conjugates. The polymer backbone was labeled with acceptor fluorophore Cy5, while donor fluorophores (Cy3 or EPI) were attached to HPMA copolymer side chains via an enzyme-cleavable GFLG linker. This design allows elucidating separately the fate of the drug and of the polymer backbone using fluorescence resonance energy transfer (FRET). The degradable diblock conjugate (2P-EPI) was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization using a bifunctional chain transfer agent (Peptide2CTA). The pharmacokinetics (PK) and therapeutic effect of 2P-EPI (Mw ~100 kDa) were determined in mice bearing human ovarian carcinoma A2780 xenografts. Compared to 1st generation conjugate (P-EPI, Mw <50 kDa), 2P-EPI demonstrated remarkably improved PK such as fourfold terminal half-life (33.22 ± 3.18 h for 2P-EPI vs. 7.55 ± 3.18 h for P-EPI), which is primarily attributed to the increased molecular weight of the polymer carrier. Notably, complete tumor remission and long-term inhibition of tumorigenesis (100 days) were achieved in mice (n=5) treated with 2P-EPI. Moreover, in vitro cell uptake and intracellular drug release were determined via FRET intensity changes. The results establish a solid foundation for future in vivo tracking of drug delivery and chain scission of polymeric conjugates by FRET imaging.

Zhang L, Liu F, Li G, et al.
Twin-Arginine Translocation Peptide Conjugated Epirubicin-Loaded Nanoparticles for Enhanced Tumor Penetrating and Targeting.
J Pharm Sci. 2015; 104(12):4185-96 [PubMed] Related Publications
One major obstacle in the application of drug delivery systems for cancer chemotherapy is their poor penetration in tumor tissues. Conjugating active ligand moieties to the surface of nanoparticles may be a promising approach for enhancing the tumor accumulation and penetration of nanoparticles. Herein, the cell-penetrating peptide twin-arginine translocation (Tat)-conjugated epirubicin-loaded poly(lactic-glycolic acid) nanoparticles were prepared to achieve deep tumor penetration. The morphology and size of nanoparticles were characterized by scanning electron microscopy and dynamic light scattering, and the biological behaviors of nanoparticles were evaluated. It is demonstrated that Tat-conjugated nanoparticles have a significant improvement in antitumor activity and biodistribution compared with nonconjugated nanoparticles. Importantly, Tat conjugated on the surface of nanoparticles could facilitate the encapsulated drug penetration into deeper tumor tissue. Additionally, Tat-conjugated nanoparticles have good biocompatibility, as demonstrated by hemolytic tests, in vitro cytotoxicity, and histology study. These results suggested that the Tat-conjugated nanoparticles, as a powerful delivery system for chemotherapeutic drug, would have a promising application in human cancer therapy.

Lo YL, Lee HP, Tu WC
The Use of a Liposomal Formulation Incorporating an Antimicrobial Peptide from Tilapia as a New Adjuvant to Epirubicin in Human Squamous Cell Carcinoma and Pluripotent Testicular Embryonic Carcinoma Cells.
Int J Mol Sci. 2015; 16(9):22711-34 [PubMed] Article available free on PMC after 01/04/2017 Related Publications
This study aims to explore the effects and mechanisms of hepcidin, a potential antimicrobial peptide from Tilapia, and epirubicin (Epi), an antineoplastic agent, on the generation of reactive oxygen species (ROS) and link the ROS levels to the reversal mechanisms of multidrug resistance (MDR) by epirubicin and hepcidin in human squamous cell carcinoma SCC15 and human embryonal carcinoma NT2D1 cells. The cells, pretreated with hepcidin, epirubicin, or a combination of these compounds in PEGylated liposomes, were used to validate the molecular mechanisms involved in inhibiting efflux transporters and inducing apoptosis as evaluated by cytotoxicity, intracellular accumulation, mRNA levels, cell cycle distribution, and caspase activity of this combination. We found that hepcidin significantly enhanced the cytotoxicity of epirubicin in liposomes. The co-incubation of epirubicin with hepcidin in liposomes intensified the ROS production, including hydrogen peroxide and superoxide free radicals. Hepcidin significantly increased epirubicin intracellular uptake into NT2D1 and SCC15 cells, as supported by the diminished mRNA expressions of MDR1, MDR-associated protein (MRP) 1, and MRP2. Hepcidin and/or epirubicin in liposomes triggered apoptosis, as verified by the reduced mitochondrial membrane potential, increased sub-G1 phase of cell cycle, incremental populations of apoptosis using annexin V/PI assay, and chromatin condensation. As far as we know, this is the first example showing that PEGylated liposomal TH1-5 and epirubicin gives rise to cell death in human squamous carcinoma and testicular embryonic carcinoma cells through the reduced epirubicin efflux via ROS-mediated suppression of P-gp and MRPs and concomitant initiation of mitochondrial apoptosis pathway. Hence, hepcidin in PEGylated liposomes may function as an adjuvant to anticancer drugs, thus demonstrating a novel strategy for reversing MDR.

Yamaguchi N, Fujii T, Aoi S, et al.
Comparison of cardiac events associated with liposomal doxorubicin, epirubicin and doxorubicin in breast cancer: a Bayesian network meta-analysis.
Eur J Cancer. 2015; 51(16):2314-20 [PubMed] Related Publications
BACKGROUND: Anthracyclines play a broad and important role in the care of patients with either operable or metastatic breast cancer. However cardiotoxicity narrows the therapeutic index of this drug class leading to potentially clinically meaningful treatment delays or discontinuations. We conducted a Bayesian network meta-analysis, a validated statistical methodology, allowing direct and indirect comparison of cardiotoxicity of different anthracycline and non-anthracycline regimens.
METHODS: We conducted a systematic review of prospective randomised controlled trials through MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and Google Scholar comparing non-anthracycline based regimens (NON), doxorubicin (DOX), epirubicin (EPI) and liposomal doxorubicin (LD). We included studies published up to 1st January 2014 in both adjuvant and metastatic contexts. Notably, HER2/neu-targeted regimens were excluded. We assessed the studies' eligibility criteria and data collection with consensus of two independent authors. Our primary outcome measure was cardiac events grade 3 or greater (CE3) in accordance with Common Terminology Criteria for Adverse Events (CTCAE) Version 4.0. A Bayesian pairwise and network meta-analysis was conducted to estimate pooled Odds Ratio (OR).
FINDINGS: Nineteen randomised controlled trials met eligibility criteria and were included in this analysis. We found a trend showing that LD is less cardiotoxic than DOX with an OR of 0.60 (95% confidence interval (CI) 0.34-1.07) There was no difference between Epi and LD with an OR of 0.95 (95%CI 0.39-2.33). DOX is more cardiotoxic than Non with an OR of 1.57 (95%CI 0.90-2.72).
INTERPRETATION: DOX has higher CE3 rates than NON does. LD statistically trended to lower cardiac event rates than DOX. Non-statistical significance among EPI, LD and DOX with regard to cardiac toxicity indicates that avoidance of CE3 should not motivate selection of a particular anthracycline in otherwise healthy women in whom total lifetime anthracycline exposure will likely be limited. Overall low incidence of CE3 with any type of anthracycline indicates that we can safely use any anthracycline if cumulative dose limits are not exceeded. While CE3 does not limit our choice of anthracycline LD appears to be the least cardiotoxic.
FUNDING: Takeo Fujii is supported by the grant named Young Investigator Award for Study Abroad in Clinical Epidemiology from St. Luke's Life Science Institution.

Wang XF, Zhao ZF, Chen MH, et al.
Epirubicin inhibits growth and alters the malignant phenotype of the U‑87 glioma cell line.
Mol Med Rep. 2015; 12(4):5917-23 [PubMed] Related Publications
Epirubicin, an anthracycline derivative, is one of the main line treatments for brain tumors. The aim of the present study was to verify that epirubicin alters the growth and morphological characteristics of U‑87 glioma cells. In the present study, the effects of epirubicin were tested using cellular and biochemical assays, which demonstrated its anti‑proliferative and cytotoxic effects, with an IC50 of 6.3 µM for the U‑87 cell line, while rat normal neuronal cells were resistant to epirubicin. Epirubicin also reduced the secretion of matrix metalloproteinase‑9 by 48 and 56% at concentrations of 2.5 and 5 µM, respectively. Exposure to epirubicin also diminished levels of vascular endothelial growth factor in U‑87 cells. Furthermore, a cell migration assay showed a significant decrease in cell migration from 28 to 59% following exposure to 1 µM epirubicin. The present study demonstrated the cytotoxic, anti‑proliferative and anti‑migrative potential of epirubicin against glioma cells in vitro.

Wu J, Li S, Jia W, et al.
Reduced Let-7a Is Associated with Chemoresistance in Primary Breast Cancer.
PLoS One. 2015; 10(7):e0133643 [PubMed] Article available free on PMC after 01/04/2017 Related Publications
Chemotherapy resistance remains an important problem in the breast cancer clinic. The ability to predict the patients who would respond to a distinct therapy would help to optimize tailored treatment options. miRNAs can mediate a number of genes in response to drug-induced acute cellular stress. Several studies suggest that let-7 miRNA may be involved in the chemosensitivity of cancer cell lines in vitro. However, it is not known whether this phenomenon occurs in clinical breast tumors. The present study showed that lower let-7a expression was associated with epirubicin resistance in primary breast tumors. Moreover, upregulation of let-7a expression sensitized resistant breast tumor cell lines to epirubicin by enhancing cellular apoptosis in vitro. Collectively, these findings indicate that lower expression of let-7a miRNA can induce chemoresistance in breast cancer by enhancing cellular apoptosis and suggest that let-7a may be used as a therapeutic target to modulate epirubicin-based chemotherapy resistance.

Shi F, Yang F, He X, et al.
Inhibitory effect of epirubicin-loaded lipid microbubbles with conjugated anti-ABCG2 antibody combined with therapeutic ultrasound on multiple myeloma cancer stem cells.
J Drug Target. 2016; 24(1):34-46 [PubMed] Related Publications
Ultrasound-targeted microbubble destruction (UTMD) technique is thought to improve the chemotherapeutic agent delivery from microbubbles (MBs) in tumor tissues and reduce the side effects in non-tumor tissues. Multiple myeloma (MM) is a bone marrow cancer and remains to be an incurable disease. In this study, we used the UTMD technique to investigate the inhibitory effect of our developed novel reagent on MM cancer stem cells (CD138(-)CD34(-)MM CSCs) that are MM cells with CD138(-)CD34(-) phenotypes, responsible for MM-initiating potential, drug resistance and eventual relapse. The preparatory steps of novel reagent was first epirubicin (EPI)-loaded in the lipid MBs that was consisted of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000]-biotin, dipalmitoyl-phosphatidylglycerol and 25-NBD-cholesterol, then anti-ABCG2 monoclonal antibody (mAb) was conjugated onto the MB surface to form EPI-MBs+mAb. CD138(-)CD34(-)MM CSCs were isolated from human MM RPMI 8226 cell line by the magnetic associated cell sorting method. The results showed that the attenuated proliferation, migration and invasion ability, and increased apoptosis were observed when MM CSCs were incubated with a various agents. EPI-MBs+mAb combined with therapeutic ultrasound significantly promoted the MM CSC apoptosis compared with EPI, EPI-MBs alone or EPI-MBs+mAb without ultrasound exposure. These results suggest that the developed EPI-MBs+mAb combined with therapeutic ultrasound remarkably induced MM CSC apoptosis in vitro.

Koie T, Ohyama C, Hosogoe S, et al.
Oncological outcomes of a single but extensive transurethral resection followed by appropriate intra-vesical instillation therapy for newly diagnosed non-muscle-invasive bladder cancer.
Int Urol Nephrol. 2015; 47(9):1509-14 [PubMed] Related Publications
PURPOSE: A second transurethral resection (TUR) has been recommended by guidelines for high-grade non-muscle-invasive bladder cancer (NMIBC). However, the impact of surgical quality and post-TUR intra-vesical instillation therapy on oncologic outcome still remains unclear for newly diagnosed NMIBC. We conducted a retrospective cohort study for the patients who underwent extensive TUR followed by appropriate intra-vesical therapy for newly diagnosed NMIBC to assess their oncological outcomes.
METHODS: We treated a cohort of 150 patients with NMIBC by our single but extensive TUR protocol at Hirosaki University Hospital between January 2005 and May 2012. The extensive TUR procedure comprised complete resection of all visible tumors including the muscle layer with a separate cold cup-biopsy of the marginal bottom. After visible tumors resection, additional resection for 5 mm wider area around the first surgical margin was performed. TUR was conducted by three expert urologists who had common agreement with the extensive TUR. All patients received 50 mg of epirubicin instillation immediately after TUR. Out of 150 patients, 74 patients who had multiple tumors or high-grade T1 disease received 40 mg of bacillus Calmette-Guérin Tokyo 172 strain once a week for six consecutive weeks. Patients who received second TUR were not included. The endpoints in this study were the recurrence-, progression-free, cancer-specific, and overall survivals.
RESULTS: The 5-year recurrence- and progression-free survival rates were 77.2 and 98.0 %, respectively. The 5-year cancer-specific and overall survival rates were 98.0 and 92.6 %, respectively. The 5-year recurrence- and progression-free survival rates in high-grade T1 disease were 77.1 and 97.6 %, respectively, which were not significantly different from those in the cohort with Ta or low-grade BC. Cystoscopy revealed that 93 % of the patients were tumor-free, at the first cystoscopy, and four patients (3 %) showed progression to stage T2 or higher disease during the first year.
CONCLUSION: While the present study has several limitations, including single-arm and retrospective nature, a single but extensive TUR combined with adjuvant intravesical treatment may have acceptable oncological outcomes in NMIBC patients.

Karunarathna U, Kongsema M, Zona S, et al.
OTUB1 inhibits the ubiquitination and degradation of FOXM1 in breast cancer and epirubicin resistance.
Oncogene. 2016; 35(11):1433-44 [PubMed] Article available free on PMC after 01/04/2017 Related Publications
The forkhead transcription factor FOXM1 has a key role in DNA damage response, and its deregulated overexpression is associated with genotoxic drug resistance in breast cancer. However, little is known about the posttranslational mechanisms by which FOXM1 expression is regulated by genotoxic agents and how they are deregulated in resistant cells. Initial co-immunoprecipitation studies verified previous proteomic analysis finding that the OTUB1 is a novel FOXM1-interacting protein. Western blot analysis showed that both OTUB1 and FOXM1 expression reduced upon genotoxic agent treatment in MCF-7 cells, but remained relatively constant in resistant cells. FOXM1 expression reduced upon OTUB1 depletion by siRNA and increased with OTUB1 overexpression in MCF-7 cells, arguing that OTUB1 positively regulates FOXM1 expression. In agreement, co-immunoprecipitation experiments demonstrated that FOXM1 expression is associated with OTUB1 binding but inversely correlates with conjugation to the protein degradation-associated Lys-48-linked ubiquitin-chains. Overexpression of wild-type (WT) OTUB1, but not the OTUB1(C91S) mutant, disrupted the formation of Lys48-linked ubiquitin-conjugates on FOXM1. Importantly, knockdown of OTUB1 by siRNA resulted in an increase in turnover of FOXM1 in MCF-7 cells treated with the protein synthesis inhibitor cycloheximide, whereas overexpression of WT OTUB1, but not the OTUB1(C91S) mutant, significantly enhances the half-life of FOXM1. In addition, proliferative and clonogenic assays also show that OTUB1 can enhance the proliferative rate and epirubicin resistance through targeting FOXM1, as OTUB1 has little effect on FOXM1-deficient cells. The physiological relevance of the regulation of FOXM1 by OTUB1 is further underscored by the significant correlations between FOXM1 and OTUB1 expression in breast cancer patient samples. Cox-regression survival analysis indicates that OTUB1 overexpression is linked to poorer outcome in particular in patients treated with chemotherapy. Collectively, these data suggest that OTUB1 limits the ubiquitination and degradation of FOXM1 in breast cancer and has a key role in genotoxic agent resistance.

Disclaimer: This site is for educational purposes only; it can not be used in diagnosis or treatment.

[Home]    Page last updated: 07 March, 2017     © CancerIndex, Established 1996