Enterolactone and trabectedin suppress epithelial ovarian cancer synergistically via upregulating THBS1.

Epithelial ovarian cancer (EOC) is the most common and fatal subtype of ovarian malignancies, with no effective therapeutics available. Our previous studies have demonstrated extraordinary suppressive efficacy of enterolactone (ENL) on EOC. A chemotherapeutic agent, trabectedin (Trabe), is shown to be effective on ovarian cancer, especially when combined with other therapeutics, such as pegylated liposomal doxorubicin or oxaliplatin. Thrombospondin 1 (THBS1), a kind of matrix glycoprotein, plays important roles against cancer development through inhibiting angiogenesis but whether it is involved in the suppression of EOC by ENL or Trabe remains unknown. To test combined suppressive effects of ENL and Trabe on EOC and possible involvement of THBS1 in the anticancer activities of ENL and Trabe. The EOC cell line ES-2 was transfected with overexpressed THBS1 by lentivirus vector. We employed tube formation assay to evaluate the anti-angiogenesis activity of ENL and of its combined use with Trabe after THBS1 overexpression and established drug intervention and xenograft nude mouse cancer models to assess the in vivo effects of the hypothesized synergistic suppression between the agents and the involvement of THBS1. Mouse fecal samples were collected for 16S rDNA sequencing and microbiota analysis. We detected strong inhibitory activities of ENL and Trabe against the proliferation and migration of cancer cells and observed synergistic effects between ENL and Trabe in suppressing EOC. ENL and Trabe, given either separately or in combination, could suppress the tube formation capability of human microvascular endothelial cells, and this inhibitory effect became even stronger with THBS1 overexpression. In the ENL plus Trabe combination group, the expression of tissue inhibitor of metalloproteinases 3 and cluster of differentiation 36 was both upregulated, whereas matrix metalloproteinase 9, vascular endothelial growth factor, and cluster of differentiation 47 were all decreased. With the overexpression of THBS1, the results became even more pronounced. In animal experiments, combined use of ENL and Trabe showed superior inhibitory effects to either single agent and significantly suppressed tumor growth, and the overexpression of THBS1 further enhanced the anti-cancer activities of the drug combination group. ENL and Trabe synergistically suppress EOC and THBS1 could remarkably facilitate the synergistic anticancer effects of ENL and Trabe.

Therapeutic Targets for Bone and Soft-Tissue Sarcomas.

Due to the rarity and heterogeneity of bone and soft-tissue sarcomas, investigation into molecular targets and new treatments has been particularly challenging. Although intensive chemotherapy and establishment of surgical procedures have improved the outcomes of patients with sarcoma, the curative rate of recurrent and metastatic sarcomas is still not satisfactory. Recent basic science research has revealed some of the mechanisms of progression and metastasis of malignancies including proliferation, apoptosis, angiogenesis, tumor microenvironment, migration, invasion, and regulation of antitumor immune systems. Based on these basic studies, new anticancer drugs, including pazopanib, trabectedin, eribulin, and immune checkpoint inhibitors have been developed and the efficacies and safety of the new drugs have been assessed by clinical trials. This review summarizes new molecular therapeutic targets and advances in the treatment for bone and soft tissue sarcomas.

Trabectedin and Eribulin: Where Do They Fit in the Management of Soft Tissue Sarcoma?

OPINION STATEMENT: Trabectedin and eribulin are two agents that have been recently approved for the treatment of specific soft tissue sarcoma subtypes. They have proved to be a much-needed line of additional treatment for patients with these rare tumors, but their activity remains admittedly modest in most cases. Further exploitation of these novel agents is likely to require a more granular understanding of the salient mechanisms of action. For example, if as some studies suggest, eribulin derives its benefit from restructuring of tumor vasculature to improve efficacy of subsequent lines of therapy, then patients may benefit from its use earlier in the treatment pathway. The sequencing of trabectedin with other agents is also worth examining. In a disease like myxoid liposarcoma, consideration should be given to using trabectedin before other salvage regimens like gemcitabine and docetaxel, given its tolerability and excellent efficacy against this sarcoma subtype. Also, to be further investigated is the use of trabectedin in sarcoma subtypes which were excluded from the phase III study, but in which activity has been documented in earlier trials and subsequent reports. Combinations of trabectedin with other agents, particularly doxorubicin, have been explored, but the data to date do not support the routine use of these regimens.

Hyperthermia adds to trabectedin effectiveness and thermal enhancement is associated with BRCA2 degradation and impairment of DNA homologous recombination repair.

The tetrahydroisoquinoline trabectedin is a marine compound with approved activity against human soft-tissue sarcoma. It exerts antiproliferative activity mainly by specific binding to the DNA and inducing DNA double-strand breaks (DSB). As homologous recombination repair (HRR)-deficient tumors are more susceptible to trabectedin, hyperthermia-mediated on-demand induction of HRR deficiency represents a novel and promising strategy to boost trabectedin treatment. For the first time, we demonstrate enhancement of trabectedin effectiveness in human sarcoma cell lines by heat and characterize cellular events and molecular mechanisms related to heat-induced effects. Hyperthermic temperatures (41.8 or 43°C) enhanced significantly trabectedin-related clonogenic cell death and G2/M cell cycle arrest followed by cell type-dependent induction of apoptosis or senescence. Heat combination increased accumulation of γH2AX foci as key marker of DSBs. Expression of BRCA2 protein, an integral protein of the HRR machinery, was significantly decreased by heat. Consequently, recruitment of downstream RAD51 to γH2AX-positive repair foci was almost abolished indicating relevant impairment of HRR by heat. Accordingly, enhancement of trabectedin effectiveness was significantly augmented in BRCA2-proficient cells by hyperthermia and alleviated in BRCA2 knockout or siRNA-transfected BRCA2 knockdown cells. In peripheral blood mononuclear cells isolated from sarcoma patients, increased numbers of nuclear γH2AX foci were detected after systemic treatment with trabectedin and hyperthermia of the tumor region. The findings establish BRCA2 degradation by heat as a key factor for a novel treatment strategy that allows targeted chemosensitization to trabectedin and other DNA damaging antitumor drugs by on-demand induction of HRR deficiency.

Hallmarks of hyperthermia in driving the future of clinical hyperthermia as targeted therapy: translation into clinical application.

Regional hyperthermia is described as a targeted therapy and the definitions of six hallmarks of hyperthermia are proposed, representing the pleiotropic effect of this therapeutic modality to counteract tumour growth and progression. We recommend the considerations of these hallmarks in the design of clinical trials involving regional hyperthermia as targeted therapy. Randomised clinical studies using loco-regional hyperthermia as an adjuvant to radiotherapy or to chemotherapy for locally advanced tumours demonstrate the benefit of the combination compared to either of the standard treatments alone for tumour response, disease control, and patient survival outcome. These impressive results were obtained from proof-of-concept trials for superficial or deep-seated malignancies in unselected patients. None of these trials was designed as tailored approaches for the treatment of specified targets or to select potentially more sensitive subpopulations of patients using eligibility criteria. Based upon clinical examples of targeted chemotherapy, some guidelines are described for the successful development of targeted therapeutic combinations. We also retrospectively analyse the stepwise process of generating an ongoing new clinical trial using hyperthermia as targeted therapy to evade DNA repair in combination with a DNA damaging anticancer agent to implement this new vision.

Topotecan, pegylated liposomal doxorubicin hydrochloride, paclitaxel, trabectedin and gemcitabine for advanced recurrent or refractory ovarian cancer: a systematic review and economic evaluation.

BACKGROUND: Ovarian cancer is the fifth most common cancer in the UK, and the fourth most common cause of cancer death. Of those people successfully treated with first-line chemotherapy, 55-75% will relapse within 2 years. At this time, it is uncertain which chemotherapy regimen is more clinically effective and cost-effective for the treatment of recurrent, advanced ovarian cancer. OBJECTIVES: To determine the comparative clinical effectiveness and cost-effectiveness of topotecan (Hycamtin(®), GlaxoSmithKline), pegylated liposomal doxorubicin hydrochloride (PLDH; Caelyx(®), Schering-Plough), paclitaxel (Taxol(®), Bristol-Myers Squibb), trabectedin (Yondelis(®), PharmaMar) and gemcitabine (Gemzar(®), Eli Lilly and Company) for the treatment of advanced, recurrent ovarian cancer. DATA SOURCES: Electronic databases (MEDLINE(®), EMBASE, Cochrane Central Register of Controlled Trials, Health Technology Assessment database, NHS Economic Evaluations Database) and trial registries were searched, and company submissions were reviewed. Databases were searched from inception to May 2013. METHODS: A systematic review of the clinical and economic literature was carried out following standard methodological principles. Double-blind, randomised, placebo-controlled trials, evaluating topotecan, PLDH, paclitaxel, trabectedin and gemcitabine, and economic evaluations were included. A network meta-analysis (NMA) was carried out. A de novo economic model was developed. RESULTS: For most outcomes measuring clinical response, two networks were constructed: one evaluating platinum-based regimens and one evaluating non-platinum-based regimens. In people with platinum-sensitive disease, NMA found statistically significant benefits for PLDH plus platinum, and paclitaxel plus platinum for overall survival (OS) compared with platinum monotherapy. PLDH plus platinum significantly prolonged progression-free survival (PFS) compared with paclitaxel plus platinum. Of the non-platinum-based treatments, PLDH monotherapy and trabectedin plus PLDH were found to significantly increase OS, but not PFS, compared with topotecan monotherapy. In people with platinum-resistant/-refractory (PRR) disease, NMA found no statistically significant differences for any treatment compared with alternative regimens in OS and PFS. Economic modelling indicated that, for people with platinum-sensitive disease and receiving platinum-based therapy, the estimated probabilistic incremental cost-effectiveness ratio [ICER; incremental cost per additional quality-adjusted life-year (QALY)] for paclitaxel plus platinum compared with platinum was £24,539. Gemcitabine plus carboplatin was extendedly dominated, and PLDH plus platinum was strictly dominated. For people with platinum-sensitive disease and receiving non-platinum-based therapy, the probabilistic ICERs associated with PLDH compared with paclitaxel, and trabectedin plus PLDH compared with PLDH, were estimated to be £25,931 and £81,353, respectively. Topotecan was strictly dominated. For people with PRR disease, the probabilistic ICER associated with topotecan compared with PLDH was estimated to be £324,188. Paclitaxel was strictly dominated. LIMITATIONS: As platinum- and non-platinum-based treatments were evaluated separately, the comparative clinical effectiveness and cost-effectiveness of these regimens is uncertain in patients with platinum-sensitive disease. CONCLUSIONS: For platinum-sensitive disease, it was not possible to compare the clinical effectiveness and cost-effectiveness of platinum-based therapies with non-platinum-based therapies. For people with platinum-sensitive disease and treated with platinum-based therapies, paclitaxel plus platinum could be considered cost-effective compared with platinum at a threshold of £30,000 per additional QALY. For people with platinum-sensitive disease and treated with non-platinum-based therapies, it is unclear whether PLDH would be considered cost-effective compared with paclitaxel at a threshold of £30,000 per additional QALY; trabectedin plus PLDH is unlikely to be considered cost-effective compared with PLDH. For patients with PRR disease, it is unlikely that topotecan would be considered cost-effective compared with PLDH. Randomised controlled trials comparing platinum with non-platinum-based treatments might help to verify the comparative effectiveness of these regimens. STUDY REGISTRATION: This study is registered as PROSPERO CRD42013003555. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Response to trabectedin in a patient with advanced synovial sarcoma with lung metastases.

Trabectedin is an alkylating agent registered in Europe for the treatment of advanced metastatic soft-tissue sarcomas, whose activity has been documented mainly in liposarcomas or leiomyosarcomas. Here, we report the response achieved in a patient with lung metastases from synovial sarcoma. A man with a large synovial sarcoma of the axilla underwent three cycles of neoadjuvant epirubicin+ifosfamide before complete excision, followed by three additional cycles of chemotherapy and radiotherapy. After 14 months, bilateral lung metastases appeared and were first treated with a prolonged 14-day continuous infusion of high-dose ifosfamide without response, and then with second-line trabectedin. A partial radiological response was achieved; dosage was reduced to 1.1 mg/m because of mild asthenia, grade 3 neutropenia, grade 3 nausea and vomiting, and reversible transaminase elevation. After 9 months of treatment, the lung nodules progressed, the patient received sorafenib, but further progressed and died 19 months after the first appearance of lung metastases. Trabectedin was the only drug that led to a radiological response in this patient with synovial sarcoma, despite being administered at 75% of the standard dose because of dose-limiting nausea and vomiting, in line with more recent data demonstrating activity in translocated sarcomas. We believe that trabectedin represents an attractive option for the treatment of metastatic synovial sarcoma and further clinical studies are warranted.

Herbal-drug interaction induced rhabdomyolysis in a liposarcoma patient receiving trabectedin.

BACKGROUND: Rhabdomyolysis is an uncommon side effect of trabectedin which is used for the second line therapy of metastatic sarcoma after anthracycline and ifosfamide failure. This side effect may be due to pharmacokinetic interactions caused by shared mechanisms of metabolism involving the cytochrome P450 (CYP) system in the liver. Here, for the first time in literature, we describe the unexpected onset of heavy toxicity, including rhabdomyolysis, after the fourth course of trabectedin in a patient with retroperitoneal liposarcoma who at the same time was taking an alternative herbal medicine suspected of triggering this adverse event. CASE PRESENTATION: This is the case of a 56 year old Caucasian man affected by a relapsed de-differentiated liposarcoma who, after the fourth cycle of second-line chemotherapy with trabectedin, complained of sudden weakness, difficulty walking and diffuse muscle pain necessitating complete bed rest. Upon admission to our ward the patient showed grade (G) 4 pancytopenia and a marked increase in liver lytic enzymes, serum levels of myoglobin, creatine phosphokinase (CPK) and lactate dehydrogenase. No cardiac or kidney function injuries were present. Based on these clinical and laboratory features, our conclusive diagnosis was of rhabdomyolysis induced by trabectedin.The patient did not report any trauma or muscular overexertion and no co-morbidities were present. He had not received any drugs during treatment with trabectedin, but upon further questioning the patient informed us he had been taking a folk medicine preparation of chokeberry (Aronia melanocarpa) daily during the last course of trabectedin and in the 2 subsequent weeks.One week after hospitalization and cessation of intake of chokeberry extract, CPK and other markers of myolysis slowly returned to standard range, and the patient noted a progressive recovery of muscle strength.The patient was discharged on day 14 when a blood transfusion and parenteral hydration gradually lowered general toxicity. Progressive mobilization of the patient was obtained as well as a complete normalization of the laboratory findings. CONCLUSIONS: The level of evidence of drug interaction leading to the adverse event observed in our patient was 2 (probable). Thus our case underlines the importance of understanding rare treatment-related toxicities such as trabectedin-induced rhabdomyolysis and the possible role of the drug-drug interactions in the pathogenesis of this rare side effect. Furthermore, this report draws attention to a potential problem of particular concern, that of nutritional supplements and complementary and alternative drug interactions. These are not widely recognized and can cause treatment failure.

Trabectedin has promising antineoplastic activity in high-grade meningioma.

BACKGROUND: Meningiomas are common intracranial tumors arising from the meninges and usually are benign. However, a few meningiomas have aggressive behavior and, for such patients, effective treatment options are needed. Trabectedin is a novel, marine-derived, antineoplastic agent that has been approved and is used routinely as therapy for advanced soft tissue sarcoma and ovarian cancer. METHODS: The authors investigated the in vitro effects of trabectedin alone and in combination with hydroxyurea, cisplatin, and doxorubicin in primary cell cultures of benign (n = 9), atypical (n = 6), and anaplastic (n = 4) meningiomas using chemosensitivity assays (3-[4,5dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide [MTT]), Western blot analysis, cell cycle analysis, and immunofluorescent staining. RESULTS: Strong antimeningioma activity of trabectedin was observed and was characterized by distinct cell cycle arrest, down-regulation of multiple cyclins, deregulated expression of cell death-regulatory genes, and massive apoptosis induction. Cytotoxic activity was especially intense in higher grade meningiomas with a half-maximal inhibitory concentration <10 nM. Combination with trabectedin synergistically enhanced the antimeningioma activity of hydroxyurea but also enhanced the activity of doxorubicin and cisplatin. On the basis of these findings, trabectedin was given to 1 patient who had heavily pretreated, anaplastic meningioma, and a favorable response was observed with radiologic disease stabilization, marked reductions in brain edema and requirement for corticosteroids, and improvement of clinical symptoms. However, treatment had to be discontinued after 5 cycles because of adverse drug effects. CONCLUSIONS: The current results indicated that trabectedin may represent a promising new therapeutic option for patients with aggressive meningioma and should be evaluated in prospective clinical studies.