Trabectedin for Women With Ovarian Carcinoma After Treatment With Platinum and Taxanes Fails

Trabectedin (ET-743) in prostate cancer: Endoplasmic reticulum stress-induced apoptotic effect

Trabectedin is a chemotherapy agent originating from a tunicate, Ecteinascidia turbinata. In this study, DNA-independent action mechanisms of trabectedin are investigated in prostate cancer (PCa) cells. Cell viability was assessed via XTT assay. Apoptosis was evaluated via flow cytometry. Tetramethylrodamine ethyl ester (TMRE) dye was utilized to determine mitochondrial membrane potential (MMP). Cell cycle distribution was investigated via flow cytometric analysis. Reactive oxygen species (ROS) were monitored using fluorescence CM-H2DCFDA dye. Changes in CHOP, p-eIF2α, GRP78 and p-PERK which are endoplasmic reticulum (ER) stress-involved proteins were investigated via western blot. Trabectedin induced cytotoxicity and cell cycle arrest at the G2/M phase. Trabectedin decreased MMP via ROS generation in PCa cells. ER stress-related proteins CHOP, p-eIF2α, GRP78 and p-PERK were also elevated by trabectedin treatment indicating the induction of ER stress-induced apoptosis. The results of this study show that trabectedin may be an effective chemotherapeutic for PCa.

Trabectedin suppresses escape from therapy-induced senescence in tumor cells by interfering with glutamine metabolism

Conventional and targeted cancer therapies may induce a cellular senescence program termed therapy-induced senescence. However, unlike normal cells, cancer cells are able to evade the senescence cell cycle arrest and to resume proliferation, driving tumor recurrence after treatments. Cells that escape from therapy-induced senescence are characterized by a plastic, cancer stem cell-like phenotype, and recent studies are beginning to define their unique metabolic features, such as glutamine dependence. Here, we show that the antineoplastic drug trabectedin suppresses escape from therapy-induced senescence in all cell lines studied, and reduces breast cancer stem-like cells, at concentrations that do not affect the viability of senescent tumor cells. We demonstrate that trabectedin downregulates both the glutamine transporter SLC1A5 and glutamine synthetase, thereby interfering with glutamine metabolism. On the whole, our results indicate that trabectedin targets a glutamine-dependent cancer stem-like cell population involved in evasion from therapy-induced senescence and suggest a therapeutic potential for trabectedin combined with pro-senescence chemotherapy in tumor treatment.

Trabectedin in Cancers: Mechanisms and Clinical Applications

Trabectedin, a tetrahydroisoquinoline alkaloid, is the first marine antineoplastic agent approved with special anticancer mechanisms involving DNA binding, DNA repair pathways, transcription regulation and regulation of the tumor microenvironment. It has favorable clinical applications, especially for the treatment of patients with advanced soft tissue sarcoma, who failed in anthracyclines and ifosfamide therapy or could not receive these agents. Currently, trabectedin monotherapy regimen and regimens of combined therapy with other agents are both widely used for the treatment of malignancies, including soft tissue sarcomas, ovarian cancer, breast cancer, and non-small-cell lung cancer. In this review, we summarized the basic information and some updated knowledge on trabectedin, including its molecular structure, metabolism in various cancers, pharmaceutical mechanisms, clinical applications, drug combination, and adverse reactions, along with prospections on its possibly more optimal use in cancer treatment.

Chemotherapy resistance in epithelial ovarian cancer: Mechanisms and emerging treatments

Ovarian cancer (OC) remains a fatal malignancy because most patients experience recurrent disease, which is resistant to chemotherapy. The outcomes for patients with platinum-resistant OC are poor, response rates to further chemotherapy are low and median survival is lower than 12 months. The complexity of platinum-resistant OC, which comprises a heterogeneous spectrum of diseases, is indeed far from being completely understood. Therefore, comprehending tumors' biological behaviour to identify reliable biomarkers, which may predict responses to therapies, is a demanding challenge to improve OC management. In the age of precision medicine, efforts to overcome platinum resistance in OC represent a dynamic and vast field in which innovative drugs and clinical trials rapidly develop. This review will present the exceptional biochemical environment implicated in OC and highlights mechanisms of chemoresistance. Furthermore, innovative molecules and new therapeutic opportunities are presented, along with currently available therapies and ongoing clinical trials.

Trabectedin (Yondelis®) as a Therapeutic Option in Gynecological Cancers: A Focus on its Mechanisms of Action, Clinical Activity and Genomic Predictors of Drug Response

The use of predictive biomarkers provides potential individualized cancer therapeutic options to prevent therapy failure as well as serious toxicities. Several recent studies showed that predictive and prognostic biomarkers are a notable personalized strategy to improve patients' care in several cancers. Trabectedin (Yondelis®) is a cytotoxic agent, derived from a marine organism, harbouring a significant antitumor activity against several cancers such as soft tissue sarcoma, ovarian, and breast cancers. Recently and with the advent of molecular genetic testing, BRCA mutational status was found as an important predictor of response to this anticancer drug, especially in gynecological cancers. The aim of this updated review is to discuss the mechanisms of action of trabectedin against the wellknown cancer hallmarks described until today. The current advances were also examined related to genomic biomarkers that can be used in the future to predict the efficacy of this potent anticancer natural molecule in various gynecological cancers.

Marine Natural Products from Tunicates and Their Associated Microbes

Marine tunicates are identified as a potential source of marine natural products (MNPs), demonstrating a wide range of biological properties, like antimicrobial and anticancer activities. The symbiotic relationship between tunicates and specific microbial groups has revealed the acquisition of microbial compounds by tunicates for defensive purpose. For instance, yellow pigmented compounds, "tambjamines", produced by the tunicate, Sigillina signifera (Sluiter, 1909), primarily originated from their bacterial symbionts, which are involved in their chemical defense function, indicating the ecological role of symbiotic microbial association with tunicates. This review has garnered comprehensive literature on MNPs produced by tunicates and their symbiotic microbionts. Various sections covered in this review include tunicates' ecological functions, biological activities, such as antimicrobial, antitumor, and anticancer activities, metabolic origins, utilization of invasive tunicates, and research gaps. Apart from the literature content, 20 different chemical databases were explored to identify tunicates-derived MNPs. In addition, the management and exploitation of tunicate resources in the global oceans are detailed for their ecological and biotechnological implications.

Trabectedin for reversing platinum resistance and resensitization to platinum in patients with recurrent ovarian cancer

Aims: We evaluated trabectedin in patients with platinum-resistant/refractory and partially platinum-sensitive recurrent ovarian cancer and the outcomes after reintroduction of platinum. Methods: Twenty-seven patients (platinum-resistant/refractory n = 24/PPS; n = 3) treated with trabectedin were retrospectively analyzed. Results: Trabectedin resulted in an objective response rate (ORR) of 18.2% with a 59.1% of disease control rate (ORR plus stable disease). The median progression-free and overall survival were 3.0 and 21.3 months, respectively. Subsequently, 17 patients were retreated with platinum and yield an ORR of 41.2% and DCR of 47.0%. The median progression-free and overall survival after platinum rechallenge were 5.0 and 14.7 months, respectively. Conclusion: Our results suggest that trabectedin may contribute to resensitize tumor cells to platinum rechallenge.

Starvation tactics using natural compounds for advanced cancers: pharmacodynamics, clinical efficacy, and predictive biomarkers

The high mortality associated with oncological diseases is mostly due to tumors in advanced stages, and their management is a major challenge in modern oncology. Angiogenesis is a defined hallmark of cancer and predisposes to metastatic invasion and dissemination and is therefore an important druggable target for cancer drug discovery. Recently, because of drug resistance and poor prognosis, new anticancer drugs from natural sources targeting tumor vessels have attracted more attention and have been used in several randomized and controlled clinical trials as therapeutic options. Here, we outline and discuss potential natural compounds as salvage treatment for advanced cancers from recent and ongoing clinical trials and real-world studies. We also discuss predictive biomarkers for patients' selection to optimize the use of these potential anticancer drugs.

Trabectedin modulates the senescence-associated secretory phenotype and promotes cell death in senescent tumor cells by targeting NF-κB

Therapy-induced senescence is a major cellular response to chemotherapy in solid tumors. Senescent tumor cells acquire a secretory phenotype, or SASP, and produce pro-inflammatory factors, whose expression is largely under NF-κB transcriptional control. Secreted factors play a positive role in driving antitumor immunity, but also exert negative influences on the microenvironment, and promote tumor growth and metastasis. Moreover, subsets of cancer cells can escape the senescence arrest, driving tumor recurrence after treatments. Hence, removal the senescent tumor cells, or reprogramming of the senescent secretome, have become attractive therapeutic options.

The marine drug trabectedin was shown to inhibit the production of pro-inflammatory mediators by tumor-infiltrating immune cells and by myxoid liposarcoma cells. Here, we demonstrate that trabectedin inhibits the SASP, thus limiting the pro-tumoral activities of senescent tumor cells in vitro. We show that trabectedin modulates NF-κB transcriptional activity in senescent tumor cells. This results in disruption of the balance between antiapoptotic and proapoptotic signals, and sensitization of cells to Fas-mediated apoptosis. Further, we found that trabectedin inhibits escape from therapy-induced senescence, at concentrations that do not affect the viability of bulk tumor population.

Overall, our data demonstrate that trabectedin has the potential to inhibit multiple detrimental effects of therapy-induced senescence.

Real-World Management of Trabectedin/Pegylated Liposomal Doxorubicin in Platinum-Sensitive Recurrent Ovarian Cancer Patients: A National Survey

BACKGROUND

Trabectedin (T) plus pegylated liposomal doxorubicin (PLD) is approved for treatment of platinum-sensitive recurrent ovarian cancer (ROC). Despite the recommendations and guidelines, variations in managing T/PLD administration in routine clinical practice cannot be excluded. We aimed at setting up an Italian survey collecting data about management of T/PLD administration in ROC patients.

METHODS

We carried out the development of a questionnaire-based survey on routine clinical practice in the management of ROC patients administered T/PLD. The survey registered the physicians' approach to modification/discontinuation of treatment, type of modifications, reasons why, and so on. The survey was transmitted to medical oncologists and gynecologic oncologists practicing in national centers/institutions.

RESULTS

Fifty-eight Italian centers/institutions returned the compiled questionnaire; participants practiced at community cancer centers or hospitals (56.9%), academic institutions (36.2%), and other settings (private clinics, etc) (6.9%). There was no statistically significant difference in the distribution of practice setting according to geographic areas. Most responders were medical oncologists (84.5%) and were members (82.8%) of at least 1 scientific society or cooperative group. Almost 31.5% of responders reported interruption of the whole treatment, mostly because of toxicity (41.2%), followed by patients' choice (29.4%), or achievement of clinical benefit (23.5%). Dose reduction was referred by 47.4% of responders. Reduction of dose for both drugs was referred by 88.5% of responders, and the extent of dose reduction ranged between 10% and 30%.

CONCLUSIONS

This survey highlights the gaps in transposing evidence-based or consensus guidelines in the real-world management of T/PLD administration; these findings could be useful in order to focus the attention on specific knowledge and/or experience gaps and plan pertinent educational programs.

Tumor promoting role of anti-tumor macrophages in tumor microenvironment

Recent advances in tumor biology demand detailed analysis of the complex interaction of tumor cells with their adjacent microenvironment (tumor stroma) to understand the various mechanisms involved in tumor growth and metastasis. Mononuclear phagocytes or macrophages, a type of innate immune cells, defend the organism against infection and injury. On the otherhand, tumor associated macrophages (TAMs) constitute a significant part of the tumor-infiltrating immune cells, have been linked to the growth, angiogenesis, and metastasis of a variety of cancers, most likely through polarization of TAMs to the M2 (alternative) phenotype. Clinical and experimental evidences have shown that cancer tissues with high infiltration of TAMs are associated with poor patient prognosis and resistance to therapies, thus, targeting of TAMs in tumors is considered as a promising immunotherapeutic strategy. Depletion of M2 TAMs or 're-education' of them as anti-tumor effectors might contribute significantly to the search of new modalities in anti-cancer treatments. Basic questions on the factors responsible for homing of macrophages in tumors, mechanism of conversion of M1 to M2 TAMs, their functionality and, finally, the possible ways to target M2 TAMs are discussed.

Emesis and nausea related to single agent trabectedin in ovarian cancer patients: a sub-study of the MITO15 project

The MITO 15 was a prospective, single-arm trial, evaluating trabectedin monotherapy in patients with recurrent ovarian cancer (OC) who were BRCA mutation-carriers or had a BRCAness phenotype. It is largely reported that trabectedin may induce nausea and vomiting but the real emetogenic potential of the drug, in the different schedules, has never been fully described; furthermore, OC patients are known to have an enhanced risk of developing nausea and vomiting due to female gender, abdominal spreading of the disease, and major surgery experienced by most of them. We thought to carry on a sub-study in the MITO 15 context focused on chemotherapy-induced nausea and vomiting (CINV) associated with trabectedin single agent. For all patients enrolled in the trial, we evaluated the antiemetic regimen at the first cycle, acute and delayed CINV, any rescue therapy, any change in the prophylactic antiemetic regimen, and the potential relationship between dexamethasone dosage and incidence of CINV. Overall, our findings were consistent with literature and confirmed that trabectedin can be classified as moderately emetogenic. We observed slightly higher rates of both nausea and vomiting compared to previous experiences with trabectedin monotherapy, probably due to intrinsic features of our population: all females and suffering from ovarian cancer. It seems that in preventing acute CINV, the combination of three drugs was more effective than the doublet; however, the difference did not reach statistical significance; further studies are required to verify such hypothesis. Given the extreme heterogeneity of the antiemetic regimens used, it appears that a standard antiemetic protocol does not exist and more specific guidelines for clinicians are needed.

Chemotherapy for epithelial ovarian, fallopian tube and primary peritoneal cancer

Chemotherapy plays a key role in the management of women with epithelial ovarian, fallopian tube and primary peritoneal cancer (EOC). Platinum- and taxane-based regimens are the standard of care for adjuvant treatment in early-stage EOC and first-line therapy for advanced stage disease. Efforts to define the optimal scheduling, timing and route of administration are ongoing. The majority of women with EOC will develop recurrent disease, and treatment options for these women are depend on the time that has elapsed from first-line therapy. Platinum-based doublet chemotherapy is preferred for women with platinum-sensitive recurrent cancer. In platinum-resistant relapsed EOC, options are much more limited, and careful consideration of symptoms, performance status, anticipated toxicity and quality of life is essential when recommending chemotherapy for these women.

Drug Monographs: Trabectedin and Trifluridine-Tipiracil

The complexity of cancer chemotherapy requires pharmacists be familiar with the complicated regimens and highly toxic agents used. This column reviews various issues related to preparation, dispensing, and administration of antineoplastic therapy, and the agents, both commercially available and investigational, used to treat malignant diseases.

Enhanced G2/M Arrest, Caspase Related Apoptosis and Reduced E-Cadherin Dependent Intercellular Adhesion by Trabectedin in Prostate Cancer Stem Cells

Trabectedin (Yondelis, ET-743) is a marine-derived tetrahydroisoquinoline alkaloid. It is originally derived from the Caribbean marine tunicate Ecteinascidia turbinata and currently produced synthetically. Trabectedin is active against a variety of tumor cell lines growing in culture. The present study focused on the effect of trabectedin in cell proliferation, cell cycle progression, apoptosis and spheroid formation in prostate cancer stem cells (CSCs). Cluster of differentiation (CD) 133^+high/CD44^+high prostate CSCs were isolated from the DU145 and PC-3 human prostate cancer cell line through flow cytometry. We studied the growth-inhibitory effects of trabectedin and its molecular mechanisms on human prostate CSCs and non-CSCs. DU-145 and PC-3 CSCs were treated with 0.1, 1, 10 and 100 nM trabectedin for 24, 48 and 72 h and the growth inhibition rates were examined using the sphere-forming assay. Annexin-V assay and immunofluorescence analyses were performed for the detection of the cell death. Concentration-dependent effects of trabectedin on the cell cycle were also evaluated. The cells were exposed to the different doses of trabectedin for 24, 48 and 72 h to evaluate the effect of trabectedin on the number and diameter of spheroids. According to the results, trabectedin induced cytotoxicity and apoptosis at the IC₅₀ dose, resulting in a significant increase expression of caspase-3, caspase-8, caspase-9, p53 and decrease expression of bcl-2 in dose-dependent manner. Cell cycle analyses revealed that trabectedin induces dose-dependent G2/M-phase cell cycle arrest, particularly at high-dose treatments. Three-dimensional culture studies showed that trabectedin reduced the number and diameter of spheroids of DU145 and PC3 CSCs. Furthermore, we have found that trabectedin disrupted cell-cell interactions via E-cadherin in prostasphere of DU-145 and PC-3 CSCs. Our results showed that trabectedin inhibits cellular proliferation and accelerates apoptotic events in prostate CSCs; and may be a potential effective therapeutic agent against prostate cancer.

Trabectedin plus pegylated liposomal doxorubicin: retrospective analysis in heavily pretreated platinum-sensitive ovarian cancer

Purpose

This retrospective analysis evaluated treatment with trabectedin plus pegylated liposomal doxorubicin (PLD) in 34 heavily pretreated patients (median number of previous lines, 3; range, 2-10) with platinum-sensitive relapsed ovarian cancer (ROC) at a single center in Italy.

Methods

Trabectedin/PLD treatment consisted of trabectedin administered every 3 weeks as a 3-hour intravenous (i.v.) infusion at a dose of 1.1 mg/m², immediately after PLD 30 mg/m² i.v. infusion. Study objectives were the evaluation of the objective response rate (ORR), progression-free survival (PFS) and overall survival (OS).

Results

Three complete responses and 8 partial responses were observed, with an ORR of 32.4% (95% CI, 17.450.5%). Median PFS was 6.1 months (95% CI, 4.4-8.9 months). Median OS was 16.3 months (95% CI, 6.8-23.5). Most responses (9 of 11) were found in patients with partially platinum-sensitive disease (ORR 40.9% in this subset; median PFS 6.8 months and median OS 20.8 months). Grade 3 treatment-related adverse events consisted of nausea/vomiting (n = 5; 14.7%), mucositis (n = 2; 5.9%), alanine aminotransferase increase, anemia and neutropenia (n = 1 each; 2.9%).

Conclusions

The overall findings appear consistent with those previously observed in a randomized controlled clinical trial, and support the use of trabectedin/PLD in heavily pretreated patients with platinum-sensitive ROC, especially those with partially platinum-sensitive disease.

Phase I study of the safety and pharmacokinetics of trabectedin with docetaxel in patients with advanced malignancies

PURPOSE

Combination therapy with trabectedin and docetaxel was evaluated in patients with advanced malignancies.

METHODS

In this open-label phase 1 study, docetaxel (60 or 75 mg/m(2); 1-h intravenous infusion) was given on day 1 of a 21-day cycle in combination with escalating doses of trabectedin (0.4-1.3 mg/m(2) by 3-h intravenous infusion, 1 h after docetaxel) and prophylactic granulocyte colony-stimulating factor (G-CSF). Maximum tolerated dose (MTD) as primary objective and safety, plasma pharmacokinetics, and antitumor activity as secondary objectives were assessed.

RESULTS

Patients (N = 49) received a median of four cycles of treatment. MTD was 1.3 mg/m(2) trabectedin and 60 mg/m(2) docetaxel for patients with limited and 1.1 mg/m(2) trabectedin and 60 mg/m(2) docetaxel for patients with unlimited prior chemotherapy. Dose-limiting toxicities (during cycle 1) included elevated alanine aminotransferase (ALT) and fatigue in patients with limited prior chemotherapy and elevated ALT and febrile neutropenia in those with unlimited prior chemotherapy. The most common drug-related adverse events were nausea (65 %), fatigue (63 %), and neutropenia (53 %). One patient achieved a complete response. Thirty patients had stable disease, and 11 had stable disease for ≥6 months. Pharmacokinetic results for trabectedin plus docetaxel were similar to those previously reported for the single agents.

CONCLUSION

In patients with previously treated, advanced malignancies, the combination of therapeutic doses of trabectedin and docetaxel showed clinical activity and was tolerable with prophylactic G-CSF, with no evidence of clinically important drug interactions.

Trabectedin: Supportive care strategies and safety profile

Trabectedin is an approved antineoplastic agent for the treatment of adult patients with advanced soft tissue sarcomas or in combination with pegylated liposomal doxorubicin (PLD) in patients with relapsed platinum sensitive ovarian cancer. The mechanism of action is still not fully understood but many typical side effects seen with other chemotherapy drugs are less common, mild or unreported. Although this apparent favorable safety profile suggests a well-tolerated and manageable therapeutic option in the palliative care setting, trabectedin does have specific adverse side effects which can be hazardous for individual patients. The most commonly observed toxicities with trabectedin include neutropenia, nausea, vomiting, and increases in liver transaminases, anemia, fatigue, thrombocytopenia, anorexia and diarrhea. However, for most patients the appropriate use of supportive care strategies can reduce or overcome these side effects. We present a concise review of the safety data of trabectedin with the corresponding overview of the supportive care strategies.

Combination treatment with trabectedin and irinotecan or topotecan has synergistic effects against ovarian clear cell carcinoma cells

OBJECTIVES

The objective of this study was to investigate the chemotherapeutic agents that produce the strongest synergistic effects when combined with trabectedin against ovarian clear cell carcinoma (CCC), which is regarded as an aggressive chemoresistant histological subtype.

METHODS

Using 4 human CCC cell lines (RMG1, RMG2, KOC7C, and HAC2), the cytotoxicities of trabectedin, SN-38, topotecan, doxorubicin, cisplatin, and paclitaxel as single agents were first assessed using the MTS assay. Then, the cytotoxicities of combination treatments involving trabectedin and 1 of the other 4 agents were evaluated by isobologram analysis to examine whether these combinations displayed synergistic, additive, or antagonistic effects. The antitumor activities of the combination treatments were also examined using cisplatin-resistant and paclitaxel-resistant CCC sublines, which were derived from the parental CCC cells by continuously exposing them to cisplatin or paclitaxel. Finally, we determined the effect of everolimus on the antitumor efficacy of trabectedin-based combination chemotherapy.

RESULTS

Concurrent exposure to trabectedin and SN-38 or topotecan resulted in synergistic interactions in all 4 CCC cell lines. Among the tested combinations, trabectedin plus SN-38 was the most effective cytotoxic regimen. The combination of trabectedin plus SN-38 also had strong synergistic effects on both the cisplatin-resistant and paclitaxel-resistant CCC cell lines. Treatment with everolimus significantly enhanced the antitumor activity of trabectedin plus SN-38 or topotecan.

CONCLUSIONS

Combination treatment with trabectedin and SN-38 displays the greatest cytotoxic effect against ovarian CCC. Our in vitro study provides the rationale for future clinical trials of trabectedin plus irinotecan with or without everolimus in patients with ovarian CCC in both the front-line chemotherapy setting and as a second-line treatment of recurrent CCC that had previously been treated with cisplatin or paclitaxel.

Trabectedin therapy as an emerging treatment strategy for recurrent platinum-sensitive ovarian cancer

Epithelial ovarian cancer (OC) is a common gynecologic malignancy in women. The standard treatment for OC is maximal cytoreductive surgical debulking followed by platinum-based chemotherapy. Despite the high response rate to primary therapy, approximately 85% of patients will develop recurrent ovarian cancer (ROC). This review identifies the clinical use of trabectedin in the treatment algorithm for ROC, with specific emphasis on platinum-sensitive ROC, for which trabectedin in combination with pegylated liposomal doxorubicin has been approved as a treatment protocol. The main mechanisms of action of trabectedin at the cellular level and in the tumor microenvironment is also discussed as bases for identifying biomarkers for selecting patients who may largely benefit from trabectedin-based therapies.

Tumor necrosis factor-alpha-converting enzyme activities and tumor-associated macrophages in breast cancer

The role of the tumor microenvironment especially of tumor-associated macrophages (TAMs) in the progression and metastatic spread of breast cancer is well established. TAMs have primarily a M2 (wound-healing) phenotype with minimal cytotoxic activities. The mechanisms by which tumor cells influence TAMs to display a pro-tumor phenotype are still debated although the key roles of immunomodulatory cytokines released by tumor cells, including colony-stimulating factor 1, tumor necrosis factor (TNF) and soluble TNF receptors 1/2, soluble vascular cell adhesion molecule 1, soluble interleukin 6 receptor and amphiregulin, have been demonstrated. Importantly, these factors are released through ectodomain shedding by the activities of the tumor necrosis factor-alpha-converting enzyme (TACE/ADAM17). The role of TACE activation leading to autocrine effects on tumor progression has been extensively studied. In contrast, limited information is available on the role of tumor cell TACE activities on TAMs in breast cancer. TACE inhibitors, currently in clinical trials, will certainly affect TAMs and subsequently treatment outcomes based on the substrates it releases. Furthermore, whether targeting a subset of the molecules shed by TACE, specifically those leading to TAMs with altered functions and phenotype, holds greater therapeutic promises than past clinical trials of TACE antagonists' remains to be determined. Here, the potential roles of TACE ectodomain shedding in the breast tumor microenvironment are reviewed with a focus on the release of tumor-derived immunomodulatory factors shed by TACE that directs TAM phenotypes and functions.

Trabectedin as a single-agent treatment of advanced breast cancer after anthracycline and taxane treatment: a multicenter, randomized, phase II study comparing 2 administration regimens

BACKGROUND

The purpose of this study was to assess the efficacy and safety of trabectedin for advanced breast cancer.

PATIENTS AND METHODS

In an open-label, phase II, multicenter study, women with advanced breast cancer previously treated with ≤ 2 lines of chemotherapy for advanced disease, including both anthracyclines and taxanes, were randomized (1:1) to 3-hour infusions of trabectedin 1.3 mg/m(2) once every 3 weeks (1/3 treatment arm) or 0.58 mg/m(2) every week for 3 of 4 weeks (3/4 treatment arm). The primary end point was objective response. Secondary end points included time to progression (TTP), progression-free survival (PFS), and overall survival (OS).

RESULTS

Fifty-two women (median age, 50 years; median chemotherapy agents, 4) were enrolled. Relative trabectedin dose intensities were 81% and 76% in the 1/3 and 3/4 treatment arms, respectively. Objective response rates were 12% (3 of 25) and 4% (1 of 27), respectively. Stable disease was observed in 14 (56%) and 11 (41%) patients in the 1/3 and 3/4 treatment arms, respectively, with median durations of 3.5 and 3.7 months. Median TTP and PFS were higher in the 1/3 treatment arm (3.1 months each) than in the 3/4 treatment arm (2.0 months each). At a median follow-up of 7 months in both treatment arms, median OS was not reached in the 1/3 treatment arm and was 9.4 months in the 3/4 treatment arm. The most frequent drug-related adverse events in the 1/3 and 3/4 treatment arms, respectively, were alanine aminotransferase (ALT) level increases (68% vs. 63%), nausea (56% vs. 59%), and asthenia (56% vs. 48%). Neutropenia and increases in ALT levels were the most frequent grade 3/4 events. Both types of events were usually transient and reversible.

CONCLUSION

In the population studied, trabectedin showed a manageable safety profile for both regimens analyzed. There were higher objective response rates and a longer PFS in the 1/3 treatment arm compared with the 3/4 treatment arm.

The Intercellular Metabolic Interplay between Tumor and Immune Cells

Functional and effective immune response requires a metabolic rewiring of immune cells to meet their energetic and anabolic demands. Beyond this, the availability of extracellular and intracellular metabolites may serve as metabolic signals interconnecting with cellular signaling events to influence cellular fate and immunological function. As such, tumor microenvironment represents a dramatic example of metabolic derangement, where the highly metabolic demanding tumor cells may compromise the function of some immune cells by competing nutrients (a form of intercellular competition), meanwhile may support the function of other immune cells by forming a metabolic symbiosis (a form of intercellular collaboration). It has been well known that tumor cells harness immune system through information exchanges that are largely attributed to soluble protein factors and intercellular junctions. In this review, we will discuss recent advance on tumor metabolism and immune metabolism, as well as provide examples of metabolic communications between tumor cells and immune system, which may represent a novel mechanism of conveying tumor-immune privilege.

Pharmacological modulation of monocytes and macrophages

Mononuclear phagocytes are major players in diverse pathological conditions which include chronic inflammatory diseases, infection, autoimmunity, atherosclerosis, metabolic disorders, and cancer. Plasticity is a fundamental property of cells of the monocyte-macrophage lineage and a variety of modulators profoundly affect monocytes and macrophages. Tumor-associated macrophages (TAMs) provide a paradigm for macrophage plasticity and anticancer therapeutic modalities (chemotherapy, radiotherapy, and immunotherapy) profoundly affect their function. The development of innovative strategies targeting cells of the monocyte-macrophage lineage may pave the way to innovative therapies for a wide range of diseases.

Clinical utility of trabectedin for the treatment of ovarian cancer: current evidence

Among the pharmaceutical options available for treatment of ovarian cancer, attention has been increasingly focused on trabectedin (ET-743), a drug which displays a unique mechanism of action and has been shown to be active in several human malignancies. Currently, single agent trabectedin is approved for treatment of patients with advanced soft tissue sarcoma after failure of anthracyclines and ifosfamide, and in association with pegylated liposomal doxorubicin for treatment of patients with relapsed partially platinum-sensitive ovarian cancer. This review aims at summarizing the available evidence about the clinical role of trabectedin in the management of patients with epithelial ovarian cancer. Novel perspectives coming from a better understanding of trabectedin mechanisms of action and definition of patients subgroups likely susceptible to benefit of trabectedin treatment are also presented.

Trabectedin as a single agent and in combination with pegylated liposomal doxorubicin - activity against ovarian cancer cells

Over 225 000 new cases of ovarian cancer are diagnosed each year. Symptoms are often vague, so most cases are detected when the disease is at an advanced stage. There is a need to find new drugs which will be able to treat ovarian cancer effectively. One of the most promising antineoplastic agents is trabectedin (Yondelis), derived from the marine tunicate Ecteinascidia turbinata, approved by the European Union in July 2007 for the treatment of soft-tissue sarcomas. This drug shows a mechanism of action based on the inhibition of the nucleotide excision repair system. Trabectedin shows anti-tumour activity in vitro and in vivo in ovarian, breast, prostate, renal, melanoma and non-small cell lung cancer cell lines. Trabectedin in combination with pegylated liposomal doxorubicin demonstrates synergistic antineoplastic activity.

Investigational agents for epithelial ovarian cancer

Ovarian cancer is the leading cause of gynecologic cancer deaths and accounts for 4% of women's cancer diagnoses and 5% of all cancer mortalities. Despite the ability of current chemotherapy and cytoreductive surgery to put patients in remission, most patients with advanced cancer will eventually relapse. Many advances in the treatment of ovarian cancer have been reported in the past several years and a historical background is provided. Attention will then turn to analogs of current chemotherapeutic agents, new cytotoxic drugs, targeted molecular therapy, intraperitoneal therapy and immunotherapy. This review will give a perspective on current drugs, potential agents and upcoming clinical trials.

Current status of bevacizumab in advanced ovarian cancer

Ovarian cancer is the most lethal gynecological cancer, mainly because of the delay in diagnosis. Recently, much effort has been put into investigating and introducing novel targeted agents into clinical practice, with the aim of improving prognosis and quality of life. Angiogenesis is a possible target. The aim of this review is to investigate the most common molecular pathways of angiogenesis, which have provided novel targets for tailored therapy in patients with ovarian cancer. These therapeutic strategies include monoclonal antibodies and tyrosine-kinase inhibitors. These drugs have as molecular targets vascular endothelial growth factor, vascular endothelial growth factor receptors, platelet-derived growth factor, fibroblast growth factor, and angiopoietin. Bevacizumab was investigated in several Phase III studies, with interesting results. Today, there is strong evidence for introducing bevacizumab in the treatment of patients with advanced and recurrent ovarian cancer. Nevertheless, further investigations and large clinical trials are needed to understand the safety and effectiveness of bevacizumab, the optimal duration and timing of treatment, and activity in association with other chemotherapeutic and targeted agents. It also is necessary to identify biologic factors predictive of efficacy to choose the most appropriate antiangiogenic agent in the integrated treatment of epithelial ovarian cancer.

A diverse induction of apoptosis by trabectedin in MCF-7 (HER2-/ER+) and MDA-MB-453 (HER2+/ER-) breast cancer cells

Trabectedin (Yondelis, ET-743), a semi synthetic tetrahydroisoquinoline alkaloid that was originally derived from the marine tunicate Ecteinascidia turbinata. The objective of this study was to investigate whether trabectedin mediated apoptosis shows any diversity in human breast cancer cell lines with different genotypes. Trabectedin induced cytotoxicity and apoptosis in both breast cancer cells in a time and concentration-dependent manner. The expression levels of the death receptor pathway molecules, TRAIL-R1/DR4, TRAIL-R2/DR5, FAS/TNFRSF6, TNF RI/TNFRSF1A, and FADD were significantly increased by 2.6-, 3.1-, 1.7-, 11.2- and 4.0-fold by trabectedin treatment in MCF-7 cells. However, in MDA-MB-453 cells, the mitochondrial pathway related pro-apoptotic proteins Bax, Bad, Cytochrome c, Smac/DIABLO, and Cleaved Caspase-3 expressions were induced by 4.2-, 3.6-, 4.8-, 4.5-, and 4.4-fold, and the expression levels of anti-apoptotic proteins Bcl-2 and Bcl-XL were reduced by 4.8- and 5.2-fold in MDA-MB-453 cells. Moreover, trabectedin treatment increased the generation of ROS in both breast cancer cells. We have shown that trabectedin causes selective activation of extrinsic and intrinsic apoptotic pathways in two genotypically different breast cancer cells. This preliminary data might guide clinicians to choose appropriate combination agents with trabectedin based on different molecular subtypes of breast cancer.

Comparison of in vitro and in vivo biological effects of trabectedin, lurbinectedin (PM01183) and Zalypsis® (PM00104)

This study: (i) investigated the in vitro cytotoxicity and mode of action of lurbinectedin (PM01183) and Zalypsis® (PM00104) compared with trabectedin in cell lines deficient in specific mechanisms of repair, (ii) evaluated their in vivo antitumor activity against a series of murine tumors and human xenografts. The antiproliferative activity, the DNA damage and the cell cycle perturbations induced by the three compounds on tumor lines were very similar. Nucleotide Excision Repair (NER) deficient cells were approximately fourfold more resistant to trabectedin, lurbinectedin and Zalypsis®. Cells deficient in non-homologous end joining (NHEJ), MRN complex and translesion synthesis (TLS) were slightly more sensitive to the three compounds (approximately fivefold) while cells deficient in homologous recombination (HR) were markedly more sensitive (150-200-fold). All three compounds showed a good antitumor activity in several in vivo models. Lurbinectedin and trabectedin had a similar pattern of antitumor activity in murine tumors and in xenografts, whereas Zalypsis® appeared to have a distinct spectrum of activity. The fact that no relationship whatsoever was found between the in vitro cytotoxic potency and the in vivo antitumor activity, suggests that in addition to direct cytotoxic mechanisms other host-mediated effects are involved in the in vivo pharmacological effects.

Palliative systemic therapy for women with recurrent epithelial ovarian cancer: current options

OBJECTIVES

To review the available systemic treatments for women with recurrent ovarian cancer.

METHODS

A literature review was conducted for recurrent ovarian cancer articles in English, including randomized trials, Phase II trials, or reviews.

RESULTS

We discuss the efficacy and toxicity outcomes associated with systemic therapy for platinum-sensitive and platinum-resistant ovarian cancer. Clearly, platinum-based combination systemic therapy shows a prolonged progression-free interval compared with single-agent chemotherapy with a low toxicity profile. No clear superior management strategy exists for platinum-resistant/refractory disease. Novel targeted antiangiogenic agents (eg, bevacizumab), angiopoeitin inhibitors (eg, AMG 386), and poly ADP ribose polymerase inhibitors (eg, olaparib) are reviewed.

CONCLUSION

Although combination platinum-based chemotherapy has shown benefits for women with platinum-sensitive recurrent ovarian cancer, the optimal treatment strategy for those with platinum-resistant or platinum-refractory disease is not clear. Molecular and genetic targeted therapies may provide opportunities for those women with tumor profiles that show sensitivity for specific agents.

Long-term outcome and effect of maintenance therapy in patients with advanced sarcoma treated with trabectedin: an analysis of 181 patients of the French ATU compassionate use program

BACKGROUND

The long term outcome of advanced sarcoma patients treated with trabectedin outside of clinical trials and the utility of maintenance treatment has not been reported.

METHODS

Between 2003 and 2008, patients with advanced sarcoma failing doxorubicin could be treated within a compassionate use program (ATU, Temporary Use Authorization) of trabectedin in France using the standard 3-weekly regimen. Data from 181 patients (55%) were collected from 11 centres and analyzed.

RESULTS

Trabectedin was given in first, second, third or fourth line in metastatic phase in 6%, 37%, 33% and 23% of patients respectively. With a median follow-up of 6 years, median PFS and OS were 3.6 months and 16.1 months respectively. The median number of cycles was 3 (range 1-19). Best response were partial response (PR, n = 18, 10%), stable disease (SD, n = 69, 39%) and progressive disease (PD, n = 83, 46%), non evaluable (NE, n = 9, 5%). Thirty patients (17%) had to be hospitalized for treatment- related side effects. Independent prognostic factors in multivariate analysis (Cox model) were myxoid LPS and line of trabectedin for PFS, and myxoid LPS and retroperitoneal sarcomas for OS. Patients in PR or SD after 6 cycles continuing treatment had a better PFS (median 5.3 vs 10.5 months, p = 0.001) and OS (median 13.9 vs 33.4 months, p = 0.009) as compared to patients who stopped after 6 cycles.

CONCLUSIONS

In this compassionate use program, trabectedin yielded similar or better PFS and OS than in clinical trials. Maintenance treatment beyond 6 cycles was associated with an improved survival.

Macrophages in malignant pleural effusions - alternatively activated tumor associated macrophages

Pleural macrophages are involved in local defense mechanisms against environmental pollution, bacteria and cancer. Their main function encompasses phagocytosis of degenerated mesothelial cells. In human pleural effusions macrophages represent more than half of all cells. A model of polarized macrophage activation (M1 and M2) was proposed, which defines a functionally different macrophage populations generated in response to various factors present in the inflamed environment. Tumor associated macrophages are a major component of the inflammatory infiltrate of most cancers. They can promote the proliferation and spread of cancer cells in the early stages of carcinogenesis and during metastasis. Macrophages isolated from malignant pleural effusions as well as tumor associated macrophages exhibit weak cytotoxic activity against tumor cells, increase their proliferative activity and may protect tumor cells from apoptosis. Defining biology of macrophages present in specific environment of the pleural effusion could allow the introduction of innovative diagnostic and therapeutic strategies.

A retrospective analysis of antitumour activity with trabectedin in translocation-related sarcomas

AIMS

Approximately 20% of soft tissue sarcomas (STS) have subtype-specific chromosomal translocations; these generate chimeric oncoproteins which can act as abnormal transcription factors. Since trabectedin can bind to DNA and displace transcription factors, antitumour activity was explored in translocation-related sarcoma (TRS) subtypes.

METHODS

The current retrospective pooled analysis includes data from 81 patients with TRS treated in 8 phase II trials.

RESULTS

TRS subtypes were: synovial sarcoma (SS, n=45), myxoid-round cell liposarcoma (MRC-L-sarcoma, n=27), alveolar soft part sarcoma (ASPS, n=4), endometrial stromal sarcoma (ESS, n=3) and clear cell sarcoma (CCS, n=2). All but one patient had received prior chemotherapy (median of 2 lines). Patients received a median of 4 trabectedin cycles (range, 1-48; median dose intensity=0.40 mg/m(2)/week). Partial responses according to Response Evaluation Criteria in Solid Tumours (RECIST) occurred in 8 patients (ORR=10%; 95% CI, 4-19%): four in MRC-L-sarcoma; three in SS and one in ESS. Tumour control rate (ORR plus stable disease) was 59% (95% CI, 48-70%). Median PFS was 4.1 months (6-month PFS rate=40%). Median overall survival was 17.4 months (survival rate at 12 months=60%). Trabectedin had a manageable safety profile.

CONCLUSION

Trabectedin demonstrates encouraging disease control in TRS. Since these promising results were generally noted in patients following chemotherapy, a phase III randomised trial in first-line is ongoing to compare trabectedin with doxorubicin-based chemotherapy in patients with TRS.

Macrophages in tumor microenvironments and the progression of tumors

Macrophages are widely distributed innate immune cells that play indispensable roles in the innate and adaptive immune response to pathogens and in-tissue homeostasis. Macrophages can be activated by a variety of stimuli and polarized to functionally different phenotypes. Two distinct subsets of macrophages have been proposed, including classically activated (M1) and alternatively activated (M2) macrophages. M1 macrophages express a series of proinflammatory cytokines, chemokines, and effector molecules, such as IL-12, IL-23, TNF-α, iNOS and MHCI/II. In contrast, M2 macrophages express a wide array of anti-inflammatory molecules, such as IL-10, TGF-β, and arginase1. In most tumors, the infiltrated macrophages are considered to be of the M2 phenotype, which provides an immunosuppressive microenvironment for tumor growth. Furthermore, tumor-associated macrophages secrete many cytokines, chemokines, and proteases, which promote tumor angiogenesis, growth, metastasis, and immunosuppression. Recently, it was also found that tumor-associated macrophages interact with cancer stem cells. This interaction leads to tumorigenesis, metastasis, and drug resistance. So mediating macrophage to resist tumors is considered to be potential therapy.

A systems biology approach to characterize the regulatory networks leading to trabectedin resistance in an in vitro model of myxoid liposarcoma

Trabectedin, a new antitumor compound originally derived from a marine tunicate, is clinically effective in soft tissue sarcoma. The drug has shown a high selectivity for myxoid liposarcoma, characterized by the translocation t(12;16)(q13; p11) leading to the expression of FUS-CHOP fusion gene. Trabectedin appears to act interfering with mechanisms of transcription regulation. In particular, the transactivating activity of FUS-CHOP was found to be impaired by trabectedin treatment. Even after prolonged response resistance occurs and thus it is important to elucidate the mechanisms of resistance to trabectedin. To this end we developed and characterized a myxoid liposarcoma cell line resistant to trabectedin (402-91/ET), obtained by exposing the parental 402-91 cell line to stepwise increases in drug concentration. The aim of this study was to compare mRNAs, miRNAs and proteins profiles of 402-91 and 402-91/ET cells through a systems biology approach. We identified 3,083 genes, 47 miRNAs and 336 proteins differentially expressed between 402-91 and 402-91/ET cell lines. Interestingly three miRNAs among those differentially expressed, miR-130a, miR-21 and miR-7, harbored CHOP binding sites in their promoter region. We used computational approaches to integrate the three regulatory layers and to generate a molecular map describing the altered circuits in sensitive and resistant cell lines. By combining transcriptomic and proteomic data, we reconstructed two different networks, i.e. apoptosis and cell cycle regulation, that could play a key role in modulating trabectedin resistance. This approach highlights the central role of genes such as CCDN1, RB1, E2F4, TNF, CDKN1C and ABL1 in both pre- and post-transcriptional regulatory network. The validation of these results in in vivo models might be clinically relevant to stratify myxoid liposarcoma patients with different sensitivity to trabectedin treatment.