Trabectedin, a drug acting on both cancer cells and the tumour microenvironment

Tumor organoids in cancer medicine: from model systems to natural compound screening

CONTEXT

The advent of tissue engineering and biomedical techniques has significantly advanced the development of three-dimensional (3D) cell culture systems, particularly tumor organoids. These self-assembled 3D cell clusters closely replicate the histopathological, genetic, and phenotypic characteristics of primary tissues, making them invaluable tools in cancer research and drug screening.

OBJECTIVE

This review addresses the challenges in developing in vitro models that accurately reflect tumor heterogeneity and explores the application of tumor organoids in cancer research, with a specific focus on the screening of natural products for antitumor therapies.

METHODS

This review synthesizes information from major databases, including Chemical Abstracts, Medicinal and Aromatic Plants Abstracts, ScienceDirect, Google Scholar, Scopus, PubMed and Springer Link. Publications were selected without date restrictions, using terms such as 'organoid', 'natural product', 'pharmacological', 'extract', 'nanomaterial' and 'traditional uses'. Articles related to agriculture, ecology, synthetic work or published in languages other than English were excluded.

RESULTS AND CONCLUSIONS

The review identifies key challenges related to the efficiency and variability of organoid generation and discusses ongoing efforts to enhance their predictive capabilities in drug screening and personalized medicine. Recent studies utilizing patient-derived organoid models for natural compound screening are highlighted, demonstrating the potential of these models in developing new classes of anticancer agents. The integration of natural products with patient-derived organoid models presents a promising approach for discovering novel anticancer compounds and elucidating their mechanisms of action.

Locking the gates of immortality: targeting alternative lengthening of telomeres (ALT) pathways

Telomere maintenance is essential for the unlimited proliferation of cancer cells. While most cancers reactivate telomerase to preserve telomeres, approximately 10-15% utilize the alternative lengthening of telomeres (ALT), a telomerase-independent mechanism driven by homologous recombination. ALT is primarily observed in sarcomas and neuroepithelial tumors and it is characterized by hallmarks such as heterogeneous telomere lengths, the presence of ALT-associated PML bodies (APBs), extrachromosomal telomeric repeats (ECTRs), and elevated replication stress. This review has a threefold aim: (1) to examine the mechanisms of ALT activation, (2) to highlight existing therapeutic interventions targeting ALT components and telosomic complexes, and, (3) to pinpoint potential molecular targets for novel anticancer treatments. Therapeutic strategies focus on disrupting APBs, stabilizing G-quadruplex structures, and inhibiting replication stress proteins such as FANCM and SMARCAL1. Emerging evidence highlights the role of shelterin proteins like TRF1 and TRF2, chromatin remodeling factors such as ATRX and DAXX, and the dysregulated cGAS-STING pathway in facilitating ALT activity. Moreover, the inhibitory role of RAP1-SUN1 protein interactions in telomere recombination provides a novel therapeutic avenue. Recent advances have elucidated the intricate balance of replication stress, DNA damage response, and recombination in ALT regulation. These insights can help overcome challenges posed by ALT + cancers, including their ability to transition from telomerase-dependent states. Targeting ALT-specific vulnerabilities offers a promising direction for developing innovative therapies that exploit the unique biology of ALT-driven tumors.

Quinazolinone Derivative MR2938 Protects DSS-Induced Barrier Dysfunction in Mice Through Regulating Gut Microbiota

Background/Objectives: Ulcerative colitis (UC), a chronic inflammatory bowel disease (IBD), is characterized by colorectal immune infiltration and significant microbiota compositional changes. Gut microbiota homeostasis is necessary to maintain the healthy state of humans. MR2938, a quinazolin-4(3H)-one derivative derived from the marine natural product penipanoid C, alleviated DSS-induced colitis in a dose-dependent manner. Herein, we aimed to investigate the impact of MR2938 on the gut microbiota in dextran sodium sulfate (DSS)-induced colitis in mice and to elucidate the role of the gut microbiota in the therapeutic mechanism of MR2938 for alleviating colitis. Methods: Acute colitis was induced with DSS in mice. Mice were administered with 100 mg/kg or 50 mg/kg of MR2938. Cecal content was also preserved in liquid nitrogen and subsequently analyzed following 16S RNA sequencing. Antibiotic cocktail-induced microbiome depletion was performed to further investigate the relationship between MR2938 and gut microbiota. The inflammatory factor levels were performed by quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA). Alcian blue staining and immunofluorescence were used to estimate the intestinal barrier. Results: The 16S rRNA sequencing revealed microbiota modulation by MR2938. Compared with the model group, the 100 mg/kg MR2938 group was associated with higher abundances of Entercoccus and a lower abundance of Staphylococcus, while the 50 mg/kg MR2938 group was associated with higher abundances of Lactobacillus and a lower abundance of Staphylococcus. The antibiotic-mediated microbiota depletion experiments demonstrated that the gut microbiota primarily contributed to barrier function protection, with little impact on inflammatory factor levels during the MR2938 treatment. Conclusions: These findings suggest that intestinal flora play a crucial role in MR2938's therapeutic mechanism for alleviating colitis.

Trabectedin promotes oncolytic virus antitumor efficacy, viral gene expression, and immune effector function in models of bone sarcoma

We previously reported that the DNA alkylator and transcriptional-blocking chemotherapeutic agent trabectedin enhances oncolytic herpes simplex viroimmunotherapy in human sarcoma xenograft models, though the mechanism remained to be elucidated. Here we report trabectedin disrupts the intrinsic cellular antiviral response which increases viral transcript presence in the human tumor cells. We also extended our synergy findings to syngeneic murine sarcoma models, which are poorly susceptible to virus infection. In the absence of robust virus replication, we found trabectedin enhanced viroimmunotherapy efficacy by reducing infiltrating immunosuppressive CD4 T and myeloid cells and stimulating granzyme expression in infiltrating T and natural killer cells to cause immune-mediated tumor regressions. Thus, trabectedin enhances both the direct virus-mediated killing of tumor cells and the viral-induced activation of cytotoxic effector lymphocytes to cause tumor regressions across models. Our data provide a strong rationale for clinical translation as both mechanisms should be simultaneously active in human patients.

Role of PD-1/PD-L1 signaling axis in oncogenesis and its targeting by bioactive natural compounds for cancer immunotherapy

Cancer is a global health problem and one of the leading causes of mortality. Immune checkpoint inhibitors have revolutionized the field of oncology, emerging as a powerful treatment strategy. A key pathway that has garnered considerable attention is programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1). The interaction between PD-L1 expressed on tumor cells and PD-1 reduces the innate immune response and thus compromises the capability of the body's immune system. Furthermore, it controls the phenotype and functionality of innate and adaptive immune components. A range of monoclonal antibodies, including avelumab, atezolizumab, camrelizumab, dostarlimab, durvalumab, sinitilimab, toripalimab, and zimberelimab, have been developed for targeting the interaction between PD-1 and PD-L1. These agents can induce a broad spectrum of autoimmune-like complications that may affect any organ system. Recent studies have focused on the effect of various natural compounds that inhibit immune checkpoints. This could contribute to the existing arsenal of anticancer drugs. Several bioactive natural agents have been shown to affect the PD-1/PD-L1 signaling axis, promoting tumor cell apoptosis, influencing cell proliferation, and eventually leading to tumor cell death and inhibiting cancer progression. However, there is a substantial knowledge gap regarding the role of different natural compounds targeting PD-1 in the context of cancer. Hence, this review aims to provide a common connection between PD-1/PD-L1 blockade and the anticancer effects of distinct natural molecules. Moreover, the primary focus will be on the underlying mechanism of action as well as the clinical efficacy of bioactive molecules. Current challenges along with the scope of future research directions targeting PD-1/PD-L1 interactions through natural substances are also discussed.

Metabolomic analysis revealed the inflammatory and oxidative stress regulation in response to Vibrio infection in Plectropomus leopardus

Frequent outbreaks of infectious diseases in aquaculture have led to significant economic losses. The leopard coral grouper (Plectropomus leopardus) often suffers from vibriosis. Improving host immunity presents a superior strategy for disease control, with minimal side effects compared to the use of antibiotics, highlighting the necessity of exploring the mechanisms underlying the fish's response to pathogen infections. Here, we conducted a comparative metabolomic analysis on the livers of the P. leopardus infected with Vibrio harveyi. A total of 1124 differential metabolites (DMs) were identified, with 190, 218, 359, and 353 DMs being identified at 6, 12, 24, and 48 h post-infection (hpi), respectively. Then, based on the time series analysis, we found that the lipid metabolism pathways were modulated in response to the Vibrio infection, with an increase in the quantity of eicosanoids and gycerophospholipids (GPLs), as well as a decrease in the quantity of bile acids (BAs), vitamin D, and sex hormones. Furthermore, 13 enriched pathways involving 31 DMs were identified through KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analyses. We identified histamine, 15(S)-HpETE, and anandamide in the transient receptor potential (TRP) channels pathway, as well as (7S,8S)-DiHODE, 5S,8R-DiHODE, and 13(S)-HpODE in the linoleic acid (LA) metabolism pathway. The DM levels increased, which may be attributed to inflammation. The DMs in the thyroid hormone synthesis pathway were identified, and the contents of nicotinamide adenine dinucleotide phosphate (NADPH) and glutathione (GSH) decreased, which may be crucial in antioxidants. Our findings highlighted the dynamic adjustments in lipid metabolism and the response to inflammation and oxidative stress during the infection of V. harveyi in P. leopardus. This study not only deepens our understanding of the metabolic underpinnings of fish immune responses but also lays the groundwork for research into functional metabolomics and mechanisms of disease resistance.

Mechanism of efficacy of trabectedin against myxoid liposarcoma entails detachment of the FUS-DDIT3 transcription factor from its DNA binding sites

BACKGROUND

The marine drug trabectedin has shown unusual effectiveness in the treatment of myxoid liposarcoma (MLPS), a liposarcoma characterized by the expression of the FUS-DDIT3 chimera. Trabectedin elicits a significant transcriptional response in MLPS resulting in cellular depletion and reactivation of adipogenesis. However, the role of the chimeric protein in the mechanism of action of the drug is not entirely understood.

METHODS

FUS-DDIT3-specific binding sites were assessed through Chromatin Immunoprecipitation Sequencing (ChIP-Seq). Trabectedin-induced effects were studied on pre-established patient-derived xenograft models of MLPS, one sensitive to (ML017) and one resistant against (ML017ET) trabectedin at different time points (24 and 72 h, 15 days). Data were integrated with RNA-Seq from the same models.

RESULTS

Through ChIP-Seq, here we demonstrate that trabectedin inhibits the binding of FUS-DDIT3 to its target genes, restoring adipocyte differentiation in a patient-derived xenograft model of MLPS sensitive to trabectedin. In addition, complementary RNA-Seq data on the same model demonstrates a two-phase effect of trabectedin, characterized by an initial FUS-DDIT3-independent cytotoxicity, followed by a transcriptionally active pro-differentiation phase due to the long-lasting detachment of the chimera from the DNA. Interestingly, in a trabectedin-resistant MLPS model, the effect of trabectedin on FUS-DDIT3 rapidly decreased over time, and prolonged treatment was no longer able to induce any transcription or post-transcriptional modifications.

CONCLUSIONS

These findings explain the unusual mechanism underlying trabectedin's effectiveness against MLPS by pinpointing the chimera's role in inducing the differentiation block responsible for MLPS pathogenesis. Additionally, the findings hint at a potential mechanism of resistance acquired in vivo.

Macrophages: Key Players in the Battle against Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a challenging subtype of breast cancer characterized by the absence of estrogen and progesterone receptors and HER2 expression, leading to limited treatment options and a poorer prognosis. TNBC is particularly prevalent in premenopausal African-descent women and is associated with aggressive tumor behavior and higher metastatic potential. Tumor-associated macrophages (TAMs) are abundantly present within the TNBC microenvironment and play pivotal roles in promoting tumor growth, progression, and metastasis through various mechanisms, including immune suppression and enhancement of angiogenesis. This review provides an in-depth overview of TNBC, focusing on its epidemiology, its molecular characteristics, and the critical influence of TAMs. It discusses the pathological and molecular aspects that define TNBC's aggressive nature and reviews current and emerging therapeutic strategies aimed at targeting these dynamics. Special attention is given to the role of TAMs, exploring their potential as therapeutic targets due to their significant impact on tumor behavior and patient outcomes. This review aims to highlight the complexities of the TNBC landscape and to present the innovative approaches that are currently being pursued to improve therapeutic efficacy and patient survival.

Multifaceted Characterization and Therapeutic Evaluation of Co-precipitated Cobalt Ferrite Nanoparticles for Magnetic Hyperthermia Cancer Therapy

Aim

Magnetic-mediated hyperthermia has emerged as a promising therapeutic approach for treating cancer. This technique employs the heat dissipated by the magnetic nanoparticles when subjected to an external varying magnetic field, to bring about localized hyperthermia in tumor tissues. Owing to their conducive and tuneable "physical, chemical, and magnetic" characteristics, cobalt ferrite (CoFe2O4) nanoparticles are recognized as emerging contenders. The aim of the present work was to enhance the magnetic characteristics and guarantee the efficacy of CoFe2 O4 nanoparticles in targeting and eliminating cancer cells.

Methods

CoFe2O4 nanoparticles were synthesized using the chemical co-precipitation route and underwent rigorous structural, morphological, and magnetic characterization techniques. The synthesized particles were then subjected to in vitro studies to evaluate their cytotoxicity and antimicrobial susceptibility.

Results

The characterization techniques confirmed the cubic structure, ferrite phase, and spherical and magnetic nature of CoFe2O4 nanoparticles. The zeta potential was found to be - 0.0048V (4.8 mV). Cytotoxicity analysis exhibited decreased cell viability with increasing concentrations of CoFe2O4 nanoparticles. Antimicrobial studies displayed good inhibiting properties.

Conclusion

The zeta potential of the synthesized CoFe2O4 nanoparticles was found to be higher than that of the breast cancer cells (MCF-7) which proves the synthesized drug to be effective. The in vitro studies also disclose the efficacy of the drug over cancer cells.

S-p-bromobenzyl-glutathione cyclopentyl diester (BBGC) as novel therapeutic strategy to enhance trabectedin anti-tumor effect in soft tissue sarcoma preclinical models

Trabectedin, approved for the treatment of soft tissue sarcoma (STS), interferes with cell division and genetic transcription processes. Due to its strong anti-tumor activity in only certain histotypes, several studies on trabectedin combinations are currently ongoing to improve its efficacy. In this study, we aimed to investigate novel potential therapeutic strategies to enhance the anti-tumor effect of trabectedin using integrated in silico, in vitro, and in vivo approaches. For in silico analysis, we screened two public datasets, GSEA M5190 and TCGA SARC. Fibrosarcoma, leiomyosarcoma, dedifferentiated, and myxoid liposarcoma cell lines were used for in vitro studies. For in vivo experiments, fibrosarcoma orthotopic murine model was developed. In silico analysis identified Glo1 as the only druggable target upregulated after trabectedin treatment and correlated with poor prognosis. The specific Glo1 inhibitor, S-p-bromobenzylglutathione cyclopentyl diester (BBGC), increased trabectedin cytotoxicity in STS cells, and restored drug sensitivity in myxoid liposarcoma cells resistant to trabectedin. Moreover, the combined treatment with BBGC and trabectedin had a synergistic antitumor effect in vivo without any additional toxicity to mice. Based on these results, we believe that BBGC warrants further investigation to evaluate its potential clinical use in combination with trabectedin.

Salinity Stress Acclimation Strategies in Chlamydomonas sp. Revealed by Physiological, Morphological and Transcriptomic Approaches

Climate changes may include variations in salinity concentrations at sea by changing ocean dynamics. These variations may be especially challenging for marine photosynthetic organisms, affecting their growth and distribution. Chlamydomonas spp. are ubiquitous and are often found in extreme salinity conditions. For this reason, they are considered good model species to study salinity adaptation strategies. In the current study, we used an integrated approach to study the Chlamydomonas sp. CCMP225 response to salinities of 20‱ and 70‱, by combining physiological, morphological, and transcriptomic analyses, and comparing differentially expressed genes in the exponential and stationary growth phases under the two salinity conditions. The results showed that the strain is able to grow under all tested salinity conditions and maintains a surprisingly high photosynthetic efficiency even under high salinities. However, at the highest salinity condition, the cells lose their flagella. The transcriptomic analysis highlighted the up- or down-regulation of specific gene categories, helping to identify key genes responding to salinity stress. Overall, the findings may be of interest to the marine biology, ecology, and biotechnology communities, to better understand species adaptation mechanisms under possible global change scenarios and the potential activation of enzymes involved in the synthesis of bioactive molecules.

Using nanotechnology to progress the utilization of marine natural products in combating multidrug resistance in cancer: A prospective strategy

Achieving targeted, customized, and combination therapies with clarity of the involved molecular pathways is crucial in the treatment as well as overcoming multidrug resistance (MDR) in cancer. Nanotechnology has emerged as an innovative and promising approach to address the problem of drug resistance. Developing nano-formulation-based therapies using therapeutic agents poses a synergistic effect to overcome MDR in cancer. In this review, we aimed to highlight the important pathways involved in the progression of MDR in cancer mediated through nanotechnology-based approaches that have been employed to circumvent them in recent years. Here, we also discussed the potential use of marine metabolites to treat MDR in cancer, utilizing active drug-targeting nanomedicine-based techniques to enhance selective drug accumulation in cancer cells. The discussion also provides future insights for developing complex targeted, multistage responsive nanomedical drug delivery systems for effective cancer treatments. We propose more combinational studies and their validation for the possible marine-based nanoformulations for future development.

HMGA1 regulates trabectedin sensitivity in advanced soft-tissue sarcoma (STS): A Spanish Group for Research on Sarcomas (GEIS) study

HMGA1 is a structural epigenetic chromatin factor that has been associated with tumor progression and drug resistance. Here, we reported the prognostic/predictive value of HMGA1 for trabectedin in advanced soft-tissue sarcoma (STS) and the effect of inhibiting HMGA1 or the mTOR downstream pathway in trabectedin activity. The prognostic/predictive value of HMGA1 expression was assessed in a cohort of 301 STS patients at mRNA (n = 133) and protein level (n = 272), by HTG EdgeSeq transcriptomics and immunohistochemistry, respectively. The effect of HMGA1 silencing on trabectedin activity and gene expression profiling was measured in leiomyosarcoma cells. The effect of combining mTOR inhibitors with trabectedin was assessed on cell viability in vitro studies, whereas in vivo studies tested the activity of this combination. HMGA1 mRNA and protein expression were significantly associated with worse progression-free survival of trabectedin and worse overall survival in STS. HMGA1 silencing sensitized leiomyosarcoma cells for trabectedin treatment, reducing the spheroid area and increasing cell death. The downregulation of HGMA1 significantly decreased the enrichment of some specific gene sets, including the PI3K/AKT/mTOR pathway. The inhibition of mTOR, sensitized leiomyosarcoma cultures for trabectedin treatment, increasing cell death. In in vivo studies, the combination of rapamycin with trabectedin downregulated HMGA1 expression and stabilized tumor growth of 3-methylcholantrene-induced sarcoma-like models. HMGA1 is an adverse prognostic factor for trabectedin treatment in advanced STS. HMGA1 silencing increases trabectedin efficacy, in part by modulating the mTOR signaling pathway. Trabectedin plus mTOR inhibitors are active in preclinical models of sarcoma, downregulating HMGA1 expression levels and stabilizing tumor growth.

Trabectedin Enhances Oncolytic Virotherapy by Reducing Barriers to Virus Spread and Cytotoxic Immunity in Preclinical Pediatric Bone Sarcoma

We previously reported that the DNA alkylator and transcriptional-blocking chemotherapeutic agent trabectedin enhances oncolytic herpes simplex viroimmunotherapy in human sarcoma xenograft models, though the mechanism remained to be elucidated. Here we report trabectedin disrupts the intrinsic cellular anti-viral response which increases viral transcript spread throughout the human tumor cells. We also extended our synergy findings to syngeneic murine sarcoma models, which are poorly susceptible to virus infection. In the absence of robust virus replication, we found trabectedin enhanced viroimmunotherapy efficacy by reducing immunosuppressive macrophages and stimulating granzyme expression in infiltrating T and NK cells to cause immune-mediated tumor regressions. Thus, trabectedin enhances both the direct virus-mediated killing of tumor cells and the viral-induced activation of cytotoxic effector lymphocytes to cause tumor regressions across models. Our data provide a strong rationale for clinical translation as both mechanisms should be simultaneously active in human patients.

In ovarian cancer maraviroc potentiates the antitumoral activity and further inhibits the formation of a tumor-promoting microenvironment by trabectedin

Ovarian cancer (OC) is the fifth most frequent cause of cancer-related death in women. Chemotherapy agent trabectedin, affecting cancer cells and tumor microenvironment, has been approved for the treatment of relapsed platinum-sensitive OC patients. CCR5-antagonist maraviroc inhibits tumor growth, metastasis, and enhances the antitumoral activity of DNA-damaging drugs. Here, we found that OC cells expressed CCR5 receptor but did not secret CCR5-ligands. Maraviroc treatment did not affect OC cell viability, but strongly potentiated the antiproliferative activity, apoptosis induction, cell cycle blockage, DNA damage, and ROS formation by trabectedin. In A2780cis cisplatin-resistant cells, the cross-resistance to trabectedin was overcame by the combination with maraviroc. Maraviroc enhanced trabectedin cytotoxicity in OC 3Dimensional spheroids and THP-1-monocytes. Both maraviroc and trabectedin interact with drug efflux pump MDR1/P-gp, overexpressed in recurrent OC patients. Maraviroc increased trabectedin intracellular accumulation and the MDR1-inhibitor verapamil, like maraviroc, increased trabectedin cytotoxicity. In OC tumor xenografts the combination with maraviroc further reduced tumor growth, angiogenesis, and monocyte infiltration by trabectedin. In conclusion, this study offers a preclinical rationale for the use of maraviroc as new option to improve trabectedin activity in relapsed chemoresistant OC patients.

Marine-Derived Anticancer Agents Targeting Apoptotic Pathways: Exploring the Depths for Novel Cancer Therapies

Extensive research has been conducted on the isolation and study of bioactive compounds derived from marine sources. Several natural products have demonstrated potential as inducers of apoptosis and are currently under investigation in clinical trials. These marine-derived compounds selectively interact with extrinsic and intrinsic apoptotic pathways using a variety of molecular mechanisms, resulting in cell shrinkage, chromatin condensation, cytoplasmic blebs, apoptotic bodies, and phagocytosis by adjacent parenchymal cells, neoplastic cells, or macrophages. Numerous marine-derived compounds are currently undergoing rigorous examination for their potential application in cancer therapy. This review examines a total of 21 marine-derived compounds, along with their synthetic derivatives, sourced from marine organisms such as sponges, corals, tunicates, mollusks, ascidians, algae, cyanobacteria, fungi, and actinobacteria. These compounds are currently undergoing preclinical and clinical trials to evaluate their potential as apoptosis inducers for the treatment of different types of cancer. This review further examined the compound's properties and mode of action, preclinical investigations, clinical trial studies on single or combination therapy, and the prospective development of marine-derived anticancer therapies.

In-Silico Identification of Novel Pharmacological Synergisms: The Trabectedin Case

The in-silico strategy of identifying novel uses for already existing drugs, known as drug repositioning, has enhanced drug discovery. Previous studies have shown a positive correlation between expression changes induced by the anticancer agent trabectedin and those caused by irinotecan, a topoisomerase I inhibitor. Leveraging the availability of transcriptional datasets, we developed a general in-silico drug-repositioning approach that we applied to investigate novel trabectedin synergisms. We set a workflow allowing the identification of genes selectively modulated by a drug and possible novel drug interactions. To show its effectiveness, we selected trabectedin as a case-study drug. We retrieved eight transcriptional cancer datasets including controls and samples treated with trabectedin or its analog lurbinectedin. We compared gene signature associated with each dataset to the 476,251 signatures from the Connectivity Map database. The most significant connections referred to mitomycin-c, topoisomerase II inhibitors, a PKC inhibitor, a Chk1 inhibitor, an antifungal agent, and an antagonist of the glutamate receptor. Genes coherently modulated by the drugs were involved in cell cycle, PPARalpha, and Rho GTPases pathways. Our in-silico approach for drug synergism identification showed that trabectedin modulates specific pathways that are shared with other drugs, suggesting possible synergisms.

Phytotherapeutics in Cancer: From Potential Drug Candidates to Clinical Translation

Annually, a significant number of individuals succumb to cancer, an anomalous cellular condition characterized by uncontrolled cellular proliferation and the emergence of highly perilous tumors. Identifying underlying molecular mechanism(s) driving disease progression has led to various inventive therapeutic approaches, many of which are presently under pre-clinical and/or clinical trials. Over the recent years, numerous alternative strategies for addressing cancer have also been proposed and put into practice. This article delineates the modern therapeutic drugs employed in cancer treatment and their associated toxicity. Due to inherent drug toxicity associated with most modern treatments, demand rises for alternative therapies and phytochemicals with minimal side effects and proven efficacy against cancer. Analogs of taxol, Vinca alkaloids like vincristine and vinblastine, and podophyllotoxin represent a few illustrative examples in this context. The phytochemicals often work by modifying the activity of molecular pathways that are thought to be involved in the onset and progression of cancer. The principal objective of this study is to provide an overview of our current understanding regarding the pharmacologic effects and molecular targets of the active compounds found in natural products for cancer treatment and collate information about the recent advancements in this realm. The authors' interest in advancing the field of phytochemical research stems from both the potential of these compounds for use as drugs as well as their scientific validity. Accordingly, the significance of herbal formulations is underscored, shedding light on anticancer phytochemicals that are sought after at both pre-clinical and clinical levels, with discussion on the opportunities and challenges in pre-clinical and clinical cancer studies.

Immune Cells in the Tumor Microenvironment of Soft Tissue Sarcomas

Soft tissue sarcomas (STSs) are a rare heterogeneous group of malignant neoplasms characterized by their aggressive course and poor response to treatment. This determines the relevance of research aimed at studying the pathogenesis of STSs. By now, it is known that STSs is characterized by complex relationships between the tumor cells and immune cells of the microenvironment. Dynamic interactions between tumor cells and components of the microenvironment enhance adaptation to changing environmental conditions, which provides the high aggressive potential of STSs and resistance to antitumor therapy. Today, active research is being conducted to find effective antitumor drugs and to evaluate the possibility of using therapy with immune cells of STS. The difficulty in assessing the efficacy of new antitumor options is primarily due to the high heterogeneity of this group of malignant neoplasms. Studying the role of immune cells in the microenvironment in the progression STSs and resistance to antitumor therapies will provide the discovery of new biomarkers of the disease and the prediction of response to immunotherapy. In addition, it will help to initially divide patients into subgroups of good and poor response to immunotherapy, thus avoiding wasting precious time in selecting the appropriate antitumor agent.

Metabolic Clues to Bile Acid Patterns and Prolonged Survival in Patients with Metastatic Soft-Tissue Sarcoma Treated with Trabectedin

Metastatic soft-tissue sarcomas (mSTS) encompass a highly heterogeneous group of rare tumours characterized by different clinical behaviours and outcomes. Currently, prognostic factors for mSTS are very limited, posing significant challenges in predicting patient survival. Within a cohort of 39 mSTS patients undergoing trabectedin treatment, it was remarkable to find one patient who underwent 73 cycles of trabectedin achieving an unforeseen clinical outcome. To identify contributing factors to her exceptional long-term survival, we have explored circulation metabolomics and biohumoral biomarkers to uncover a potential distinct host biochemical phenotype. The long-term survival patient compared with the other mSTS patients exhibited a distinctive metabolic profile characterized by remarkably higher levels of ursodeoxycholic acid (UDCA) derivatives and vitamin D and lower levels of lithocholic acid (LCA) derivatives, as well as reduced levels of inflammatory C-Reactive Protein 4 (C-RP4) biomarker. Despite its exploratory nature, this study reveals a potential association between specific bile acid metabolic profiles and mSTS patients' prognosis. Enhanced clinical understanding of the interplay between bile acid metabolism and disease progression could pave the way for new targeted therapeutic interventions which may improve the overall survival of mSTS patients.

Selection of Natural Compounds with HMGA-Interfering Activities and Cancer Cell Cytotoxicity

HMGA proteins are intrinsically disordered (ID) chromatin architectural factors characterized by three DNA binding domains (AT-hooks) that allow them to bind into the DNA minor groove of AT-rich stretches. HMGA are functionally involved in regulating transcription, RNA processing, DNA repair, and chromatin remodeling and dynamics. These proteins are highly expressed and play essential functions during embryonic development. They are almost undetectable in adult tissues but are re-expressed at high levels in all cancers where they are involved in neoplastic transformation and cancer progression. We focused on identifying new small molecules capable of binding into the minor groove of AT-rich DNA sequences that could compete with HMGA for DNA binding and, thus, potentially interfere with their activities. Here, a docking-based virtual screening of a unique high diversity in-house library composed of around 1000 individual natural products identified 16 natural compounds as potential minor groove binders that could inhibit the interaction between HMGA and DNA. To verify the ability of these selected compounds to compete with HMGA proteins, we screened them using electrophoretic mobility shift assays. We identified Sorocein C, a Diels-Alder (D-A)-type adducts, isolated from Sorocea ilicifolia and Sorocea bonplandii with an HMGA/DNA-displacing activity and compared its activity with that of two structurally related compounds, Sorocein A and Sorocein B. All these compounds showed a cytotoxicity effect on cancer cells, suggesting that the Sorocein-structural family may provide new and yet unexplored chemotypes for the development of minor groove binders to be evaluated as anticancer agents.

Emerging pharmaceutical therapies of Ascidian-derived natural products and derivatives

In a growing multidrug-resistant environment, the identification of potential new drug candidates with an acceptable safety profile is a substantial crux in pharmaceutical discovery. This review discusses several aspects and properties of approved marine natural products derived from ascidian sources (phylum Chordata, subphylum Tunicata) and/or their deduced analogues including their biosynthetic origin, (bio)chemical preclinical assessments and known efficacy-safety profiles, clinical status in trials, but also translational developments, opportunities and final conclusions. The review also describes the preclinical assessments of a large number of other ascidian compounds that have not been involved in clinical trials yet. Finally, the emerging research on the connectivity of the ascidian hosts and their independent or obligate symbiotic guests is discussed. The review covers the latest information on the topic of ascidian-derived marine natural products over the last two decades including 2022, with the majority of publications published in the last decade.

Current topics and management of head and neck sarcomas

Given the low incidence, variety of histological types, and heterogeneous biological features of head and neck sarcomas, there is limited high-quality evidence available to head and neck oncologists. For resectable sarcomas, surgical resection followed by radiotherapy is the principle of local treatment, and perioperative chemotherapy is considered for chemotherapy-sensitive sarcomas. They often originate in anatomical border areas such as the skull base and mediastinum, and they require a multidisciplinary treatment approach considering functional and cosmetic impairment. Moreover, head and neck sarcomas may exhibit different behaviour and characteristics than sarcomas of other areas. In recent years, the molecular biological features of sarcomas have been used for the pathological diagnosis and development of novel agents. This review describes the historical background and recent topics that head and neck oncologists should know about this rare tumour from the following five perspectives: (i) epidemiology and general characteristics of head and neck sarcomas; (ii) changes in histopathological diagnosis in the genomic era; (iii) current standard treatment by histological type and clinical questions specific to head and neck; (iv) new drugs for advanced and metastatic soft tissue sarcomas; and (v) proton and carbon ion radiotherapy for head and neck sarcomas.

Formal Synthesis of Ecteinascidin 743 from N-Cbz-l-tyrosine

A formal total synthesis of ecteinascidin 743 and lurbinectedin is achieved. Key features involve a Pictet-Spengler cyclization coupling of the tetrahydroisoquinoline and phenylalaninol moieties prepared by a common route with high yield and selectivity, a Parikh-Doering oxidation with good chemoselectivity and functionality tolerance, and a light-mediated A-ring elaboration of pentacyclic methoxyquinone substrates. By the approach, the known advanced intermediate (4-step conversion to Et-743) can be obtained conveniently in 21 total steps from N-Cbz-l-tyrosine.

Host obesity alters the ovarian tumor immune microenvironment and impacts response to standard of care chemotherapy

BACKGROUND

The majority of women with epithelial ovarian cancer (OvCa) are diagnosed with metastatic disease, resulting in a poor 5-year survival of 31%. Obesity is a recognized non-infectious pandemic that increases OvCa incidence, enhances metastatic success and reduces survival. We have previously demonstrated a link between obesity and OvCa metastatic success in a diet-induced obesity mouse model wherein a significantly enhanced tumor burden was associated with a decreased M1/M2 tumor-associated macrophage ratio (Liu Y et al. Can, Res. 2015; 75:5046-57).

METHODS

The objective of this study was to use pre-clinical murine models of diet-induced obesity to evaluate the effect of a high fat diet (HFD) on response to standard of care chemotherapy and to assess obesity-associated changes in the tumor microenvironment. Archived tumor tissues from ovarian cancer patients of defined body mass index (BMI) were also evaluated using multiplexed immunofluorescence analysis of immune markers.

RESULTS

We observed a significantly diminished response to standard of care paclitaxel/carboplatin chemotherapy in HFD mice relative to low fat diet (LFD) controls. A corresponding decrease in the M1/M2 macrophage ratio and enhanced tumor fibrosis were observed both in murine DIO studies and in human tumors from women with BMI > 30.

CONCLUSIONS

Our data suggest that the reported negative impact of obesity on OvCa patient survival may be due in part to the effect of the altered M1/M2 tumor-associated macrophage ratio and enhanced fibrosis on chemosensitivity. These data demonstrate a contribution of host obesity to ovarian tumor progression and therapeutic response and support future combination strategies targeting macrophage polarization and/or fibrosis in the obese host.

Cancer chemotherapy and beyond: Current status, drug candidates, associated risks and progress in targeted therapeutics

Cancer is an abnormal state of cells where they undergo uncontrolled proliferation and produce aggressive malignancies that causes millions of deaths every year. With the new understanding of the molecular mechanism(s) of disease progression, our knowledge about the disease is snowballing, leading to the evolution of many new therapeutic regimes and their successive trials. In the past few decades, various combinations of therapies have been proposed and are presently employed in the treatment of diverse cancers. Targeted drug therapy, immunotherapy, and personalized medicines are now largely being employed, which were not common a few years back. The field of cancer discoveries and therapeutics are evolving fast as cancer type-specific biomarkers are progressively being identified and several types of cancers are nowadays undergoing systematic therapies, extending patients' disease-free survival thereafter. Although growing evidence shows that a systematic and targeted approach could be the future of cancer medicine, chemotherapy remains a largely opted therapeutic option despite its known side effects on the patient's physical and psychological health. Chemotherapeutic agents/pharmaceuticals served a great purpose over the past few decades and have remained the frontline choice for advanced-stage malignancies where surgery and/or radiation therapy cannot be prescribed due to specific reasons. The present report succinctly reviews the existing and contemporary advancements in chemotherapy and assesses the status of the enrolled drugs/pharmaceuticals; it also comprehensively discusses the emerging role of specific/targeted therapeutic strategies that are presently being employed to achieve better clinical success/survival rate in cancer patients.

Cervical cancer benefits from trabectedin combination with the β-blocker propranolol: in vitro and ex vivo evaluations in patient-derived organoids

Background: Cervical cancer (CC) is characterized by genomic alterations in DNA repair genes, which could favor treatment with agents causing DNA double-strand breaks (DSBs), such as trabectedin. Hence, we evaluated the capability of trabectedin to inhibit CC viability and used ovarian cancer (OC) models as a reference. Since chronic stress may promote gynecological cancer and may hinder the efficacy of therapy, we investigated the potential of targeting β-adrenergic receptors with propranolol to enhance trabectedin efficacy and change tumor immunogenicity. Methods: OC cell lines, Caov-3 and SK-OV-3, CC cell lines, HeLa and OV2008, and patient-derived organoids were used as study models. MTT and 3D cell viability assays were used for drug(s) IC₅₀ determination. The analysis of apoptosis, JC-1 mitochondrial membrane depolarization, cell cycle, and protein expression was performed by flow cytometry. Cell target modulation analyses were carried out by gene expression, Western blotting, immunofluorescence, and immunocytochemistry. Results: Trabectedin reduced the proliferation of both CC and OC cell lines and notably of CC patient-derived organoids. Mechanistically, trabectedin caused DNA DSBs and S-phase cell cycle arrest. Despite DNA DSBs, cells failed the formation of nuclear RAD51 foci and underwent apoptosis. Under norepinephrine stimulation, propranolol enhanced trabectedin efficacy, further inducing apoptosis through the involvement of mitochondria, Erk1/2 activation, and the increase of inducible COX-2. Notably, trabectedin and propranolol affected the expression of PD1 in both CC and OC cell lines. Conclusion: Overall, our results show that CC is responsive to trabectedin and provide translational evidence that could benefit CC treatment options. Our study pointed out that combined treatment offset trabectedin resistance caused by β-adrenergic receptor activation in both ovarian and cervical cancer models.

Trabectedin induces ferroptosis via regulation of HIF-1α/IRP1/TFR1 and Keap1/Nrf2/GPX4 axis in non-small cell lung cancer cells

BACKGROUND AND OBJECTIVES

Non-small cell lung cancer (NSCLC) is a global health concern. NSCLC treatment outcomes are generally poor due to treatment resistance or toxicity. Ferroptosis is a novel cell death triggered by iron accumulation, reactive oxygen species (ROS), and lipid peroxidation. Ferroptosis may kill cancer cells, particularly those resistant to apoptosis.

MATERIALS AND METHODS

The Cell Counting Kit-8 assay assessed NSCLC cell viability after trabectedin treatment. Flow cytometry with Annexin V-FITC staining evaluated cell death. ROS, iron, lipid peroxidation, and GSH levels were measured using commercial kits. qRT-PCR and western blots evaluated messenger RNA and protein levels. Proteins were inhibited using short interfering RNA transfection and specific inhibitors.

RESULTS

Trabectedin was cytotoxic to NSCLC cells regardless of p53 status. Trabectedin upregulated iron, ROS, and lipid peroxidation in NSCLC cells, causing ferroptosis. Trabectedin increases iron and ROS levels by upregulating transferrin receptor 1 and the HIF-1/IRP1 axis. In NSCLC cells, trabectedin suppresses glutathione peroxidase 4, followed by the Keap1/Nrf2 axis.

CONCLUSIONS

Our findings imply that trabectedin may treat NSCLC effectively.

Long-Time Progression-Free Survival with Trabectedin in Chemorefractory Metastatic Leiomyosarcoma of the Retroperitoneum: A Case Report

We present the case of a 46-year-old mother of a young child who was diagnosed with metastatic leiomyosarcoma. At diagnosis, the tumor had already infiltrated the vena cava, infiltration of the pancreas was suspected, and pulmonary metastases had been histologically confirmed. The goal of treatment was to prolong survival and gain quality time for the family. When the patient had not responded to 4 cycles of doxorubicin, trabectedin was initiated. After an initial partial remission with a reduction in the size of the primary leiomyosarcoma as well as some pulmonary metastases, the disease remained stable for a total of 10 months. Upon progression, the patient did not further respond to subsequent treatment lines. The presented case shows that second-line trabectedin may represent a promising option for patients with chemotherapy-resistant leiomyosarcoma to prolong survival while preserving quality of life.

Recent Advancement in Anticancer Compounds from Marine Organisms: Approval, Use and Bioinformatic Approaches to Predict New Targets

In recent years, the study of anticancer bioactive compounds from marine sources has received wide interest. Contextually, world regulatory authorities have approved several marine molecules, and new synthetic derivatives have also been synthesized and structurally improved for the treatment of numerous forms of cancer. However, the administration of drugs in cancer patients requires careful evaluation since their interaction with individual biological macromolecules, such as proteins or nucleic acids, determines variable downstream effects. This is reflected in a constant search for personalized therapies that lay the foundations of modern medicine. The new knowledge acquired on cancer mechanisms has certainly allowed advancements in tumor prevention, but unfortunately, due to the huge complexity and heterogeneity of cancer, we are still looking for a definitive therapy and clinical approaches. In this review, we discuss the significance of recently approved molecules originating from the marine environment, starting from their organism of origin to their structure and mechanism of action. Subsequently, these bio-compounds are used as models to illustrate possible bioinformatics approaches for the search of new targets that are useful for improving the knowledge on anticancer therapies.

Target Identification of 22-(4-Pyridinecarbonyl) Jorunnamycin A, a Tetrahydroisoquinoline Derivative from the Sponge Xestospongia sp., in Mediating Non-Small-Cell Lung Cancer Cell Apoptosis

A dysregulation of the cell-death mechanism contributes to poor prognosis in lung cancer. New potent chemotherapeutic agents targeting apoptosis-deregulating molecules have been discovered. In this study, 22-(4-pyridinecarbonyl) jorunnamycin A (22-(4'py)-JA), a synthetic derivative of bistetrahydroisoquinolinequinone from the Thai blue sponge, was semisynthesized by the Steglich esterification method, and its pharmacological mechanism in non-small-cell lung cancer (NSCLC) was elucidated by a network pharmacology approach. All predicted targets of 22-(4'py)-JA and genes related to NSCLC were retrieved from drug-target and gene databases. A total of 78 core targets were identified, and their associations were analyzed by STRING and Cytoscape. Gene ontology and KEGG pathway enrichment analyses revealed that molecules in mitogen-activated protein kinase (MAPK) signaling were potential targets of 22-(4'py)-JA in the induction of NSCLC apoptosis. In silico molecular docking analysis displayed a possible interaction of ERK1/2 and MEK1 with 22-(4'py)-JA. In vitro anticancer activity showed that 22-(4'py)-JA has strong cytotoxic and apoptosis-inducing effects in H460, H292 and A549 NSCLC cells. Furthermore, immunoblotting confirmed that 22-(4'py)-JA induced apoptotic cell death in an ERK/MEK/Bcl-2-dependent manner. The present study demonstrated that 22-(4'py)-JA exhibited a potent anticancer effect that could be further developed for clinical application and showed that network pharmacology approaches are a powerful tool to illustrate the molecular pathways of new drugs or compounds.

Preclinical Evaluation of Trabectedin in Combination With Targeted Inhibitors for Treatment of Metastatic Uveal Melanoma

Purpose

Uveal melanoma (UM) is considered a rare disease; yet, it is the most common intraocular malignancy in adults. Although the primary tumor may be efficiently managed, more than 50% of patients with UM develop distant metastases. The mortality at the first year after diagnosis of metastatic UM has been estimated at 81%, and the poor prognosis has not improved in the past years due to the lack of effective therapies.

Methods

In order to search for novel therapeutic possibilities for metastatic UM, we performed a small-scale screen of targeted drug combinations. We verified the targets of the tested compounds by western blotting and PCR and clarified the mechanism of action of the selected combinations by caspase 3 and 7 activity assay and flow cytometry. The best two combinations were tested in a mouse patient-derived xenograft (PDX) UM model as putative therapeutics for metastatic UM.

Results

Combinations of the multitarget drug trabectedin with either the CK2/CLK double-inhibitor CX-4945 (silmitasertib) or the c-MET/TAM (TYRO3, Axl, MERTK) receptor inhibitors foretinib and cabozantinib demonstrated synergistic effects and induced apoptosis (relative caspase 3 and 7 activity increased up to 20.5-fold in UM cell lines). In the case of the combination of foretinib and cabozantinib, inhibition of the TAM receptors, but not c-Met, was essential to inhibit the growth of UM cells. Monotreatment with trabectedin inhibited tumor growth by 42%, 49%, and 35% in the MM26, MM309, and MM339 PDX mouse models, respectively.

Conclusions

Trabectedin alone or in combination with cabozantinib inhibited tumor growth in PDX UM mouse models. Blocking of MERTK, rather than TYRO3, activity inhibited UM cell growth and synergized with trabectedin.

Transcription regulators and ultra-rare and other rare translocation-related sarcomas treated with trabectedin: A proof of principle from a post-hoc analysis

Background

Among sarcomas, which are rare cancers with an incidence of <6 per 100.000/year cases, ultra-rare sarcomas have an incidence of approximately ≤1/1,000,000/year cases and altogether account for ~20% of all soft tissue sarcomas (STS) and bone sarcomas. The Italian Sarcoma Group has recently performed a non-interventional, retrospective TrObs study with data from 512 anthracycline-pretreated patients with advanced multiple STS histologies and treated with trabectedin (Palmerini, Cancers 2021; ClinicalTrials.gov Identifier: NCT02793050).

Methods

A post-hoc analysis of case series to evaluate the efficacy and safety of trabectedin on patients with ultra-rare and other rare translocation-related sarcomas included in TrObs study was performed. Main outcomes comprised investigator-assessed overall response rate (ORR), disease control rate (DCR), progression-free survival (PFS) and safety.

Results

Thirty-six patients (18 women) with ultra-rare and other rare sarcoma and a median age of 53.0 years (range: 22-81) were included. Most patients had solitary fibrous tumor (SFT; n=11) followed by epithelioid sarcoma (n=5), malignant peripheral nerve sheath tumor (MPNST; n=4), extraskeletal myxoid chondrosarcoma (EMC; n=3), desmoplastic small round cell tumor (DSRCT; n=3), and alveolar soft part sarcoma (ASPS), rhabdomyosarcoma and clear cell sarcoma (n=2 each). Thirty-five patients had metastatic disease and 23 patients received trabectedin as a second-line treatment. Among 35 patients evaluable for response, two patients with SFT and ASPS had a partial response and one patient with DSRCT obtained a complete response, reaching an ORR of 8.6% (95% CI: 2.8-23.4%). Among patients with an ORR, 6-months PFS was 100% in patients with ASPS, 45.7% in patients with SFT and 33.3% in those with DSRCT. Two patients with epithelioid sarcoma and myoepithelioma had disease stabilization lasting >24 months. Nine patients had at least one grade 3/4 adverse event, mostly being bone marrow toxicity (n=6).

Conclusions

Trabectedin has some anti-tumor activity in some ultra-rare and other rare sarcomas, particularly translocation-related sarcomas, with the well-known manageable safety profile.

Trabectedin Is Active against Two Novel, Patient-Derived Solitary Fibrous Pleural Tumor Cell Lines and Synergizes with Ponatinib

Solitary fibrous tumor of the pleura (SFT) is a rare disease. Besides surgery combined with radiotherapy in nondisseminated stages, curative options are currently absent. Out of fourteen primo-cell cultures, established from surgical SFT specimens, two showed stable in vitro growth. Both cell models harbored the characteristic NAB2-STAT6 fusion and were further investigated by different preclinical methods assessing cell viability, clone formation, and protein regulation upon single-drug treatment or in response to selected treatment combinations. Both fusion-positive cell models showed-in line with the clinical experience and the literature-a low to moderate response to most of the tested cytotoxic and targeted agents. However, the multi-tyrosine kinase inhibitors ponatinib and dasatinib, as well as the anti-sarcoma compound trabectedin, revealed promising activity against SFT growth. Furthermore, both cell models spontaneously presented strong FGFR downstream signaling targetable by ponatinib. Most interestingly, the combination of either ponatinib or dasatinib with trabectedin showed synergistic effects. In conclusion, this study identified novel trabectedin-based treatment combinations with clinically approved tyrosine kinase inhibitors, using two newly established NAB2-STAT6 fusion-positive cell models. These findings can be the basis for anti-SFT drug repurposing approaches in this rare and therapy-refractory disease.

Formal Synthesis of Ecteinascidin 743 via an Intramolecular Cascade Heck Reaction to Construct the Diazabicyclo[3.3.1]nonane Framework

A synthetic route to ecteinascidin 743 has been established via an intramolecular cascade Heck reaction to construct the diazabicyclo[3.3.1]nonane skeleton while controlling the two contiguous stereogenic centers. The strategically formed five-membered ring was oxidatively cleaved to generate a dialdehyde intermediate, from which the B ring of ecteinascidin 743 was constructed.

Trabectedin and lurbinectedin: Mechanisms of action, clinical impact, and future perspectives in uterine and soft tissue sarcoma, ovarian carcinoma, and endometrial carcinoma

The ecteinascidins trabectedin and lurbinectedin are very interesting antineoplastic agents, with a favorable toxicity profile and peculiar mechanisms of action. These drugs form adducts in the minor groove of DNA, which produce single-strand breaks (SSBs) and double-strand breaks (DSBs) and trigger a series of events resulting in cell cycle arrest and apoptosis. Moreover, the ecteinascidins interact with the tumor microenvironment, reduce the number of tumor-associated macrophages, and inhibit the secretion of cytokines and chemokines. Trabectedin has been approved by the Federal Drug Administration (FDA) for patients with unresectable or metastatic liposarcoma or leiomyosarcoma who received a prior anthracycline-based regimen. Moreover, trabectedin in combination with pegylated liposomal doxorubicin (PLD) has been approved in the European Union for the treatment of platinum-sensitive recurrent ovarian cancer. Lurbinectedin has been approved by the FDA for patients with metastatic small cell lung cancer with disease progression on or after platinum-based chemotherapy. The review assesses in vitro and in vivo experimental studies on the antineoplastic effects of both ecteinascidins as well as the clinical trials on the activity of trabectedin in uterine sarcoma and ovarian carcinoma and of lurbinectedin in ovarian carcinoma and endometrial carcinoma.

Marine Natural Products in Clinical Use

Marine natural products are potent and promising sources of drugs among other natural products of plant, animal, and microbial origin. To date, 20 drugs from marine sources are in clinical use. Most approved marine compounds are antineoplastic, but some are also used for chronic neuropathic pain, for heparin overdosage, as haptens and vaccine carriers, and for omega-3 fatty-acid supplementation in the diet. Marine drugs have diverse structural characteristics and mechanisms of action. A considerable increase in the number of marine drugs approved for clinical use has occurred in the past few decades, which may be attributed to increasing research on marine compounds in laboratories across the world. In the present manuscript, we comprehensively studied all marine drugs that have been successfully used in the clinic. Researchers and clinicians are hopeful to discover many more drugs, as a large number of marine natural compounds are being investigated in preclinical and clinical studies.

How Chemotherapy Affects the Tumor Immune Microenvironment: A Narrative Review

Chemotherapy is much more effective in immunocompetent mice than in immunodeficient ones, and it is now acknowledged that an efficient immune system is necessary to optimize chemotherapy activity and efficacy. Furthermore, chemotherapy itself may reinvigorate immune response in different ways: by targeting cancer cells through the induction of cell stress, the release of damage signals and the induction of immunogenic cell death, by targeting immune cells, inhibiting immune suppressive cells and/or activating immune effector cells; and by targeting the host physiology through changes in the balance of gut microbiome. All these effects acting on immune and non-immune components interfere with the tumor microenvironment, leading to the different activity and efficacy of treatments. This article describes the correlation between chemotherapy and the immune changes induced in the tumor microenvironment. Our ultimate aim is to pave the way for the identification of the best drugs or combinations, the doses, the schedules and the right sequences to use when chemotherapy is combined with immunotherapy.

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.

Targeting the Tumor Microenvironment: A Close Up of Tumor-Associated Macrophages and Neutrophils

The importance of the tumor microenvironment (TME) in dynamically regulating cancer progression and influencing the therapeutic outcome is widely accepted and appreciated. Several therapeutic strategies to modify or modulate the TME, like angiogenesis or immune checkpoint inhibitors, showed clinical efficacy and received approval from regulatory authorities. Within recent decades, new promising strategies targeting myeloid cells have been implemented in preclinical cancer models. The predominance of specific cell phenotypes in the TME has been attributed to pro- or anti-tumoral. Hence, their modulation can, in turn, alter the responses to standard-of-care treatments, making them more or less effective. Here, we summarize and discuss the current knowledge and the correlated challenges about the tumor-associated macrophages and neutrophils targeting strategies, current treatments, and future developments.

Trabectedin and Radiation Therapy for Cardiac Metastasis From Leiomyosarcoma: A Case Report and Review of the Literature

Leiomyosarcoma (LMS) is one of the most frequent subtypes of soft-tissue sarcomas (STSs). Metastatic spread to the heart in cancer patients carries a poor prognosis and there is no known effective treatment. Cardiac metastases of STSs are very rare. Here we present the case of a 55-year-old patient who underwent surgical resection of a retroperitoneal leiomyosarcoma and then developed widespread metastatic disease, treated with a combination of local treatment and systemic therapy. Three years after surgical resection she presented with a cardiac intraventricular mass, which was treated with radiation therapy, while receiving systemic therapy with trabectedin. Such combination therapy was well-tolerated and effective, allowing a substantial dimensional reduction which is perduring to date, 18 months after diagnosis of cardiac metastasis. Available literature and data point to the feasibility and good tolerability of radiation therapy and trabectedin in metastatic sarcoma, yet this is the first report on the effectiveness of the combination for the treatment of cardiac disease. The extended survival since a metastatic relapse (more than 3 years) is likely the result of integrated systemic and loco-regional treatment, which should be always discussed within the framework of a multiprofessional and multidisciplinary setting.

DNA repair and damage pathways in mesothelioma development and therapy

Malignant mesothelioma (MMe) is an aggressive neoplasm that occurs through the transformation of mesothelial cells. Asbestos exposure is the main risk factor for MMe carcinogenesis. Other important etiologies for MMe development include DNA damage, over-activation of survival signaling pathways, and failure of DNA damage response (DDR). In this review article, first, we will describe the most important signaling pathways that contribute to MMe development and their interaction with DDR. Then, the contribution of DDR failure in MMe progression will be discussed. Finally, we will review the latest MMe therapeutic strategies that target the DDR pathway.

A Phase 1/2 Trial Combining Avelumab and Trabectedin for Advanced Liposarcoma and Leiomyosarcoma

PURPOSE

Leiomyosarcoma (LMS) and liposarcoma (LPS) frequently express PD-L1 but are generally resistant to PD-1/PD-L1 inhibition (ICI). Trabectedin is FDA-approved for LMS and LPS. This study aimed to evaluate the safety and efficacy of trabectedin with anti-PD-L1 antibody avelumab in patients with advanced LMS and LPS.

PATIENTS AND METHODS

A single-arm, open-label, Phase 1/2 study tested avelumab with trabectedin for advanced LMS and LPS. The phase I portion evaluated safety and feasibility of trabectedin (1, 1.2 and 1.5 mg/m2) with avelumab at standard dosing. Primary endpoint of the phase II portion was objective response rate (ORR) by RECIST 1.1. Correlative studies included T-cell receptor sequencing (TCRseq), multiplex immunohistochemistry, and tumor gene expression.

RESULTS

33 patients were evaluable; 24 with LMS (6 uterine and 18 non-uterine) and 11 with LPS. In Phase 1, dose limiting toxicities (DLTs) were observed in 2 of 6 patients at both trabectedin 1.2 and 1.5 mg/m2. The recommended Phase 2 dose (RP2D) was 1.0 mg/m2 trabectedin and 800 mg avelumab. Of 23 patients evaluable at RP2D, three (13%) had partial response (PR), ten (43%) had stable disease (SD) as best response. 6-month PFS was 52%; median PFS was 8.3 months. Patients with PR had higher Simpson Clonality score on TCRseq from peripheral blood mononuclear cells (PBMC) versus those with SD (0.182 vs 0.067, p = 0.02) or PD (0.182 vs 0.064, p = 0.01).

CONCLUSIONS

Although the trial did not meet the primary ORR endpoint, PFS compared favorably to prior studies of trabectedin warranting further investigation.

Effects of the Anti-Tumor Agents Trabectedin and Lurbinectedin on Immune Cells of the Tumor Microenvironment

Immune cells in the tumor micro-environment (TME) establish a complex relationship with cancer cells and may strongly influence disease progression and response to therapy. It is well established that myeloid cells infiltrating tumor tissues favor cancer progression. Tumor-Associated Macrophages (TAMs) are abundantly present at the TME and actively promote cancer cell proliferation and distant spreading, as well as contribute to an immune-suppressive milieu. Active research of the last decade has provided novel therapeutic approaches aimed at depleting TAMs and/or at reprogramming their functional activities. We reported some years ago that the registered anti-tumor agent trabectedin and its analogue lurbinectedin have numerous mechanisms of action that also involve direct effects on immune cells, opening up new interesting points of view. Trabectedin and lurbinectedin share the unique feature of being able to simultaneously kill cancer cells and to affect several features of the TME, most notably by inducing the rapid and selective apoptosis of monocytes and macrophages, and by inhibiting the transcription of several inflammatory mediators. Furthermore, depletion of TAMs alleviates the immunosuppressive milieu and rescues T cell functional activities, thus enhancing the anti-tumor response to immunotherapy with checkpoint inhibitors. In view of the growing interest in tumor-infiltrating immune cells, the availability of antineoplastic compounds showing immunomodulatory effects on innate and adaptive immunity deserves particular attention in the oncology field.

The Role of Trabectedin in Soft Tissue Sarcoma

Background: Systemic chemotherapy for advanced disease is another therapeutic option in the management of metastases in soft tissue sarcoma (STS). Doxorubicin either alone or in combination with ifosfamide has been used as first-line chemotherapy. Furthermore, in the past decade, new drugs have been shown to be effective in the treatment of advanced STS after the failure of first-line anthracycline-based chemotherapy: trabectedin, pazopanib and eribulin. However, the appropriate usage of these agents has not been established. Methods: We summarized clinical trials of trabectedin focusing on the efficacy and toxicity of trabectedin in the treatment of STS. Results: Trabectedin can be administered safely and effectively to the patients with advanced STS at second line setting or later. Although trabectedin may be effective as first-line treatment in selected patients, anthracycline-based chemotherapy should be recommended because no regimen in addition to trabectedin has proved to be unequivocally superior to doxorubicin as the first-line treatment for locally advanced or metastatic STS. Nucleotide excision repair (NER) and homologous recombination (HRe) repair may be of particular importance as efficacy of trabectedin. Conclusion: Trabectedin has shown a favorable toxicity profile and is an alternative therapeutic option in patients with advanced STS.

Impact of Co-Culture on the Metabolism of Marine Microorganisms

Natural products from plants have been listed for hundreds of years as a source of biologically active molecules. In recent years, the marine environment has demonstrated its ability to provide new structural entities. More than 70% of our planet’s surface is covered by oceans, and with the technical advances in diving and remotely operated vehicles, it is becoming easier to collect samples. Although the risk of rediscovery is significant, the discovery of silent gene clusters and innovative analytical techniques has renewed interest in natural product research. Different strategies have been proposed to activate these silent genes, including co-culture, or mixed fermentation, a cultivation-based approach. This review highlights the potential of co-culture of marine microorganisms to induce the production of new metabolites as well as to increase the yields of respective target metabolites with pharmacological potential, and moreover to indirectly improve the biological activity of a crude extract.

Macrophages as a Therapeutic Target in Metastatic Prostate Cancer: A Way to Overcome Immunotherapy Resistance?

Prostate cancer (PC) is the most common malignancy and the fifth cause of cancer death in men. The treatment for localized or locally advanced stages offers a high probability of cure. Even though the therapeutic landscape has significantly improved over the last decade, metastatic PC (mPC) still has a poor prognosis mainly due to the development of therapy resistance. In this context, the use of immunotherapy alone or in combination with other drugs has been explored in recent years. However, T-cell directed immune checkpoint inhibitors (ICIs) have shown limited activity with inconclusive results in mPC patients, most likely due to the highly immunosuppressive PC tumor microenvironment (TME). In this scenario, targeting macrophages, a highly abundant immunosuppressive cell type in the TME, could offer a new therapeutic strategy to improve immunotherapy efficacy. In this review, we summarize the growing field of macrophage-directed immunotherapies and discuss how these could be applied in the treatment of mPC, focusing on their combination with ICIs.

Bioactive Molecules from Ciliates: Structure, Activity, and Applicative Potential

Ciliates are a rich source of molecules synthesized to socialize, compete ecologically, and interact with prey and predators. Their isolation from laboratory cultures is often straightforward, permitting the study of their mechanisms of action and their assessment for applied research. This review focuses on three classes of these bioactive molecules: (i) water‐borne, cysteine‐rich proteins that are used as signaling pheromones in self/nonself recognition phenomena; (ii) cell membrane‐associated lipophilic terpenoids that are used in interspecies competitions for habitat colonization; (iii) cortical granule‐associated molecules of various chemical nature that primarily serve offence/defense functions.

Simplified hybrids of two anticancer bistetrahydroisoquinoline alkaloids ecteinascidin 743 and cribrostatin 4 and inhibitory activity against proliferation of cancer cells

A series of simplified hybrids/analogues of natural alkaloids ecteinascidin 743 and cribrostatin 4 have been synthesized and evaluated.

Trabectedin-Related Heart Failure: Case Report and a Systematic Review of the Literature

New drugs come not only with benefits but also with unexpected toxicities which need to be promptly recognized and managed. Starting from a scholar case of acute heart failure with preserved ejection fraction following the administration of trabectedin (ET-743, Yondelis^®) in a patient with a metastatic solitary fibrous tumor, we performed a systematic review of the literature encompassing the results of previous cardiac safety analysis published ten years ago, a review of clinical trials published during the last 10 years as well as single-case descriptions related to trabectedin cardiotoxicity. The estimated incidence of cardiac toxicity was 3,4% among patients receiving trabectedin, with recent data suggesting a higher rate of heart failure than previously recognized. Previous or concomitant anthracyclines exposure may represent a risk factor. Assaying for NT-pro-BNP may be useful for the early detection of individuals with trabectedin-induced heart failure.