Trabectedin overcomes doxorubicin-resistance, counteracts tumor-immunosuppressive reprogramming of monocytes and decreases xenograft growth in Hodgkin lymphoma

Targeting regulated cell death (RCD) in hematological malignancies: Recent advances and therapeutic potential

Regulated cell death (RCD) is a form of cell death that can be regulated by numerous biomacromolecules. Accumulating evidence suggests that dysregulated expression and altered localization of related proteins in RCD promote the development of cancer. Targeting subroutines of RCD with pharmacological small-molecule compounds is becoming a promising therapeutic avenue for anti-tumor treatment, especially in hematological malignancies. Herein, we summarize the aberrant mechanisms of apoptosis, necroptosis, pyroptosis, PANoptosis, and ferroptosis in hematological malignancies. In particular, we focus on the relationship between cell death and tumorigenesis, anti-tumor immunotherapy, and drug resistance in hematological malignancies. Furthermore, we discuss the emerging therapeutic strategies targeting different RCD subroutines. This review aims to summarize the significance and potential mechanisms of RCD in hematological malignancies, along with the development and utilization of pertinent therapeutic strategies.

Strategies to reprogram anti-inflammatory macrophages towards pro-inflammatory macrophages to support cancer immunotherapies

Tumor-associated myeloid cells, including macrophages and myeloid-derived suppressor cells, can be highly prevalent in solid tumors and play a significant role in the development of the tumor. Therefore, myeloid cells are being considered potential targets for cancer immunotherapies. In this review, we focused on strategies aimed at targeting tumor-associated macrophages (TAMs). Most strategies were studied preclinically but we also included a limited number of clinical studies based on these strategies. We describe possible underlying mechanisms and discuss future challenges and prospects.

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.

In Doxorubicin-Adapted Hodgkin Lymphoma Cells, Acquiring Multidrug Resistance and Improved Immunosuppressive Abilities, Doxorubicin Activity Was Enhanced by Chloroquine and GW4869

Classical Hodgkin lymphoma (cHL) is a highly curable disease (70-80%), even though long-term toxicities, drug resistance, and predicting clinical responses to therapy are major challenges in cHL treatment. To solve these problems, we characterized two cHL cell lines with acquired resistance to doxorubicin, KM-H2dx and HDLM-2dx (HRSdx), generated from KM-H2 and HDLM-2 cells, respectively. HRSdx cells developed cross-resistance to vinblastine, bendamustin, cisplatin, dacarbazine, gemcitabine, brentuximab vedotin (BV), and γ-radiation. Both HDLM-2 and HDLM-2dx cells had intrinsic resistance to BV but not to the drug MMAE. HDLM-2dx acquired cross-resistance to caelyx. HRSdx cells had in common decreased CD71, CD80, CD54, cyt-ROS, HLA-DR, DDR1, and CD44; increased Bcl-2, CD58, COX2, CD26, CCR5, and invasive capability; increased CCL5, TARC, PGE2, and TGF-β; and the capability of hijacking monocytes. In HRSdx cells less sensitive to DNA damage and oxidative stress, the efflux drug transporters MDR1 and MRP1 were not up-regulated, and doxorubicin accumulated in the cytoplasm rather than in the nucleus. Both the autophagy inhibitor chloroquine and extracellular vesicle (EV) release inhibitor GW4869 enhanced doxorubicin activity and counteracted doxorubicin resistance. In conclusion, this study identifies common modulated antigens in HRSdx cells, the associated cross-resistance patterns, and new potential therapeutic options to enhance doxorubicin activity and overcome resistance.

Potential Associations between Vascular Biology and Hodgkin's Lymphoma: An Overview

Hodgkin's lymphoma (HL) is a lymphatic neoplasm typically found in the cervical lymph nodes. The disease is multifactorial, and in recent years, the relationships between various vascular molecules have been explored in the field of vascular biology. The connection between vascular biology and HL is intricate and the roles of several pathways remain unclear. This review summarizes the cellular and molecular relationships between vascular biology and HL. Proteins associated with various functions in vascular biology, including cytokines (TNF-α, IL-1, IL-13, and IL-21), chemokines (CXCL10, CXCL12, and CCL21), adhesion molecules (ELAM-1/VCAM-1), and growth factors (BDNF/NT-3, platelet-derived growth factor receptor-α), have been linked to tumor activity. Notable tumor activities include the induction of paracrine activation of NF-kB-dependent pathways, upregulation of adhesion molecule regulation, genome amplification, and effective loss of antigen presentation mediated by MHC-II. Preclinical study models, primarily those using cell culture, have been optimized for HL. Animal models, particularly mice, are also used as alternatives to complex biological systems, with studies primarily focusing on the physiopathogenic evaluation of the disease. These biomolecules warrant further study because they may shed light on obscure pathways and serve as targets for prevention and/or treatment interventions.

Precision Killing of M2 Macrophages with Phage-Displayed Peptide-Photosensitizer Conjugates

Among the immunosuppressive cells recruited to the tumor microenvironment, macrophages are particularly abundant and involved in angiogenesis, metastasis, and resistance to current cancer therapies. A strategy that simultaneously targets tumor cells and macrophages, particularly pro-tumoral M2 macrophages, would have significant clinical impact for various types of solid malignancies. By the use of phage display technology, we have recently developed a synthetic peptide, named NW, which binds to M1 and M2 macrophages with high affinity. Additional affinity selection on M2 macrophages identified only dominant peptides whose binding motifs are similar to that of the NW peptide. To reduce the frequency of selecting such dominating peptides, the peptide library was affinity selected on M2 macrophages blocked with NW peptide. This approach resulted in the selection of peptides that bind to M2, but not M1 macrophages. To explore the therapeutic potential of the selected peptides, the M13 phage-displayed peptides were conjugated to the photosensitizer IR700, which has been used for cancer photoimmunotherapy. The phage displaying a dominant peptide (SPILWLNAPPWA) killed both M1 and M2 macrophages, while those displaying the M2-specific peptides killed M2 macrophages only upon near-infrared light exposure. A significant fraction of the M2 macrophages were also killed with the untargeted M13 phage-IR700 conjugates. Hence, M2 macrophages can also be selectively targeted by the wild type M13 phage, which displayed a significant tropism to these cells. The benefits of this photoimmunotherapy include an automatic self-targeting ability of the wild type M13 phage, and the option of genetic manipulation of the phage genome to include tumor targeting peptides, allowing the killing of both M2 macrophages and cancer cells.

A prognostic model based on necroptosis-related genes for prognosis and therapy in bladder cancer

Bladder cancer, one of the most prevalent malignant cancers, has high rate of recurrence and metastasis. Owing to genomic instability and high-level heterogeneity of bladder cancer, chemotherapy and immunotherapy drugs sensitivity and lack of prognostic markers, the prognosis of bladder cancer is unclear. Necroptosis is a programmed modality of necrotic cell death in a caspase-independent form. Despite the fact that necroptosis plays a critical role in tumor growth, cancer metastasis, and cancer patient prognosis, necroptosis-related gene sets have rarely been studied in bladder cancer. As a result, the development of new necroptosis-related prognostic indicators for bladder cancer patients is critical. Herein, we assessed the necroptosis landscape of bladder cancer patients from The Cancer Genome Atlas database and classified them into two unique necroptosis-related patterns, using the consensus clustering. Then, using five prognosis-related genes, we constructed a prognostic model (risk score), which contained 5 genes (ANXA1, DOK7, FKBP10, MAP1B and SPOCD1). And a nomogram model was also developed to offer the clinic with a more useful prognostic indicator. We found that risk score was significantly associated with clinicopathological characteristics, TIME, and tumor mutation burden in patients with bladder cancer. Moreover, risk score was a valid guide for immunotherapy, chemotherapy, and targeted drugs. In our study, DOK7 was chosen to further verify our prognosis model, and functional assays indicated that knockdown the expression of DOK7 could prompt bladder cancer proliferation and migration. Our work demonstrated the potential role of prognostic model based on necroptosis genes in the prognosis, immune landscape and response efficacy of immunotherapy of bladder cancer.

Knockdown of membrane-bound complement regulatory proteins suppresses colon cancer growth in mice through inducing tumor cell apoptosis

CD46, CD55 and CD59 are membrane-bound complement regulatory proteins (mCRPs) and highly expressed in many tumor tissues. Our analysis by RNA sequencing and qRT-PCR revealed that the expression of mCRPs was significantly elevated in cancer tissues of 15 patients with colon cancer. To further investigate the role of mCRPs in the development of colon cancer, we suppressed the expression of mCRPs by CD46-shRNA, CD55-shRNA and CD59-shRNA in colon cancer cell lines, SW620 and HT-29 cells. The results indicated that CD46-shRNA, CD55-shRNA and CD59-shRNA effectively reduced the expression of mCRPs, accompanied with the increased LDH release and the percentage of Annexin V + 7-AAD- early phase of apoptotic cells. The similar cytotoxic effects were also observed in the cells treated with CD46 neutralizing antibody (aCD46), associated with the increased C5b-9 deposition, cleaved caspase-3 and Bax expression in the treated cells. The cytotoxic effects by mCRPs knock-down were potentiated in the cells co-treated with doxorubicin (Dox). In addition, STAT3, STAT6, and p38 MAPK inhibitors, including C188-9, AS1517499 and SB203580 effectively reduced the expression of CD46 in the treated colon cells, associated with increased cell apoptosis and LDH release. Further study with mouse model revealed that mCRPs knockdown by mCRPs-shRNA significantly reduced colon cancer growth, associated with increased expression of Bax, cleaved caspase-3 and C5b-9 deposition, but reduced expression of Bcl-2, IL-6 and IL-1beta in tumor tissues of nude mice transplanted with SW620 cells. Thereby, mCRPs expression in human colon cancer cells were upregulated by STAT3/STAT6/p38 MAPK signaling and mCRPs knockdown reduced colon cancer growth in mice through inducing tumor cell apoptosis.

Consecutive Inhibition of Telomerase and Alternative Lengthening Pathway Promotes Hodgkin's Lymphoma Cell Death

Telomere maintenance is key during cancer development. Malignant cells can either use telomerase or an alternative lengthening of telomere (ALT) pathway to maintain their telomere length. In Hodgkin's Lymphoma (HL), the presence of telomerase activation is established. The activation of ALT has been reported recently. Our data confirm this notion describing co-localization of the phosphorylated form of telomeric repeat-binding factor 1 (pT371-TRF1) with ALT-associated promyelocytic leukemia bodies. Surprisingly, to our knowledge, there are no published studies targeting both telomere maintenance pathways in HL. Consequently, we investigated, for the first time, the effects of both telomerase and ALT inhibition on HL cell viability: We inhibited telomerase and/or ALT, given either individually, simultaneously, or consecutively. We report that the inhibition of telomerase using BIBR1532 followed by ALT inhibition, using trabectedin, caused a decrease of greater than 90% in cell viability in three patient-derived HL cell lines. Our results suggest that HL cells are most vulnerable to the consecutive inhibition of telomerase followed by ALT inhibition.

Chitosan-based nanoscale systems for doxorubicin delivery: Exploring biomedical application in cancer therapy

Green chemistry has been a growing multidisciplinary field in recent years showing great promise in biomedical applications, especially for cancer therapy. Chitosan (CS) is an abundant biopolymer derived from chitin and is present in insects and fungi. This polysaccharide has favorable characteristics, including biocompatibility, biodegradability, and ease of modification by enzymes and chemicals. CS-based nanoparticles (CS-NPs) have shown potential in the treatment of cancer and other diseases, affording targeted delivery and overcoming drug resistance. The current review emphasizes on the application of CS-NPs for the delivery of a chemotherapeutic agent, doxorubicin (DOX), in cancer therapy as they promote internalization of DOX in cancer cells and prevent the activity of P-glycoprotein (P-gp) to reverse drug resistance. These nanoarchitectures can provide co-delivery of DOX with antitumor agents such as curcumin and cisplatin to induce synergistic cancer therapy. Furthermore, co-loading of DOX with siRNA, shRNA, and miRNA can suppress tumor progression and provide chemosensitivity. Various nanostructures, including lipid-, carbon-, polymeric- and metal-based nanoparticles, are modifiable with CS for DOX delivery, while functionalization of CS-NPs with ligands such as hyaluronic acid promotes selectivity toward tumor cells and prevents DOX resistance. The CS-NPs demonstrate high encapsulation efficiency and due to protonation of amine groups of CS, pH-sensitive release of DOX can occur. Furthermore, redox- and light-responsive CS-NPs have been prepared for DOX delivery in cancer treatment. Leveraging these characteristics and in view of the biocompatibility of CS-NPs, we expect to soon see significant progress towards clinical translation.

Marine biome-derived secondary metabolites, a class of promising antineoplastic agents: A systematic review on their classification, mechanism of action and future perspectives

Cancer is one of the most deadly diseases on the planet. Over the past decades, numerous antineoplastic compounds have been discovered from natural resources such as medicinal plants and marine species as part of multiple drug discovery initiatives. Notably, several marine flora (e.g. Ascophyllum nodosum, Sargassum thunbergii) have been identified as a rich source for novel cytotoxic compounds of different chemical forms. Despite the availability of enormous chemically enhanced new resources, the anticancer potential of marine flora and fauna has received little attention. Interestingly, numerous marine-derived secondary metabolites (e.g., Cytarabine, Trabectedin) have exhibited anticancer effects in preclinical cancer models. Most of the anticancer drugs obtained from marine sources stimulated apoptotic signal transduction pathways in cancer cells, such as the intrinsic and extrinsic pathways. This review highlights the sources of different cytotoxic secondary metabolites obtained from marine bacteria, algae, fungi, invertebrates, and vertebrates. Furthermore, this review provides a comprehensive overview of the utilisation of numerous marine-derived cytotoxic compounds as anticancer drugs, as well as their modes of action (e.g., molecular target). Finally, it also discusses the future prospects of marine-derived drug developments and their constraints.

Novel Agents For Relapsed and Refractory Classical Hodgkin Lymphoma: A Review

Classical Hodgkin lymphoma (cHL) is the most common type of HL that occurs mainly in people aged between 15–30 and over 55 years. Although its general prognosis is favorable, 10%–30% of patients with cHL will ultimately develop relapsed or refractory disease (r/r cHL). Improving the cure rate of r/r cHL has proven to be challenging. Some novel agents, such as brentuximab vedotin and immune checkpoint inhibitors, which have been used in conventional regimens for patients with r/r cHL in the past decade, have been shown to have good curative effects. This paper reviews the conventional regimens for patients with r/r cHL and focuses on the newest clinical trials and treatment measures to prolong prognosis and reduce adverse events. The evaluation of prognosis plays a vital role in analyzing the risk of relapse or disease progression; thus, finding new predictive strategies may help treat patients with r/r cHL more efficaciously.

Role and Mechanisms of Tumor-Associated Macrophages in Hematological Malignancies

Mounting evidence has revealed that many nontumor cells in the tumor microenvironment, such as fibroblasts, endothelial cells, mesenchymal stem cells, and leukocytes, are strongly involved in tumor progression. In hematological malignancies, tumor-associated macrophages (TAMs) are considered to be an important component that promotes tumor growth and can be polarized into different phenotypes with protumor or antitumor roles. This Review emphasizes research related to the role and mechanisms of TAMs in hematological malignancies. TAMs lead to poor prognosis by influencing tumor progression at the molecular level, including nurturing cancer stem cells and laying the foundation for metastasis. Although detailed molecular mechanisms have not been clarified, TAMs may be a new therapeutic target in hematological disease treatment.

Identification and Assessment of Necroptosis-Related Genes in Clinical Prognosis and Immune Cells in Diffuse Large B-Cell Lymphoma

Background

With the unveiling of new mechanisms and the advent of new drugs, the prognosis of diffuse large B-cell lymphoma (DLBCL) becomes promising, but some patients still progress to the relapse or refractory stage. Necroptosis, as a relatively novel programmed cell death, is involved in the development of multiple tumors. There are no relevant studies on the prognostic significance of necroptosis in DLBCL to date.

Methods

We identified the differential necroptosis-related genes (NRGs) by comparing the DLBCL and normal control in GSE12195 and GSE56315 datasets. TCGA DLBC and GSE10846 containing clinical information and microarray expression profiling were merged as the entire cohort. We performed consensus clusters based on NRGs and two clusters were obtained. Kaplan–Meier (K-M) survival analysis, GSVA, GO, KEGG, and ssGSEA were used to analyze the survival, function, and immune microenvironment between two clusters. With LASSO and proportional hazard model construction, we identified differentially expressed genes (DEGs) between NRG clusters, calculated the risk score, established a prognostic model, and validated its value by calibration and ROC curves. The entire cohort was divided into the training and test cohort, and GSE87371 was included as an external validation cohort. K-M, copy number variation, tumor mutation burden, and drug sensitivity were also analyzed.

Results

We found significant differences in prognosis between the two NRG clusters. Cluster A with a poor prognosis had a decreased expression of NRGs and a relatively suppressed immune microenvironment. GSVA analysis indicated that cluster A was related to the downregulation of the TGF-β signaling pathway and the activation of the Notch signaling pathway. The risk score had an accurate predictive ability. The nomogram could help predict the survival probability of DLBCL patients in the entire cohort and the external validation cohort. The area under the curve (AUC) of the nomogram, risk score, and International Prognostic Index was 0.723, 0.712, and 0.537, respectively. γ/δ T cells and Macrophage 1 cells decreased while Macrophage 2 cells and Natural Killer resting cells increased in the high-risk group. In addition, the high-risk group was more sensitive to the PI3K inhibitor and the PDK inhibitor.

Conclusion

We explored the potential role of necroptosis in DLBCL from multiple perspectives and provided a prognostic nomogram for the survival prediction of DLBCL. Necroptosis was downregulated and was correlated with an immunosuppressed tumor microenvironment and poor prognosis in DLBCL. Our study may deepen the understanding and facilitate the development of new therapy targets for DLBCL.

Novel Immune-Related Gene Signature for Risk Stratification and Prognosis of Survival in ER (+) and/or PR (+) and HER2 (-) Breast Cancer

Background: Although intrinsic molecular subtype has been widely used, there remains great clinical heterogeneity of prognosis in the estrogen receptor (ER)- and/or progesterone receptor (PR)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer (BC).

Methods: The transcriptome expression data of messenger RNA (mRNA) were downloaded from The Cancer Genome Atlas (TCGA), Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), and the Gene Expression Omnibus (GEO) databases. Immune-related genes were acquired from the ImmPort database and additional literature search. Univariate Cox, LASSO regression, and multivariate Cox regression were used to screen prognostic immune-related genes and establish the risk signature. The correlation between the risk signature and clinical characteristics, the abundances of immune cells within the tumor microenvironment, and cancer phenotypes were further assessed.

Results: Of note, 102 immune-related prognostic genes were identified in the METABRIC dataset by univariate Cox analysis. Consecutively, 7 immune-related genes (SHMT2, AGA, COL17A1, FLT3, SLC7A2, ATP6AP1, and CCL19) were selected to establish the risk signature by LASSO regression and multivariate Cox analysis. Its performance was further verified in TCGA and GSE21653 datasets. Multivariate Cox analysis showed that the risk signature was an independent prognostic factor. The 7-gene signature showed a significant correlation with intrinsic molecular subtypes and 70-gene signature. Furthermore, the CD4⁺ memory T cells were significantly higher in the low-risk group while a significantly higher proportion of M0-type macrophages was found in the high-risk group in both METABRIC and TCGA cohorts, which may have an influence on the prognosis. Furthermore, we found that the low-risk group may be associated with the immune-related pathway and the high-risk group was with the cell cycle-related pathway, which also showed an impact on the prognosis.

Conclusion: These seven immune-related gene risk signatures provided an effective method for prognostic stratification in ER (+) and/or PR (+) and HER2 (−) BC.

Current and Emerging Approaches to Study Microenvironmental Interactions and Drug Activity in Classical Hodgkin Lymphoma

Simple Summary

In classical Hodgkin Lymphoma (cHL), the tumor microenvironment (TME) plays an important role in tumor progression and treatment response, making its evaluation critical for determining prognosis, treatment strategies and predicting an increase in drug toxicity. Therefore, there is a need to utilize more complex systems to study the cHL-TME and its interplay with tumor cells. To evaluate new anticancer drugs and to find the mechanisms of drug resistance, this review summarizes emerging approaches for the analysis of the TME composition and to identify the state of the disease; the in vitro techniques used to determine the mechanisms involved in the building of an immunosuppressive and protective TME; new 3-dimensional (3D) models, the heterospheroids (HS), developed to mimic TME interactions. Here, we describe the present and likely future clinical applications indicated by the results of these studies and propose a classification for the in vitro culture methods used to study TME interactions in cHL.

Abstract

Classic Hodgkin lymphoma is characterized by a few tumor cells surrounded by a protective and immunosuppressive tumor microenvironment (TME) composed by a wide variety of noncancerous cells that are an active part of the disease. Therefore, new techniques to study the cHL-TME and new therapeutic strategies targeting specifically tumor cells, reactivating the antitumor immunity, counteracting the protective effects of the TME, were developed. Here, we describe new methods used to study the cell composition, the phenotype, and the spatial distribution of Hodgkin and Reed–Sternberg (HRS) cells and of noncancerous cells in tumor tissues. Moreover, we propose a classification, with increasing complexity, of the in vitro functional studies used to clarify the interactions leading not only to HRS cell survival, growth and drug resistance, but also to the immunosuppressive tumor education of monocytes, T lymphocytes and fibroblasts. This classification also includes new 3-dimensional (3D) models, obtained by cultivating HRS cells in extracellular matrix scaffolds or in sponge scaffolds, under non-adherent conditions with noncancerous cells to form heterospheroids (HS), implanted in developing chick eggs (ovo model). We report results obtained with these approaches and their applications in clinical setting.

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.

Molecular imaging of tumor-associated macrophages in cancer immunotherapy

Tumor-associated macrophages (TAMs), the most abundant inflammatory cell group in the tumor microenvironment, play an essential role in tumor immune regulation. The infiltration degree of TAMs in the tumor microenvironment is closely related to tumor growth and metastasis, and TAMs have become a promising target in tumor immunotherapy. Molecular imaging is a new interdisciplinary subject that combines medical imaging technology with molecular biology, nuclear medicine, radiation medicine, and computer science. The latest progress in molecular imaging allows the biological processes of cells to be visualized in vivo, which makes it possible to better understand the density and distribution of macrophages in the tumor microenvironment. This review mainly discusses the application of targeting TAM in tumor immunotherapy and the imaging characteristics and progress of targeting TAM molecular probes using various imaging techniques.

Doxorubicin-loaded graphene oxide nanocomposites in cancer medicine: Stimuli-responsive carriers, co-delivery and suppressing resistance

INTRODUCTION

The application of doxorubicin (DOX) in cancer therapy has been limited due to its drug resistance and poor internalization. Graphene oxide (GO) nanostructures have the capacity for DOX delivery while promoting its cytotoxicity in cancer.

AREAS COVERED

The favorable characteristics of GO nanocomposites, preparation method, and application in cancer therapy are described. Then, DOX resistance in cancer is discussed. The GO-mediated photothermal therapy and DOX delivery for cancer suppression are described. Preparation of stimuli-responsive GO nanocomposites, surface functionalization, hybrid nanoparticles, and theranostic applications are emphasized in DOX chemotherapy.

EXPERT OPINION

Graphene oxide nanoparticle-based photothermal therapy maximizes the anti-cancer activity of DOX against cancer cells. Apart from DOX delivery, GO nanomaterials are capable of loading anti-cancer agents and genetic tools to minimize drug resistance and enhance the cytolytic impact of DOX in cancer eradication. To enhance DOX accumulation in cancer cells, stimuli-responsive (redox-, light-, enzyme- and pH-sensitive) GO nanoparticles have been developed for DOX delivery. Further development of targeted delivery of DOX-loaded GO nanomaterials against cancer cells may be achieved by surface modification of polymers such as polyethylene glycol, hyaluronic acid, and chitosan. Doxorubicin-loaded GO nanoparticles have demonstrated theranostic potential for simultaneous diagnosis and therapy. Hybridization of GO with other nanocarriers such as silica and gold nanoparticles further broadens their potential anti-cancer therapy applications.

Inhibition of tumor-associated macrophages by trabectedin improves the antitumor adaptive immunity in response to anti-PD-1 therapy

A considerable proportion of cancer patients are resistant or only partially responsive to immune checkpoint blockade immunotherapy. Tumor‐Associated Macrophages (TAMs) infiltrating the tumor stroma suppress the adaptive immune responses and, hence, promote tumor immune evasion. Depletion of TAMs or modulation of their protumoral functions is actively pursued, with the purpose of relieving this state of immunesuppression. We previously reported that trabectedin, a registered antitumor compound, selectively reduces monocytes and TAMs in treated tumors. However, its putative effects on the adaptive immunity are still unclear. In this study, we investigated whether treatment of tumor‐bearing mice with trabectedin modulates the presence and functional activity of T‐lymphocytes.

In treated tumors, there was a significant upregulation of T cell‐associated genes, including CD3, CD8, perforin, granzyme B, and IFN‐responsive genes (MX1, CXCL10, and PD‐1), indicating that T lymphocytes were activated after treatment. Notably, the mRNA levels of the Pdcd1 gene, coding for PD‐1, were strongly increased. Using a fibrosarcoma model poorly responsive to PD‐1‐immunotherapy, treatment with trabectedin prior to anti‐PD‐1 resulted in improved antitumor efficacy. In conclusion, pretreatment with trabectedin enhances the therapeutic response to checkpoint inhibitor‐based immunotherapy. These findings provide a good rational for the combination of trabectedin with immunotherapy regimens.

Tumor-Associated Macrophages in Bladder Cancer: Biological Role, Impact on Therapeutic Response and Perspectives for Immunotherapy

Tumor-associated macrophages (TAMs) are one of the most abundant infiltrating immune cells of solid tumors. Despite their possible dual role, i.e., pro- or anti-tumoral, there is considerable evidence showing that the accumulation of TAMs promotes tumor progression rather than slowing it. Several strategies are being developed and clinically tested to target these cells. Bladder cancer (BCa) is one of the most common cancers, and despite heavy treatments, including immune checkpoint inhibitors (ICIs), the overall patient survival for advanced BCa is still poor. TAMs are present in bladder tumors and play a significant role in BCa development. However, few investigations have analyzed the effect of targeting TAMs in BCa. In this review, we focus on the importance of TAMs in a cancerous bladder, their association with patient outcome and treatment efficiency as well as on how current BCa treatments impact these cells. We also report different strategies used in other cancer types to develop new immunotherapeutic strategies with the aim of improving BCa management through TAMs targeting.

Immune Microenvironment Features and Dynamics in Hodgkin Lymphoma

Simple Summary

As happens in all neoplasms, the many reciprocal interactions taking place between neoplastic cells and the other reactive cells impact the course of the disease. Hodgkin Lymphoma is an haematologic malignancy where most of the pathological tissue is indeed composed by reactive cells and few neoplastic cells. Consequently, it represents an interesting subject for the description of the neoplastic and non-neoplastic cells interaction. In this review we report and discuss the more recent findings of microenvironmental studies about this disease.

Abstract

Classical Hodgkin’s lymphoma (cHL) accounts for 10% of all lymphoma diagnosis. The peculiar feature of the disease is the presence of large multinucleated Reed–Sternberg and mononuclear Hodgkin cells interspersed with a reactive microenvironment (ME). Due to the production of a large number of cytokines, Hodgkin cells (HCs) and Hodgkin Reed–Sternberg cells (HRSCs) attract and favour the expansion of different immune cell populations, modifying their functional status in order to receive prosurvival stimuli and to turn off the antitumour immune response. To this purpose HRSCs shape a biological niche by organizing the spatial distribution of cells in the ME. This review will highlight the contribution of the ME in the pathogenesis and prognosis of cHL and its role as a possible therapeutic target.