Targeting Tumor Microenvironment Research Articles

Chronic prostatitis/chronic pelvic pain syndrome and prostate cancer: study of immune cells and cytokines.

Prostate cancer and prostatitis are both significant health concerns. A large number of studies have established that the occurrence of the two is closely related. However, the most common prostatitis, type III chronic prostatitis/chronic pelvic pain syndromes (CP/CPPS), is reported to not correlate with the occurrence of prostate cancer. Although the etiology of CP/CPPS is unknown, it may be related to the autoimmune mechanism favored by most studies. Manipulating the immune system and targeting tumor microenvironment are promising new methods for the treatment of prostate cancer. Therefore, this review focuses on the immune cells and cytokines of CP/CPPS and prostate cancer from the perspective of biological immunology and immune microenvironment. We discuss T-regulatory (Treg) and T helper 17 (Th17) cells dysfunction, the abnormal regulation of T helper 1(Th1) and T helper 2 (Th2) cells, macrophages, and their related cytokines as key activators in CP/CPPS. In addition, we discuss the roles of Treg and Th17 cells, Th1 and Th2 cells, and related cytokines in modulating prostate cancer progression. This review highlights the concept that immune cells and cytokines provide a research strategy for the etiology of CP/CPPS and offer potentially promising targets for the treatment of prostate cancer.

TMIC-59. INVESTIGATING PHYSIOLOGY OF THERAPY RESISTANT, TUMOR-INITIATING GBM CELLS IN HYPOXIC NICHES USING SPATIALLY-SENSITIVE HYPOXIA REPORTER SYSTEM AND SINGLE-CELL RNA SEQUENCING

Abstract Glioblastoma (GBM) is the most common and lethal brain cancer that invariably recurs after therapy due to presence of resistant GBM cells within hypoxic and peri-necrotic regions. Eradicating such GBM cells, which constitute a major source of tumor recurrence, is important to curb disease relapse. An endogenously expressed, spatially sensitive hypoxia reporter would therefore be a valuable tool to evaluate hypoxic zones in GBM in detail, and to measure the efficacy of hypoxia-activated drugs. For this purpose, we engineered a lentiviral vector that carries a hypoxia reporter, consisting of HIF response elements (HRE) that drive expression of UnaG fluorescent protein, which fluoresces independent of oxidative maturation. We validated the sensitivity of our reporter in vitro using U87MG, GBM2, and patient-derived GBM stem cell lines, and we performed intracranial transplantations of GBM cells in SCID mice to identify cells undergoing hypoxic stress in in vivo microenvironment. In addition, GL261 murine GBM cells with hypoxia reporter were intracranially implanted in C57BL/6 mice as syngeneic model for studies on immune responses. Brains from our transplant studies were dissociated and single-cell RNA sequencing (Drop-Seq) was performed to investigate heterogeneity in response to hypoxia within GBM cells and the cellular composition of microenvironment. We will also apply a hypoxia-activated prodrug, Evofosfamide (Evo), in our ongoing studies that can potentially eradicate hypoxic tumor cells and increase T cell infiltration and reverse immune suppression. As hypoxic niches are thought to confer resistance to radiation therapy (XRT), combining XRT with Evo could thus improve therapy efficacy. Our hypoxia gene reporter, combined with single-cell transcriptomics, could therefore serve as an effective tool to enable fundamental investigation of GBM microenvironment and could be used to evaluate therapies targeting tumor microenvironment to enhance GBM patient survival.

Immunotherapy with molecular targeted drug for thyroid cancer

Abstract In recent years, therapeutic development using immune checkpoint inhibitors has been made in various cancers, and the efficacy of combination therapy with cytotoxic agents, molecular target drugs (including drugs targeting tumor microenvironment), or immune checkpoint inhibitors targeting other than PD-1/PD-L1 have been investigating to improve clinical outcomes. Aims of this presentation will be to understand the development status of combination therapy with immune checkpoint inhibitors and molecule-targeted drugs for thyroid cancer, and to discuss the future perspectives in thyroid cancer in reference to the drug development status in other cancers.

Proof of concept of plasmonic thermal destruction of surface cancers by gold nanoparticles obtained by green chemistry

A greener approach for the design of surface plasmon resonant gold nanoparticles has been obtained with a hydrosoluble fraction of an endemic asteraceae medicinal plant. This medicinal plant is originated from Indian Ocean and demonstrates its bioreducing activity in the design of stable green nanomedicine in aqueous media. This article describes the preclinical assessment of the efficacy of these novel nanocandidates on murine model by intratumoral and intravenous injections. It definitely demonstrates two key points in the treatment of cancer: 1) optimization of the tumor microenvironment targeting by specific ligands for a limited damage on healthy tissue, 2) the need to screen the specific irradiation dose (time, power) taking into account the type of tumor.

Abstract 4850: The relevance of using proper preclinical models when developing therapeutics for localized or bone metastatic prostate cancer

Abstract Early stages of prostate cancer are sensitive to androgen deprivation therapy, but upon progression the disease develops to metastatic castration-resistant prostate cancer, where bone is the dominant metastatic site. Despite of recent advances in drug development, the advanced stage is still incurable. Tumor microenvironment in metastatic locations differs from the primary site and may cause resistance to used therapy and modulate tumor properties. Therefore, it is crucial to use proper models in preclinical drug development. Aim of this study was to establish predictive preclinical in vitro and in vivo prostate cancer models that can be used in drug development when targeting cancer cells or tumor microenvironment at different stages. Androgen receptor (AR) positive human prostate cancer cell line LNCaP was used in all studies. In the in vitro assay, the effects of the antiandrogen enzalutamide on viability of LNCaP cells was determined using CellTiter Glo assay in the presence and absence of a synthetic androgen R1881. In two in vivo studies, male NMRI nude mice were used. In a subcutaneous model, part of the mice received dihydrotestosterone (DHT) supplement prior to cancer cell inoculation. In a bone metastasis model, LNCaP cells were inoculated into tibia bone marrow. The mice were randomized to treatment groups based on similar serum PSA levels and cancer-induced changes in bone determined by X-ray imaging at 6 weeks after inoculation of the cancer cells. The mice were treated with 300 kBq/kg of Radium-223 dichloride or vehicle at 6 and 10 weeks. Bone lesions were followed by X-ray imaging during the study. The study was terminated at 12 weeks after inoculation of the cancer cells and the tibias were removed for histological analysis and AR staining. In the in vitro assay, 0.1 and 0.01 nM R1881 increased LNCaP cell viability, and enzalutamide reduced cell viability in the presence of R1881 compared to the group with only R1881. In the subcutaneous model, tumors formed within 2-3 weeks after inoculation and the maximum tumor volume was reached within 10-12 weeks. LNCaP tumors grew in NMRI nude mice without DHT supplement, but DHT supplement supported tumor growth. In the bone metastasis model, LNCaP tumors induced osteoblastic-mixed bone lesions without additional androgen supplement, and immunohistochemical staining demonstrated strong AR expression. Radium-223 dichloride reduced the progression of tumor-induced bone lesions, decreased serum PSA levels, and decreased tumor area analyzed by histology. This study showcases relevant models that can be used at different phases of preclinical drug development when evaluating efficacy or safety of new therapeutics as mono- or combination therapies. The choice of a preclinical model and key readouts should be carefully selected based on whether developing therapeutics for localized or metastatic prostate cancer. Citation Format: Tiina E. Kähkönen, Jenni H.E. Mäki-Jouppila, Mari I. Suominen, Jussi M. Halleen, Jenni Bernoulli. The relevance of using proper preclinical models when developing therapeutics for localized or bone metastatic prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4850.

Automatic and label-free identification of blood vessels in gliomas using the combination of multiphoton microscopy and image analysis.

Currently, the targeted treatment of tumor based on the tumor microenvironment is newly developed. Blood vessels are the key parts in the tumor microenvironment, which is taken as a new visible target for tumor therapy. Multiphoton microscopy (MPM), based on the second harmonic generation and two-photon excited fluorescence, is available to make the label-free analysis on the blood vessels in human gliomas. MPM can reveal the vascular morphological characteristics in gliomas, including vascular malformation, intense vascular proliferation, perivascular collagen deposition, perivascular lymphocytes aggregation and microvascular proliferation. In addition, the image analysis algorithms were developed to automatically calculate the perivascular collagen content, vascular cavity area, lumen area, wall area and vessel number. Thus, the vascular morphology, the perivascular collagen deposition and intense vascular proliferation degree can be further quantitatively characterized. Compared with the pathological analysis, the combination of MPM and image analysis has potential advantages in making a quantitative and qualitative analyzing on vascular morphology in glioma microenvironment. As micro-endoscope and two-photon fiberscope are technologically improved, this combined method will be a useful imaging way to make the real-time research on the targeting tumor microenvironment in gliomas.

Targeting Tumor Microenvironment for Cancer Therapy.

Cancer development is highly associated to the physiological state of the tumor microenvironment (TME). Despite the existing heterogeneity of tumors from the same or from different anatomical locations, common features can be found in the TME maturation of epithelial-derived tumors. Genetic alterations in tumor cells result in hyperplasia, uncontrolled growth, resistance to apoptosis, and metabolic shift towards anaerobic glycolysis (Warburg effect). These events create hypoxia, oxidative stress and acidosis within the TME triggering an adjustment of the extracellular matrix (ECM), a response from neighbor stromal cells (e.g., fibroblasts) and immune cells (lymphocytes and macrophages), inducing angiogenesis and, ultimately, resulting in metastasis. Exosomes secreted by TME cells are central players in all these events. The TME profile is preponderant on prognosis and impacts efficacy of anti-cancer therapies. Hence, a big effort has been made to develop new therapeutic strategies towards a more efficient targeting of TME. These efforts focus on: (i) therapeutic strategies targeting TME components, extending from conventional therapeutics, to combined therapies and nanomedicines; and (ii) the development of models that accurately resemble the TME for bench investigations, including tumor-tissue explants, “tumor on a chip” or multicellular tumor-spheroids.

Targeting Cancer Cells and Tumor Microenvironment in Preclinical and Clinical Models of Hodgkin Lymphoma Using the Dual PI3Kδ/γ Inhibitor RP6530.

Tumor-associated macrophages (TAMs) and the hyperactivation of the PI3K/AKT pathway are involved in the pathogenesis of Hodgkin lymphoma and affect disease outcome. Because the δ and γ isoforms of PI3K are overexpressed in Hodgkin/Reed-Sternberg (HRS) cells and the tumor microenvironment (TME), we propose that the PI3Kδ/γ inhibitor RP6530 might affect both HRS cells and TME, ultimately leading to an enhanced antitumor response. Hodgkin lymphoma cell lines (L-540, KM-H2, and L-428) and primary human macrophages were used to investigate the activity of RP6530 in vitro and in vivo in Hodgkin lymphoma cell line xenografts. In vitro, RP6530 besides killing and inhibiting the proliferation of Hodgkin lymphoma cells, downregulated lactic acid metabolism, switching the activation of macrophages from an immunosuppressive M2-like phenotype to a more inflammatory M1-like state. By RNA sequencing, we define tumor glycolysis as a specific PI3Kδ/γ-dependent pathway implicated in the metabolic reprogramming of cancer cells. We identify the metabolic regulator pyruvate kinase M2 as the main mediator of tumor-induced immunosuppressive phenotype of macrophages. Furthermore, we show in human tumor xenografts that RP6530 repolarizes TAMs into proinflammatory macrophages and inhibits tumor vasculature, leading to tumor regression. Interestingly, patients with Hodgkin lymphoma experiencing objective responses (complete response and partial response) in a phase I trial using RP6530 showed a significant inhibition of circulating myeloid-derived suppressor cells and an average mean reduction in serum thymus and activation-regulated chemokine levels of 40% (range, 4%-76%). Our results support PI3Kδ/γ inhibition as a novel therapeutic strategy that targets both malignant cells and the TME to treat patients with Hodgkin lymphoma.

Genomic Landscape of Multiple Myeloma with Elevated Lactate Dehydrogenase

Background Multiple Myeloma (MM) is a malignant clonal plasma cell disorder. Elevated Lactate Dehydrogenase (LDH) has been associated with drug resistance and short survival. The biologic basis of this observation is uncertain. In this study, we sought to define the genomic landscape of MM patients with high LDH. Methods Utilizing data from the Multiple Myeloma Research Foundation (MMRF) CoMMpass database, we identified a cohort of patients with baseline LDH values and RNA-seq data available for inclusion. The RNA-seq data was analyzed to predict differentially expressed genes. We evaluated for enrichment of high risk cytogenetic changes within the high LDH group. Overall survival (OS) was estimated by Kaplan Meier method and a log-rank test. Results We identified 871 patients who met inclusion criteria (High LDH N = 143; Normal LDH N = 728). LDH continued to remain a poor prognostic factor consistent with prior literature, with median survival 660 days vs 795 days (p = 0.02852). There was no difference in the non-synchronous mutations between high vs normal LDH group. Hypergeometric test revealed Del(17p13) was significantly enriched (p = 0.011) in the high LDH subset compared to normal LDH. While there was no statistically significant difference in the presence of t(4;14) (p = 0.16) and t(14;16) (p = 0.21). GSEA detected 572 gene sets significantly up-regulated in the high LDH group (FDR q The ClueGO analysis using two separate sets of up-regulated DEGs revealed upregulation of different molecular signatures. The first gene set (fold > 1.5x) showed significant enrichments (p 2x) was strongly associated (p Conclusion Elevated LDH was confirmed as a poor prognostic factor in the MMRF CoMMpass cohort. Overrepresentation of Del17p likely contributes to poor prognosis. In MM, overexpression of proteolytic and cell adhesion signatures, evasion/suppression of host immune system along with hyper-proliferative signatures via cell division and RTK pathways in MM patients with high LDH offers insight into the aggressive disease in these patients. Targeting tumor microenvironment and RTK pathways may provide novel therapeutic strategies in this subtype of MM.

Role of Tumor Specific niche in Colon Cancer Progression and Emerging Therapies by Targeting Tumor Microenvironment.

Colorectal cancer is the third most common form of cancer worldwide leading to escalating mortality rates and mainly includes hereditary, sporadic and colitis-associated cancer development. The escalated mortality rates is due to the limited treatment options as this form of cancer is usually not easy to diagnose in its early stages and are highly invasive leading to rapid metastasis of the malignant cells to the neighbouring tissue. In order to combat this limitation several chemotherapeutic regimens are now being combined with targeted therapies after the knowledge acquired on the inevitable effects of the tumor microenvironment on the colon cancer growth and progress. The colon tumor niche mainly consists of a large mass of tumor cells along with various immune cells, inflammatory cells, tumor macrophages and fibroblasts that infiltrate the tumor as it is a site of predominant inflammation. Among cells of the microenvironment, mesenchymal stem cells (MSCs) exhibiting ability to evolve into cancer associated fibroblasts (CAFs) have recently generated a major interest in the field. The physiological state of the tumor microenvironment is closely connected to discrete steps of tumorigenesis. The colon cancer cells elicit various factors with their direct interaction with MSCs or via paracrine fashion, which modulate these cells to promote cancer instead of performing their innate function of abating cancer progression. This review intends to highlight the necessity to exploit the cellular landscape of tumor microenvironment of colon cancer and a detailed understanding of the interactions between tumor epithelial cells and their stromal/inflammatory elements will aid in future perspectives for designing therapeutic regimens targeting tumor microenvironment to improve the clinical outcome of colon cancer.

Genomic Landscape of Multiple Myeloma with Elevated Lactate Dehydrogenase

BackgroundMultiple Myeloma (MM) is a heterogeneous disorder of clonal plasma cells. Genetic aberrations are important in heterogeneity and have prognostic and perhaps therapeutic implications. Elevated Lactate Dehydrogenase (LDH) has been associated with drug resistance and short survival. The biologic basis of this observation is uncertain. In this study, we sought to define the genomic landscape of MM patients with high LDH to understand pathophysiology and identify therapeutic targets.MethodsUtilizing data from the Multiple Myeloma Research Foundation (MMRF) CoMMpass database (IA12), which includes over 1000 newly-diagnosed MM patients with enriched tumor and matched constitutional samples analyzed using whole genome/exome and RNA sequencing (RNA-seq), we identified a cohort of patients with baseline LDH values and RNA-seq data available for inclusion. High LDH was defined as LDH greater than upper limit of normal (>4.68 microkatals/L). The RNA-seq data was analyzed to predict differentially expressed genes, then gene set enrichment analyses using GSEA and ClueGO were performed to assess for highly enriched pathways and gene ontologies (GO). Thereafter we analyzed to see if there was an enrichment of high risk cytogenetic changes within the high LDH group. Overall survival (OS) was estimated by Kaplan Meier method and a log-rank test.ResultsWe identified 871 patients who met inclusion criteria (High LDH N=143; Normal LDH N=728). LDH continued to remain a poor prognostic factor consistent with prior literature, with median survival 660 days vs 795 days (p=0.02852).Among the patients who underwent autologous transplant (N=385), LDH continued to be associated with poor prognosis with median overall survival (800.5 vs 878.8 days, p=0.01933). Patient characteristics and other clinical variables are submitted separately (Bal et al. ASH 2018).There was no difference in the non-synchronous mutations between the two groups when stratified by baseline LDH levels.To assess for enrichment of the known cytogenetic changes, we performed the hypergeometric test on the samples with both baseline LDH and cytogenetic information. Del(17p13) was significantly enriched (p=0.011) in the high LDH subset compared to normal LDH. (18.48% vs 10.36%) while there was no statistically significant difference in the presence of t(4;14) (p=0.16, 15.65% vs 11.8%) and t(14;16) (p=0.21, 6% vs 4%).GSEA detected 572 gene sets significantly up-regulated in the high LDH group (FDR q < 25%) compared to those with normal LDH including genes involved in the processing of capped intron containing pre-mRNA, recruitment of mitotic centrosome proteins and complexes, mRNA splicing and the proliferation signal in solid tumors leading to metastatic potential. No significantly down-regulated gene set was detected at same significance level.The ClueGO analysis using two separate sets of up-regulated DEGs (fold > 1.5x or fold > 2x, FDR < 0.05 for both) revealed upregulated molecular signatures in similar functional categories as the GSEA in patients with high LDH. The first gene set (fold > 1.5x) showed significant enrichments (p < 0.005) in cell cycle-related pathways, including microtubule cytoskeleton organization, polo-like kinase mediated events, regulation of cell cycle phase transition, regulation of nuclear division and kinesins which provide the myeloma cells with a proliferative advantage. The second gene set (fold > 2x) was strongly associated (p < 0.005) with sympathetic nervous system development (NELL2, NTRK1, and SOX11), collagen biosynthesis (ADAMTS family) and O-linked glycosylation (COL11A family). These genes play a role in lymphocyte differentiation, anti-apoptosis, local invasion, and metastasis.ConclusionElevated LDH was confirmed as a poor prognostic factor in the MMRF CoMMpass cohort. Overrepresentation of Del17p in this population likely contributes to poor prognosis. In MM, the bone marrow microenvironment is crucial in the differentiation, migration, proliferation and survival. Overexpression of proteolytic and cell adhesion signatures, evasion/suppression of host immune system along with hyper-proliferative signatures via cell division and RTK pathways in MM patients with high LDH offers insight into the aggressive disease in these patients. Targeting tumor microenvironment and RTK pathways may provide novel therapeutic strategies in this subtype of MM DisclosuresNo relevant conflicts of interest to declare.

Targeting Tumor Microenvironment by Bioreduction-Activated Nanoparticles for Light-Triggered Virotherapy.

Solid tumors characteristically display higher levels of lactate production due to anaerobic metabolism of glucose. Meanwhile, the U.S. Food and Drug Administration (FDA) has approved virotherapy for use in cancer treatment; however systemic administration remains as a particular challenge. Here we report exploitation of tumor lactate production in designing a hypoxia-responsive carrier, self-assembled from hyaluronic acid (HA) conjugated with 6-(2-nitroimidazole)hexylamine, for localized release of recombinant adeno-associated virus serotype 2 (AAV2). The carrier is loaded with lactate oxidase (LOX) and is permeable to small molecules such as the lactate that accumulates in the tumor. Subsequently, LOX oxidizes the lactate to pyruvate inside the carrier, accompanied by internal lowering of oxygen partial pressure. Bioreduction of the 2-nitroimidazole of the HA conjugated with 6-(2-nitroimidazole)hexylamine converts it into a hydrophilic moiety and electrostatically dissociates the carrier and virus. Efficacious and specific delivery was proven by transduction of a photosensitive protein (KillerRed), enabling significant limitation in tumor growth in vivo with photodynamic therapy. An approximate 2.44-fold reduction in tumor weight was achieved after a 2-week course, compared with control groups. Furthermore, conjugation of the AAV2 with iron oxide nanoparticles ("magnetized" AAV2) facilitated magnetic resonance imaging tracking of the virus in vivo. Taken together, the solid tumor microenvironment promotes bioreduction of the lactate-responsive carrier, providing rapid and specific delivery of AAV2 for light-triggered virotherapy via systemic administration.

Stimulus-responsive gold nanotheranostic platforms for targeting the tumor microenvironment

Gold nanoparticles with unique optical and photo-thermal properties have promising application in nanotheranostics, achieving the integration of diagnosis and therapy in a single platform. Compared with normal physiological environment, tumor tissue has a unique and complex tumor microenvironment, which plays a key role in tumor progression, metastasis, angiogenesis and even drug resistance. In recent years, many gold nanotheranostic platforms have been developed to target tumor microenvironment associated with acidic pH, hypoxia, angiogenesis, immune responses, pathological pressure gradients and extracellular matrix (ECM). In the present article, we have given special emphasis on key strategies for gold nanoparticles functionalization and highlighted recent advances in rational design of gold nanotheranostic platforms capable of utilizing, overcoming or modulating tumor microenvironment for effective cancer theranostics.

Carbon-Based Nanomaterials for Cancer Therapy via Targeting Tumor Microenvironment.

Cancer remains one of the major health problems all over the world and conventional therapeutic approaches have failed to attain an effective cure. Tumor microenvironments (TME) present a unique challenge in tumor therapy due to their complex structures and multiple components, which also serve as the soil for tumor growth, development, invasion, and migration. The complex TME includes immune cells, fibrous collagen structures, and tortuous blood vessels, in which conventional therapeutic approaches are rendered useless. State-of-the-art nanotechnologies have potential to cope with the threats of malignant tumors. With unique physiochemical properties, carbon nanomaterials (CNMs), including graphene, fullerenes, carbon nanotubes, and carbon quantum dots, offer opportunities to resolve the hurdles, by targeting not only cancer cells but also the TME. This review summarizes the progress about CNM-based cancer therapy strategies, which mainly focuses on both the treatment for cancer cells and TME-targeted modulation. In the last, the challenges for TME-based therapy via CNMs are discussed, which will be important in guiding current basic research to clinical translation in the future.

Epigenetic Targeting of Adipocytes Inhibits High-Grade Serous Ovarian Cancer Cell Migration and Invasion.

Ovarian cancer (OC) cells frequently metastasize to the omentum, and adipocytes play a significant role in ovarian tumor progression. Therapeutic interventions targeting aberrant DNA methylation in ovarian tumors have shown promise in the clinic, but the effects of epigenetic therapy on the tumor microenvironment are understudied. Here, we examined the effect of adipocytes on OC cell behavior in culture and impact of targeting DNA methylation in adipocytes on OC metastasis. The presence of adipocytes increased OC cell migration and invasion, and proximal and direct coculture of adipocytes increased OC proliferation alone or after treatment with carboplatin. Treatment of adipocytes with hypomethylating agent guadecitabine decreased migration and invasion of OC cells toward adipocytes. Subcellular protein fractionation of adipocytes treated with guadecitabine revealed decreased DNA methyltransferase 1 (DNMT1) levels even in the presence of DNA synthesis inhibitor, aphidicolin. Methyl-Capture- and RNA-sequencing analysis of guadecitabine-treated adipocytes revealed derepression of tumor-suppressor genes and epithelial-mesenchymal transition inhibitors. SUSD2, a secreted tumor suppressor downregulated by promoter CpG island methylation in adipocytes, was upregulated after guadecitabine treatment, and recombinant SUSD2 decreased OC cell migration and invasion. Integrated analysis of the methylomic and transcriptomic data identified pathways associated with inhibition of matrix metalloproteases and fatty acid α-oxidation, suggesting a possible mechanism of how epigenetic therapy of adipocytes decreases metastasis. In conclusion, the effect of DNMT inhibitor on fully differentiated adipocytes suggests that hypomethylating agents may affect the tumor microenvironment to decrease cancer cell metastasis.Implications: Epigenetic targeting of tumor microenvironment can affect metastatic behavior of ovarian cancer cells. Mol Cancer Res; 16(8); 1226-40. ©2018 AACR.

A Small β-Carboline Derivative "B-9-3" Modulates TGF-β Signaling Pathway Causing Tumor Regression in Vivo.

Targeting tumor microenvironment (TME) is crucial in order to overcome the anti-cancer therapy resistance. In this study, we report the antitumor activity of a newly synthesized β-carboline derivative “B-9-3.” Here, this small molecule showed a promising antitumor activity in vivo along with an enhanced immune response as reflected by a reduction of regulatory T cells and increased CD4+/CD8+ T cells. Further, B-9-3 decreased the number of myofibroblasts not only in the tumor but also in the lung suggesting an anti-metastatic action. The reduction of myofibroblasts was associated with lower expression of epithelial-to-mesenchymal transition markers and a decrease of phosphorylated SMAD2/3 complex indicating the implication of TGF-β signaling pathway in B-9-3’s effect. The blockade of myofibroblasts induction by B-9-3 was also verified in vitro in human fibroblasts treated with TGF-β. To elucidate the mechanism of B-9-3’s action on TGF-β pathway, first, we investigated the molecular interaction between B-9-3 and TGF-β receptors using docking method. Data showed a weak interaction of B-9-3 with the ATP-binding pocket of TGFβRI but a strong one with a ternary complex formed of extracellular domains of TGFβRI, TGFβRII, and TGF-β. In addition, the role of TGFβRI and TGFβRII in B-9-3’s activity was explored in vitro. B-9-3 did not decrease any of the two receptors’ protein level and only reduced phosphorylated SMAD2/3 suggesting that its effect was more probably due to its interaction with the ternary complex rather than decreasing the expression of TGF-β receptors or interfering with their ATP-binding domains. B-9-3 is a small active molecule which acts on the TGF-β signaling pathway and improves the TME to inhibit the proliferation and the metastasis of the tumor with the potential for clinical application.

Nanoparticles Targeting and Remodeling Tumor Microenvironment for Cancer Theranostics.

The tumor microenvironment (TME) is featured with aberrant vasculatures, specific physiological parameters, viscoelastic extracellular matrix and stromal cells, which are important factors in tumor initiation, development and metastasis. The components in TME form physical/biological barriers for drug delivery and therapy, and also contribute to resistance to treatment and immunosuppression. The advances in nanobiotechnology have offered a myriad of nanoparticles for targeting and treating tumors through the passive or active targeting strategies. However, the barriers in TME always limit the drug delivery and therapeutic efficacy of nanoparticles. To cope with this, recent strategies have employed nanoparticles to target and remodel tumor microenvironment, while a variety of nanoparticles have been developed with different functions for this score. In this review, we have described the typical features of tumor microenvironment along with their roles in tumor progression, and then focused on recent progresses in development and application of nanoparticles to target and remodel TME for enhanced cancer therapy.

Synergistic tumor microenvironment targeting and blood–brain barrier penetration via a pH-responsive dual-ligand strategy for enhanced breast cancer and brain metastasis therapy

Cancer associated fibroblasts (CAFs) which shape the tumor microenvironment (TME) and the presence of blood brain barrier (BBB) remain great challenges in targeting breast cancer and its brain metastasis. Herein, we reported a strategy using PTX-loaded liposome co-modified with acid-cleavable folic acid (FA) and BBB transmigrating cell penetrating peptide dNP2 peptide (cFd-Lip/PTX) for enhanced delivery to orthotopic breast cancer and its brain metastasis. Compared with single ligand or non-cleavable Fd modified liposomes, cFd-Lip exhibited synergistic TME targeting and BBB transmigration. Moreover, upon arrival at the TME, the acid-cleavable cFd-Lip/PTX showed sensitive cleavage of FA, which reduced the hindrance effect and maximized the function of both FA and dNP2 peptide. Consequently, efficient targeting of folate receptor (FR)-positive tumor cells and FR-negative CAFs was achieved, leading to enhanced anti-tumor activity. This strategy provides a feasible approach to the cascade targeting of TME and BBB transmigration in orthotopic and metastatic cancer treatment.

Bioengineered carboxymethyl cellulose-doxorubicin prodrug hydrogels for topical chemotherapy of melanoma skin cancer

Melanoma is the most aggressive type of skin cancer with high rates of mortality. Despite encouraging advances demonstrated by anticancer drug carriers in recent years, developing ideal drug delivery systems to target tumor microenvironment by overcoming physiological barriers and chemotherapy side effects still remain intimidating challenges. Herein, we designed and developed a novel carbohydrate-based prodrug composed of carboxymethylcellulose (CMC) polymer bioconjugated with anticancer drug doxorubicin hydrochloride (DOX) by covalent amide bonds and crosslinked with citric acid for producing advanced hydrogels. The results demonstrated the effect of CMC hydrogel network structure with distinct degree of substitution of carboxymethyl groups of the cellulose backbone regarding to the process of bioconjugation and on tailoring the DOX release kinetics in vitro and the cytotoxicity towards melanoma cancer cells in vitro. To this end, an innovative platform was developed based on polysaccharide-drug hydrogels offering promising perspectives for skin disease applications associated with topical chemotherapy of melanoma.

Prognostic implications of tumor-infiltrating macrophages, M2 macrophages, regulatory T-cells, and indoleamine 2,3-dioxygenase-positive cells in primary diffuse large B-cell lymphoma of the central nervous system

ABSTRACTPrimary diffuse large B-cell lymphoma of the central nervous system (CNS-DLBCL) is an aggressive disease with a poor prognosis. The status of the tumor immune microenvironment in CNS-DLBCL remains unclear. We investigated the prognostic implications of tumor-associated macrophages (TAMs), regulatory T-cells (Tregs), and indoleamine 2,3-dioxygenase (IDO)+ cells in primary CNS-DLBCL (n = 114) by immunohistochemical analysis. The numbers of tumor-infiltrating immune cells, including CD68+ TAMs, CD163+ or CD204+ M2 macrophages, FOXP3+ Tregs, and IDO+ cells were all significantly lower in CNS-DLBCL versus systemic DLBCL (n = 165; all P < 0.001), but with little difference in the ratio of CD163+/CD68+ or CD204+/CD68+ cells. An increase in CD68+ cell numbers was significantly associated with prolonged progression-free survival (PFS) and overall survival in patients with CNS-DLBCL (P = 0.004 and 0.021, respectively). In contrast, an increase in CD204+ cell numbers or a higher ratio of CD204+/CD68+ cells was related to a shorter PFS (P = 0.020 and 0.063, respectively). An increase in IDO+ cell numbers was associated with a significantly longer PFS (P = 0.019). In combination, the status of low IDO+ cell numbers combined with low CD68+ cell numbers, high CD204+ cell numbers, or a high CD204+/CD68+ cell ratio all predicted poor PFS in multivariate analyses. This study showed that an increase in CD204+ cell numbers, suggestive of M2 macrophages, was associated with poor clinical outcome in CNS-DLBCL, whereas increased CD68+ or IDO+ cell numbers were related to a favorable prognosis. The analysis of tumor-infiltrating immune cells could help in predicting the prognosis of CNS-DLBCL patients and determining therapeutic strategies targeting tumor microenvironment.