Docetaxel promotes the generation of anti-tumorigenic human macrophages

The efficacy and safety of a taxane-based chemotherapy regimen combined with a PD-1 inhibitor in HNSCC: a multicenter real-world study

OBJECTIVE

This study aims to elucidate the therapeutic efficacy and safety of a taxane-based chemotherapy in combination with immune checkpoint inhibitors regimen in patients diagnosed with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC).

METHODS

We retrospectively collected clinical data from 154 patients who received at least two cycles of PD-1 inhibitors in combination with a taxane-based chemotherapy as first-line treatment in seven hospitals in Hunan Province, between December 2018 and December 2023. These patients were subjected to long-term follow-up.

RESULTS

The study included 154 eligible patients, with a median follow-up period of 21.5 months. The median PFS was 8.7 months, while the median OS was 16.7 months. The 12-month PFS rate was 43.6%, and the 12-month OS rate was 60.1%. At 24 months, the PFS rate was 34.4%, and the OS rate was 36.9%. With 26 complete responses (16.9%) and 52 partial responses (33.8%), the ORR was 50.6%. Stable disease was observed in 54 patients (35.1%), resulting in a disease control rate of 85.7%, while 22 patients showed progressive disease. In the univariate analysis, the distant organ metastasis had a statistically significant impact on both PFS and OS. Subsequent radiotherapy following this protocol also showed a statistically significant effect on PFS and OS. However, radiotherapy before recurrent metastasis did not significantly affect PFS, though it did have a significant impact on OS. Other factors analyzed did not show a statistically significant effect on PFS and OS. Multivariate analysis indicated that the distant organ metastasis and subsequent radiotherapy following this protocol were independent prognostic factors for PFS in patients with R/M HNSCC, and the latter was also an independent prognostic factor for OS in these patients. Regarding safety, during treatment anemia was observed in 97 patients, leukopenia in 64, neutropenia in 33, thrombocytopenia in 28, transaminase elevation in 46, hypothyroidism in 46 patients, and one patient stopped taking the medication due to a serious adverse reaction. No treatment-related deaths occurred.

CONCLUSION

The combination of PD-1 inhibitors with a a taxane-based chemotherapy regimen as a first-line treatment for R/M HNSCC patients demonstrates good therapeutic efficacy and acceptable safety profiles.

Macrophages in tumor cell migration and metastasis

Tumor-associated macrophages (TAMs) are a phenotypically diverse, highly plastic population of cells in the tumor microenvironment (TME) that have long been known to promote cancer progression. In this review, we summarize TAM ontogeny and polarization, and then explore how TAMs enhance tumor cell migration through the TME, thus facilitating metastasis. We also discuss how chemotherapy and host factors including diet, obesity, and race, impact TAM phenotype and cancer progression. In brief, TAMs induce epithelial-mesenchymal transition (EMT) in tumor cells, giving them a migratory phenotype. They promote extracellular matrix (ECM) remodeling, allowing tumor cells to migrate more easily. TAMs also provide chemotactic signals that promote tumor cell directional migration towards blood vessels, and then participate in the signaling cascade at the blood vessel that allows tumor cells to intravasate and disseminate throughout the body. Furthermore, while chemotherapy can repolarize TAMs to induce an anti-tumor response, these cytotoxic drugs can also lead to macrophage-mediated tumor relapse and metastasis. Patient response to chemotherapy may be dependent on patient-specific factors such as diet, obesity, and race, as these factors have been shown to alter macrophage phenotype and affect cancer-related outcomes. More research on how chemotherapy and patient-specific factors impact TAMs and cancer progression is needed to refine treatment strategies for cancer patients.

Advances in and prospects of immunotherapy for prostate cancer

Immunotherapy has shown promising therapeutic effects in hematological malignancies and certain solid tumors and has emerged as a critical and highly potential treatment modality for cancer. However, prostate cancer falls under the category of immune-resistant cold tumors, for which immunotherapy exhibits limited efficacy in patients with solid tumors. Thus, it is important to gain a deeper understanding of the tumor microenvironment in prostate cancer to facilitate immune system activation and overcome immune suppression to advance immunotherapy for prostate cancer. In this review, we discuss the immunosuppressive microenvironment of prostate cancer, which is characterized by the presence of few tumor-infiltrating lymphocytes, abundant immunosuppressive cells, low immunogenicity, and a noninflammatory phenotype, which significantly influences the efficacy of immunotherapy for prostate cancer. Immunotherapy is mainly achieved by activating the host immune system and overcoming immunosuppression. In this regard, we summarize the therapeutic advances in immune checkpoint blockade, immunogenic cell death, reversal of the immunosuppressive tumor microenvironment, tumor vaccines, immune adjuvants, chimeric antigen receptor T-cell therapy, and overcoming penetration barriers in prostate cancer, with the aim of providing novel research insights and approaches to enhance the effectiveness of immunotherapy for prostate cancer.

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.

Immunogenic chemotherapy: great potential for improving response rates

The activation of anti-tumor immunity is critical in treating cancers. Recent studies indicate that several chemotherapy agents can stimulate anti-tumor immunity by inducing immunogenic cell death and durably eradicate tumors. This suggests that immunogenic chemotherapy holds great potential for improving response rates. However, chemotherapy in practice has only had limited success in inducing long-term survival or cure of cancers when used either alone or in combination with immunotherapy. We think that this is because the importance of dose, schedule, and tumor model dependence of chemotherapy-activated anti-tumor immunity is under-appreciated. Here, we review immune modulation function of representative chemotherapy agents and propose a model of immunogenic chemotherapy-induced long-lasting responses that rely on synergetic interaction between killing tumor cells and inducing anti-tumor immunity. We comb through several chemotherapy treatment schedules, and identify the needs for chemotherapy dose and schedule optimization and combination therapy with immunotherapy when chemotherapy dosage or immune responsiveness is too low. We further review tumor cell intrinsic factors that affect the optimal chemotherapy dose and schedule. Lastly, we review the biomarkers indicating responsiveness to chemotherapy and/or immunotherapy treatments. A deep understanding of how chemotherapy activates anti-tumor immunity and how to monitor its responsiveness can lead to the development of more effective chemotherapy or chemo-immunotherapy, thereby improving the efficacy of cancer treatment.

Cooperative Treatment of Gastric Cancer Using B7-H7 siRNA and Docetaxel; How Could They Modify Their Effectiveness?

Purpose

Despite the high prevalence of gastric cancer (GC), drug resistance is a major problem for effective chemotherapy. B7-H7 is a novel member of the B7 superfamily and is expressed in most common cancers. However, the role of B7-H7 on the aggressiveness of GC and chemosensitivity has remained unknown. Therefore, this study was designed to assess the effect of B7-H7 suppression using small interference RNA (siRNA) in combination with docetaxel on GC cells.

Methods

MTT test was applied to determine the IC50 of docetaxel and the combined effect of B7-H7 siRNA and docetaxel on the viability of the MKN-45 cells. To determine B7-H7, BCL-2, BAX, and caspase-3-8-9 genes expression, qRT-PCR was performed. Furthermore, flow cytometry was applied to evaluate apoptosis and the cell cycle status. Finally, to evaluate the effect of this combination therapy on migratory capacity and colony-forming ability, wound healing assay and colony formation test were employed, respectively.

Results

B7-H7 suppression increased the chemo-sensitivity of MKN-45 cells to docetaxel. The expression of B7-H7 mRNA was reduced after using B7-H7 siRNA and docetaxel in MKN-45 GC cells. Also, B7-H7 suppression alongside docetaxel reduced cell migration and colony formation rate, arrested the cell cycle at the G2-M phase, and induced apoptosis by modulating the expression of apoptotic target genes.

Conclusion

B7-H7 plays a significant role in the chemo-sensitivity and pathogenesis of GC. Therefore, B7-H7 suppression, in combination with docetaxel, may be a promising therapeutic approach in treating GC.

Intelligent delivery system targeting PD-1/PD-L1 pathway for cancer immunotherapy

The drugs targeting the PD-1/PD-L1 pathway have gained abundant clinical applications for cancer immunotherapy. However, only a part of patients benefit from such immunotherapy. Thus, brilliant novel tactic to increase the response rate of patients is on the agenda. Nanocarriers, particularly the rationally designed intelligent delivery systems with controllable therapeutic agent release ability and improved tumor targeting capacity, are firmly recommended. In light of this, state-of-the-art nanocarriers that are responsive to tumor-specific microenvironments (internal stimuli, including tumor acidic microenvironment, high level of GSH and ROS, specifically upregulated enzymes) or external stimuli (e.g., light, ultrasound, radiation) and release the target immunomodulators at tumor sites feature the advantages of increased anti-tumor potency but decreased off-target toxicity. Given the fantastic past achievements and the rapid developments in this field, the future is promising. In this review, intelligent delivery platforms targeting the PD-1/PD-L1 axis are attentively appraised. Specifically, mechanisms of the action of these stimuli-responsive drug release platforms are summarized to raise some guidelines for prior PD-1/PD-L1-based nanocarrier designs. Finally, the conclusion and outlook in intelligent delivery system targeting PD-1/PD-L1 pathway for cancer immunotherapy are outlined.

Glioblastoma immuno-endothelial multicellular microtissue as a 3D in vitro evaluation tool of anti-cancer nano-therapeutics

Despite being the most prevalent and lethal type of adult brain cancer, glioblastoma (GBM) remains intractable. Promising anti-GBM nanoparticle (NP) systems have been developed to improve the anti-cancer performance of difficult-to-deliver therapeutics, with particular emphasis on tumor targeting strategies. However, current disease modeling toolboxes lack close-to-native in vitro models that emulate GBM microenvironment and bioarchitecture, thus partially hindering translation due to poorly predicted clinical responses. Herein, human GBM heterotypic multicellular tumor microtissues (MCTMs) are generated through high-throughput 3D modeling of U-251 MG tumor cells, tissue differentiated macrophages isolated from peripheral monocytes, and brain microvascular primary endothelial cells. GBM MCTMs mimicked tumor spatial organization, extracellular matrix production and necrosis areas. The bioactivity of a model drug, docetaxel (DTX), and of tumor-targeted DTX-loaded polymeric NPs with a surface L-Histidine moiety (H-NPs), were assessed in the MCTMs. MCTMs cell uptake and anti-proliferative effect was 8- and 3-times higher for H-NPs, respectively, compared to the non-targeted NPs and to free DTX. H-NPs provided a decrease of MCTMs anti-inflammatory M2-macrophages, while increasing their pro-inflammatory M1 counterparts. Moreover, H-NPs showed a particular biomolecular signature through reduced secretion of an array of medium cytokines (IFN-γ, IL-1β, IL-1Ra, IL-6, IL-8, TGF-β). Overall, MCTMs provide an in vitro biomimetic model to recapitulate key cellular and structural features of GBM and improve in vivo drug response predictability, fostering future clinical translation of anti-GBM nano-therapeutic strategies.

The effects of dendritic cell-based vaccines in the tumor microenvironment: Impact on myeloid-derived suppressor cells

Dendritic cells (DCs) are a heterogenous population of professional antigen presenting cells whose main role is diminished in a variety of malignancies, including cancer, leading to ineffective immune responses. Those mechanisms are inhibited due to the immunosuppressive conditions found in the tumor microenvironment (TME), where myeloid-derived suppressor cells (MDSCs), a heterogeneous population of immature myeloid cells known to play a key role in tumor immunoevasion by inhibiting T-cell responses, are extremely accumulated. In addition, it has been demonstrated that MDSCs not only suppress DC functions, but also their maturation and development within the myeloid linage. Considering that an increased number of DCs as well as the improvement in their functions boost antitumor immunity, DC-based vaccines were developed two decades ago, and promising results have been obtained throughout these years. Therefore, the remodeling of the TME promoted by DC vaccination has also been explored. Here, we aim to review the effectiveness of different DCs-based vaccines in murine models and cancer patients, either alone or synergistically combined with other treatments, being especially focused on their effect on the MDSC population.

Inflammatory markers S100A8/A9 and metabolic alteration for evaluating signs of early phase toxicity of anticancer agent treatment

Anticancer agents can cause various side effects, including tissue damages/inflammatory reactions. Drug-responsive biomarkers are essential for evaluating drug toxicity in disease processes. S100 calcium-binding proteins A8/A9 (S100A8/A9) are highly expressed in neutrophils and monocytes/macrophages accumulated at inflammatory sites and are known to be related to tissue damage/inflammation; however, their response to drug toxicity has not been reported. Herein, we investigated the effects of anticancer agents (doxorubicin, cisplatin, and docetaxel) on S100A8/A9 gene expression profiles in four representative tissues (heart, kidney, liver, and lung) in normal C57BL/6J mice. Both S100A8/A9 expression was transiently or time-dependently elevated in four tissues within 48 h after dosing of the three anticancer agents under toxicity-inducing conditions. S100A8/A9 patterns differed among agents and tissues. This result suggests that S100A8/A9 is useful for evaluating anticancer agent-induced tissue damage. Metabolomic analysis revealed that some metabolites showed temporal patterns similar to that of S100A8/A9 expression. The amounts of fumarate (doxorubicin-treated heart), tyrosine (cisplatin-treated kidney), acetylcarnosine (doxorubicin-treated liver), and 2-phosphoglycerate (docetaxel-treated lung) showed similar patterns to that of S100A8/A9 expression. Although these metabolites showed different behaviors between tissues and serum, they may be useful marker candidates for evaluating anticancer agent-induced tissue damage at an earlier stage after dosing.

The Effects of Tamoxifen on Tolerogenic Cells in Cancer

Tamoxifen (TAM) is the most prescribed selective estrogen receptor modulator (SERM) to treat hormone-receptor-positive breast cancer patients and has been used for more than 20 years. Its role as a hormone therapy is well established; however, the potential role in modulating tolerogenic cells needs to be better clarified. Infiltrating tumor-microenvironment-regulatory T cells (TME-Tregs) are important as they serve a suppressive function through the transcription factor Forkhead box P3 (Foxp3). Abundant studies have suggested that Foxp3 regulates the expression of several genes (CTLA-4, PD-1, LAG-3, TIM-3, TIGIT, TNFR2) involved in carcinogenesis to utilize its tumor suppressor function through knockout models. TAM is indirectly concomitant via the Cre/loxP system by allowing nuclear translocation of the fusion protein, excision of the floxed STOP cassette and heritable expression of encoding fluorescent protein in a cohort of cells that express Foxp3. Moreover, TAM administration in breast cancer treatment has shown its effects directly through MDSCs by the enrichment of its leukocyte populations, such as NK and NKT cells, while it impairs the differentiation and activation of DCs. However, the fundamental mechanisms of the reduction of this pool by TAM are unknown. Here, we review the vital effects of TAM on Tregs for a precise mechanistic understanding of cancer immunotherapies.

The immune modifying effects of chemotherapy and advances in chemo-immunotherapy

Immune checkpoint inhibitors (ICIs) have transformed the treatment paradigm for several malignancies. While the use of single-agent or combined ICIs has achieved acceptable disease control rates in a variety of solid tumors, such approaches have yet to show substantial therapeutic efficacy in select difficult-to-treat cancer types. Recently, select chemotherapy regimens are emerging as extensive modifiers of the tumor microenvironment, leading to the reprogramming of local immune responses. Accordingly, data is now emerging to suggest that certain anti-neoplastic agents modulate various immune cell processes, most notably the cross-presentation of tumor antigens, leukocyte trafficking, and cytokine biosynthesis. As such, the combination of ICIs and cytotoxic chemotherapy are beginning to show promise in many cancers that have long been considered poorly responsive to ICI-based immunotherapy. Here, we discuss past and present attempts to advance chemo-immunotherapy in these difficult-to-treat cancer histologies, mechanisms through which select chemotherapies modify tumor immunogenicity, as well as important considerations when designing such approaches to maximize efficacy and improve therapeutic response rates.

Copper-based nanomaterials for cancer theranostics

Copper-based nanomaterials (Cu-based NMs) with favorable biocompatibility and unique properties have attracted the attention of many biomedical researchers. Cu-based NMs are one of the most widely studied materials in cancer treatment. In recent years, great progress has been made in the field of biomedicine, especially in the treatment and diagnosis of tumors. This review begins with the classification of Cu-based NMs and the recent synthetic strategies of Cu-based NMs. Then, according to the abundant and special properties of Cu-based NMs, their application in biomedicine is summarized in detail. For biomedical imaging, such as photoacoustic imaging, positron emission tomography imaging, and multimodal imaging based on Cu-based NMs are summarized, as well as strategies to improve the diagnostic effectiveness. Moreover, a series of unique structures and functions as well as the underlying property activity relationship of Cu-based NMs were shown to highlight their promising therapeutic performance. Cu-based NMs have been widely used in monotherapies, such as photothermal therapy (PTT) and chemodynamic therapy (CDT). Moreover, the sophisticated design in composition, structure, and surface fabrication of Cu-based NMs can endow these NMs with more modalities in cancer diagnosis and therapy. To further improve the efficiency of cancer treatment, combined therapy based on Cu-based NMs was introduced in detail. Finally, the challenges, critical factors, and future prospects for the clinical translation of Cu-based NMs as multifunctional theranostic agents were also considered and discussed. The aim of this review is to provide a better understanding and key consideration for the rational design of this increasingly important new paradigm of Cu-based NMs as theranostic agents. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Revisiting the therapeutic potential of tocotrienol

The therapeutic potential of the tocotrienol group stems from its nutraceutical properties as a dietary supplement. It is largely considered to be safe when consumed at low doses for attenuating pathophysiology as shown by animal models, in vitro assays, and ongoing human trials. Medical researchers and the allied sciences have experimented with tocotrienols for many decades, but its therapeutic potential was limited to adjuvant or concurrent treatment regimens. Recent studies have focused on targeted drug delivery by enhancing the bioavailability through carriers, self-sustained emulsions, nanoparticles, and ethosomes. Epigenetic modulation and computer remodeling are other means that will help increase chemosensitivity. This review will focus on the systemic intracellular anti-cancer, antioxidant, and anti-inflammatory mechanisms that are stimulated and/or regulated by tocotrienols while highlighting its potent therapeutic properties in a diverse group of clinical diseases.

Translational Learnings in the Development of Chemo-Immunotherapy Combination to Bypass the Cold Tumor Microenvironment in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal cancers, with a 5-year relative survival rate of 5%. The desmoplastic stroma found in the tumor microenvironment of PDAC is suggested to be partly responsible for the resistance to most therapeutic strategies. This review outlines the clinical results obtained with an immune checkpoint inhibitor in PDAC and discusses the rationale to use a combination of chemotherapy and immune checkpoint therapy. Moreover, essential parameters to take into account in designing an efficient combination have been highlighted.

The emerging role of immune checkpoint inhibitors for the treatment of breast cancer

INTRODUCTION

Breast cancer has traditionally been viewed as immunogenically 'cold,' but two immune checkpoint inhibitors have been approved in combination with chemotherapy for PD-L1 positive advanced triple-negative breast cancer (TNBC), and pembrolizumab was also recently approved for early stage TNBC. As the landscape is rapidly evolving, a comprehensive review of checkpoint inhibitors in breast cancer is needed to aid clinicians in selecting appropriate candidates for therapy, and to highlight ongoing promising studies in this area and topics in need of further investigation.

AREA COVERED

This review summarizes the latest evidence from completed and ongoing trials of immune checkpoint inhibitors. Ongoing studies were identified using a search of ClinicalTrials.gov with the term 'breast cancer' along with specific checkpoint inhibitor agents.

EXPERT OPINION

A number of novel combination strategies are under investigation to enhance response and overcome resistance to immunotherapy, with promising preliminary data from checkpoint inhibitors targeting TIGIT, combinations with small molecule inhibitors such as lenvatinib, and injectable agents directly influencing the immune microenvironment. As immunotherapy enters into the curative setting, biomarkers predictive of immunotherapy benefit are needed, as PD-L1 status has not been a helpful discriminator in completed trials in early-stage breast cancer.

Ccl3 enhances docetaxel chemosensitivity in breast cancer by triggering proinflammatory macrophage polarization

Background

Although the antitumor efficacy of docetaxel (DTX) has long been attributed to the antimitotic activities, its impact on the tumor microenvironment (TME) has recently gained more attention. Macrophages are a major component of the TME and play a critical role in DTX efficacy; however, the underlying action mechanisms remain unclear.

Methods

DTX chemotherapeutic efficacy was demonstrated via both macrophage depletion and C–C motif chemokine ligand 3 (Ccl3)-knockout transgenic allograft mouse model. Ccl3-knockdown and Ccl3-overexpressing breast cancer cell allografts were used for the in vivo study. Combination therapy was used to evaluate the effect of Ccl3 induction on DTX chemosensitivity. Vital regulatory molecules and pathways were identified using RNA sequencing. Macrophage phagocytosis of cancer cells and its influence on cancer cell proliferation under DTX treatment were assessed using an in vitro coculture assay. Serum and tumor samples from patients with breast cancer were used to demonstrate the clinical relevance of our study.

Results

Our study revealed that Ccl3 induced by DTX in macrophages and cancer cells was indispensable for the chemotherapeutic efficacy of DTX. DTX-induced Ccl3 promoted proinflammatory macrophage polarization and subsequently facilitated phagocytosis of breast cancer cells and cancer stem cells. Ccl3 overexpression in cancer cells promoted proinflammatory macrophage polarization to suppress tumor progression and increase DTX chemosensitivity. Mechanistically, DTX induced Ccl3 by relieving the inhibition of cAMP-response element binding protein on Ccl3 via reactive oxygen species accumulation, and Ccl3 then promoted proinflammatory macrophage polarization via activation of the Ccl3–C-C motif chemokine receptor 5–p38/interferon regulatory factor 5 pathway. High CCL3 expression predicted better prognosis, and high CCL3 induction revealed better DTX chemosensitivity in patients with breast cancer. Furthermore, both the Creb inhibitor and recombinant mouse Ccl3 significantly enhanced DTX chemosensitivity.

Conclusions

Our results indicate that Ccl3 induced by DTX triggers proinflammatory macrophage polarization and subsequently facilitates phagocytosis of cancer cells. Ccl3 induction in combination with DTX may provide a promising therapeutic rationale for increasing DTX chemosensitivity in breast cancer.

Activation of the chemokine receptor 3 pathway leads to a better response to immune checkpoint inhibitors in patients with metastatic urothelial carcinoma

Immune checkpoint inhibitors (ICIs) have made important breakthrough in anti-tumor therapy, however, no single biomarker can accurately predict their efficacy. Studies have found that tumor microenvironment is a key factor for determining the response to ICI therapy. Cytokine receptor 3 (C-X-C Motif Chemokine Receptor 3, CXCR3) pathway has been reported to play an important role in the migration, activation, and response of immune cells. We analyzed survival data, genomics, and clinical data from patients with metastatic urothelial carcinoma (mUC) who received ICI treatment to explore the relationship between CXCR3 pathway activation and the effectiveness of ICIs. The Cancer Genome Atlas Bladder Urothelial Carcinoma cohort and six other cohorts receiving ICI treatment were used for mechanism exploration and validation. In the ICI cohort, we performed univariate and multivariate COX analyses and discovered that patients in the CXCR3-high group were more sensitive to ICI treatment. A Kaplan–Meier analysis demonstrated that patients in the high CXCR3-high group had a better prognosis than those in the CXCR3-low group (P = 0.0001, Hazard Ratio = 0.56; 95% CI 0.42−0.75). CIBERSORT analysis found that mUC patients in the CXCR3-high group had higher levels of activated CD8+ T cells, M1 macrophages, and activated NK cells and less regulatory T cell (Treg) infiltration. Immunogenicity analysis showed the CXCR3-high group had higher tumor neoantigen burden (TNB). Our study suggests that CXCR3 pathway activation may be a novel predictive biomarker for the effectiveness of immunotherapy in mUC patients.

Pembrolizumab plus docetaxel for the treatment of recurrent/metastatic head and neck cancer: A prospective phase I/II study

BACKGROUND

Taxane-based checkpoint inhibitor combination therapy might improve the outcome in recurrent/metastatic (R/M) head and neck cancer (HNSCC) patients. Thus, we investigated the efficacy and safety of docetaxel (DTX) plus pembrolizumab (P) in a prospective phase I/II trial.

METHODS

Platinum-resistant R/M HNSCC patients received DTX 75 mg/m^2 plus P 200 mg for up to six cycles followed by P maintenance therapy. The primary endpoint was overall response rate (ORR) and safety. Secondary endpoints comprised disease control rate (DCR), overall survival (OS) and progression free survival (PFS).

RESULTS

Twenty-two patients were enrolled. Nine patients (40.9%) had a primary tumor in the oropharynx, 8 (36.4%) in the oral cavity, 3 (13.6%) in the hypopharynx and 2 (9.1%) in the larynx. The ORR was 22.7% (95% CI 10.1%-43.4%) and one (4.5%) complete response was achieved. The DCR was 54.6% (95% 34.7%-73.1%). The median PFS was 5.8 months (95% CI 2.7-11.6) and the median OS 21.3 months (95% CI 6.3-31.1). The 1-year PFS and OS rates were 27.3% and 68.2%, respectively. While the most frequent adverse event (AE) was myelosuppression, which was reported in all 22 patients, 3 (13.6%) patients experienced grade 3 febrile neutropenia. The most common immune-related AEs were grade skin rash (40.9%) and hypothyroidism (40.9%). One patient (4.5%) experienced grade 5 immune thrombocytopenia.

CONCLUSION

DXT in combination with P shows promising activity accompanied with a manageable side effect profile in pre-treated R/M HNSCC patients.

Brazilian green propolis: A novel tool to improve the cytotoxic and immunomodulatory action of docetaxel on MCF-7 breast cancer cells and on women monocyte

Docetaxel (DTX) is used against breast cancer despite its side effects such as toxicity and immunosuppression. Here we investigated the cytotoxic and immunomodulatory effects of the ethanol solution extract of propolis (EEP) in combination with DTX on MCF-7 breast cancer cells and on women's monocyte. The cytotoxic potential of EEP + DTX was assessed by MTT assay and the type of tumor cell death was evaluated by flow cytometry. The effects of EEP + DTX on the migration and invasion of MCF-7 cells were analyzed. Cytokine production by monocytes was assessed by ELISA and the expression of cell surface markers was evaluated by flow cytometry. We also assessed the fungicidal activity of monocytes against Candida albicans and the generation of reactive oxygen species (ROS). Finally, the impact of the supernatants of treated monocytes in the viability, migration, and invasiveness of tumor cells was assessed. EEP enhanced the cytotoxicity of DTX alone against MCF-7 cells by inducing necrosis and inhibiting their migratory ability. EEP + DTX exerted no cytotoxic effects on monocytes and stimulated HLA-DR expression, TNF-α, and IL-6 production, exerted an immunorestorative action in the fungicidal activity, and reduced the oxidative stress. Our findings have practical implications and reveal new insights for complementary medicine.

Corneal dendritic cells and the subbasal nerve plexus following neurotoxic treatment with oxaliplatin or paclitaxel

Immune cell infiltration has been implicated in neurotoxic chemotherapy for cancer treatment. However, our understanding of immune processes is still incomplete and current methods of observing immune cells are time consuming or invasive. Corneal dendritic cells are potent antigen-presenting cells and can be imaged with in-vivo corneal confocal microscopy. Corneal dendritic cell densities and nerve parameters in patients treated with neurotoxic chemotherapy were investigated. Patients treated for cancer with oxaliplatin (n = 39) or paclitaxel (n = 48), 3 to 24 months prior to assessment were recruited along with 40 healthy controls. Immature (ImDC), mature (MDC) and total dendritic cell densities (TotalDC), and corneal nerve parameters were analyzed from in-vivo corneal confocal microscopy images. ImDC was increased in the oxaliplatin group (Median, Md = 22.7 cells/mm2) compared to healthy controls (Md = 10.1 cells/mm2, p = 0.001), but not in the paclitaxel group (Md = 10.6 cells/mm2). ImDC was also associated with higher oxaliplatin cumulative dose (r = 0.33, p = 0.04) and treatment cycles (r = 0.40, p = 0.01). There was no significant difference in MDC between the three groups (p > 0.05). Corneal nerve parameters were reduced in both oxaliplatin and paclitaxel groups compared to healthy controls (p < 0.05). There is evidence of elevation of corneal ImDC in oxaliplatin-treated patients. Further investigation is required to explore this potential link through longitudinal studies and animal or laboratory-based immunohistochemical research.

NK Cells in the Tumor Microenvironment as New Potential Players Mediating Chemotherapy Effects in Metastatic Melanoma

Until the last decade, chemotherapy was the standard treatment for metastatic cutaneous melanoma, even with poor results. The introduction of immune checkpoints inhibitors (ICIs) radically changed the outcome, increasing 5-year survival from 5% to 60%. However, there is still a large portion of unresponsive patients that would need further therapies. NK cells are skin-resident innate cytotoxic lymphocytes that recognize and kill virus-infected as well as cancer cells thanks to a balance between inhibitory and activating signals delivered by surface molecules expressed by the target. Since NK cells are equipped with cytotoxic machinery but lack of antigen restriction and needing to be primed, they are nowadays gaining attention as an alternative to T cells to be exploited in immunotherapy. However, their usage suffers of the same limitations reported for T cells, that is the loss of immunogenicity by target cells and the difficulty to penetrate and be activated in the suppressive tumor microenvironment (TME). Several evidence showed that chemotherapy used in metastatic melanoma therapy possess immunomodulatory properties that may restore NK cells functions within TME. Here, we will discuss the capability of such chemotherapeutics to: i) up-regulate melanoma cells susceptibility to NK cell-mediated killing, ii) promote NK cells infiltration within TME, iii) target other immune cell subsets that affect NK cells activities. Alongside traditional systemic melanoma chemotherapy, a new pharmacological strategy based on nanocarriers loaded with chemotherapeutics is developing. The use of nanotechnologies represents a very promising approach to improve drug tolerability and effectiveness thanks to the targeted delivery of the therapeutic molecules. Here, we will also discuss the recent developments in using nanocarriers to deliver anti-cancer drugs within the melanoma microenvironment in order to improve chemotherapeutics effects. Overall, we highlight the possibility to use standard chemotherapeutics, possibly delivered by nanosystems, to enhance NK cells anti-tumor cytotoxicity. Combined with immunotherapies targeting NK cells, this may represent a valuable alternative approach to treat those patients that do not respond to current ICIs.

Intermittent fasting suppressed splenic CD205+ G-MDSC accumulation in a murine breast cancer model by attenuating cell trafficking and inducing apoptosis

Immune-based interventions are the most promising approach for new cancer treatments to achieve long-term cancer-free survival. However, the expansion of myeloid-derived suppression cells (MDSCs) attenuates the therapeutic potential of immunotherapy. We recently showed that CD205+ granulocytic MDSCs (G-MDSCs), but not T cells, are sensitive to glucose deficiency. Intermittent fasting (IF) may inhibit the growth of malignant cells by reducing serum glucose levels, but little is known regarding the influence of IF on MDSC expansion. Herein, we observed that IF selectively inhibited splenic accumulation of CD205+ G-MDSCs in a 4T1 and 4T07 transplant murine breast cancer model. The efficiency of IF in suppressing tumor growth was comparable to that of docetaxel. Further examination revealed that CXCR4 expression was concentrated in CD205+ subsets of tumor-induced G-MDSCs. Downregulation of CXCR4 correlated with a reduction in CD205+ G-MDSC trafficking from bone marrow to the spleen under IF treatment. In addition, ex vivo culture assays showed that glucose deficiency and 2-deoxy-D-glucose (2DG) treatment selectively induced massive death of splenic CD205+ G-MDSCs. Interestingly, 2DG emulated the phenomena of IF selectively suppressing the accumulation of CD205+ G-MDSCs in the spleen, upregulating cleaved caspase 3 in the tumor, downregulating Ki67 in the lung, and retarding the growth of transplanted 4T1 and 4T07 murine breast tumors. These findings suggest that IF inhibited cell trafficking through the downregulation of CXCR4 and induced apoptosis by altering glucose metabolism; this, suppressed the accumulation of tumor-induced splenic CD205+ G-MDSCs and in turn enhanced antitumor immunity.

Breast cancer: Muscarinic receptors as new targets for tumor therapy

The development of breast cancer is a complex process that involves the participation of different factors. Several authors have demonstrated the overexpression of muscarinic acetylcholine receptors (mAChRs) in different tumor tissues and their role in the modulation of tumor biology, positioning them as therapeutic targets in cancer. The conventional treatment for breast cancer involves surgery, radiotherapy, and/or chemotherapy. The latter presents disadvantages such as limited specificity, the appearance of resistance to treatment and other side effects. To prevent these side effects, several schedules of drug administration, like metronomic therapy, have been developed. Metronomic therapy is a type of chemotherapy in which one or more drugs are administered at low concentrations repetitively. Recently, two chemotherapeutic agents usually used to treat breast cancer have been considered able to activate mAChRs. The combination of low concentrations of these chemotherapeutic agents with muscarinic agonists could be a useful option to be applied in breast cancer treatment, since this combination not only reduces tumor cell survival without affecting normal cells, but also decreases pathological neo-angiogenesis, the expression of drug extrusion proteins and the cancer stem cell fraction. In this review, we focus on the previous evidences that have positioned mAChRs as relevant therapeutic targets in breast cancer and analyze the effects of administering muscarinic agonists in combination with conventional chemotherapeutic agents in a metronomic schedule.

The immune microenvironment and relation to outcome in patients with advanced breast cancer treated with docetaxel with or without gemcitabine

Preclinical studies suggest that some effects of conventional chemotherapy, and in particular, gemcitabine, are mediated through enhanced antitumor immune responses. The objective of this study was to use material from a randomized clinical trial to evaluate whether patients with preexisting immune infiltrates responded better to treatment with gemcitabine + docetaxel (GD) compared to docetaxel alone. Formalin fixed, paraffin-embedded breast cancer tissues from SBG0102 phase 3 trial patients randomly assigned to treatment with GD or docetaxel were used. Immunohistochemical staining for CD8, FOXP3, LAG3, PD-1, PD-L1 and CD163 was performed. Tumor infiltrating lymphocytes (TILs) and tumor associated macrophages were evaluated. Prespecified statistical analyses were performed in a formal prospective-retrospective design. Time to progression was primary endpoint and overall survival secondary endpoint. Correlations between biomarker status and endpoints were evaluated using the Kaplan–Meier method and Cox proportional hazards models. Biomarker data was obtained for 237 patients. There was no difference in treatment effect according to biomarker status for the whole cohort. In planned subgroup analysis by PAM50 subtype, in non-luminal (basal-like and HER2E) breast cancers FOXP3 was a significant predictor of treatment effect with GD compared to docetaxel, with a HR of 0.22 (0.09–0.52) for tumors with low FOXP3 compared to HR 0.92 (0.47–1.80) for high FOXP3 TILs (P_interaction = 0.01). Immune biomarkers were not predictive of added benefit of gemcitabine in a cohort of mixed breast cancer subtypes. However, in non-luminal breast cancers, patients with low FOXP3+ TILs may have significant benefit from added gemcitabine.

Role of innate immunity in chemotherapy-induced peripheral neuropathy

It has become increasingly clear that the innate immune system plays an essential role in the generation of many types of neuropathic pain including that which accompanies cancer treatment. In this article we review current findings of the role of the innate immune system in contributing to cancer treatment pain at the distal endings of peripheral nerve, in the nerve trunk, in the dorsal root ganglion and in the spinal dorsal horn.

Resistance to Immune Checkpoint Blockade in Uterine Leiomyosarcoma: What Can We Learn from Other Cancer Types?

The onset of immune checkpoint blockade (ICB) therapy over the last decade has transformed the therapeutic landscape in oncology. ICB has shown unprecedented clinical activity and durable responses in a variety of difficult-to-treat cancers. However, despite these promising long-term responses, a majority of patients fail to respond to single-agent therapy, demonstrating primary or acquired resistance. Uterine leiomyosarcoma (uLMS) is a rare high-risk gynecological cancer with very limited treatment options. Despite research indicating a strong potential for ICB in uLMS, a clinical trial assessing the response to immunotherapy with single-agent nivolumab in advanced-stage uLMS showed no clinical benefit. Many mechanisms of resistance to ICB have been characterized in a variety of tumor types, and many more continue to be uncovered. However, the mechanisms of resistance to ICB in uLMS remain largely unexplored. By elucidating and targeting mechanisms of resistance, treatments can be tailored to improve clinical outcomes. Therefore, in this review we will explore what is known about the immunosuppressive microenvironment of uLMS, link these data to possible resistance mechanisms extrapolated from other cancer types, and discuss potential therapeutic strategies to overcome resistance.

Π electron-stabilized polymeric micelles potentiate docetaxel therapy in advanced-stage gastrointestinal cancer

Gastrointestinal (GI) cancers are among the most lethal malignancies. The treatment of advanced-stage GI cancer involves standard chemotherapeutic drugs, such as docetaxel, as well as targeted therapeutics and immunomodulatory agents, all of which are only moderately effective. We here show that Π electron-stabilized polymeric micelles based on PEG-b-p(HPMAm-Bz) can be loaded highly efficiently with docetaxel (loading capacity up to 23 wt%) and potentiate chemotherapy responses in multiple advanced-stage GI cancer mouse models. Complete cures and full tumor regression were achieved upon intravenously administering micellar docetaxel in subcutaneous gastric cancer cell line-derived xenografts (CDX), as well as in CDX models with intraperitoneal and lung metastases. Nanoformulated docetaxel also outperformed conventional docetaxel in a patient-derived xenograft (PDX) model, doubling the extent of tumor growth inhibition. Furthermore, micellar docetaxel modulated the tumor immune microenvironment in CDX and PDX tumors, increasing the ratio between M1-and M2-like macrophages, and toxicologically, it was found to be very well-tolerated. These findings demonstrate that Π electron-stabilized polymeric micelles loaded with docetaxel hold significant potential for the treatment of advanced-stage GI cancers.

Intratumoral submicron particle docetaxel inhibits syngeneic Renca renal cancer growth and increases CD4+, CD8+, and Treg levels in peripheral blood

Administration of chemotherapeutics as direct injections into tumors offers increased anti-tumor activity and reduced systemic toxicity. In this study, the Renca syngeneic murine xenograft model of renal cancer was used to evaluate the effects of intratumoral (IT) submicron particle docetaxel (NanoDoce®) on tumor growth and immunomodulation. Tumor volume (TV) was compared to controls, including intravenous (IV) chemotherapy. Flow cytometry of peripheral bloods and tumors was used to evaluate immune cell populations. Groups of animals were inoculated with a second Renca tumor at a site distant from the primary tumor. IT NanoDoce significantly reduced primary TV and reduced the growth rates of untreated secondary tumors. CD4+, CD8+ and Treg populations were increased in peripheral bloods from animals administered IT NanoDoce. Additional evaluation of the effect of IT NanoDoce on peripheral and local immune cell populations as well as the impact on sites of distant tumor growth are warranted.

Androgen Receptor and Its Splicing Variant 7 Expression in Peripheral Blood Mononuclear Cells and in Circulating Tumor Cells in Metastatic Castration-Resistant Prostate Cancer

Androgen receptor (AR) signaling remains crucial in castration-resistant prostate cancer (CRPC). Since it is also essential in immune cells, we studied whether the expression of AR full-length (ARFL) and its splicing variant ARV7 in peripheral blood mononuclear cells (PBMC) predicts systemic treatment response in mCRPC in comparison with circulating-tumor cells (CTC). We measured ARFL and ARV7 mRNA in PBMC and CTC from patients prior to receiving abiraterone (AA), enzalutamide (E), or taxanes by a pre-amplification plus quantitative reverse-transcription PCR. They were also tested in LNCaP-ARV7-transfected and in 22RV1 docetaxel-resistant (22RV1DR) cells. We studied 171 PBMC from 136 patients and from 24 non-cancer controls, and 47 CTC from 22 patients. High PBMC ARV7 levels correlated with worse AA/E and better taxane response. In taxane-treated patients high PBMC ARFL also correlated with longer progression-free survival (PFS). High ARV7 and ARFL expression were independently associated with better biochemical-PFS. Conversely, high CTC ARV7 and ARFL correlated with shorter radiological-PFS and overall survival, respectively. High ARV7 in 22RV1DR and LNCaP-ARV7 cells correlated with taxane resistance. In conclusion, ARFL and ARV7 at PBMC or CTC have a different predictive role in the taxane response, suggesting a potential influence of the AR pathway from PBMC in such response modulation.

Tumor-Targeted Drug and CpG Delivery System for Phototherapy and Docetaxel-Enhanced Immunotherapy with Polarization toward M1-Type Macrophages on Triple Negative Breast Cancers

Cancer immunotherapy has achieved promising clinical responses in recent years owing to the potential of controlling metastatic disease. However, there is a limited research to prove the superior therapeutic efficacy of immunotherapy on breast cancer compared with melanoma and non-small-cell lung cancer because of its limited expression of PD-L1, low infiltration of cytotoxic T lymphocytes (CTLs), and high level of myeloid-derived suppressor cells (MDSCs). Herein, a multifunctional nanoplatform (FA-CuS/DTX@PEI-PpIX-CpG nanocomposites, denoted as FA-CD@PP-CpG) for synergistic phototherapy (photodynamic therapy (PDT), photothermal therapy (PTT) included) and docetaxel (DTX)-enhanced immunotherapy is successfully developed. The nanocomposites exhibit excellent PDT efficacy and photothermal conversion capability under 650 and 808 nm irradiation, respectively. More significantly, FA-CD@PP-CpG with no obvious side effects can remarkably inhibit the tumor growth in vivo based on a 4T1-tumor-bearing mice modal. A low dosage of loaded DTX in FA-CD@PP-CpG can promote infiltration of CTLs to improve efficacy of anti-PD-L1 antibody (aPD-L1), suppress MDSCs, and effectively polarize MDSCs toward M1 phenotype to reduce tumor burden, further to enhance the antitumor efficacy. Taken together, FA-CD@PP-CpG nanocomposites offer an efficient synergistic therapeutic modality in docetaxel-enhanced immunotherapy for clinical application of breast cancer.

Impact of systemic therapy on circulating leukocyte populations in patients with metastatic breast cancer

Tumors affect the immune system, locally and systemically. The frequencies of specific circulating immune cell populations correlate with disease progression as well as prognosis of the patients. Although largely neglected, conventional antitumoral therapies often possess immunomodulatory properties and affect the levels of specific immune cell populations. Most information, however, derive from animal or in vitro studies. As this could impact prognosis as well as response to therapy, further studies of the effects of treatment on circulating immune cells in patients are warranted. In this pilot study, we evaluated a wide panel of circulating immune cells over time (up to six months) in ten patients with metastatic breast cancer receiving standard antitumoral regimens. Overall, endocrine therapy tends to enrich for natural killer (NK) and natural killer T (NKT) cells in the circulation, whereas both chemotherapy and endocrine therapy reduce the levels of circulating monocytic myeloid-derived suppressor cells (Mo-MDSCs). This indicates that the systemic immunosuppressive profile observed in patients tends to revert over the course of systemic therapy and holds promise for future combination treatment with standard antitumoral agents and immunotherapy.

Cytotoxic Chemotherapy as an Immune Stimulus: A Molecular Perspective on Turning Up the Immunological Heat on Cancer

Cytotoxic chemotherapeutics (CCTs) are widely used in the treatment of cancer. Although their mechanisms of action have been best understood in terms of targeting the apparatus of mitosis, an ability to stimulate anti-tumor immune responses is increasing the recognition of these agents as immunotherapies. Immune checkpoint blockade antibodies neutralize important, but specific, immune-regulatory interactions such as PD-1/PD-L1 and CTLA-4 to improve the anti-tumor immune response. However, CCTs can provide a broad-acting immune-stimulus against cancer, promoting both T-cell priming and recruitment to the tumor, which compliments the effects of immune checkpoint blockade. A key pathway in this process is "immunogenic cell death" (ICD) which occurs as a result of tumor cell endoplasmic reticulum stress and apoptosis elicited by CCTs. ICD involves a series of non-redundant signaling events which break tolerance and license anti-tumor antigen-specific T-cells, allowing CCTs to act as "in situ" tumor vaccination tools. Not all responses are tumor cell-intrinsic, as CCTs can also modulate the broader tumor microenvironment. This modulation occurs through preferential depletion of stromal cells which suppress and neutralize robust anti-tumor immune responses, such as myeloid cell populations and Tregs, while effector CD8⁺ and CD4⁺ T-cells and NK cells are relatively spared. The immune-stimulating effects of CCTs are dependent on chemotherapy class, dose and tumor cell sensitivity to the agent, highlighting the need to understand the underlying biology of these responses. This mini review considers the immune-stimulating effects of CCTs from a molecular perspective, specifically highlighting considerations for their utilization in the context of combinations with immunotherapy.

Local Injection of Submicron Particle Docetaxel is Associated with Tumor Eradication, Reduced Systemic Toxicity and an Immunologic Response in Uro-Oncologic Xenografts

Intratumoral (IT) administration of submicron particle docetaxel (NanoDoce^®, NanOlogy LLC, Fort Worth, TX, USA) and its efficacy against genitourinary-oncologic xenografts in rats and mice, xenograft-site docetaxel concentrations and immune-cell infiltration were studied. IT-NanoDoce^®, IV-docetaxel and IT-vehicle were administered to clear cell renal carcinoma (786-O: rats), transitional cell bladder carcinoma (UM-UC-3: mice) and prostate carcinoma (PC-3: mice). Treatments were given every 7 days with 1, 2, or 3 doses administered. Animals were followed for tumor growth and clinical signs. At necropsy, 786-O and UM-UC-3 tumor-site tissues were evaluated by H&E and IHC and analyzed by LC-MS/MS for docetaxel concentration. Two and 3 cycles of IT-NanoDoce^® significantly reduced UM-UC-3 tumor volume (p < 0.01) and eliminated most UM-UC-3 and 786-O tumors. In both models, NanoDoce^® treatment was associated with (peri)tumor-infiltrating immune cells. Lymphoid structures were observed in IT-NanoDoce^®-treated UM-UC-3 animals adjacent to tumor sites. IT-vehicle and IV-docetaxel exhibited limited immune-cell infiltration. In both studies, high levels of docetaxel were detected in NanoDoce^®-treated animals up to 50 days post-treatment. In the PC-3 study, IT-NanoDoce^® and IV-docetaxel resulted in similar tumor reduction. NanoDoce^® significantly reduced tumor volume compared to IT-vehicle in all xenografts (p < 0.0001). We hypothesize that local, persistent, therapeutic levels of docetaxel from IT-NanoDoce^® reduces tumor burden while increasing immune-cell infiltration. IT NanoDoce^® treatment of prostate, renal and bladder cancer may result in enhanced tumoricidal effects.

The Potential of Combining Tubulin-Targeting Anticancer Therapeutics and Immune Therapy

Cancer immune therapy has recently shown tremendous promise to combat many different cancers. The microtubule is a well-defined and very effective cancer therapeutic target. Interestingly, several lines of evidence now suggest that microtubules are intimately connected to the body’s immune responses. This raises the possibility that the combination of microtubule inhibitors and immune therapy can be a highly effective option for cancer treatments. However, our understanding on this potentially important aspect is still very limited, due in part to the multifaceted nature of microtubule functions. Microtubules are not only involved in maintaining cell morphology, but also a variety of cellular processes, including the movement of secretory vesicles and organelles, intracellular macromolecular assembly, signaling pathways, and cell division. Microtubule inhibitors may be subdivided into two classes: Anti-depolymerization agents such as the taxane family, and anti-polymerization agents such as colchicine and vinka alkaloids. These two different classes may have different effects on immune cell subtypes. Anti-depolymerization agents can not only induce NK cells, but also appear to inhibit T regulatory (Treg) cells. However, different inhibitors may have different functions even among the same class. For example, the doxetaxel anti-depolymerization agent up-regulates cytotoxic T cells, while paclitaxel down-regulates them. Certain anti-polymerization agents such as colchicine appear to down-regulate most immune cell types, while inducing dendritic cell maturation and increasing M1 macrophage population. In contrast, the vinblastine anti-polymerization agent activates many of these cell types, albeit down-regulating Treg cells. In this review, we focus on the various effects of tubulin inhibitors on the activities of the body’s immune system, in the hope of paving the way to develop an effective cancer therapy by combining tubulin-targeting anticancer agents and immune therapy.