Chemomodulation of human dendritic cell function by antineoplastic agents in low noncytotoxic concentrations

The future of metronomic chemotherapy: experimental and computational approaches of drug repurposing

Metronomic chemotherapy (MC), long-term continuous administration of anticancer drugs, is gaining attention as an alternative to the traditional maximum tolerated dose (MTD) chemotherapy. By combining MC with other treatments, the therapeutic efficacy is enhanced while minimizing toxicity. MC employs multiple mechanisms, making it a versatile approach against various cancers. However, drug resistance limits the long-term effectiveness of MC, necessitating ongoing development of anticancer drugs. Traditional drug discovery is lengthy and costly due to processes like target protein identification, virtual screening, lead optimization, and safety and efficacy evaluations. Drug repurposing (DR), which screens FDA-approved drugs for new uses, is emerging as a cost-effective alternative. Both experimental and computational methods, such as protein binding assays, in vitro cytotoxicity tests, structure-based screening, and several types of association analyses (Similarity-Based, Network-Based, and Target Gene), along with retrospective clinical analyses, are employed for virtual screening. This review covers the mechanisms of MC, its application in various cancers, DR strategies, examples of repurposed drugs, and the associated challenges and future directions.

Efficacy and safety of metronomic oral vinorelbine and its combination therapy as second- and later-line regimens for advanced non-small-cell lung cancer: a retrospective analysis

OBJECTIVE

This retrospective analysis aimed to evaluate the efficacy and adverse reactions of metronomic oral vinorelbine and its combination therapy as second- and later-line regimens for advanced non-small-cell lung cancer (NSCLC).

METHODS

NSCLC patients undergoing metronomic oral vinorelbine as second- and later-line regimens in Fujian Cancer Hospital from October 2018 to October 2022 were enrolled, and patients' demographic and clinical characteristics were collected. The efficacy and safety of metronomic oral vinorelbine monotherapy and its combination therapy regimens were compared.

RESULTS

Of 57 study subjects, 63.2% received third- and later-line therapy, with median progression-free survival (mPFS) of 4 months, overall response rate (ORR) of 10.5%, and disease control rate (DCR) of 80.7%. The incidence of therapy-related adverse events was 42.1%, and there was only one case presenting grades 3 and 4 adverse events (1.8%). Among driver gene-negative participants, vinorelbine combination therapy regimens achieved longer mPFS (4.6 vs. 1.2 months, hazards ratio = 0.11, P < 0.0001) and comparable toxicity in relative to metronomic oral vinorelbine, and metronomic oral vinorelbine combined with immune checkpoint inhibitors showed the highest response, with mPFS of 5.6 months (95% CI 4.8 to 6.4 months), ORR of 25%, and DCR of 81.3%. Among participants with gradual resistance to osimertinib, continuing osimertinib in combination with metronomic oral vinorelbine achieved mPFS of 6.3 months (95% CI 0.1 to 12.5 months) and DCR of 86.7%.

CONCLUSION

Metronomic oral vinorelbine and its combination therapy regimens are favorable options as second- and later-line therapy for advanced NSCLC patients, with acceptable efficacy and tolerable toxicity. Vinorelbine combination therapy regimens show higher efficacy and comparable toxicity in relative to metronomic oral vinorelbine, and metronomic oral vinorelbine may have a synergistic effect with immunotherapy and EGFR-TKI targeted therapy.

Immunotherapy for head and neck cancer: Fundamentals and therapeutic development

Squamous cell carcinoma of the head and neck (SCCHN) has been treated by multidisciplinary therapy consisting of surgery, radiotherapy, and cancer chemotherapy, but the recent advent of immunotherapy has produced significant changes in treatment systems and the results of these therapies. Immunotherapy has greatly improved the outcome of recurrent metastatic SCCHN, and the development of new treatment methods based on immunotherapy is now being applied not only to recurrent metastatic cases but also to locally advanced cases. To understand and practice cancer immunotherapy, it is important to understand the immune environment surrounding cancer, and the changes to which it is subject. Currently, the anti-PD-1 antibody drugs nivolumab and pembrolizumab are the only immunotherapies with proven efficacy in head and neck cancer. However, anti-PD-L1 and anti-CTLA-4 antibody drugs have also been shown to be useful in other types of cancer and are being incorporated into clinical practice. In head and neck cancer, numerous clinical trials have aimed to improve efficacy and safety by combining immunotherapy with other drug therapies and treatment modalities. Combinations of immunotherapy with cancer drugs with different mechanisms of action (cytotoxic agents, molecular-targeted agents, immune checkpoint inhibitors), as well as with radiation therapy and surgery are being investigated, and have the potential to significantly change medical care for these patients. The application of cancer immunotherapy not only to daily clinical practice but also to further therapeutic development requires a clear and complete understanding of the fundamentals of cancer immunotherapy, and knowledge of the numerous clinical studies conducted, both past and present. The results of these trials are numerous, both positive and negative, and a comprehensive understanding of this wide range of completed and ongoing clinical trials is critical to a systematic and comprehensive understanding of their scope and lessons learnt. In this article, after outlining the concepts of ``cancer immune cycle,'' ``cancer immune editing,'' and ``tumor microenvironment'' to provide an understanding of the basics of cancer immunity, we summarize the basics and clinical trial data on representative immune checkpoint inhibitors used in various cancer types, as well as recent therapeutic developments in cancer immunotherapy and the current status of these new treatments.

A randomized phase II study of metronomic cyclophosphamide and methotrexate (CM) with or without bevacizumab in patients with advanced breast cancer

PURPOSE

Metronomic chemotherapy has the potential to offer tumor control with reduced toxicity when compared to standard dose chemotherapy in patients with metastatic breast cancer. As metronomic chemotherapy may target the tumor microvasculature, it has the potential for synergistic effects with antiangiogenic agents such as the VEGF-A inhibitor bevacizumab.

METHODS

In this randomized phase II study, patients with metastatic breast cancer were randomized to receive metronomic oral cyclophosphamide and methotrexate (CM) combined with bevacizumab (Arm A) or CM alone (Arm B). The primary endpoint was objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety and tolerability.

RESULTS

A total of 55 patients were enrolled, with 34 patients treated on Arm A and 21 patients treated on Arm B. The ORR was modestly higher in Arm A (26%) than in Arm B (10%); neither met the 40% cutoff for further clinical evaluation. The median time to progression (TTP) was 5.52 months (3.22-13.6) on Arm A and 1.82 months (1.54-6.70) on Arm B (log-rank p = 0.008). The median OS was 29.6 months (17.2-NA) on Arm A and 16.2 months (15.7-NA) on Arm B (log-rank p = 0.7). Common all-grade adverse events in both arms included nausea, fatigue, and elevated AST.

CONCLUSION

The combination of metronomic CM with bevacizumab significantly improved PFS over CM alone, although there was no significant difference in OS. Oral metronomic chemotherapy alone has limited activity in advanced breast cancer.

CLINICALTRIALS

gov Identifier: NCT00083031. Date of Registration: May 17, 2004.

Metronomic Temozolomide (mTMZ) and Bevacizumab-The Safe and Effective Frontier for Treating Metastatic Neuroendocrine Tumors (NETs): A Single-Center Experience

Addressing the persistent challenges in treating metastatic neuroendocrine tumors (NETs) demands ongoing refinement and innovation in therapeutic strategies. This study investigates the potential advantages of combining metronomic temozolomide (mTMZ) with bevacizumab for patients diagnosed with metastatic NETs, particularly focusing on those with a Ki-67 index under 55%. Data from 30 patients were analyzed, using key performance indicators such as progression-free survival (PFS), overall survival (OS), and response rates to therapy, to gauge the treatment's efficacy. The results were encouraging: the median PFS recorded was 16.3 months, and the OS was 25.9 months. The disease control rate (DCR) reached an impressive 86.7%, and the objective response rate (ORR) stood at 63.3%. The treatment regimen was well-tolerated, with no reported instances of grade 4 toxicities. Such a safety profile indicates that this regimen may be particularly advantageous for older, fragile patients who might struggle with conventional dosage levels. These initial findings suggest that the mTMZ and bevacizumab combination could potentially rival the conventional temozolomide-capecitabine therapy in managing metastatic NETs. We aimed to meticulously assess the efficacy of the mTMZ and bevacizumab combination in treating metastatic NETs. Given the initial promising results, a more conclusive understanding of its efficacy will require further research through larger, multicenter prospective clinical trials.

It's high-time to re-evaluate the value of induced-chemotherapy for reinforcing immunotherapy in colorectal cancer

Immunotherapy has made significant advances in the treatment of colorectal cancer (CRC), revolutionizing the therapeutic landscape and highlighting the indispensable role of the tumor immune microenvironment. However, some CRCs have shown poor response to immunotherapy, prompting investigation into the underlying reasons. It has been discovered that certain chemotherapeutic agents possess immune-stimulatory properties, including the induction of immunogenic cell death (ICD), the generation and processing of non-mutated neoantigens (NM-neoAgs), and the B cell follicle-driven T cell response. Based on these findings, the concept of inducing chemotherapy has been introduced, and the combination of inducing chemotherapy and immunotherapy has become a standard treatment option for certain cancers. Clinical trials have confirmed the feasibility and safety of this approach in CRC, offering a promising method for improving the efficacy of immunotherapy. Nevertheless, there are still many challenges and difficulties ahead, and further research is required to optimize its use.

The modulation of local and systemic anti-tumor immune response induced by methotrexate nanoconjugate in murine MC38 colon carcinoma and B16 F0 melanoma tumor models

Methotrexate (MTX) which is one of the longest-used cytostatics, belongs to the group of antimetabolites and is used for treatment in different types of cancer as well as during autoimmune diseases. MTX can act as a modulator enable to create the optimal environment to generate the specific anti-tumor immune response. A novel system for MTX delivery is its conjugation with high-molecular-weight carriers such as hydroxyethyl starch (HES), a modified amylopectin-based polymer applied in medicine as a colloidal plasma volume expander. Such modification prolongs the plasma half-life of the HES-MTX nanoconjugate and improves the distribution of the drug in the body. In the current study, we focused on evaluating the dose-dependent therapeutic efficacy of chemotherapy with HES-MTX nanoconjugate compared to the free form of MTX, and examining the time-dependent changes in the local and systemic anti-tumor immune response induced by this therapy. To confirm the higher effectiveness of HES-MTX in comparison to MTX, we analyzed its action using murine MC38 colon carcinoma and B16 F0 melanoma tumor models. It was noted that HES-MTX at a dose of 20 mg/kg b.w. was more effective in tumor growth inhibition than MTX in both tumor models. One of the main differences between the two analyzed tumor models concerned the kinetics of the appearance of the immunomodulation. In MC38 tumors, the beneficial change in the tumor microenvironment (TME) landscape, manifested by the depletion of pro-tumor immune cells, and increased influx of cells with strong anti-tumor activity was noted already 3 days after HES-MTX administration, while in B16 F0 model, these changes occurred 10 days after the start of therapy. Thus, the immunomodulatory potential of the HES-MTX nanoconjugate may be closely related to the specific immune cell composition of the TME, which combined with additional treatment such as immunotherapies, would enhance the therapeutic potential of the nanoconjugate.

Chemo-Immunotherapy: A New Trend in Cancer Treatment

Chemotherapy has been the basis of advanced cancer treatment for decades. This therapy has largely been considered immunosuppressive, yet accumulated preclinical and clinical evidence shows that certain chemotherapeutic drugs, under defined conditions, may stimulate antitumor immunity and potentiate immune checkpoint inhibitor (ICI)-based therapy. Its effectiveness has been highlighted by recent regulatory approvals of various combinations of chemotherapy with ICIs in several tumors, particularly in some difficult-to-treat cancers. This review discusses the immune modulatory properties of chemotherapy and how they may be harnessed to develop novel chemo-immunotherapy combinations. It also highlights the key determinants of the success of chemo-immunotherapy and provides an overview of the combined chemo-immunotherapies that have been clinically approved.

Metronomic chemotherapy as a potential partner of immune checkpoint inhibitors for metastatic colorectal cancer treatment

The use of immune checkpoint inhibitors (ICIs) in clinical practice for the treatment of metastatic colorectal cancer (mCRC) is currently limited to patients with deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H), which comprise less than 5% of all mCRC cases. Combining ICIs with anti-angiogenic inhibitors, which modulate the tumor microenvironment, may reinforce and synergize the anti-tumor immune responses of ICIs. In mCRCs, combinations of pembrolizumab and lenvatinib have shown good efficacy in early phase trials. These results suggest the potential utility of immune modulators as partners in combination treatment with ICIs in immunologically cold microsatellite stable, as well as hot dMMR/MSI-H tumors. Unlike conventional pulsatile maximum tolerated dose chemotherapy, low-dose metronomic (LDM) chemotherapy recruits immune cells and normalizes vascular-immune crosstalk, similar to anti-angiogenic drugs. LDM chemotherapy mostly modulates the tumor stroma rather than directly killing tumor cells. Here, we review the mechanism of LDM chemotherapy in terms of immune modulation and its potential as a combination partner with ICIs for the treatment of patients with mCRC tumors, most of which are immunologically cold.

Metronomic Chemotherapy: Anti-Tumor Pathways and Combination with Immune Checkpoint Inhibitors

Increasing evidence pinpoints metronomic chemotherapy, a frequent and low dose drug administration with no prolonged drug-free intervals, as a potential tool to fight certain types of cancers. The primary identified targets of metronomic chemotherapy were the tumor endothelial cells involved in angiogenesis. After this, metronomic chemotherapy has been shown to efficiently target the heterogeneous population of tumor cells and, more importantly, elicit the innate and adaptive immune system reverting the "cold" to "hot" tumor immunologic phenotype. Although metronomic chemotherapy is primarily used in the context of a palliative setting, with the development of new immunotherapeutic drugs, a synergistic therapeutic role of the combined metronomic chemotherapy and immune checkpoint inhibitors has emerged at both the preclinical and clinical levels. However, some aspects, such as the dose and the most effective scheduling, still remain unknown and need further investigation. Here, we summarize what is currently known of the underlying anti-tumor effects of the metronomic chemotherapy, the importance of the optimal therapeutic dose and time-exposure, and the potential therapeutic effect of the combined administration of metronomic chemotherapy with checkpoint inhibitors in preclinical and clinical settings.

A Mechanistic Review of Methotrexate and Celecoxib as a Potential Metronomic Chemotherapy for Oral Squamous Cell Carcinoma

The combination of low-dose methotrexate and celecoxib as metronomic chemotherapy (MCT) is a novel therapy, believed to act by modulating the immune response, inhibiting angiogenesis and its cytotoxic action, though the exact mechanism of action is unclear. Clinically, MCT was found to be very effective in delaying tumor progression in patients with head and neck squamous cell carcinoma in both curative and palliative settings. This review was aimed to give a brief insight into the mechanism of action and potential molecular alterations of MCT in the treatment of oral cancers taking into consideration the various in vivo and in vitro studies.

Topoisomerases in Immune Cell Development and Function

DNA topoisomerases (TOPs) are complex enzymatic machines with extraordinary capacity to maintain DNA topology during torsion-intensive steps of replication and transcription. Recently, TOPs have gained significant attention for their tissue-specific function, and the vital role of TOPs in immune homeostasis and dysfunction is beginning to emerge. TOPs have been implicated in various immunological disorders such as autoimmunity, B cell immunodeficiencies, and sepsis, underscoring their importance in immune regulation. However, much remains unknown about immunological underpinnings of TOPs, and a deeper understanding of the role of TOPs in the immune system will be critical for yielding significant insights into the etiology of immunological disorders. In this review, we first discuss the recent literature highlighting the contribution of TOPs in the development of immune cells, and we further provide an overview of their importance in immune cell responses.

Combined therapy with methotrexate nanoconjugate and dendritic cells with downregulated IL-10R expression modulates the tumor microenvironment and enhances the systemic anti-tumor immune response in MC38 murine colon carcinoma

Background

Understanding the negative impact of the tumor microenvironment on the creation of an effective immune response has contributed to the development of new therapeutic anti-cancer strategies. One such solution is combined therapy consisting of chemotherapeutic administration followed by dendritic cell (DC)-based vaccines. The use of cytostatic leads to the elimination of cancer cells, but can also modulate the tumor milieu. Moreover, great efforts are being made to increase the therapeutic outcome of immunotherapy, e.g. by enhancing the ability of DCs to generate an efficient immune response, even in the presence of immunosuppressive cytokines such as IL-10. The study aimed to determine the effectiveness of combined therapy with chemotherapeutic with immunomodulatory potential - HES-MTX nanoconjugate (composed of methotrexate (MTX) and hydroxyethyl starch (HES)) and DCs with downregulated expression of IL-10 receptor stimulated with tumor antigens (DC/shIL-10R/TAg) applied in MC38 murine colon carcinoma model.

Methods

With the use of lentiviral vectors the DCs with decreased expression of IL-10R were obtained and characterized. During in vivo studies MC38-tumor bearing mice received MTX or HES-MTX nanoconjugate as a sole treatment or combined with DC-based immunotherapy containing unmodified DCs or DCs transduced with shRNA against IL-10R (or control shRNA sequence). Tumor volume was monitored during the experiment. One week after the last injection of DC-based vaccines, tumor nodules and spleens were dissected for ex vivo analysis. The changes in the local and systemic anti-tumor immune response were estimated with the use of flow cytometry and ELISA methods.

Results and conclusions

In vitro studies showed that the downregulation of IL-10R expression in DCs enhances their ability to activate the specific anti-tumor immune response. The use of HES-MTX nanoconjugate and DC/shIL-10R/TAg in the therapy of MC38-tumor bearing mice resulted in the greatest tumor growth inhibition. At the local anti-tumor immune response level a decrease in the infiltration of cells with suppressor activity and an increase in the influx of effector cells into MC38 tumor tissue was observed. These changes were crucial to enhance the effective specific immune response at the systemic level, which was revealed in the greatest cytotoxic activity of spleen cells against MC38 cells.

In vitro Characterization of Enhanced Human Immune Responses by GM-CSF Encoding HSV-1-Induced Melanoma Cells

PURPOSE

We studied the innate and adaptive immune response against melanoma cells after JS-1 (wild-type herpes simplex virus 1, wt HSV-1) or Talimogene laherparepvec (T-VEC) infection and evaluated the antitumoral efficacy in human melanoma cells. We analyzed the putative synergistic biological and immunological effects of JS-1 or T-VEC combined with cytostatic drugs in human tumor and immune cells. T-VEC is a genetically modified strain of HSV-1. Genetic modifications (insertion of the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene) were made to attenuate the virus and increase selectivity for cancer cells. In addition to the direct oncolytic effect, we investigated the immune stimulatory effects of T-VEC by comparing it with JS-1. JS-1 is identical T-VEC except for the inserted GM-CSF gene.

MATERIALS AND METHODS

We analyzed the effects of T-VEC and JS-1 with cytostatic drugs in human tumor-immune cell coculture experiments. After coculture, the surface markers CD80, CD83 and CD86 were measured by fluorescence-activated cell sorting and the cytokines, interleukin (IL)-2, IL-6, tumor necrosis factor (TNF)-α and GM-CSF, by enzyme-linked immunosorbent assays. Furthermore, we analyzed the potential of the viruses to induce T cell activation, measured on the basis of CD4, CD8 and CD69. Analysis of these markers and cytokines allows for conclusions to be drawn concerning the maturation of dendritic cells (DCs) and the immunostimulatory effects of the treatment.

RESULTS

We documented increased activation of human cytotoxic T lymphocytes after infection by both HSV-1 strains and treatment with cytostatic drugs without significant differences between T-VEC and JS-1.

CONCLUSION

We demonstrated an immune response as a result of infection with both viruses, but T-VEC was in vitro not stronger than JS-1. The immunostimulatory effects of the viruses could be partially increased by chemotherapy, providing a rationale for future preclinical studies designed to explore T-VEC in combined regimens.

Elicitation of stem-like CD8+ T cell responses via lymph node-targeted chemoimmunotherapy evokes systemic tumor control

Background

Tumor-draining lymph nodes (TdLNs) are critical in the regulation of local and systemic antitumor T cell immunity and are implicated in coordinating responses to immunomodulatory therapies.

Methods

Biomaterial nanoparticles that deliver chemotherapeutic drug paclitaxel to TdLNs were leveraged to explore its effects in combination and immune checkpoint blockade (ICB) antibody immunotherapy to determine the benefit of TdLN-directed chemoimmunotherapy on tumor control.

Results

Accumulation of immunotherapeutic drugs in combination within TdLNs synergistically enhanced systemic T cell responses that led to improved control of local and disseminated disease and enhanced survival in multiple murine breast tumor models.

Conclusions

These findings suggest a previously underappreciated role of secondary lymphoid tissues in mediating effects of chemoimmunotherapy and demonstrate the potential for nanotechnology to unleashing drug synergies via lymph node targeted delivery to elicit improved response of breast and other cancers.

Potentiation of combined p19Arf and interferon-beta cancer gene therapy through its association with doxorubicin chemotherapy

Balancing safety and efficacy is a major consideration for cancer treatments, especially when combining cancer immunotherapy with other treatment modalities such as chemotherapy. Approaches that induce immunogenic cell death (ICD) are expected to eliminate cancer cells by direct cell killing as well as activation of an antitumor immune response. We have developed a gene therapy approach based on p19Arf and interferon-β gene transfer that, similar to conventional inducers of ICD, results in the release of DAMPS and immune activation. Here, aiming to potentiate this response, we explore whether association between our approach and treatment with doxorubicin (Dox), a known inducer of ICD, could further potentiate treatment efficacy without inducing cardiotoxicity, a critical side effect of Dox. Using central composite rotational design analysis, we show that cooperation between gene transfer and chemotherapy killed MCA205 and B16F10 cells and permitted the application of reduced viral and drug doses. The treatments also cooperated to induce elevated levels of ICD markers in MCA205, which correlated with improved efficacy of immunotherapy in vivo. Treatment of subcutaneous MCA205 tumors associating gene transfer and low dose (10 mg/kg) chemotherapy resulted in inhibition of tumor progression. Moreover, the reduced dose did not cause cardiotoxicity as compared to the therapeutic dose of Dox (20 mg/kg). The association of p19Arf/interferon-β gene transfer and Dox chemotherapy potentiated antitumor response and minimized cardiotoxicity.

Chemotherapy reinforces anti-tumor immune response and enhances clinical efficacy of immune checkpoint inhibitors

New evidence suggests that the clinical success of chemotherapy is not merely due to tumor cell toxicity but also arises from the restoration of immunosurveillance, which has been immensely neglected in previous preclinical and clinical researches. There is an urgent need for novel insights into molecular mechanisms and regimens that uplift the efficacy of immunotherapy since only a minority of cancer patients are responsive to immune checkpoint inhibitors (ICIs). Recent findings on combination therapy of chemotherapy and ICIs have shown promising results. This strategy increases tumor recognition and elimination by the host immune system while reducing immunosuppression by the tumor microenvironment. Currently, several preclinical studies are investigating molecular mechanisms that give rise to the immunomodulation by chemotherapeutic agents and exploit them in combination therapy with ICIs in order to achieve a synergistic clinical activity. In this review, we summarize studies that exhibit the capacity of conventional chemotherapeutics to elicit anti-tumor immune responses, thereby facilitating anti-tumor activities of the ICIs. In conclusion, combining chemotherapeutics with ICIs appears to be a promising approach for improving cancer treatment outcomes.

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.

How Chemotherapy Affects the Tumor Immune Microenvironment: A Narrative Review

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

Sonicated Bordetella bronchiseptica Bacterin Can Protect Dendritic Cells from Differential Cytotoxicity Caused by Doxorubicin and Vincristine and Enhance Their Antigen-Presenting Capability

Doxorubicin (DOX) and vincristine (VC) are anti-cancer drugs commonly used for lymphoma in veterinary and human medicine. However, there are several side effects caused by these drugs. In this study, the protective effects of sonicated Bordetella bronchiseptica bacterin (sBb) on dendritic cells (DCs) damaged by two anti-cancer drugs were investigated. DCs play important roles in the innate and adaptive immunity of hosts, especially activating T cells that can suppress tumor growth. The metabolic activity of DCs significantly increased after the treatment with sBb compared to that of control DCs. In addition, there was a marked change in mitochondrial integrity between DOX-treated DC and DOX + sBb-treated DCs. Flow cytometric analysis also demonstrated that sBb upregulated the expression of the surface markers of DCs, particularly CD54. In mixed lymphocyte responses, sBb significantly increased the antigen-presenting capability of DCs. In particular, sBb increased the capability of control DCs by approximately 150% and that of VC-treated DCs by 221%. These results suggest that sBb can be used as a potential immunostimulatory agent to protect DCs from anti-cancer drug-induced damage and provide fundamental information about using a combination of DCs and vincristine in immunotherapy.

Metronomic Chemotherapy in Prostate Cancer

Despite the significant expansion of the therapeutic armamentarium associated with the introduction of novel endocrine therapies, cytotoxic agents, radiopharmaceuticals, and PARP inhibitors, progression of metastatic castration-resistant prostate cancer (mCRPC) beyond treatment options remains the leading cause of death in advanced prostate cancer patients. Metronomic chemotherapy (MC) is an old concept of wise utilization of cytotoxic agents administered continuously and at low doses. The metronomic is unique due to its multidimensional mechanisms of action involving: (i) inhibition of cancer cell proliferation, (ii) inhibition of angiogenesis, (iii) mitigation of tumor-related immunosuppression, (iv) impairment of cancer stem cell functions, and (v) modulation of tumor and host microbiome. MC has been extensively studied in advanced prostate cancer before the advent of novel therapies, and its actual activity in contemporary, heavily pretreated mCRPC patients is unknown. We have conducted a prospective analysis of consecutive cases of mCRPC patients who failed all available standard therapies to find the optimal MC regimen for phase II studies. The metronomic combination of weekly paclitaxel 60 mg/m² i.v. with capecitabine 1500 mg/d p.o. and cyclophosphamide 50 mg/d p.o. was selected as the preferred regimen for a planned phase II study in heavily pretreated mCRPC patients.

Ganoderma lucidum polysaccharides inhibit in vitro tumorigenesis, cancer stem cell properties and epithelial-mesenchymal transition in oral squamous cell carcinoma

ETHNOPHARMACOLOGICAL RELEVANCE

The polysaccharides of the millenary mushroom Ganoderma lucidum (GL) have been shown for decades to present anti-tumor activities, but few studies evaluated its importance on cancer stem cells and EMT process. Cancer stem cells (CSC) drive the development of carcinoma and are also involved in cancer treatment failure, being a good target for treatment success. Also, the process of epithelial-mesenchymal transition (EMT) is involved in metastasis and cancer relapse. Besides that, the increasing incidence worldwide of oral squamous cell carcinoma (OSCC) became a public health issue with a high rate of metastasis and poor quality of life for patients during and after treatment.

AIM OF THE STUDY

to evaluate G. lucidum polysaccharides (GLPS) in vitro effects on OSCC, focusing on hallmarks associated with tumorigenesis using the SCC-9, a squamous cells carcinoma lineage from the tongue.

MATERIALS AND METHODS

SCC-9 cells were treated in vitro for 72h with different GLPS concentrations. The controls cells were maintained with culture media only and cisplatin was used as treatment control. After the treatment period, the cells were evaluated.

RESULTS

GLPS treatment changed cell morphology and granularity, delayed migration, decreased colony, and impaired sphere formation, thereby leading to a non-invasive and less proliferative behavior of tumoral cells. Additionally, GLPS downregulated CSC, EMT, and drug sensitivity (ABC) markers.

CONCLUSIONS

These results show that the natural product GLPS has the potential to be an important ally for tongue squamous cell carcinoma treatment, bringing the millenary compound to modern therapy, providing a basis for future studies and the improvement of life quality for OSCC patients.

Current Strategies for Tumor Photodynamic Therapy Combined With Immunotherapy

Photodynamic therapy (PDT) is a low invasive antitumor therapy with fewer side effects. On the other hand, immunotherapy also has significant clinical applications in the treatment of cancer. Both therapies, on their own, have some limitations and are incapable of meeting the demands of the current cancer treatment. The efficacy of PDT and immunotherapy against tumor metastasis and tumor recurrence may be improved by combination strategies. In this review, we discussed the possibility that PDT could be used to activate immune responses by inducing immunogenic cell death or generating cancer vaccines. Furthermore, we explored the latest advances in PDT antitumor therapy in combination with some immunotherapy such as immune adjuvants, inhibitors of immune suppression, and immune checkpoint blockade.

Chemotherapeutic drugs: Cell death- and resistance-related signaling pathways. Are they really as smart as the tumor cells?

Chemotherapeutic drugs kill cancer cells or control their progression all over the patient's body, while radiation- and surgery-based treatments perform in a particular site. Based on their mechanisms of action, they are classified into different groups, including alkylating substrates, antimetabolite agents, anti-tumor antibiotics, inhibitors of topoisomerase I and II, mitotic inhibitors, and finally, corticosteroids. Although chemotherapeutic drugs have brought about more life expectancy, two major and severe complications during chemotherapy are chemoresistance and tumor relapse. Therefore, we aimed to review the underlying intracellular signaling pathways involved in cell death and resistance in different chemotherapeutic drug families to clarify the shortcomings in the conventional single chemotherapy applications. Moreover, we have summarized the current combination chemotherapy applications, including numerous combined-, and encapsulated-combined-chemotherapeutic drugs. We further discussed the possibilities and applications of precision medicine, machine learning, next-generation sequencing (NGS), and whole-exome sequencing (WES) in promoting cancer immunotherapies. Finally, some of the recent clinical trials concerning the application of immunotherapies and combination chemotherapies were included as well, in order to provide a practical perspective toward the future of therapies in cancer cases.

Repositioning of Antiparasitic Drugs for Tumor Treatment

Drug repositioning is a strategy for identifying new antitumor drugs; this strategy allows existing and approved clinical drugs to be innovatively repurposed to treat tumors. Based on the similarities between parasitic diseases and cancer, recent studies aimed to investigate the efficacy of existing antiparasitic drugs in cancer. In this review, we selected two antihelminthic drugs (macrolides and benzimidazoles) and two antiprotozoal drugs (artemisinin and its derivatives, and quinolines) and summarized the research progresses made to date on the role of these drugs in cancer. Overall, these drugs regulate tumor growth via multiple targets, pathways, and modes of action. These antiparasitic drugs are good candidates for comprehensive, in-depth analyses of tumor occurrence and development. In-depth studies may improve the current tumor diagnoses and treatment regimens. However, for clinical application, current investigations are still insufficient, warranting more comprehensive analyses.

Anti-Cancer Treatment Strategies in the Older Population: Time to Test More?

Aging is a well-recognized risk factor for the development of cancer. The incidence of new cancer diagnoses has increased globally given the rising senior population. Many hypotheses for this increased risk have been postulated over decades, including increased genetic and epigenetic mutations and the concept of immunosenescence. The optimal treatment strategies for this population with cancer are unclear. Older cancer patients are traditionally under-represented in clinical trials developed to set the standard of care, leading to undertreatment or increased toxicity. With this background, it is crucial to investigate new opportunities that belong to the most recent findings of an anti-cancer agent, such as immune-checkpoint inhibitors, to manage these daily clinical issues and eventually combine them with alternative administration strategies of antiblastic drugs such as metronomic chemotherapy.

Immunomodulatory potential of anticancer therapy composed of methotrexate nanoconjugate and dendritic cell‑based vaccines in murine colon carcinoma

Chemotherapy with low-molecular weight compounds, despite elimination of cancer cells, entails adverse effects. To overcome this disadvantage, innovative drug delivery systems are being developed, including conjugation of macromolecular carriers with therapeutics, e.g. a nanoconjugate of hydroxyethyl starch and methotrexate (HES-MTX). The purpose of the present study was to determine whether HES-MTX, applied as a chemotherapeutic, is able to modulate the immune response and support the antitumor response generated by dendritic cells (DCs) used subsequently as immunotherapeutic vaccines. Therefore, MTX or HES-MTX was administered, as sole treatment or combined with DC-based vaccines, to MC38 colon carcinoma tumor-bearing mice. Alterations in antitumor immune response were evaluated by multiparameter flow cytometry analyses and functional assays. The results demonstrated that the nanoconjugate possesses greater immunomodulatory potential than MTX as reflected by changes in the landscape of immune cells infiltrating the tumor and increased cytotoxicity of splenic lymphocytes. In contrast to MTX, therapy with HES-MTX as sole treatment or combined with DC-based vaccines, contributed to significant tumor growth inhibition. However, only treatment with HES-MTX and DC-based vaccines activated the systemic specific antitumor response. In conclusion, due to its immunomodulatory properties, the HES-MTX nanoconjugate could become a potent anticancer agent used in both chemo- and chemoimmunotherapeutic treatment schemes.

Potential therapeutic effect of low-dose paclitaxel in melanoma patients resistant to immune checkpoint blockade: A pilot study

The low dose application of chemotherapeutic agents such as paclitaxel was previously shown to initiate anti-tumor activity by neutralizing myeloid-derived suppressor cells (MDSCs) in melanoma mouse models. Here, we investigated immunomodulating effects of low-dose paclitaxel in 9 metastatic melanoma patients resistant to prior treatments. Three patients showed response to therapy (two partial responses and one stable disease). In responding patients, paclitaxel decreased the frequency and immunosuppressive pattern of MDSCs in the peripheral blood and skin metastases. Furthermore, paclitaxel modulated levels of inflammatory mediators in the serum. In addition, responders displayed enhanced frequencies of tumor-infiltrating CD8⁺ T cells and their activity indicated by the upregulation of CD25 and TCR ζ-chain expression. Our study suggests that low-dose paclitaxel treatment could improve clinical outcome of some advanced melanoma patients by enhancing anti-tumor immunity and might be proposed for combined melanoma immunotherapy.

Combinations using checkpoint blockade to overcome resistance

The advent of immunotherapy for cancer represented a paradigm shift in the treatment approach of neoplasia. Immune-checkpoint inhibitors (ICIs) were demonstrated to significantly improve outcomes, including overall survival across several cancer types, with yearly-durable responses. Nevertheless, many patients derive minor or no benefit with immune checkpoint (IC)-blockade, including patients with cancer types traditionally considered immunogenic. Combination strategies of ICIs with chemotherapy, radiotherapy, targeted therapies or other immunotherapy compounds have been conceived in order to boost the immune-responses and potentially overcome resistance to ICIs. This review focuses on mechanisms underlying resistance to IC-blockade and provides an overview of potential advantages and limitations of combination strategies currently under investigation.

Could microtubule inhibitors be the best choice of therapy in gastric cancer with high immune activity: mutant DYNC1H1 as a biomarker

Immune checkpoint blockade (ICB) has achieved unprecedented breakthroughs in various cancers, including gastric cancer (GC) with high immune activity (MSI-H or TMB-H), yet clinical benefits from ICB were moderate. Here we aimed to identify the most appropriate drugs which can improve outcomes in GC. We firstly compared MSI-H and TMB-H GC samples with normal samples in TCGA-STAD cohort, respectively. After that, Connectivity Map database repurposed nine candidate drugs (CMap score < -90). Then, microtubule inhibitors (MTIs) were screened as the significant candidate drugs with their representative gene sets strongly enriched (p < 0.05) via GSEA. GDSC database validated higher activities of some MTIs in GC cells with MSI-H and TMB-H (p < 0.05). Furthermore, some MTIs activities were positively associated with mutant Dynein Cytoplasmic 1 Heavy Chain 1 (DYNC1H1) (p < 0.05) based on NCI-60 cancer cell line panel. DYNC1H1 was high frequently alteration in GC and was positively associated with TMB-H and MSI-H. Mutant DYNC1H1 may be accompanied with down-regulation of MTIs-related genes in GC or change the binding pocket to sensitize MTIs. Overall, this study suggested that some MTIs may be the best candidate drugs to treat GC with high immune activity, especially patients with DYNC1H1 mutated.

Combinatorial drug therapy in cancer - New insights

Cancer can arise due to mutations in numerous pathways present in our body and thus has many alternatives for getting aggravated. Due to this attribute, it gets difficult to treat cancer patients with monotherapy alone and has a risk of not being eliminated to the full extent. This necessitates the introduction of combinatorial therapy as it employs cancer treatment using more than one method and shows a greater success rate. Combinatorial therapy involves a complementary combination of two different therapies like a combination of radio and immunotherapy or a combination of drugs that can target more than one pathway of cancer formation like combining CDK targeting drugs with Growth factors targeting drugs. In this review, we discuss the various aspects of cancer which include, its causes; four regulatory mechanisms namely: apoptosis, cyclin-dependent kinases, tumor suppressor genes, and growth factors; some of the pathways involved; treatment: monotherapy and combinatorial therapy and combinatorial drug formulation in chemotherapy. The present review gives a holistic account of the different mechanisms of therapies and also drug combinations that may serve to not only complement the monotherapy but can also surpass the resistance against monotherapy agents.

Blocking drug-induced autophagy with chloroquine in HCT-116 colon cancer cells enhances DC maturation and T cell responses induced by tumor cell lysate

Autophagy is an important mechanism for tumor escape, allowing tumor cells to recover from the damage induced by chemotherapy, radiation therapy, and immunotherapy and contributing to the development of resistance. The pharmacological inhibition of autophagy contributes to increase the efficacy of antineoplastic agents. Exposing tumor cells to low concentrations of select autophagy-inducing antineoplastic agents increases their immunogenicity and enhances their ability to stimulate dendritic cell (DC) maturation. We tested whether the application of an autophagy-inhibiting agent, chloroquine (CQ), in combination with low concentrations of 5-fluorouracil (5-FU) increases the ability of tumor cells to induce DC maturation. DCs sensitized with the lysate of HCT-116 cells previously exposed to such a combination enhanced the DC maturation/activation ability. These matured DCs also increased the allogeneic responsiveness of both CD4+ and CD8+ T cells, which showed a greater proliferative response than those from DCs sensitized with control lysates. The T cells expanded in such cocultures were CD69+ and PD-1- and produced higher levels of IFN-γ and lower levels of IL-10, consistent with the preferential activation of Th1 cells. Cocultures of autologous DCs and lymphocytes improved the generation of cytotoxic T lymphocytes, as assessed by the expression of CD107a, perforin, and granzyme B. The drug combination increased the expression of genes related to the CEACAM family (BECN1, ATGs, MAPLC3B, ULK1, SQSTM1) and tumor suppressors (PCBP1). Furthermore, the decreased expression of genes related to metastasis and tumor progression (BNIP3, BNIP3L, FOSL2, HES1, LAMB3, LOXL2, NDRG1, P4HA1, PIK3R2) was noted. The combination of 5-FU and CQ increases the ability of tumor cells to drive DC maturation and enhances the ability of DCs to stimulate T cell responses.

Metronomic Maintenance for High-Risk Pediatric Malignancies: One Size Will Not Fit All

Maintenance therapy sometimes relies on the use of metronomic chemotherapy (MC); that is, the continuous administration of low-dose chemotherapy. Maintenance therapy has been successfully used for decades in pediatric patients with acute lymphoblastic leukemia (ALL) and recent results have demonstrated improved outcomes in patients with pediatric high-risk rhabdomyosarcoma (RMS) on maintenance therapy. Here, we review the use of metronomic maintenance therapy in pediatric cancer and discuss its mechanisms of action on the tumor microenvironment and cancer cells. We also discuss its potential use as a chemotherapy alone or in combination with targeted therapies, immunotherapies, or agents for drug repurposing.

Poly(cyclodextrin)-Polydrug Nanocomplexes as Synthetic Oncolytic Virus for Locoregional Melanoma Chemoimmunotherapy

Despite the approval of oncolytic virus therapy for advanced melanoma, its intrinsic limitations that include the risk of persistent viral infection and cost-intensive manufacturing motivate the development of analogous approaches that are free from the disadvantages of virus-based therapies. Herein, we report a nanoassembly comprised of multivalent host-guest interactions between polymerized paclitaxel (pPTX) and nitric oxide incorporated polymerized β-cyclodextrin (pCD-pSNO) that through its bioactive components and when used locoregionally recapitulates the therapeutic effects of oncolytic virus. The resultant pPTX/pCD-pSNO exhibits significantly enhanced cytotoxicity, immunogenic cell death, dendritic cell activation and T cell expansion in vitro compared to free agents alone or in combination. In vivo, intratumoral administration of pPTX/pCD-pSNO results in activation and expansion of dendritic cells systemically, but with a corresponding expansion of myeloid-derived suppressor cells and suppression of CD8+ T cell expansion. When combined with antibody targeting cytotoxic T lymphocyte antigen-4 that blunts this molecule's signaling effects on T cells, intratumoral pPTX/pCD-pSNO treatment elicits potent anticancer effects that significantly prolong animal survival. This formulation thus leverages the chemo- and immunotherapeutic synergies of paclitaxel and nitric oxide and suggests the potential for virus-free nanoformulations to mimic the therapeutic action and benefits of oncolytic viruses.

A study of capecitabine metronomic chemotherapy is non-inferior to conventional chemotherapy as maintenance strategy in responders after induction therapy in metastatic colorectal cancer

Background

The aim of this study is to demonstrate that capecitabine metronomic chemotherapy is non-inferior to capecitabine conventional chemotherapy as maintenance treatment, in patients who have responded to 16–18 weeks first-line chemotherapy in metastatic colorectal cancer (mCRC).

Methods

The study design is a prospective, randomized, open label, phase II clinical trial. Those patients with mCRC who respond well after 16–18 weeks of standard doublet chemotherapy as induction may be enrolled into this study, and randomly assigned to the capecitabine metronomic group or standard dosage group. The duration of disease control after randomization and progression-free survival after enrollment are the primary endpoints. Overall survival, safety, and quality of life are the secondary endpoints. The sample size required to achieve the research objectives of this project is 79 patients in each group. The study recently started on 1 January 2018, and will last for 36 months.

Discussion

This project is intended to study the efficacy and safety of capecitabine metronomic chemotherapy in the maintenance treatment of advanced colorectal cancer, and to explore the strategy of “low toxicity, high efficiency, economy, and individualization”, which is suitable for China’s national conditions and pharmacoeconomics. It has great prospects for clinical application and a clear socioeconomic value.

Trial registration

ClinicalTrials.gov: NCT03158610. Registered on 15 May 2017.

Open-label Phase II trial to evaluate safety and efficacy of second-line metronomic oral vinorelbine-atezolizumab combination for stage-IV non-small-cell lung cancer - VinMetAtezo trial, (GFPC‡ 04-2017)

Metronomic chemotherapy is defined as frequent low-dose administration without prolonged drug-free breaks. Combining immune-checkpoint inhibitors and metronomic chemotherapy is a new approach to improve responses and delay onset of resistance to immune-checkpoint inhibitors. This multicenter, Phase II, open-label, single-arm study was designed to assess the safety and efficacy of metronomic oral vinorelbine in combination with immune-checkpoint inhibitors in advanced non-small-cell lung cancers progressing after first-line platinum-based chemotherapy. The recommended metronomic oral vinorelbine dose will be determined during a safety run-in period including 12 patients; the main study will include 59 additional patients. The primary outcome is progression-free survival at 4 months. Secondary outcomes are safety of the combination, median overall survival, objective response rate, disease-control rate at 4 months and quality of life (NCT03801304).

The antimetastatic activity of orlistat is accompanied by an antitumoral immune response in mouse melanoma

PURPOSE

Fatty acid synthase (FASN), the multifunctional enzyme responsible for endogenous fatty acid synthesis, is highly expressed and associated with poor prognosis in several human cancers, including melanoma. Our group has previously shown that pharmacological inhibition of FASN with orlistat decreases proliferation, promotes apoptosis, and reduces the metastatic spread of B16-F10 cells in experimental models of melanoma. While most of the orlistat antitumor properties seem to be closely related to direct effects on malignant cells, its impact on the host immune system is still unknown.

METHODS

The effects of orlistat on the phenotype and activation status of infiltrating leukocytes in primary tumors and metastatic lymph nodes were assessed using a model of spontaneous melanoma metastasis (B16-F10 cells/C57BL/6 mice). Cells from the primary tumors and lymph nodes were mechanically dissociated and immune cells phenotyped by flow cytometry. The expression of IL-12p35, IL-12p40, and inducible nitric oxide synthase (iNOS) was analyzed by qRT-PCR and production of nitrite (NO₂^-) evaluated in serum samples with the Griess method.

RESULTS

Orlistat-treated mice exhibited a 25% reduction in the number of mediastinal lymph node metastases (mean 3.96 ± 0.78, 95% CI 3.63-4.28) compared to the controls (mean 5.7 ± 1.72; 95% CI 5.01-6.43). The drug elicited an antitumor immune response against experimental melanomas by increasing maturation of intratumoral dendritic cells (DC), stimulating the expression of cytotoxicity markers in CD8 T lymphocytes and natural killer (NK) cells, as well as reducing regulatory T cells (Tregs). Moreover, the orlistat-treatment increased serum levels of nitric oxide (NO) concentrations.

CONCLUSION

Taken together, these findings suggest that orlistat supports an antitumor response against experimental melanomas by increasing CD80/CD81-positive and IL-12-positive DC populations, granzyme b/NKG2D-positive NK populations, and perforin/granzyme b-positive CD8 T lymphocytes as well as reducing Tregs counts within experimental melanomas.

Temozolomide for immunomodulation in the treatment of glioblastoma

Temozolomide is the most widely used chemotherapy for patients with glioblastoma (GBM) despite the fact that approximately half of treated patients have temozolomide resistance and all patients eventually fail therapy. Due to the limited efficacy of existing therapies, immunotherapy is being widely investigated for patients with GBM. However, initial immunotherapy trials in GBM patients have had disappointing results as monotherapy. Therefore, combinatorial treatment strategies are being investigated. Temozolomide has several effects on the immune system that are dependent on mode of delivery and the dosing strategy, which may have unpredicted effects on immunotherapy. Here we summarize the immune modulating role of temozolomide alone and in combination with immunotherapies such as dendritic cell vaccines, T-cell therapy, and immune checkpoint inhibitors for patients with GBM.

Modulator role of infliximab and methotrexate through the transient receptor potential melastatin 2 (TRPM2) channel in neutrophils of patients with rheumatoid arthritis: a pilot study

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic, systemic, inflammatory disease causing symmetric polyarthritis. In this study, we aimed to investigate the effects of infliximab (INF) and methotrexate (MTX) on apoptosis, oxidative stress, and calcium signaling in the neutrophils of RA patients.

MATERIAL AND METHODS

Neutrophils were isolated from 10 patients with newly diagnosed RA and 10 healthy controls. They were divided into four groups (control, RA, RA + MTX, RA + INF) and incubated with MTX and INF. In the cell viability (MTT) test, the ideal non-toxic dose and incubation time of MTX were found to be 0.1 mM and 1 h, respectively. The neutrophils were also incubated with the TRPM2 channel blocker N-(p-amylcinnamoyl) anthranilic acid (ACA).

RESULTS

Intracellular free Ca²⁺ concentration, intracellular reactive oxygen species (ROS) production, mitochondrial depolarization, lipid peroxidation, apoptosis, and caspase 3 and caspase 9 activities were found to be significantly higher in the neutrophils of RA patients compared to controls. MTT, reduced glutathione (GSH) level, and glutathione peroxidase (GSHPx) activity were significantly lower in the neutrophils of RA patients. However, MTT, GSH and GSHPx values were detected to be significantly increased with INF and MTX therapies. The Ca²⁺ concentrations were further decreased by the ACA therapy.

CONCLUSIONS

Our results suggest that INF and MTX are useful antagonists in apoptosis and mitochondrial oxidative stress in the neutrophils of RA patients. INF and MTX decreased the Ca²⁺ concentration through inhibition of the TRPM2 channel in the neutrophils of RA patients. It may be a new pathway in the mechanisms of anti-rheumatic drugs.

Safety and Activity of Metronomic Temozolomide in Second-Line Treatment of Advanced Neuroendocrine Neoplasms

Background. Platinum-based chemotherapy is the mainstay of front-line treatment of patients affected by pluri-metastatic intermediate/high grade NeuroEndocrine Neoplasms (NENs). However, there are no standard second-line treatments at disease progression. Previous clinical experiences have evidenced that temozolomide (TMZ), an oral analog of dacarbazine, is active against NENs at standard doses of 150 to 200 mg/mq per day on days 1 to 5 of a 28-day cycle, even if a significant treatment-related toxicity is reported. Methods. Metastatic NENs patients were treated at the ENETS (European NeuroEndocrine Tumor Society) center of excellence of Naples (Italy), from 2014 to 2017 with a second-line alternative metronomic schedule of TMZ, 75 mg/m²per os “one week on/one week off”. Toxicity was graded with NCI-CTC criteria v4.0; objective responses with RECIST v1.1 and performance status (PS) according to ECOG. Results. Twenty-six consecutive patients were treated. Median age was 65.5 years. The predominant primary organs were pancreas and lung. Grading was G2 in 11 patients, G3 in 15. More than half of patients had a PS 2 (15 vs. 11 with PS 1). The median time-on-temozolomide therapy was 12.2 months (95% CI: 11.4–19.6). No G3/G4 toxicities were registered. Complete response was obtained in 1 patient, partial response in 4, stable disease in 19 (disease control rate: 92.3%), and progressive disease in 2. The median overall survival from TMZ start was 28.3 months. PS improved in 73% of patients. Conclusions. Metronomic TMZ is a suitable treatment for G2 and G3 NENs particularly in PS 2 patients. Prospective and larger trials are needed to confirm these results.

Toll-like receptor-targeted particles: A paradigm to manipulate the tumor microenvironment for cancer immunotherapy

The expression of Toll-like receptors (TLRs) on antigen presenting cells, especially dendritic cells, offers several sensitive mediators to trigger an adaptive immune response, which potentially can be exploited to detect and eliminate pathogenic objects. Consequently, numerous agonists that target TLRs are being used clinically either alone or in combination with other therapies to strengthen the immune system in the battle against cancer. This review summarizes the roles of TLRs in tumor biology, and focuses on relevant TLR-dependent antitumor pathways and the conjugation of TLR agonists as adjuvants to nano- and micro-particles for boosting responses leading to cancer suppression and eradication. STATEMENT OF SIGNIFICANCE: Toll-like receptors (TLRs), which express on antigen presenting cells, such as dendritic cells and macrophages, play an important role in sensing pathogenic agents and inducing adaptive immunity. As a result, several TLR agonists have been investigating as therapeutic agents individually or in combination with other treatment modalities for cancer treatment through boosting the immune system. This review aims to focus on the roles of TLRs in cancer and TLR-dependent antitumor pathways as well as the use of different nano- or micro-particles bearing TLR agonists for tumor inhibition and elimination.

A peptide-modified solid lipid nanoparticle formulation of paclitaxel modulates immunity and outperforms dacarbazine in a murine melanoma model

Melanoma is a highly aggressive skin cancer. A paclitaxel formulation of solid lipid nanoparticles modified with Tyr-3-octreotide (PSM) is employed to treat melanoma that highly expresses somatostatin receptors (SSTRs). PSM exerts more apoptotic and anti-invasive effects in B16F10 mice melanoma cells as compared to dacarbazine (DTIC), an approved chemotherapeutic drug for treating aggressive melanoma. Besides, PSM induces one of the biomarkers of immunogenic cell death in vitro and in vivo as confirmed by calreticulin exposure on the B16F10 cell surface. We observed a significant number of CD8 positive T cells in the tumor bed of the PSM treated group. As a result, PSM effectively reduces tumor volume in vivo as compared to DTIC. PSM also induces a favorable systemic immune response as determined in the spleen and sera of the treated animals. Importantly, PSM can reduce the number of nodule formations in the experimental lung metastasis model. Our experimentations indicate that the metronomic PSM exhibits remarkable anti-melanoma activities without any observable toxicity. This immune modulation behavior of PSM can be exploited for the therapy of melanoma and probably for other malignancies.

CAR-T with License to Kill Solid Tumors in Search of a Winning Strategy

Artificial receptors designed for adoptive immune therapies need to absolve dual functions: antigen recognition and abilities to trigger the lytic machinery of reprogrammed effector T lymphocytes. In this way, CAR-T cells deliver their cytotoxic hit to cancer cells expressing targeted tumor antigens, bypassing the limitation of HLA-restricted antigen recognition. Expanding technologies have proposed a wide repertoire of soluble and cellular "immunological weapons" to kill tumor cells; they include monoclonal antibodies recognizing tumor associated antigens on tumor cells and immune cell checkpoint inhibition receptors expressed on tumor specific T cells. Moreover, a wide range of formidable chimeric antigen receptors diversely conceived to sustain quality, strength and duration of signals delivered by engineered T cells have been designed to specifically target tumor cells while minimize off-target toxicities. The latter immunological weapons have shown distinct efficacy and outstanding palmarès in curing leukemia, but limited and durable effects for solid tumors. General experience with checkpoint inhibitors and CAR-T cell immunotherapy has identified a series of variables, weaknesses and strengths, influencing the clinical outcome of the oncologic illness. These aspects will be shortly outlined with the intent of identifying the still "missing strategy" to combat epithelial cancers.

Augmenting the synergies of chemotherapy and immunotherapy through drug delivery

Despite the recent approvals of multiple cancer immunotherapies, low tumor immunogenicity and immunosuppressive tumor microenvironments prevent a large portion of patients from responding to these treatment modalities. Given the immunomodulatory and adjuvant effects of conventional chemotherapy as well as its widespread clinical use, the use of chemotherapy in combination with immunotherapy (so-called chemoimmunotherapy) is an attractive approach to potentiate the effects of immunotherapy in more patient populations. However, due to the limited extent of tumor accumulation, poorly controlled interactions with the immune system, and effects on systemic healthy tissues by chemotherapeutic drugs, the incorporation of anti-cancer agents into biomaterial-based structures, such as nanocarriers, is highly attractive to improve the safety and efficacy of chemoimmunotherapy. Herein, we review the recent progress in drug delivery systems (DDSs) for potentiating the immunomodulatory effects of chemotherapeutics in chemoimmunotherapy, which represent among the most promising next generation strategies for cancer treatment in the immunotherapy era. STATEMENT OF SIGNIFICANCE: Given the benefits of cancer immunotherapy in inducing durable, albeit low rates, of patient response, interest in the immunomodulatory and adjuvant effects of conventional chemotherapy has been re-invigorated. This review article discusses the recent progress towards understanding the synergies between these two treatment types, how they can be used in combination (so-called chemoimmunotherapy), and the potential for drug delivery systems to optimize their effects in translational settings.

Enhancing antitumor response by combining immune checkpoint inhibitors with chemotherapy in solid tumors

BACKGROUND

Cancer immunotherapy has changed the standard of care for a subgroup of patients with advanced disease. Immune checkpoint blockade (ICB) in particular has shown improved survival compared with previous standards of care for several tumor types. Although proven to be successful in more immunogenic tumors, ICB is still largely ineffective in patients with tumors that are not infiltrated by immune cells, the so-called cold tumors.

PATIENTS AND METHODS

This review describes the effects of different chemotherapeutic agents on the immune system and the potential value of these different types of chemotherapy as combination partners with ICB in patients with solid tumors. Both preclinical data and currently ongoing clinical trials were evaluated. In addition, we reviewed findings regarding different dosing schedules, including the effects of an induction phase and applying metronomic doses of chemotherapy.

RESULTS

Combining ICB with other treatment modalities may lead to improved immunological conditions in the tumor microenvironment and could thereby enhance the antitumor immune response, even in tumor types that are so far unresponsive to ICB monotherapy. Chemotherapy, that was originally thought to be solely immunosuppressive, can exert immunomodulatory effects which may be beneficial in combination with immunotherapy. Each chemotherapeutic drug impacts the tumor microenvironment differently, and in order to determine the most suitable combination partners for ICB it is crucial to understand these mechanisms.

CONCLUSION

Preclinical studies demonstrate that the majority of chemotherapeutic drugs has been shown to exert immunostimulatory effects, either by inhibiting immunosuppressive cells and/or activating effector cells, or by increasing immunogenicity and increasing T-cell infiltration. However, for certain chemotherapeutic agents timing, dose and sequence of administration of chemotherapeutic agents and ICB is important. Further studies should focus on determining the optimal drug combinations, sequence effects and optimal concentration-time profiles in representative preclinical models.

Crosstalk Between PD-1/PD-L1 Blockade and Its Combinatorial Therapies in Tumor Immune Microenvironment: A Focus on HNSCC

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide with a poor prognosis and high mortality. More than two-thirds of HNSCC patients still have no effective control of clinical progression, and the five-year survival rate is < 50%. Moreover, patients with platinum-refractory HNSCC have a median survival of < 6 months. The significant toxicity and low survival rates of current treatment strategies highlight the necessity for new treatment modalities. Recently, a large number of studies have demonstrated that programmed cell death protein-1 (PD-1) and its ligand, programmed cell death protein ligand-1 (PD-L1) play an essential role in tumor initiation and progression. PD-1/PD-L1 blockade has shown a desired and long-lasting therapeutic effect in the treatment of HNSCC and other malignancies. However, only a small number of patients with HNSCC can benefit from PD-1/PD-L1 blockade monotherapy, while the majority of patients do not respond. To overcome the unsatisfactory therapeutic effect of PD-1/PD-L1 blockade monotherapy, combining other treatment options for HNSCC (including chemotherapy, radiotherapy, targeted therapy, and immunotherapy) in the treatment scheme has become a commonly used strategy. Herein, the potential mechanisms underlying the crosstalk between PD-1/PD-L1 blockade and its combinatorial therapies for HNSCC were reviewed, and it is hoped that the improved understanding of the crosstalk process would provide further ideas for the design of a combinatorial regimen with a higher efficiency and response rate for the treatment of HNSCC and other malignancies.

Turning cold tumors into hot tumors: harnessing the potential of tumor immunity using nanoparticles

INTRODUCTION

Immune checkpoint inhibitors have considerably changed the landscape of oncology. However apart from world-acclaimed success stories limited to melanoma and lung cancer, many solid tumors failed to respond to immune checkpoint inhibitors due to limited immunogenicity, unfavorable tumor micro-environments (TME), lack of infiltrating T lymphocytes or increases in Tregs. Areas covered: Combinatorial strategies are foreseen as the future of immunotherapy and using cytotoxics or modulating agents is expected to boost the efficacy of immune checkpoint inhibitors. In this respect, nanoparticles displaying unique pharmacokinetic features such as tumor targeting properties, optimal payload delivery and long-lasting interferences with TME, are promising candidates for such combinations. This review covers the basis, expectancies, limits and pitfalls of future combination between nanoparticles and immune check point inhibitors. Expert opinion: Nanoparticles allow optimal delivery of variety of payloads in tumors while sparing healthy tissue, thus triggering immunogenic cell death. Depleting tumor stroma could further help immune cells and monoclonal antibodies to better circulate in the TME, plus immune-modulating properties of the charged cytotoxics. Finally, nanoparticles themselves present immunogenicity and antigenicity likely to boost immune response at the tumor level.

PD-L1 knockdown via hybrid micelle promotes paclitaxel induced Cancer-Immunity Cycle for melanoma treatment

The Cancer-Immunity Cycle is a series of anticancer immune responses initiated and allowed to proceed and expand iteratively. Paclitaxel (PTX) is a classic chemotherapeutic agent, which could induce immunogenic cell death (ICD) to trigger the Cancer-Immunity Cycle. However, the Cycle is severely impaired by tumor cell immunosuppression of host T cell antitumor activity through the programmed cell death receptor 1 (PD-1) and programmed cell death ligand 1 (PD-L1) (PD-1/PD-L1) immune checkpoint pathway. Here, we demonstrated that PTX mediated the Cancer-Immunity Cycle could be enhanced by PD-L1 knockdown (KD) and followed mTOR pathway inhibition in tumor cells. PD-L1 siRNA (siP) and the hydrophobic chemotherapy drug PTX were co-delivered with a rationally designed hybrid micelle (HM). We showed clear evidence that the HM-siP/PTX is capable of delivering siP and PTX simultaneously to the B16F10 cells both in vitro and in vivo. We demonstrated that HM-PTX/siP reduced the expression of PD-L1 and p-S6K (a marker of mTOR pathway activation) both in vitro and in melanoma-bearing mice and attenuated synergistically tumor growth by chemical toxicity, promoting cytotoxic T-cell immunity and suppressing the mTOR pathway.