Enhanced therapeutic anti-tumor immunity induced by co-administration of 5-fluorouracil and adenovirus expressing CD40 ligand

Immunogenic Cell Death Role in Urothelial Cancer Therapy

Purpose: Bladder cancer is the 13th most common cause of cancer death with the highest lifetime cost for treatment of all cancers. This scoping review clarifies the available evidence on the role of a novel therapeutic approach called immunogenic cell death (ICD) in urothelial cancer of the bladder. Methods: In accordance with the recommendations of the Joanna Briggs Institute, we searched MEDLINE (Ovid), EMBASE, CENTRAL databases, and supplemented with manual searches through the conferences, Google scholar, and clinicaltrials.gov for published studies up to April 2022. We included literature that studied molecular mechanisms of ICD and the role of certain danger-associated molecular patterns (DAMPs) in generating ICD, safety and efficacy of different ICD inducers, and their contributions in combination with other urothelial cancer treatments. Results: Oncolytic viruses, radiotherapy, certain chemo/chemo radiation therapy combinations, photodynamic therapy, and novel agents were studied as ICD-inducing treatment modalities in the included studies. ICD was observed in vitro (murine or human urothelial carcinoma) in ten studies, eight studies were performed on mouse models (orthotopic or subcutaneous), and five clinical trials assessed patient response to ICD inducing agents. The most common studied DAMPs were Calreticulin, HMGB1, ATP, and Heat Shock Proteins (HSP) 70 and 90, which were either expressed on the cancer cells or released. Conclusion: ICD inducers were able to generate lasting antitumor immune responses with memory formation in animal studies (vaccination effect). In clinical trials these agents generally had low side effects, except for one trial, and could be used alone or in combination with other cancer treatment strategies in urothelial cancer patients.

Oncolytic Adenoviruses for Cancer Therapy

Many immuno-therapeutic strategies are currently being developed to fight cancer. In this scenario, oncolytic adenoviruses (Onc.Ads) have an interesting role for their peculiar tumor selectivity, safety, and transgene-delivery capability. The major strength of the Onc.Ads is the extraordinary immunogenicity that leads to a strong T-cell response, which, together with the possibility of the delivery of a therapeutic transgene, could be more effective than current strategies. In this review, we travel in the adenovirus (Ads) and Onc.Ads world, focusing on a variety of strategies that can enhance Onc.Ads antitumoral efficacy, passing through tumor microenvironment modulation. Onc.Ads-based therapeutic strategies constitute additional weapons in the fight against cancer and appear to potentiate conventional and immune checkpoint inhibitors (ICIs)-based therapies leading to a promising scenario.

Raised CD40L expression attenuates drug resistance in Adriamycin-resistant THP-1 cells

Acute myeloid leukemia is a common hematological malignancy that often exhibits strong drug resistance when treated using conventional chemotherapy. Although numerous studies have been carried out to develop methods of overcoming drug resistance, the results have generally been unsatisfactory. CD40 ligand (CD40L) has been shown to improve the sensitivity of cancer cells to drug treatment. In the present study, Adriamycin (ADM)-resistant human monocytic THP-1 cells (THP-1/A cells) were developed by incubating THP-1 cells with increasing concentrations of ADM. Cells were transfected with CD40L vectors to explore the potential involvement of CD40L in regulating multidrug resistance (MDR) in cancer. Cell proliferation and viability were measured using the Cell Counting Kit-8 assay; cell apoptosis was evaluated by flow cytometry, trypan blue staining and caspase-3 activity; and the expression of MDR-associated protein 1 (MRP1) and permeability glycoprotein (P-gp) was analyzed using western blotting. The results revealed that the protein expression levels of MRP1 and P-gp were downregulated by raised CD40L expression and that the combination of raised CD40L expression with daunorubicin (DNR), a drug from which ADM is derived, significantly increased the extent of cell apoptosis, indicating that drug resistance was effectively attenuated by CD40L. Collectively, these results suggested that CD40L may contribute towards reducing DNR resistance in THP-1/A cells.

Design and application of oncolytic viruses for cancer immunotherapy

The approval of the first oncolytic virus (OV) for the treatment of metastatic melanoma and the recent discovery that the use of oncolytic viruses may enhance cancer immunotherapies targeted against various immune checkpoint proteins have attracted great interest in the field of cancer virotherapy. OVs are designed to target and kill cancer cells leaving normal cell unharmed. OV infection and concomitant cancer cell killing stimulate anti-tumour immunity and modulates tumour microenvironment towards less immunosuppressive phenotype. The intrinsic capacity of OVs to turn immunologically cold tumours into immunologically hot tumours, and to increase immune cell and cytokine infiltration, can be further enhanced by arming OVs with transgenes that increase their immunostimulatory activities and direct immune responses specifically towards cancer cells. These OVs, specifically engineered to be used as cancer immunotherapeutics, can be synergized with other immune modulators or cytotoxic agents to achieve the most potent immunotherapy for cancer.

The role of immune infiltrates as prognostic biomarkers in patients with breast cancer

The presence of immune infiltrates in the tumor microenvironment has been documented in many types of cancer. Moreover, the preexistent or endogenous immunity which consists of interactions between intratumoral lymphocytes and tumor cells is mostly relevant for the successful application of various anticancer therapies, including standard chemotherapy, immune checkpoint inhibition-based immunotherapy and targeted therapies. The immunoscore defines densities of intratumoral immune infiltrates which determine poor or favorable prognosis depending on their quantity and quality in the tumor compartments. Results from large clinical studies have demonstrated an association between high densities of cytotoxic and memory TILs in the tumor compartments with improved prognosis. Importantly, we have demonstrated that differential combined densities of immune infiltrates jointly analyzed in the tumor center (TC) and the invasive margin (IM) have a significant prognostic value in breast cancer patients with poor clinicopathological parameters.

IL-6 Signaling Blockade during CD40-Mediated Immune Activation Favors Antitumor Factors by Reducing TGF-β, Collagen Type I, and PD-L1/PD-1

IL-6 plays a role in cancer pathogenesis via its connection to proteins involved in the formation of desmoplastic stroma and to immunosuppression by driving differentiation of myeloid suppressor cells together with TGF-β. Inhibition of IL-6 signaling in the tumor microenvironment may, thus, limit desmoplasia and myeloid suppressor cell differentiation. CD40 signaling can further revert myeloid cell differentiation toward antitumor active phenotypes. Hence, the simultaneous use of IL-6 blockade with CD40 stimuli may tilt the tumor microenvironment to promote antitumor immune responses. In this paper, we evaluated the mechanisms of LOAd713, an oncolytic adenovirus designed to block IL-6R signaling and to provide myeloid cell activation via a trimerized membrane-bound isoleucine zipper (TMZ) CD40L. LOAd713-infected pancreatic cancer cells were killed by oncolysis, whereas infection of stellate cells reduced factors involved in stroma formation, including TGF-β-1 and collagen type I. Virus infection prevented IL-6/GM-CSF-mediated differentiation of myeloid suppressors, but not CD163 macrophages, whereas infection of dendritic cells led to upregulation of maturation markers, including CD83, CD86, IL-12p70, and IFN-γ. Further, IL-6R blockade prevented upregulation of programed death ligand 1 (PD-L1) and PD-1 on the stimulated dendritic cells. These results suggest that LOAd713 can kill infected tumor cells and has the capacity to affect the tumor microenvironment by stimulating stellate cells and myeloid suppressors with TMZ-CD40L and IL-6R blockade. Gene transfer of murine TMZ-CD40L prolonged survival in an animal model. LOAd713 may be an interesting therapeutic option for cancers connected to IL-6 signaling, such as pancreatic cancer.

Combination of calcineurin B subunit (CnB) and 5-fluorouracil reverses 5-fluorouracil-induced immunosuppressive effect and enhances the antitumor activity in hepatocellular carcinoma

Five-fluorouracil (5-FU) is a widely used chemotherapeutic agent for digestive system tumors; however, continuous use of 5-FU may cause severe side effects, including myelosuppression and immunosuppression. Our previous study revealed that calcineurin B subunit (CnB), an innovative genetic engineering antitumor protein, possesses tumor-suppressive effects with low toxicity. CnB can bind to and activate integrin αM on macrophages, subsequently promoting the expression, and secretion of TNF-related apoptosis-inducing ligand, a specific proapoptotic cytokine. In the present study, whether the combined use of CnB and 5-FU can reverse the myelosuppression, and immunosuppressive effects of 5-FU by reactivating the immune system thus increasing antitumor efficacy, was investigated. It was demonstrated that combined treatment of 5-FU and CnB led to increased tumor-suppressive effects, as indicated by reduced tumor volume and weight when compared with 5-FU or CnB treatment alone in a hepatoma xenograph model. In addition, it was demonstrated that combined treatment inhibited the proliferation of hepatoma cells. Notably, the addition of CnB to 5-FU-based therapy completely reversed the immunosuppressive effect of 5-FU. The spleen index and total number of white blood cells in the combination group were higher compared with that of the 5-FU alone group. Furthermore, pathological examinations indicated that CnB attenuated 5-FU-induced organ damage. Based on these findings, it is proposed that CnB may serve as a novel and promising drug candidate for the improvement of 5-FU-based chemotherapy.

CPA-7 influences immune profile and elicits anti-prostate cancer effects by inhibiting activated STAT3

BACKGROUND

Platinum-based chemotherapy is emerging as the first line of treatment for castration resistant prostate cancer. Among the family of platinum (IV)-based compounds, a member known as CPA-7 inhibits the growth of multiple cancer cell lines. However, how and to what extent CPA-7 elicits its anti-prostate cancer effects in vivo is largely unknown.

METHODS

In this study, we firstly assessed the potential toxicity of the synthesized CPA-7 in a prostate cancer model as well as in normal mice. Next, we evaluated the in vitro effects of CPA-7 on the growth of prostate cancer cells using cell counting assay, and calculated the tumor sizes and cumulative survival rate of the tumor bearing mice by Kaplan-Meier method during CPA-7 treatment. Then we measured the expression level of the activated form of STAT3 (one targets of CPA-7) and its transcriptive activity post CPA-7 treatment by synergistically using western blot, IHC, and firefly luciferase reporter assays. Finally, effects of CPA-7 on immune cell trafficking in the tumor draining lymph nodes and in the spleens are evaluated with flow cytometry.

RESULTS

Treatment with CPA-7 significantly inhibited growth of prostate cancer cells in vitro, and also in mice resulting in a prolonged survival and a decreased recurrence rate. These therapeutic effects are due, at least in part, to functional depletion of STAT3 in prostate tumor tissue as well as in the surrounding areas of tumor cell invasion. CPA-7 treatment also resulted in a reduced level of regulatory T cells and increased levels of cytotoxic T and T helper cells in the spleen and in tumor infiltrating lymph nodes. This favorable effect on immune cell trafficking may account for the amnestic immune response against recurrent prostate cancer.

CONCLUSIONS

CPA-7 is a promising new therapeutic agent for prostate cancer that both inhibits tumor cell proliferation and stimulates anti-tumor immunity. It has potential as first line treatment and/or as an adjuvant for refractory prostate cancer.

Chemotherapy and immunotherapy: mapping the road ahead

Cancer immunotherapy, and in particular checkpoint blockade, is now standard clinical care for a growing number of cancers. Cytotoxic drugs have been the primary weapon against cancer for a long time and have typically been understood because of their capacity to directly kill tumour cells. It is now clear that these drugs are potential partners for checkpoint blockade and different drugs can influence the immune response to cancer through a wide variety of mechanisms. Some of these relate to immunogenic cell death, whilst others relate to changes in antigen-presentation, tumour cell targeting, or depletion of immunosuppressive cells. Here, we review some recent advances in our understanding of the immunological changes associated with chemotherapy, discuss progress in combining chemotherapy with checkpoint blockade, and comment on the difficulties encountered in translating promising preclinical data into successful treatments for cancer patients.

Evidence for Oncolytic Virotherapy: Where Have We Got to and Where Are We Going?

The last few years have seen an increased interest in immunotherapy in the treatment of malignant disease. In particular, there has been significant enthusiasm for oncolytic virotherapy, with a large amount of pre-clinical data showing promise in animal models in a wide range of tumour types. How do we move forward into the clinical setting and translate something which has such potential into meaningful clinical outcomes? Here, we review how the field of oncolytic virotherapy has developed thus far and what the future may hold.

Antithymidylate resistance enables transgene selection and cell survival for T cells in the presence of 5-fluorouracil and antifolates

Antithymidylates (AThy) constitute a class of drugs used in the treatment of cancers such as lung, colon, breast and pancreas. These drugs inhibit DNA synthesis by targeting the enzymes dihydrofolate reductase (DHFR) and/or thymidylate synthase (TYMS). AThys effectively inhibit cancer cells, and also inhibit T cells, preventing anticancer immunity, which might otherwise develop from AThy-induced cancer destruction. We establish that T cells expressing mutant DHFR--DHFR L22F, F31S (DHFR(FS))--and/or mutant TYMS--TYMS T51S, G52S (TYMS(SS))-effectively survive in toxic concentrations of AThys methotrexate, pemetrexed and 5-fluorouracil. Furthermore, we show that DHFR(FS) permitted rapid selection of an inducible suicide transgene in T cells. These findings demonstrate that AThy resistances prevent AThy cytotoxicity to T cells while permitting selection of important transgenes. This technological development could enhance in vitro and in vivo survival and selection of T-cell therapeutics being designed for a broad range of cancers.

Role of CD154 in cancer pathogenesis and immunotherapy

Many factors and molecules have been investigated as potential players in the pathogenesis or immunosurveillance of cancer. Among these, CD154 has been recognized as a co-stimulatory molecule with high potential for treating cancer, in addition to its contribution in the development of the disease. CD154 was initially described for its pivotal role in T cell-dependent humoral responses via an interaction with its classical receptor, CD40. Subsequent studies showed that CD154 is also implicated in cell-mediated immunity and inflammation via an interaction with CD40 alone or in combination with newly identified receptors, members of the integrin family, leading to the development of chronic inflammatory and autoimmune diseases. In the current article, we present an overview of the role of CD154 as a potential etiological factor in tumors inducing proliferation of malignant cells, their rescue from apoptosis and their invasiveness. In addition, this review describes the immuno-regulatory functions of CD154 against cancer reflected by its stimulation of antigen-presenting cells and the subsequent activation of effector cells, its enhancement of malignant cells' immunogenicity, its modulation of immune settings around tumors, and its initiation of proliferation inhibiting effects in malignant cells. In vitro as well as in vivo studies are outlined and a particular attention is given to clinical studies and progress reached at this point. Findings reviewed herein will improve our knowledge of the role of the CD154 system in cancers from causative to immunotherapeutic functions, paving the way for the identification of new targets for prevention and/or treatment of malignant disorders.

Consensus guidelines for the detection of immunogenic cell death

Apoptotic cells have long been considered as intrinsically tolerogenic or unable to elicit immune responses specific for dead cell-associated antigens. However, multiple stimuli can trigger a functionally peculiar type of apoptotic demise that does not go unnoticed by the adaptive arm of the immune system, which we named "immunogenic cell death" (ICD). ICD is preceded or accompanied by the emission of a series of immunostimulatory damage-associated molecular patterns (DAMPs) in a precise spatiotemporal configuration. Several anticancer agents that have been successfully employed in the clinic for decades, including various chemotherapeutics and radiotherapy, can elicit ICD. Moreover, defects in the components that underlie the capacity of the immune system to perceive cell death as immunogenic negatively influence disease outcome among cancer patients treated with ICD inducers. Thus, ICD has profound clinical and therapeutic implications. Unfortunately, the gold-standard approach to detect ICD relies on vaccination experiments involving immunocompetent murine models and syngeneic cancer cells, an approach that is incompatible with large screening campaigns. Here, we outline strategies conceived to detect surrogate markers of ICD in vitro and to screen large chemical libraries for putative ICD inducers, based on a high-content, high-throughput platform that we recently developed. Such a platform allows for the detection of multiple DAMPs, like cell surface-exposed calreticulin, extracellular ATP and high mobility group box 1 (HMGB1), and/or the processes that underlie their emission, such as endoplasmic reticulum stress, autophagy and necrotic plasma membrane permeabilization. We surmise that this technology will facilitate the development of next-generation anticancer regimens, which kill malignant cells and simultaneously convert them into a cancer-specific therapeutic vaccine.