Mechanism of Action and Applications of Interleukin 24 in Immunotherapy

Association Between Circulating Inflammatory Cytokines and Dentofacial Anomalies

INTRODUCTION AND AIMS

Previous studies have shown that some inflammatory cytokines are associated with dentofacial anomalies (DA), but the causal relationship is unclear. Therefore, the present study aimed to elucidate the relationship between circulating inflammatory cytokines, and DA risk by Mendelian randomization analysis.

METHODS

A two-way two-sample Mendelian randomization analysis was used in our study. Data on 91 inflammatory cytokines were sourced from genome-wide association studies encompassing 14,824 participants across 11 distinct cohorts and protein quantitative trait loci from deCODE (35,559 participants). Summary statistics for DA were acquired from the FinnGen consortium (9254 cases and 245,664 controls). The inverse variance weighting method was used as the primary analysis, supplemented by a series of sensitivity analyses to determine the robustness and reliability of our findings.

RESULTS

The analysis identified five cytokines - chemokine ligand 25, interleukin (IL)-10 receptor beta, IL-20, and stem cell factor - as inversely related to DA prevalence. Additionally, DA was associated with decreased levels of fibroblast growth factor (FGF)-19 and IL-24, and increased levels of FGF-23 and urokinase-type plasminogen activator. These findings were validated using protein quantitative trait loci data.

CONCLUSION

Our study substantiates an association between inflammatory cytokines and DA, emphasizing inflammation's pivotal role in the aetiology of DA.

CLINICAL SIGNIFICANCE

The findings provide a plausible genetic underpinning for the role of inflammation in DA, offering novel avenues for the development of targeted diagnostic and therapeutic strategies.

Serum level of interleukin-24 and its polymorphism in eczematic Iraqi patients

Eczema is a common skin disease associated with inflammation. Interleukin (IL)-24 is crucial in the pathogenesis of inflammatory diseases like eczema. The study objective was the assessment of IL-24 serum levels and its gene polymorphisms in eczematic Iraqi patients. This retrospective case-control study involved 145 participants, divided into 82 patients with eczema and 63 healthy controls. An enzyme-linked immunosorbent assay measured serum IL-24, while polymerase chain reaction and Sanger DNA sequencing were used for genotype analysis. Serum IL-24 level was significantly higher (P value < .001) in patients compared to controls (41.6 [interquartile range (IQR): 28.9-53.6] vs 9.8 [IQR: 0.8-19.6] pg/mL, respectively). DNA sequence illustrated 2 SNPs with polymorphic frequencies (rs1150256 G/A and rs3093425 del/ins). The first SNP (rs1150256 G/A) showed 3 genotypes (GG, AA, and G/A), while the second SNP (rs3093425) showed 3 genotypes (-/G del/Ins, G Ins/Ins, and - del/del). The subsequent investigation revealed the presence of the following findings within the DNA sequence of the PCR amplified region (329bp). In the control group, all participants had GG/G (wild type) genotype/allele for the rs1150256 SNP, while in eczematic patients, 24.4% GG, 50% GA, and 25.6% AA. For the second SNP genotype (rs3093425 del/ins), the genotype frequencies in patients vs control were (24.4% vs 84.1%, 50.0% vs 11.1%, and 25.6% vs 4.8; Del/Del, Del/Ins, and Ins/Ins, respectively). The presence of Ins compared to Del increased the risk of eczema by 8.91 (4.66-17.03); OR (95% CI). In conclusion, IL-24 is a good predictor of eczema and A-allele carrier for rs1150256 SNP, and insertion-allele carrier for rs3093425 SNP is associated with elevated serum IL-24 and higher risk of eczema.

iPSC-derived NK cells with site-specific integration of CAR19 and IL24 at the multi-copy rDNA locus enhanced antitumor activity and proliferation

The generation of chimeric antigen receptor-modified natural killer (CAR-NK) cells using induced pluripotent stem cells (iPSCs) has emerged as one of the paradigms for manufacturing off-the-shelf universal immunotherapy. However, there are still some challenges in enhancing the potency, safety, and multiple actions of CAR-NK cells. Here, iPSCs were site-specifically integrated at the ribosomal DNA (rDNA) locus with interleukin 24 (IL24) and CD19-specific chimeric antigen receptor (CAR19), and successfully differentiated into iPSC-derived NK (iNK) cells, followed by expansion using magnetic beads in vitro. Compared with the CAR19-iNK cells, IL24 armored CAR19-iNK (CAR19-IL24-iNK) cells showed higher cytotoxic capacity and amplification ability in vitro and inhibited tumor progression more effectively with better survival in a B-cell acute lymphoblastic leukaemia (B-ALL) (Nalm-6 (Luc1))-bearing mouse model. Interestingly, RNA-sequencing analysis showed that IL24 may enhance iNK cell function through nuclear factor kappa B (NFκB) pathway-related genes while exerting a direct effect on tumor cells. This study proved the feasibility and potential of combining IL24 with CAR-iNK cell therapy, suggesting a novel and promising off-the-shelf immunotherapy strategy.

Exploration of the causal associations between circulating inflammatory proteins, immune cells, and neuromyelitis optica spectrum disorder: a bidirectional Mendelian randomization study and mediation analysis

Background

An increasing body of research has demonstrated a robust correlation between circulating inflammatory proteins and neuromyelitis optica spectrum disorders (NMOSD). However, whether this association is causal or whether immune cells act as mediators currently remains unclear.

Methods

We employed bidirectional two-sample Mendelian randomization (TSMR) analysis to examine the potential causal association between circulating inflammatory proteins, immune cells, and NMOSD using data from genome-wide association studies (GWAS). Five different methods for Mendelian randomization analyses were applied, with the inverse variance-weighted (IVW) method being the primary approach. Sensitivity analyses were further performed to assess the presence of horizontal pleiotropy and heterogeneity in the results. Finally, a two-step Mendelian randomization (MR) design was employed to examine the potential mediating effects of immune cells.

Results

A notable causal relationship was observed between three circulating inflammatory proteins (CSF-1, IL-24, and TNFRSF9) and genetically predicted NMOSD. Furthermore, two immune cell phenotypes, genetically predicted CD8 on naive CD8+ T cells, and Hematopoietic Stem Cell Absolute Count were negatively and positively associated with genetically predicted NMOSD, respectively, although they did not appear to function as mediators.

Conclusion

Circulating inflammatory proteins and immune cells are causally associated with NMOSD. Immune cells do not appear to mediate the pathway linking circulating inflammatory proteins to NMOSD.

Spinal interleukin-24 contributes to neuropathic pain after peripheral nerve injury through interleukin-20 receptor2 in mice

Neuroinflammation is critically involved in nerve injury-induced neuropathic pain, characterized by local and systemic increased levels of proinflammatory cytokines. Interleukin-24 (IL-24), a key member of the IL-10 family, has been extensively studied for its therapeutic potential in various diseases, including cancer, autoimmune disorders, and bacterial infections, but whether it is involved in the regulation of neuropathic pain caused by peripheral nerve injury (PNI) has not been well established. In this study, we reported that spared nerve injury (SNI) induced a significant upregulation of IL-24 in fibroblasts, neurons, and oligodendrocyte precursor cells (OPCs, also called NG2-glia) in the affected spinal dorsal horns (SDHs), as well as dorsal root ganglions (DRGs). We also found that tumor necrosis factor α (TNF-α) induced the transcriptional expression of IL-24 in cultured fibroblasts, neurons, and NG2-glia; in addition, astrocytes, microglia, and NG2-glia treated with TNF-α exhibited a prominent increase in interleukin-20 receptor 2 (IL-20R2) expression. Furthermore, we evaluated the ability of IL-24 and IL-20R2 to attenuate pain in preclinical models of neuropathic pain. Intrathecal (i.t.) injection of IL-24 neutralizing antibody or IL-20R2 neutralizing antibody could effectively alleviate mechanical allodynia and thermal hyperalgesia after PNI. Similarly, intrathecal injection of IL-24 siRNA or IL-20R2 siRNA also alleviated mechanical allodynia after SNI. The inhibition of IL-24 reduced SNI-induced proinflammatory cytokine (IL-1β and TNF-α) production and increased anti-inflammatory cytokine (IL-10) production. Meanwhile, the inhibition of IL-20R2 also decreased IL-1β mRNA expression after SNI. Collectively, our findings revealed that IL-24/IL-20R might contribute to neuropathic pain through inflammatory response. Therefore, targeting IL-24 could be a promising strategy for treating neuropathic pain induced by PNI.

The investigation of the death-inducing potency of a recombinant Adenovector expressing Mda-7-tlyp-1 on different cancer cell lines

Aim

The potency of Adenovector expressing Mda7-tLyp1 (Ad-Mda7-tLyp1) for death induction was evaluated on the breast (MCF7), liver (HepG2), and gastric (MKN45) cancer cell lines.

Background

Mda-7 could be a possible complementary to traditional cancer therapy, and tethering to tumor-homing peptides (THPs) might improve its therapeutic efficacy.

Methods

After the preparation of recombinant Ad-Mda7-tLyp1 and Ad-Mda7, the expression of recombinant proteins was analyzed by ELISA. Adenovectors were transduced (MOI=2-5) into Hep-G2, MCF7, MKN45, and normal skin fibroblast, then tumor-killing effect was measured by cytopathic effect (CPE) monitoring, MTT viability test, BAX gene expression analysis, and Caspase3/7 assay.

Results

ELISA assay revealed a sustained level of recombinant protein secretion following Adenovector transduction. In CPE microscopy, all cancer cell lines showed a significant reduction (≥50%) in their normal phenotype after receiving Ad-Mda7-tLyp1 and Ad-Mda7. The viability was significantly lower compared to the control, indicating an anti-proliferating effect. In parallel, the viability test showed that Ad-Mda7 and Ad-Mda7-tLyp1 have a significant killing effect (≥50%) on MCF-7, Hep-G2, and MKN45 compared to normal fibroblast (P≤0.05). BAX gene expression analysis showed that both Ad-Mda7-tLyp1 and Ad-Mda7 vectors induced >2-fold increase of apoptosis (P<0.05), particularly in MCF7. Similarly, caspase3/7 activity showed a significant increase (P<0.05) following Ad-Mda7, and Ad-Mda7-tLyp1 transduction into cancer cell lines, but not in normal fibroblasts.

Conclusion

The newly constructed Ad-Mda-tlyp1 showed a suitable tumor cell killing activity and enough specificity on studied cell lines.

Unlocking the Potential of Immunotherapy in Cardiovascular Disease: A Comprehensive Review of Applications and Future Directions

Immunotherapy has emerged as a pioneering therapeutic approach that harnesses the immune system's abilities to combat diseases, particularly in the field of oncology where it has led to significant advancements. However, despite its significant impact in the field of oncology, the potential of immunotherapy in the context of cardiovascular disease (CVD) has not been thoroughly investigated. The purpose of this narrative review is to address the existing knowledge and potential uses of immunotherapy in the field of cardiovascular disease (CVD), with the intention of filling the existing gap in understanding. Furthermore, the review thoroughly examines the future prospects of this swiftly advancing field, providing insights into the aspects that necessitate further investigation and addressing the forthcoming challenges. The review is organized into four distinct sections to enhance comprehension. The first section introduces immunotherapy, presenting the fundamental concepts and principles. The second section explores the immunomodulatory mechanisms in cardiovascular disease (CVD), with a specific focus on the intricate interplay between the immune system and the development of cardiovascular pathogenesis. The utilization of immunotherapy in specific cardiovascular conditions will be examined, investigating the application of immunotherapy in the context of different cardiovascular diseases. The future prospects and challenges in immunotherapy for cardiovascular diseases will be discussed, highlighting the potential areas for future research and addressing the barriers that must be overcome to effectively implement immunotherapeutic interventions in the management of cardiovascular diseases.

Does Vitamin K2 Influence the Interplay between Diabetes Mellitus and Intervertebral Disc Degeneration in a Rat Model?

Intervertebral disc (IVD) degeneration is a common cause of low back pain in diabetes mellitus type 2 (T2DM) patients. Its pathogenesis and the vitamin (vit.) K2 influence on this disease remain unclear. Lumbar motion segments of male Zucker Diabetes Fatty (ZDF) rats (non-diabetic [control] and diabetic; fed without or with vit. K2) were used. Femur lengths and vertebral epiphyseal cross-section areas were measured. IVDs were histopathologically examined. Protein synthesis and gene expression of isolated IVD fibrochondrocytes were analyzed. T2DM rats showed histopathological IVD degeneration. Femur lengths and epiphyseal areas were smaller in T2DM rats regardless of vit. K2 feeding. Fibrochondrocytes synthesized interleukin (IL)-24 and IL-10 with no major differences between groups. Alpha smooth muscle actin (αSMA) was strongly expressed, especially in cells of vit. K2-treated animals. Gene expression of aggrecan was low, and that of collagen type 2 was high in IVD cells of diabetic animals, whether treated with vit. K2 or not. Suppressor of cytokine signaling (Socs)3 and heme oxygenase (Hmox)1 gene expression was highest in the cells of diabetic animals treated with vit. K2. Vit. K2 influenced the expression of some stress-associated markers in IVD cells of diabetic rats, but not that of IL-10 and IL-24.

Interleukin-24-mediated antitumor effects against human glioblastoma via upregulation of P38 MAPK and endogenous TRAIL-induced apoptosis and LC3-II activation-dependent autophagy

BACKGROUND

Melanoma differentiation-associated gene 7 (Mda-7) encodes IL-24, which can induce apoptosis in cancer cells. A novel gene therapy approach to treat deadly brain tumors, recombinant mda-7 adenovirus (Ad/mda-7) efficiently kills glioma cells. In this study, we investigated the factors affecting cell survival and apoptosis and autophagy mechanisms that destroy glioma cells by Ad/IL-24.

METHODS

Human glioblastoma U87 cell line was exposed to a multiplicity of infections of Ad/IL-24. Antitumor activities of Ad/IL-24 were assessed by cell proliferation (MTT) and lactate dehydrogenase (LDH) release analysis. Using flow cytometry, cell cycle arrest and apoptosis were investigated. Using the ELISA method, the tumor necrosis factor (TNF-α) level was determined as an apoptosis-promoting factor and Survivin level as an anti-apoptotic factor. The expression levels of TNF-related apoptosis inducing ligand(TRAIL) and P38 MAPK genes were assessed by the Reverse transcription-quantitative polymerase chain reaction(RT‑qPCR) method. The expression levels of caspase-3 and protein light chain 3-II (LC3-II) proteins were analyzed by flow cytometry as intervening factors in the processes of apoptosis and autophagy in the cell death signaling pathway, respectively.

RESULTS

The present findings demonstrated that transduction of IL-24 inhibited cell proliferation and induced cell cycle arrest and cell apoptosis in glioblastoma. Compared with cells of the control groups, Ad/IL24-infected U87 cells exhibited significantly increased elevated caspase-3, and TNF-α levels, while the survivin expression was decreased. TRAIL was shown to be upregulated in tumor cells after Ad/IL-24 infection and studies of the apoptotic cascade regulators indicate that Ad/IL-24 could further enhance the activation of apoptosis through the TNF family of death receptors. In the current study, we demonstrate that P38 MAPK is significantly activated by IL-24 expression. In addition, the overexpression of mda-7/IL-24 in GBM cells induced autophagy, which was triggered by the upregulation of LC3-II.

CONCLUSIONS

Our study demonstrates the antitumor effect of IL-24 on glioblastoma and may be a promising therapeutic approach for GBM cancer gene therapy.

Diffusing Alpha-Emitters Radiation Therapy Promotes a Proimmunogenic Tumor Microenvironment and Synergizes With Programmed Cell Death Protein 1 Blockade

PURPOSE

Diffusing alpha-emitters Radiation Therapy (DaRT) releases alpha-emitting atoms into the tumor microenvironment. The treatment effectively ablates human and mice xenografts and shows 100% response rates in skin or head and neck squamous cell carcinoma patients. DaRT induces specific and systemic antitumor immune activation and synergizes with immune stimulation and modulation in mice. Here, the transcriptional profile activated by DaRT, and its potential to enhance responsiveness to immune checkpoint inhibition by programmed cell death protein 1 (PD-1) blockade were studied.

METHODS AND MATERIALS

Squamous cell carcinoma tumor- bearing BALB/C mice were treated with DaRT or inert seeds in combination with anti-PD-1 (aPD-1) or IgG control antibody. Sixteen days after seed insertion, tumors and spleens were subjected to immunophenotyping and immunohistochemical staining. Combination of DaRT and aPD-1 was tested for efficacy. Gene expression analysis was performed on mRNA extracted from tumors 7 days after DaRT or inert insertion using Nanostring PanCancer-IO-360 panel, and tumors and spleens were subjected to flow cytometry analysis.

RESULTS

DaRT in combination with aPD-1 delayed tumor development, induced CD3 and CD8 lymphocytes infiltration more efficiently than either monotherapy. The combined treatment reduced splenic polymorphonuclear myeloid derived suppressor cells more than aPD-1 therapy or control. Granzyme B release in the tumor was increased only in the combinational treatment and was correlated with T-lymphocyte infiltration. Gene expression and gene set enrichment analysis of mRNA levels 7 days after DaRT insertion indicated that DaRT upregulated apoptosis, p53 signaling, G1/S-related arrest, interferon signaling and myeloid related transcription, while downregulating DNA repair, cell proliferation, and notch-related transcription. Flow cytometry showed that DaRT increased dendritic cells activation and led to changes in MDSCs distribution.

CONCLUSIONS

DaRT promotes a "hot" tumor microenvironment and changes in immune suppression that lead to a potentiation of aPD-1 blockade induced effector T cell function and improved treatment efficacy. This study provides rationale for investigating DaRT and aPD-1 combination in patients with squamous cell carcinoma.

Have Therapeutics Enhanced Our Knowledge of Axial Spondyloarthritis?

PURPOSE OF REVIEW

An overview of how the treatment landscape of axial spondyloarthritis (axSpA) has shaped our understanding of the disease.

RECENT FINDINGS

Prior to the millennium, non-steroidal anti-inflammatory drugs (NSAIDs) were the only treatment for axSpA, yet only 30% of patients responded and many developed side effects. In 2003, the first biological disease-modifying drug (bDMARD) was licensed for axSpA which substantially improved outcomes in comparison to NSAIDs. In 2022, there are now several bDMARDs for axSpA; however, they too are not universally efficacious in treating axial inflammation and may have deleterious effects on extramusculoskeletal manifestations. Nevertheless, successful or not, each bDMARD gives invaluable insight into axSpA immunobiology. This review discusses how much we have learned from the use of bDMARDs in axSpA, how this has redefined our understanding of the disease, and how we might use this knowledge to develop new and better treatments for axSpA in the future.

Concomitant inhibition of PPARγ and mTORC1 induces the differentiation of human monocytes into highly immunogenic dendritic cells

Monocytes can differentiate into macrophages (Mo-Macs) or dendritic cells (Mo-DCs). The cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) induces the differentiation of monocytes into Mo-Macs, while the combination of GM-CSF/interleukin (IL)-4 is widely used to generate Mo-DCs for clinical applications and to study human DC biology. Here, we report that pharmacological inhibition of the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) in the presence of GM-CSF and the absence of IL-4 induces monocyte differentiation into Mo-DCs. Remarkably, we find that simultaneous inhibition of PPARγ and the nutrient sensor mammalian target of rapamycin complex 1 (mTORC1) induces the differentiation of Mo-DCs with stronger phenotypic stability, superior immunogenicity, and a transcriptional profile characterized by a strong type I interferon (IFN) signature, a lower expression of a large set of tolerogenic genes, and the differential expression of several transcription factors compared with GM-CSF/IL-4 Mo-DCs. Our findings uncover a pathway that tailors Mo-DC differentiation with potential implications in the fields of DC vaccination and cancer immunotherapy.

Ferroptosis as a Potential Cell Death Mechanism Against Cisplatin-Resistant Lung Cancer Cell Line

Purpose: Drug resistance is a challenging issue in cancer chemotherapy. Cell death induction is one of the main strategies to overcome chemotherapy resistance. Notably, ferroptosis has been considered a critical cell death mechanism in recent years. Accordingly, in this study, the different cell death strategies focused on ferroptosis have been utilized to overcome cisplatin resistance in an in vitro lung cancer model. Methods: The physiological functions of Akt1 and GPX4, as critical targets for ferroptosis and apoptosis induction, were suppressed by siRNA or antagonistic agents in resistant A549 cells. Afterward, the interventions' impacts on cell viability and reactive oxygen species (ROS) amount were analyzed by flow cytometry. Moreover, the alteration in the relevant gene and protein expression levels were quantified using Real-time PCR and western blot methods. Results: The result showed that the treatment with Akt1 siRNA reversed the cisplatin resistance in the A549 cell line through the induction of apoptosis. Likewise, the combination treatment of the GPX4 siRNA or FIN56 as ferroptosis inducers alongside cisplatin elevated ROS's cellular level, reduced the cellular antioxidant genes level and increased the cisplatin cytotoxic effect. Conclusion: In conclusion, our study indicated that ferroptosis induction can be considered a promising cell death strategy in cisplatin-resistant cancer cells.

Interleukin 24 promotes cell death in renal epithelial cells and is associated with acute renal injury

Ischemia-reperfusion injury is a major cause of acute kidney injury. Many cytokines are involved in the pathogenesis of renal ischemia-reperfusion injury. IL24 is a member of the IL10 family and has gained importance because of its apoptosis-inducing effects in tumor disease besides its immunoregulative function. Littles is known about the role of IL24 in kidney disease. Using a mouse model, we found that IL24 is upregulated in the kidney after renal ischemia-reperfusion injury and that tubular epithelial cells and infiltrating inflammatory cells are the source of IL24. Mice lacking IL24 are protected from renal injury and inflammation. Cell culture studies showed that IL24 induces apoptosis in renal tubular epithelial cells, which is accompanied by an increased endoplasmatic reticulum stress response. Moreover, IL24 induces robust expression of endogenous IL24 in tubular cells, fostering ER-stress and apoptosis. In kidney transplant recipients with delayed graft function and patients at high risk to develop acute kidney injury after cardiac surgery IL24 is upregulated in the kidney and serum. Taken together, IL24 can serve as a biomarker, plays an important mechanistic role involving both extracellular and intracellular targets, and is a promising therapeutic target in patients at risk of or with ischemia-induced acute kidney injury.

IL-37 protects against airway remodeling by reversing bronchial epithelial-mesenchymal transition via IL-24 signaling pathway in chronic asthma

BACKGROUND

Epithelial-mesenchymal transition (EMT) is one of the mechanisms of airway remodeling in chronic asthma. Interleukin (IL)-24 has been implicated in the promotion of tissue fibrosis, and increased IL-24 levels have been observed in the nasal secretions and sputum of asthmatic patients. However, the role of IL-24 in asthmatic airway remodeling, especially in EMT, remains largely unknown. We aimed to explore the effect and mechanism of IL-24 on EMT and to verify whether IL-37 could alleviate IL-24-induced EMT in chronic asthma.

METHODS

BEAS-2B cells were exposed to IL-24, and cell migration was assessed by wound healing and Transwell assays. The expression of EMT-related biomarkers (E-cadherin, vimentin, and α-SMA) was evaluated after the cells were stimulated with IL-24 with or without IL-37. A murine asthma model was established by intranasal administration of house dust mite (HDM) extracts for 5 weeks, and the effects of IL-24 and IL-37 on EMT and airway remodeling were investigated by intranasal administration of si-IL-24 and rhIL-37.

RESULTS

We observed that IL-24 significantly enhanced the migration of BEAS-2B cells in vitro. IL-24 promoted the expression of the EMT biomarkers vimentin and α-SMA via the STAT3 and ERK1/2 pathways. In addition, we found that IL-37 partially reversed IL-24-induced EMT in BEAS-2B cells by blocking the ERK1/2 and STAT3 pathways. Similarly, the in vivo results showed that IL-24 was overexpressed in the airway epithelium of an HDM-induced chronic asthma model, and IL-24 silencing or IL-37 treatment could reverse EMT biomarker expression.

CONCLUSIONS

Overall, these findings indicated that IL-37 mitigated HDM-induced airway remodeling by inhibiting IL-24-mediated EMT via the ERK1/2 and STAT3 pathways, thereby providing experimental evidence for IL-24 as a novel therapeutic target and IL-37 as a promising agent for treating severe asthma.

Role of Interleukins and New Perspectives in Mechanisms of Resistance to Chemotherapy in Gastric Cancer

Gastric cancer (GC) is the fourth most common cancer in the world in terms of incidence and second in terms of mortality. Chemotherapy is the main treatment for GC. The greatest challenge and major cause of GC treatment failure is resistance to chemotherapy. As such, research is ongoing into molecular evaluation, investigating mechanisms, and screening therapeutic targets. Several mechanisms related to both the tumor cells and the tumor microenvironment (TME) are involved in resistance to chemotherapy. TME promotes the secretion of various inflammatory cytokines. Recent studies have revealed that inflammatory cytokines affect not only tumor growth, but also chemoresistance. Cytokines in TME can be detected in blood circulation and TME cells. Inflammatory cytokines could serve as potential biomarkers in the assessment of chemoresistance and influence the management of therapeutics in GC. This review presents recent data concerning research on inflammatory cytokines involved in the mechanisms of chemoresistance and provides new clues in GC treatment.

The roles and therapeutic applications of cytokines in endometrial cancer

Endometrial cancer (EC) is a common gynecological cancer globally and the most frequent gynecologic malignancy in industrialized countries. Patients are typically diagnosed when the disease is still restricted to the uterus. 5-year overall survival ranges from 70 % to 90 % in patients without metastatic disease; however, the metastatic form of the disease affects 16 % of EC patients, with a 5-year survival rate of 16.8 %. The immune system can detect abnormal cells as non-self in the early stages of carcinogenesis, producing the appropriate pro-inflammatory environment to eliminate cancer cells. In a second phase, cancer cells use various immune-editing systems to alter the profile of the immune response from pro to anti-inflammatory, resulting in immune escape. The directors of this immune switching mechanism are cytokines. Studies have reported the increased expression of several pro-and anti-inflammatory cytokines in EC tissues and cell lines, including Interleukin (IL)- 6, IL-8, IL-31, IL-33, IL-10, TGF-β, VEGF, and IL-1Ra. Immune cells producing these cytokines have also been reported to be present in EC tissues. Therefore, in this study, we aimed to show the possible mechanisms of the mentioned cytokines on EC progression, as well as the most current and prospective advancements in cytokine-based therapeutic applications.

Pulmonary inflammation and cellular responses following exposure to benzalkonium chloride: Potential impact of disrupted pulmonary surfactant homeostasis

Benzalkonium chloride (BKC) is a prototypical quaternary ammonium disinfectant. Previously, we suggested a no lethal dose level (0.005%) and an LD50 range (0.5-0.05%) of BKC following a single pharyngeal aspiration. Herein, we exposed BKC repeatedly by pharyngeal aspiration for 14 days (0.005 and 0.01%, female mice, total five times with interval of two days, 5 mice/group) and 28 days (0, 0.001, 0.005, and 0.01%, male and female mice, weekly, 16 mice/sex/group). Death following 14 days-repeated exposure did not occur. Meanwhile, chronic pathological lesions were observed in the lung tissues of mice exposed to BKC for 28 days. The total number of bronchial alveolar lavage cells increased, and pulmonary homeostasis of immunologic messenger molecules was disturbed. Following, we investigated BKC-induced cellular responses using human bronchial epithelial cells. The cytotoxicity increased rapidly with concentration. Lysosomal volume, NO production, and lipid peroxidation increased in BKC-treated cells, whereas intracellular ROS level decreased accompanying structural and functional damage of mitochondria. We also found that BKC affected the expression level of immune response, DNA damage, and amino acid biosynthesis-related molecules. More interestingly, lamellar body- and autophagosome-like structures were notably observed in cells exposed to BKC, and necrotic and apoptotic cell death were identified accompanying cell accumulation in the G2/M phase. Therefore, we suggest that repeated respiratory exposure of BKC causes pulmonary inflammation and lung tissue damage and that dead and damaged cells may contribute to the inflammatory response. In addition, the formation process of lamellar body-like structures may function as a key toxicity mechanism.

Biological Role, Mechanism of Action and the Importance of Interleukins in Kidney Diseases

Each year, the number of patients who are diagnosed with kidney disease too late is increasing, which leads to permanent renal failure. This growing problem affects people of every age, sex and origin, and its full etiopathogenesis is not fully understood, although the involvement of genetic susceptibility, infections, immune disorders or high blood pressure is suggested. Difficulties in making a correct and quick diagnosis are caused by the lack of research on early molecular markers, as well as educational and preventive activities among the public, which leads to the late detection of kidney diseases. An important role in the homeostasis and disease progression, including kidney diseases, is attributed to interleukins, which perform several biological functions and interact with other cells and tissues of the body. The aim of this article was to systematize the knowledge about the biological functions performed by interleukins in humans and their involvement in kidney diseases development. In our work, we took into account the role of interleukins in acute and chronic kidney disease and kidney transplantation.

Insights into the Mechanisms of Action of MDA-7/IL-24: A Ubiquitous Cancer-Suppressing Protein

Melanoma differentiation associated gene-7/interleukin-24 (MDA-7/IL-24), a secreted protein of the IL-10 family, was first identified more than two decades ago as a novel gene differentially expressed in terminally differentiating human metastatic melanoma cells. MDA-7/IL-24 functions as a potent tumor suppressor exerting a diverse array of functions including the inhibition of tumor growth, invasion, angiogenesis, and metastasis, and induction of potent "bystander" antitumor activity and synergy with conventional cancer therapeutics. MDA-7/IL-24 induces cancer-specific cell death through apoptosis or toxic autophagy, which was initially established in vitro and in preclinical animal models in vivo and later in a Phase I clinical trial in patients with advanced cancers. This review summarizes the history and our current understanding of the molecular/biological mechanisms of MDA-7/IL-24 action rendering it a potent cancer suppressor.

JAK2-STAT Epigenetically Regulates Tolerized Genes in Monocytes in the First Encounter With Gram-Negative Bacterial Endotoxins in Sepsis

Microbial challenges, such as widespread bacterial infection in sepsis, induce endotoxin tolerance, a state of hyporesponsiveness to subsequent infections. The participation of DNA methylation in this process is poorly known. In this study, we perform integrated analysis of DNA methylation and transcriptional changes following in vitro exposure to gram-negative bacterial lipopolysaccharide, together with analysis of ex vivo monocytes from septic patients. We identify TET2-mediated demethylation and transcriptional activation of inflammation-related genes that is specific to toll-like receptor stimulation. Changes also involve phosphorylation of STAT1, STAT3 and STAT5, elements of the JAK2 pathway. JAK2 pathway inhibition impairs the activation of tolerized genes on the first encounter with lipopolysaccharide. We then confirm the implication of the JAK2-STAT pathway in the aberrant DNA methylome of patients with sepsis caused by gram-negative bacteria. Finally, JAK2 inhibition in monocytes partially recapitulates the expression changes produced in the immunosuppressive cellular state acquired by monocytes from gram-negative sepsis, as described by single cell-RNA-sequencing. Our study evidences both the crucial role the JAK2-STAT pathway in epigenetic regulation and initial response of the tolerized genes to gram-negative bacterial endotoxins and provides a pharmacological target to prevent exacerbated responses.

Transcriptome sequencing and multi-plex imaging of prostate cancer microenvironment reveals a dominant role for monocytic cells in progression

BACKGROUND

Prostate cancer is caused by genomic aberrations in normal epithelial cells, however clinical translation of findings from analyses of cancer cells alone has been very limited. A deeper understanding of the tumour microenvironment is needed to identify the key drivers of disease progression and reveal novel therapeutic opportunities.

RESULTS

In this study, the experimental enrichment of selected cell-types, the development of a Bayesian inference model for continuous differential transcript abundance, and multiplex immunohistochemistry permitted us to define the transcriptional landscape of the prostate cancer microenvironment along the disease progression axis. An important role of monocytes and macrophages in prostate cancer progression and disease recurrence was uncovered, supported by both transcriptional landscape findings and by differential tissue composition analyses. These findings were corroborated and validated by spatial analyses at the single-cell level using multiplex immunohistochemistry.

CONCLUSIONS

This study advances our knowledge concerning the role of monocyte-derived recruitment in primary prostate cancer, and supports their key role in disease progression, patient survival and prostate microenvironment immune modulation.

The clinical significance of interleukin 24 and its potential molecular mechanism in laryngeal squamous cell carcinoma

Interleukin 24 (IL24) has been documented to be highly expressed in several cancers, but its role in laryngeal squamous cell carcinoma (LSCC) remains unclarified. In this study, to reveal the function and its clinical significance of IL24 in LSCC, multiple detecting methods were used comprehensively. IL24 protein expression was remarkably higher in LSCC (n= 49) than non-cancerous laryngeal controls (n= 26) as detected by in-house immunohistochemistry. Meanwhile, the IL24 mRNA expression was also evaluated based on high throughput data from Gene Expression Omnibus, The Cancer Genome Atlas, ArrayExpress and Oncomine databases. Consistently with the protein level, IL24 mRNA expression level was also predominantly upregulated in LSCC (n= 172) compared to non-cancerous laryngeal tissues (n= 81) with the standard mean difference (SMD) being 1.25 and the area under the curve (AUC) of the summary receiver operating characteristic (sROC) being 0.89 (95% CI = 0.86-0.92). Furthermore, the related genes of IL24 and the differentially expressed genes (DEGs) of LSCC were intersected and sent for Gene ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and the protein-protein interaction (PPI) analyses. In the GO annotation, the top terms of biological process (BP), cellular component (CC) and molecular function (MF) were extracellular matrix organization, extracellular matrix, cytokine activity, respectively. The top pathway of KEGG was ECM-receptor interaction. The PPI networks indicated the top hub genes of IL24-related genes in LSCC were SERPINE1, TGFB1, MMP1, MMP3, CSF2, and ITGA5. In conclusion, upregulating expression of IL24 may enhance the occurrence of LSCC, which owns prospect diagnostic ability and therapeutic significance in LSCC.

Therapeutic wavelengths of ultraviolet B radiation activate apoptotic, circadian rhythm, redox signalling and key canonical pathways in psoriatic epidermis

Ultraviolet B radiation (UVB) exerts pleiotropic effects on human skin. DNA damage response and repair pathways are activated by UVB; if damage cannot be repaired, apoptosis ensues. Although cumulative UVB exposure predisposes to skin cancer, UVB phototherapy is widely used as an effective treatment for psoriasis. Previous studies defined the therapeutic action spectrum of UVB and showed that psoriasis is resistant to apoptosis. This study aimed to investigate early molecular responses within psoriasis plaques following irradiation with single equi-erythemogenic doses of clinically-effective (311 nm, narrow-band) compared to clinically-ineffective (290 nm) UVB. Forty-eight micro-dissected epidermal samples from 20 psoriatic patients were analyzed using microarrays. Our bioinformatic analysis compared gene expression between 311 nm irradiated, 290 nm irradiated and control psoriasis epidermis to specifically identify 311 nm UVB differentially expressed genes (DEGs) and their upstream regulatory pathways. Key DEGs and pathways were validated by immunohistochemical analysis. There was a dynamic induction and repression of 311 nm UVB DEGs between 6 h and 18 h, only a limited number of DEGs maintained their designated expression status between time-points. Key disease and function pathways included apoptosis, cell death, cell migration and leucocyte chemotaxis. DNA damage response pathways, NRF2-mediated oxidative stress response and P53 signalling were key nodes, interconnecting apoptosis and cell cycle arrest. Interferon signalling, dendritic cell maturation, granulocyte adhesion and atherosclerotic pathways were also differentially regulated. Consistent with these findings, top transcriptional regulators of 311 nm UVB DEGs related to: a) apoptosis, DNA damage response and cell cycle control; b) innate/acquired immune regulation and inflammation; c) hypoxia/redox response and angiogenesis; d) circadian rhythmicity; f) EGR/AP1 signalling and keratinocyte differentiation; and g) mitochondrial biogenesis. This research provides important insights into the molecular targets of 311 nm UVB, underscoring key roles for apoptosis and cell death. These and the other key pathways delineated may be central to the therapeutic effects of 311 nm in psoriasis.

Hiltonol Cocktail Kills Lung Cancer Cells by Activating Cancer-Suppressors, PKR/OAS, and Restraining the Tumor Microenvironment

NSCLC (non-small cell lung cancer) is a leading cause of cancer-related deaths worldwide. Clinical trials showed that Hiltonol, a stable dsRNA representing an advanced form of polyI:C (polyinosinic-polycytidilic acid), is an adjuvant cancer-immunomodulator. However, its mechanisms of action and effect on lung cancer have not been explored pre-clinically. Here, we examined, for the first time, how a novel Hiltonol cocktail kills NSCLC cells. By retrospective analysis of NSCLC patient tissues obtained from the tumor biobank; pre-clinical studies with Hiltonol alone or Hiltonol⁺⁺⁺ cocktail [Hiltonol+anti-IL6+AG490 (JAK2 inhibitor)+Stattic (STAT3 inhibitor)]; cytokine analysis; gene knockdown and gain/loss-of-function studies, we uncovered the mechanisms of action of Hiltonol⁺⁺⁺. We demonstrated that Hiltonol⁺⁺⁺ kills the cancer cells and suppresses the metastatic potential of NSCLC through: (i) upregulation of pro-apoptotic Caspase-9 and Caspase-3, (ii) induction of cytosolic cytochrome c, (iii) modulation of pro-inflammatory cytokines (GRO, MCP-1, IL-8, and IL-6) and anticancer IL-24 in NSCLC subtypes, and (iv) upregulation of tumor suppressors, PKR (protein kinase R) and OAS (2′5′ oligoadenylate synthetase). In silico analysis showed that Lys296 of PKR and Lys66 of OAS interact with Hiltonol. These Lys residues are purportedly involved in the catalytic/signaling activity of the tumor suppressors. Furthermore, knockdown of PKR/OAS abrogated the anticancer action of Hiltonol, provoking survival of cancer cells. Ex vivo analysis of NSCLC patient tissues corroborated that loss of PKR and OAS is associated with cancer advancement. Altogether, our findings unraveled the significance of studying tumor biobank tissues, which suggests PKR and OAS as precision oncological suppressor candidates to be targeted by this novel Hiltonol⁺⁺⁺ cocktail which represents a prospective drug for development into a potent and tailored therapy for NSCLC subtypes.

Sphingosine-1-phosphate receptor 3 potentiates inflammatory programs in normal and leukemia stem cells to promote differentiation

Acute myeloid leukemia (AML) is a caricature of normal hematopoiesis, driven from leukemia stem cells (LSC) that share some hematopoietic stem cell (HSC) programs including responsiveness to inflammatory signaling. Although inflammation dysregulates mature myeloid cells and influences stemness programs and lineage determination in HSC by activating stress myelopoiesis, such roles in LSC are poorly understood. Here, we show that S1PR3, a receptor for the bioactive lipid sphingosine-1-phosphate, is a central regulator which drives myeloid differentiation and activates inflammatory programs in both HSC and LSC. S1PR3-mediated inflammatory signatures varied in a continuum from primitive to mature myeloid states across AML patient cohorts, each with distinct phenotypic and clinical properties. S1PR3 was high in LSC and blasts of mature myeloid samples with linkages to chemosensitivity, while S1PR3 activation in primitive samples promoted LSC differentiation leading to eradication. Our studies open new avenues for therapeutic target identification specific for each AML subset.

SUMO-fusion and autoinduction-based combinatorial approach for enhanced production of bioactive human interleukin-24 in Escherichia coli

High-level production of recombinant human interleukin-24 (IL-24), a multifunctional immunomodulatory cytokine, has been challenging due primarily to its aggregation as inclusion bodies in the bacterial host while persistent poor-expression in the insect/mammalian expression systems. The present study presents a robust, vector-host combination (pE-SUMO-IL24), auto-inducible medium (YNG/M9NG), and a simple purification scheme for soluble, bioactive, and cost-effective production of native-like IL-24 (nIL-24) in Escherichia coli. The final protein yield, following a three-step purification scheme (IMAC, SEC, dialysis), was 98 mg/L in shake-flask culture (with scale-up potential), which was several folds higher than reported earlier. In vitro cytotoxicity assays with HeLa and HCT116 cancer cell lines (performed using different concentrations of nIL-24) and the fluorescence activated cell sorting analysis (FACS) revealed a dose- and concentration-dependent increase in the population of pro-apoptotic cells with concomitant, statistically significant drop in the number of cells existent at G_o/G1-, S-, and G2/M-phases (P < 0.002). The bioactive nIL-24, developed through this study, holds promise for use in further functional characterizations/applications. KEY POINTS: • Yeast SUMO fusion partner at N-terminus for improved solubility of an otherwise insoluble IL-24 in E. coli. • Enhanced cell densities with concomitant several-fold increase in protein yield by lactose-inducible media. • Improved inhibition of cervical and colorectal carcinomas by native-like nIL-24 compared with Met-containing IL. • Heterologous nIL-24 may enable better understanding of the functional intricacies linked up with its unique cancer-specific features. Graphical abstract.

Clinical Significance of the Interleukin 24 mRNA Level in Head and Neck Squamous Cell Carcinoma and Its Subgroups: An In Silico Investigation

IL24 mRNA is known to have an apoptotic effect on cancer cells but not on noncancer cells. However, the expression level of the IL24 mRNA in head and neck squamous cell carcinoma (HNSCC) and its subgroups is rarely studied. In this study, the clinical implication of IL24 mRNA was evaluated in the common subgroups of HNSCC, including oral squamous cell carcinoma (OSCC), nasopharyngeal carcinoma (NPC), and laryngeal squamous cell carcinoma (LSCC) for analysis. Substantial IL24 mRNA expression data were calculated from several databases, such as the Gene Expression Omnibus (GEO), ArrayExpress, Sequence Read Archive (SRA), ONCOMINE, and The Cancer Genome Atlas (TCGA) databases. We ultimately collected a total of 41 microarrays and RNA-seq including 1,564 HNSCC and 603 noncancer tissue samples. IL24 mRNA was highly expressed in OSCC, LSCC, and NPC as shown by the separated standard mean difference (SMD), as well as HNSCC as a whole part (SMD = 1.47, 95% confdence interval (CI) = 1.24−1.70, P < 0.0001). In all subgroups, the IL24 mRNA upregulation had the ability to distinguish cancer from noncancer tissue with area under the curves (AUCs) of the summary receiver operating characteristic (sROC) higher than 0.85. In conclusion, IL24 mRNA may be used as a potential marker for cancer screening, and its clinical diagnostic value needs to be further studied. It also provides a new idea for the treatment of the IL24 gene in HNSCC and its subgroups in the future.

In silico design of two novel fusion proteins, p28-IL-24 and p28-M4, targeted to breast cancer cells

Background and purpose:

An anticancer peptide P28, has shown to be cytolethal on various cancer cells including breast cancer. Moreover, p28 can be also used as a targeting moiety in the structure of fusion proteins. IL-24 (or its truncated form, M4) is a cytokine with anticancer activity against a wide range of tumor cells. We aimed at production of a fusion protein consisted of p28 and either IL-24 or M4 to target breast cancer. However, selection of a proper linker to join the two moieties without intervening each other’s function is a key factor in the construction of fusion proteins. In the present study, the impact of different linkers on construction of the two chimeric proteins (p28-IL-24 and p28-M4) was assessed in silico.

Experimental approach:

After selection of some linkers with different lengths and characteristics, a small library of the chimeric proteins was created and assessed. Furthermore, following selection of the most suitable linker, the three-dimensional structures and dynamic behavior of both fusion proteins were evaluated by homology modeling and molecular dynamic simulation, respectively.

Findings / Results:

Based on the results, a rigid linker having the peptide sequences of AEAAAKEAAAKA showed highest freedom of action for both moieties.

Conclusion and implications:

Between the p28-IL-24 and p28-M4 fusion proteins, the former showed better stability as well as solubility and might show stronger anticancer effects in vitro and in vivo, because its peptide moieties showed to exert their activities freely.

The Evaluation of tLyP-1-Bound Mda-7/IL-24 Killing Activity on a Liver Tumor Cell Line

Introduction: The melanoma differentiation-associated gene-7 (Mda-7)/interleukin-24 (IL-24) is a tumor killing cytokine, the bystander effect of which can be enhanced through tethering to tumor homing peptides (THPs). Materials and Methods: After fusing tLyP-1, RGR, and buforin as THPs to Mda-7/IL-24, enzyme-linked immunosorbent assay (ELISA) was used to determine the secretion potency of the recombinant proteins. The killing potency of plasmids expressing IL-24, IL-24.tLyP1, IL-24.RGR, and buf.IL-24 were assessed, using MTT, Annexin/PI staining assays as well as measuring the expression level of GADD-153 and BCL2-associated X (BAX) on Huh-7 cells. Three-dimensional structural analysis and protein-receptor interaction were also evaluated by modeling. Results: The ELISA result showed that contrary to IL-24.RGR and buf.IL-24, IL-24.tLyP-1 retained the secretion potency, similar to the native form. The viability assessments showed that IL-24 and IL-24.tLyP-1 had the most growth suppressive effects in comparison with the control group (p < 0.0001). Furthermore, IL-24 and IL-24.tLyP-1 had the highest apoptotic activity and significant upregulatory effect on the GADD-153 and BAX genes (p < 0.0003). The modeling showed that peptide modifications left no detrimental effect on IL-24 attachment to the cognate receptor. Conclusion: IL-24 can tolerate tLyP-1 peptide modification by retaining its secretion potency. Tethering tLyP-1 to IL-24 can induce more apoptosis than its modified versions by RGR or buforin.

Transcriptomics Analysis of Porcine Caudal Dorsal Root Ganglia in Tail Amputated Pigs Shows Long-Term Effects on Many Pain-Associated Genes

Tail amputation by tail docking or as an extreme consequence of tail biting in commercial pig production potentially has serious implications for animal welfare. Tail amputation causes peripheral nerve injury that might be associated with lasting chronic pain. The aim of this study was to investigate the short- and long-term effects of tail amputation in pigs on caudal DRG gene expression at different stages of development, particularly in relation to genes associated with nociception and pain. Microarrays were used to analyse whole DRG transcriptomes from tail amputated and sham-treated pigs 1, 8, and 16 weeks following tail treatment at either 3 or 63 days of age (8 pigs/treatment/age/time after treatment; n = 96). Tail amputation induced marked changes in gene expression (up and down) compared to sham-treated intact controls for all treatment ages and time points after tail treatment. Sustained changes in gene expression in tail amputated pigs were still evident 4 months after tail injury. Gene correlation network analysis revealed two co-expression clusters associated with amputation: Cluster A (759 down-regulated) and Cluster B (273 up-regulated) genes. Gene ontology (GO) enrichment analysis identified 124 genes in Cluster A and 61 genes in Cluster B associated with both “inflammatory pain” and “neuropathic pain.” In Cluster A, gene family members of ion channels e.g., voltage-gated potassium channels (VGPC) and receptors e.g., GABA receptors, were significantly down-regulated compared to shams, both of which are linked to increased peripheral nerve excitability after axotomy. Up-regulated gene families in Cluster B were linked to transcriptional regulation, inflammation, tissue remodeling, and regulatory neuropeptide activity. These findings, demonstrate that tail amputation causes sustained transcriptomic expression changes in caudal DRG cells involved in inflammatory and neuropathic pain pathways.

Regulation of IL-24 in human oral keratinocytes stimulated with Tannerella forsythia

Interleukin-24 is a pleiotropic immunoregulatory cytokine and a member of the IL-20R subfamily of the IL-10 family. The aim of this study was to investigate the regulation of IL-24 in the human oral keratinocyte cell line HOK-16B following infection with Tannerella forsythia, a major periodontal pathogen. T. forsythia induced the expression of IL-24 mRNA and the secretion of glycosylated IL-24 in HOK-16B cells. Glycosylation of IL-24 is linked to its solubility and bioavailability. T. forsythia-stimulated reactive oxygen species (ROS) induced the expression of IL-24, which was regulated by IL-6. The ROS inhibitor N-acetylcysteine and MAPK inhibitors significantly reduced the expression of IL-6 and IL-24 induced by T. forsythia. Recombinant human IL-24 significantly enhanced the expression of IL-1α, IL-8, CXCL10, and MCP-1 in HOK-16B cells. Together, these results indicate that ROS, MAPKs, and IL-6 comprise the axis of IL-24 expression in HOK-16B cells stimulated with T. forsythia. Thus, IL-24 may be involved in inflammation in oral keratinocytes.

Synergistic combination of oncolytic virotherapy with CAR T-cell therapy

For patients with advanced hematological malignancies the therapeutic landscape has been transformed by the emergence of adoptive cell transfer utilizing autologous chimeric antigen receptor (CAR)-redirected T-cells. However, solid tumors have proved far more resistant to this approach. Here, we summarize the numerous challenges faced by CAR T-cells designed to target solid tumors, highlighting, in particular, issues related to impaired trafficking, expansion, and persistence. In parallel, we draw attention to exciting developments in the burgeoning field of oncolytic virotherapy and posit strategies for the synergistic combination of oncolytic viruses with CAR T-cells to improve outcomes for patients with advanced solid tumors.

Umbilical cord-derived mesenchymal stromal/stem cells expressing IL-24 induce apoptosis in gliomas

Although much progress has been made in the treatment of gliomas, the prognosis for patients with gliomas is still very poor. Stem cell-based therapies may be promising options for glioma treatment. Recently, many studies have reported that umbilical cord-derived mesenchymal stromal/stem cells (UC-MSCs) are ideal gene vehicles for tumor gene therapy. Interleukin 24 (IL-24) is a pleiotropic immunoregulatory cytokine that has an apoptotic effect on many kinds of tumor cells and can inhibit the growth of tumors specifically without damaging normal cells. In this study, we investigated UC-MSCs as a vehicle for the targeted delivery of IL-24 to tumor sites. UC-MSCs were transduced with lentiviral vectors carrying green fluorescent protein (GFP) or IL-24 complementary DNA. The results indicated that UC-MSCs could selectively migrate to glioma cells in vitro and in vivo. Injection of IL-24-UC-MSCs significantly suppressed tumor growth of glioma xenografts. The restrictive efficacy of IL-24-UC-MSCs was associated with the inhibition of proliferation as well as the induction of apoptosis in tumor cells. These findings indicate that UC-MSC-based IL-24 gene therapy may be able to suppress the growth of glioma xenografts, thereby suggesting possible future therapeutic use in the treatment of gliomas.

MDA-7/interleukin 24 (IL-24) in tumor gene therapy: application of tumor penetrating/homing peptides for improvement of the effects

INTRODUCTION

MDA-7/Interleukin-24 (IL-24), as a pleiotropic cytokine, exhibits a specific tumor suppression property that has attracted a great deal of attention. While its anti-tumor induction is mostly attributed to endogenous gene expression, attachment of secreted MDA-7/IL-24 to cognate receptors also triggers the death of cancerous cell via different pathways. Therefore, precise targeting of secreted MDA-7/IL-24 to tumor cells would render it more efficacy and specificity.

AREAS COVERED

In order to target soluble cytokines, particularly MDA-7/IL-24 to the neighbor tumor sites and enhance their therapeutic efficiency, fusing with cell penetrating peptides (CPPs) or Tumor homing peptides (THPs) seems logical due to the improvement of their bystander effects. Although the detailed anti-tumor mechanisms of endogenous mda-7/IL-24 have been largely investigated, the significance of the secreted form in these activities and methods of its improving by CPPs or THPs need more discussion.

EXPERT OPINION

While the employment of CPPs/THPs for the improvement of cytokine gene therapy is desirable, to create fusions of CPPs/THPs with MDA-7/IL-24, some hurdles are not avoidable. Regarding our expertise, herein, the importance of CPPs/THPs, needs for their elegant designing in a fusion structure, and their applications in cytokine gene therapy are discussed with a special focus on mda-7/IL-24.

The Interleukin-10 Family of Cytokines and Their Role in the CNS

Resident cells of the central nervous system (CNS) play an important role in detecting insults and initiating protective or sometimes detrimental host immunity. At peripheral sites, immune responses follow a biphasic course with the rapid, but transient, production of inflammatory mediators giving way to the delayed release of factors that promote resolution and repair. Within the CNS, it is well known that glial cells contribute to the onset and progression of neuroinflammation, but it is only now becoming apparent that microglia and astrocytes also play an important role in producing and responding to immunosuppressive factors that serve to limit the detrimental effects of such responses. Interleukin-10 (IL-10) is generally considered to be the quintessential immunosuppressive cytokine, and its ability to resolve inflammation and promote wound repair at peripheral sites is well documented. In the present review article, we discuss the evidence for the production of IL-10 by glia, and describe the ability of CNS cells, including microglia and astrocytes, to respond to this suppressive factor. Furthermore, we review the literature for the expression of other members of the IL-10 cytokine family, IL-19, IL-20, IL-22 and IL-24, within the brain, and discuss the evidence of a role for these poorly understood cytokines in the regulation of infectious and sterile neuroinflammation. In concert, the available data indicate that glia can produce IL-10 and the related cytokines IL-19 and IL-24 in a delayed manner, and these cytokines can limit glial inflammatory responses and/or provide protection against CNS insult. However, the roles of other IL-10 family members within the CNS remain unclear, with IL-20 appearing to act as a pro-inflammatory factor, while IL-22 may play a protective role in some instances and a detrimental role in others, perhaps reflecting the pleiotropic nature of this cytokine family. What is clear is that our current understanding of the role of IL-10 and related cytokines within the CNS is limited at best, and further research is required to define the actions of this understudied family in inflammatory brain disorders.

IL-24 Promotes Apoptosis through cAMP-Dependent PKA Pathways in Human Breast Cancer Cells

Interleukin 24 (IL-24) is a tumor-suppressing protein, which inhibits angiogenesis and induces cancer cell-specific apoptosis. We have shown that IL-24 regulates apoptosis through phosphorylated eukaryotic initiation factor 2 alpha (eIF2α) during endoplasmic reticulum (ER) stress in cancer. Although multiple stresses converge on eIF2α phosphorylation, the cellular outcome is not always the same. In particular, ER stress-induced apoptosis is primarily regulated through the extent of eIF2α phosphorylation and activating transcription factor 4 (ATF4) action. Our studies show for the first time that cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) activation is required for IL-24-induced cell death in a variety of breast cancer cell lines and this event increases ATF4 activity. We demonstrate an undocumented role for PKA in regulating IL-24-induced cell death, whereby PKA stimulates phosphorylation of p38 mitogen-activated protein kinase and upregulates extrinsic apoptotic factors of the Fas/FasL signaling pathway and death receptor 4 expression. We also demonstrate that phosphorylation and nuclear import of tumor suppressor TP53 occurs downstream of IL-24-mediated PKA activation. These discoveries provide the first mechanistic insights into the function of PKA as a key regulator of the extrinsic pathway, ER stress, and TP53 activation triggered by IL-24.

IL-20 receptor cytokines in autoimmune diseases

IL-19, IL-20, and IL-24 are the members of IL-10 family. They are also known as IL-20 receptor (IL-20R) cytokines as they all signal through the IL-20RA/IL-20RB receptor complex; IL-20 and IL-24 (but not IL-19) also signal through the IL-20RB/IL22RA1 receptor complex. Despite their protein structure homology and shared use of receptor complexes, they display distinct biological functions in immune regulation, tissue homeostasis, host defense, and oncogenesis. IL-20R cytokines can be expressed by both immune cells and epithelial cells, and are important for their interaction. In general, these cytokines are considered to be associated with pathogenesis of chronic inflammation and autoimmune diseases, including psoriasis, rheumatoid arthritis, and inflammatory bowel disease. However, a number of studies also highlighted their suppressive functions in regulating both innate and adaptive T cell responses and other immune cells, suggesting that the role of IL-20R cytokines in autoimmunity may be complex. In this review, we will discuss the immunobiological functions of IL-20R cytokines and how they are involved in regulating autoimmune diseases.

Crystal Structure of the Labile Complex of IL-24 with the Extracellular Domains of IL-22R1 and IL-20R2

Crystal structure of the ternary complex of human IL-24 with two receptors, IL-22R1 and IL-20R2, has been determined at 2.15 Å resolution. A crystallizable complex was created by a novel approach involving fusing the ligand with a flexible linker to the presumed low-affinity receptor, and coexpression of this construct in Drosophila S2 cells together with the presumed high-affinity receptor. This approach, which may be generally applicable to other multiprotein complexes with low-affinity components, was necessitated by the instability of IL-24 expressed by itself in either bacteria or insect cells. Although IL-24 expressed in Escherichia coli was unstable and precipitated almost immediately upon its refolding and purification, a small fraction of IL-24 remaining in the folded state was shown to be active in a cell-based assay. In the crystal structure presented here, we found that two cysteine residues in IL-24 do not form a predicted disulfide bond. Lack of structural restraint by disulfides, present in other related cytokines, is most likely reason for the low stability of IL-24. Although the contact area between IL-24 and IL-22R1 is larger than between the cytokine and IL-20R2, calculations show the latter interaction to be slightly more stable, suggesting that the shared receptor (IL-20R2) might be the higher-affinity receptor.

Eukaryotic Translation Initiation Factor 4A Down-Regulation Mediates Interleukin-24-Induced Apoptosis through Inhibition of Translation

Dysregulated activity of helicase eIF4A drives transformation to and maintenance of cancer cell phenotype by reprogramming cellular translation. Interleukin 24 (IL-24) is a tumor-suppressing protein, which has the ability to inhibit angiogenesis, sensitize cancer cells to chemotherapy, and induce cancer cell-specific apoptosis. In this study, we found that eIF4A is inhibited by IL-24. Consequently, selective reduction of translation was observed for mRNAs harboring strong secondary structures in their 5′-untranslated regions (5′UTRs). These mRNAs encode proteins, which function in cell survival and proliferation. Consistently, overexpression of eIF4A conferred cancer cells with resistance to IL-24-induced cell death. It has been established that inhibition of eIF4A triggers mitochondrial-mediated apoptosis. We showed that IL-24 induces eIF4A-dependent mitochondrial depolarization. We also showed that IL-24 induces Sigma 1 Receptor-dependent eIF4A down-regulation and mitochondrial depolarization. Thus, the progress of apoptosis triggered by IL-24 is characterized by a complex program of changes in regulation of several initiation factors, including the eIF4A.

Immunological Approaches Towards Cancer and Inflammation: A Cross Talk

The inflammation is the protective response of the body against various harmful stimuli; however, the aberrant and inappropriate activation tends to become harmful. The acute inflammatory response tends to resolved once the offending agent is subside but this acute response becomes chronic in nature when the body is unable to successfully neutralized the noxious stimuli. This chronic inflammatory microenvironment is associated with the release of various pro-inflammatory and oncogenic mediators such as nitric oxide (NO), cytokines [IL-1β, IL-2, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α)], growth factor, and chemokines. These mediators make the inflammatory microenvironment more vulnerable toward tumorigenesis. The pro-inflammatory mediators released during the chronic inflammation tends to induce several molecular signaling cascades such as nuclear factor kappa B, MAPKinase, nuclear factor erythroid 2-related factor 2, phosphoinositide-3-kinase, Janus kinases/STAT, Wnt/B-catenin, and cyclic AMP response element binding protein. The immune system and its components have a pleiotropic effect on inflammation and cancer progression. Immune components such as T cells, natural killer cells, macrophages, and neutrophils either inhibit or enhance tumor initiation depending on the type of tumor and immune cells involved. Tumor-associated macrophages and tumor-associated neutrophils are pro-tumorigenic cells highly prevalent in inflammation-mediated tumors. Similarly, presence of T regulatory (Treg) cells in an inflammatory and tumor setting suppresses the immune system, thus paving the way for oncogenesis. However, Treg cells also inhibit autoimmune inflammation. By contrast, cytotoxic T cells and T helper cells confer antitumor immunity and are associated with better prognosis in patients with cancer. Cytotoxic T cells inflict a direct cytotoxic effect on cells expressing oncogenic markers. Currently, several anti-inflammatory and antitumor therapies are under trials in which these immune cells are exploited. Adoptive cell transfer composed of tumor-infiltrating lymphocytes has been tried for the treatment of tumors after their ex vivo expansion. Mediators released by cells in a tumorigenic and inflammatory microenvironment cross talk with nearby cells, either promoting or inhibiting inflammation and cancer. Recently, several cytokine-based therapies are either being developed or are under trial to treat such types of manifestations. Monoclonal antibodies directed against TNF-α, VEGF, and IL-6 has shown promising results to ameliorate inflammation and cancer, while direct administration of IL-2 has been shown to cause tumor regression.

Role of MDA-7/IL-24 a Multifunction Protein in Human Diseases

Subtraction hybridization identified genes displaying differential expression as metastatic human melanoma cells terminally differentiated and lost tumorigenic properties by treatment with recombinant fibroblast interferon and mezerein. This approach permitted cloning of multiple genes displaying enhanced expression when melanoma cells terminally differentiated, called melanoma differentiation associated (mda) genes. One mda gene, mda-7, has risen to the top of the list based on its relevance to cancer and now inflammation and other pathological states, which based on presence of a secretory sequence, chromosomal location, and an IL-10 signature motif has been named interleukin-24 (MDA-7/IL-24). Discovered in the early 1990s, MDA-7/IL-24 has proven to be a potent, near ubiquitous cancer suppressor gene capable of inducing cancer cell death through apoptosis and toxic autophagy in cancer cells in vitro and in preclinical animal models in vivo. In addition, MDA-7/IL-24 embodied profound anticancer activity in a Phase I/II clinical trial following direct injection with an adenovirus (Ad.mda-7; INGN-241) in tumors in patients with advanced cancers. In multiple independent studies, MDA-7/IL-24 has been implicated in many pathological states involving inflammation and may play a role in inflammatory bowel disease, psoriasis, cardiovascular disease, rheumatoid arthritis, tuberculosis, and viral infection. This review provides an up-to-date review on the multifunctional gene mda-7/IL-24, which may hold potential for the therapy of not only cancer, but also other pathological states.

Cancer terminator viruses (CTV): A better solution for viral-based therapy of cancer

In principle, viral gene therapy holds significant potential for the therapy of solid cancers. However, this promise has not been fully realized and systemic administration of viruses has not proven as successful as envisioned in the clinical arena. Our research is focused on developing the next generation of efficacious viruses to specifically treat both primary cancers and a major cause of cancer lethality, metastatic tumors (that have spread from a primary site of origin to other areas in the body and are responsible for an estimated 90% of cancer deaths). We have generated a chimeric tropism-modified type 5 and 3 adenovirus that selectively replicates in cancer cells and simultaneously produces a secreted anti-cancer toxic cytokine, melanoma differentiation associated gene-7/Interleukin-24 (mda-7/IL-24), referred to as a Cancer Terminator Virus (CTV) (Ad.5/3-CTV). In preclinical animal models, injection into a primary tumor causes selective cell death and therapeutic activity is also observed in non-injected distant tumors, that is, "bystander anti-tumor activity." To enhance the impact and therapeutic utility of the CTV, we have pioneered an elegant approach in which viruses are encapsulated in microbubbles allowing "stealth delivery" to tumor cells that when treated with focused ultrasound causes viral release killing tumor cells through viral replication, and producing and secreting MDA-7/IL-24, which stimulates the immune system to attack distant cancers, inhibits tumor angiogenesis and directly promotes apoptosis in distant cancer cells. This strategy is called UTMD (ultrasound-targeted microbubble-destruction). This novel CTV and UTMD approach hold significant promise for the effective therapy of primary and disseminated tumors.

[Effect of an angiotensin-converting-enzyme inhibitor on the plasma concentration of cytokines and vasoactive molecules in patients with coronary heart disease and hypertension]

AIM

To investigate the plasma concentrations of cytokines and vasoactive molecules in patients with coronary heart disease (CHD) in the presence of hypertension in relation to the angiotensin-converting-enzyme (ACE) inhibitor level reflecting the degree of renin-angiotensin-aldosterone system (RAAS) inhibition.

SUBJECTS AND METHODS

72 patients with NYHA functional class (FC) II-III angina pectoris and 40 healthy persons at the age of 47-65 years were examined in a controlled cohort study. Enzyme immunoassay was employed to determine the serum concentrations of interleukins (IL) (IL-2, IL-12, IL-17A, and IL-24), the vasoactive molecules of bradykinin, serotonin, ACE, angiotensin-II (AT-II), NO, and endothelin-1 (ET-1), and plasma renin activity. In addition, the plasma level of the tetrapeptide N-acetyl-Ser-Asp-Lys-Pro was used as a marker for ACE inhibition.

RESULTS

The patients with CHD occurring in the presence of hypertension compared with the apparently healthy individuals displayed decreased ET-1 and NO production along with elevated levels of serotonin, AT-II, as well as IL-17A and IL-12. The found changes were accompanied by reduced renin activity. Thus, the individuals with low ACE inhibitor levels showed more pronounced production of the proinflammatory cytokine IL-17A, as well as high plasma concentrations of ACE and NO. The high ACE inhibitor level that reflects patient adherence to appropriate antihypertensive therapy is associated with the reduced production of IL-2 and with the minimum serum levels of ACE, AT-II, and NO, being characterized by the high production of IL-12 and serotonin at the same time.

CONCLUSION

In patients with CHD and hypertension, the high plasma enzyme inhibitor concentration that reflects the activity of appropriate antihypertensive therapy, by contributing to the strengthening of the mechanisms of relaxation of blood vessels, is associated with the risk for proinflammatory activation of whole blood cells and platelets. The mean ACE inhibitor levels that reflect moderate RAAS suppression and are characterized by a relatively low proinflammatory activation of mononuclear cells may be more preferable than the maximum ones, from the point of view of slowing the progression of the subclinical inflammatory process of the vascular wall and preventing possible CHD exacerbations. This determines the feasibility of estimating the plasma level of an ACE inhibitor to control the depth of inhibition of RAAS activity.