Interleukin (IL)-24 transforms the tumor microenvironment and induces anticancer immunity in a murine model of colon cancer

Novel insight into MDA-7/IL-24: A potent therapeutic target for autoimmune and inflammatory diseases

Melanoma differentiation-associated gene-7 (MDA-7)/interleukin-24 (IL-24) is a pleiotropic member of the IL-10 family of cytokines, and is involved in multiple biological processes, including cell proliferation, cell differentiation, tissue fibrosis, the inflammatory response, and antitumor activity. MDA-7/IL-24 can regulate epithelial integrity, homeostasis, mucosal immunity and host resistance to various pathogens by enhancing immune and inflammatory responses. Our recent study revealed the mechanism of MDA-7/IL-24 in promoting airway inflammation and airway remodeling through activating the JAK/STAT3 and ERK signaling pathways in bronchial epithelial cells. Herein, we summarize the cellular sources, inducers, target cells, signaling pathways, and biological effects of MDA-7/IL-24 in several allergic and autoimmune diseases. This review also synopsizes recent advances in clinical research targeting MDA-7/IL-24 or its receptors. Based on these advancements, we emphasize its potential as a target for immunotherapy and discuss the challenges of developing immunotherapeutic drugs targeting MDA-7/IL-24 or its receptors in autoimmune and inflammatory disorders.

Effects and mechanisms of N6-methyladenosine RNA methylation in environmental pollutant-induced carcinogenesis

Environmental pollution, including air pollution, plastic contamination, and heavy metal exposure, is a pressing global issue. This crisis contributes significantly to pollution-related diseases and is a critical risk factor for chronic health conditions, including cancer. Mounting evidence underscores the pivotal role of N6-methyladenosine (m6A) as a crucial regulatory mechanism in pathological processes and cancer progression. Governed by m6A writers, erasers, and readers, m6A orchestrates alterations in target gene expression, consequently playing a vital role in a spectrum of RNA processes, covering mRNA processing, translation, degradation, splicing, nuclear export, and folding. Thus, there is a growing need to pinpoint specific m6A-regulated targets in environmental pollutant-induced carcinogenesis, an emerging area of research in cancer prevention. This review consolidates the understanding of m6A modification in environmental pollutant-induced tumorigenesis, explicitly examining its implications in lung, skin, and bladder cancer. We also investigate the biological mechanisms that underlie carcinogenesis originating from pollution. Specific m6A methylation pathways, such as the HIF1A/METTL3/IGF2BP3/BIRC5 network, METTL3/YTHDF1-mediated m6A modification of IL 24, METTL3/YTHDF2 dynamically catalyzed m6A modification of AKT1, METTL3-mediated m6A-modified oxidative stress, METTL16-mediated m6A modification, site-specific ATG13 methylation-mediated autophagy, and the role of m6A in up-regulating ribosome biogenesis, all come into play in this intricate process. Furthermore, we discuss the direction regarding the interplay between pollutants and RNA metabolism, particularly in immune response, providing new information on RNA modifications for future exploration.

A Novel Platinum Resistance-Related Immune Gene Signature for Overall Survival Prediction in Patients with Ovarian Cancer

Ovarian cancer (OV) is a highly heterogeneous gynecological tumor that makes the prognostic prediction challenging. Resistance to platinum-based chemotherapy is associated with a poor prognosis in OV. There seems to be an overlap between molecular mechanisms responsible for platinum resistance and immunogenicity in OV. However, the predictive role of platinum resistance-related immune genes for OV prognosis needs to be further explored. In our study, the mRNA expression data of OV patients with corresponding clinical information were collected from The Cancer Genome Atlas (TCGA) cohort and International Cancer Genome Consortium (ICGC) cohort. A multigene signature was constructed for OV patients in the TCGA cohort using the least absolute shrinkage and selection operator (LASSO) Cox regression model according to the optimal value of λ and was validated in the ICGC cohort. Furthermore, we performed functional analysis to explore the immune status between low- and high-risk groups based on the median value of the risk score for the multigene signature. Our data showed that there were 41.1% of the platinum resistance-related genes which differentially expressed between immune score low- and high-OV patients in the TCGA cohort. Univariate Cox regression analysis identified 30 differentially expressed genes (DEGs) associated with overall survival (OS) (P < 0.05). 14 genes were identified to construct a novel platinum resistance-related immune model for classifying OV patients into the low- and high- risk groups. Patients in the low-risk group showed significantly higher OS than those in the high-risk group (P < 0.0001 in the both TCGA and ICGC cohort), which was associated with different immune status for the two risk groups. A novel platinum resistance-related immune model can be used for prognostic prediction in OV. Targeting tumor immunity may be a therapeutic alternative for OV with platinum resistance.

IL-24 is the key effector of Th9 cell-mediated tumor immunotherapy

Th9 cells are powerful effector T cells for cancer immunotherapy. However, the underlying antitumor mechanism of Th9 cells still needs to be further elucidated. Here, we show that Th9 cells express high levels of not only IL-9, but also IL-24. We found that knockout of Il24 gene in Th9 cells promotes Th9 cell proliferation in vitro, but decreases Th9 cell survival in vitro and in vivo. Interestingly, knockout of Il24 gene in Th9 cells decreases the tumor-specific cytotoxicity of Th9 cells in vitro. In addition, immunotherapy with Il24 knockout Th9 cells exhibit less tumor inhibition than regular Th9 cells in mouse tumor models. We found that inhibition of Foxo1 by a specific inhibitor downregulates IL-24 expression in Th9 cells and decreases Th9 cell antitumor efficacy in vivo. Our results identify IL-24 as a powerful antitumor effector of Th9 cells and provide a target in Th9 cell-mediated tumor therapy.

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.

Therapeutic approaches targeting molecular signaling pathways common to diabetes, lung diseases and cancer

Diabetes mellitus (DM), is the most common metabolic disease and is characterized by sustained hyperglycemia. Accumulating evidences supports a strong association between DM and numerous lung diseases including chronic obstructive pulmonary disease (COPD), fibrosis, and lung cancer (LC). The global incidence of DM-associated lung disorders is rising and several ongoing studies, including clinical trials, aim to elucidate the molecular mechanisms linking DM with lung disorders, in particular LC. Several potential mechanisms, including hyperglycemia, hyperinsulinemia, glycation, inflammation, and hypoxia, are cited as plausible links between DM and LC. In addition, studies also propose a connection between the use of anti-diabetic medications and reduction in the incidence of LC. However, the exact cause for DM associated lung diseases especially LC is not clear and is an area under intense investigation. Herein, we review the biological links reported between DM and lung disorders with an emphasis on LC. Furthermore, we report common signaling pathways (eg: TGF-β, IL-6, HIF-1, PDGF) and miRNAs that are dysregulated in DM and LC and serve as molecular targets for therapy. Finally, we propose a nanomedicine based approach for delivering therapeutics (eg: IL-24 plasmid DNA, HuR siRNA) to disrupt signaling pathways common to DM and LC and thus potentially treat DM-associated LC. Finally, we conclude that the effective modulation of commonly regulated signaling pathways would help design novel therapeutic protocols for treating DM patients diagnosed with LC.

IL-24 inhibits the malignancy of human glioblastoma cells via destabilization of Zeb1

Glioblastoma (GBM) is the most common and fatal type of primary malignant tumours in the central nervous system. Cytokines such as interleukins (ILs) play an important role in GBM progression. Our present study found that IL-24 is down-regulated in GBM cells. Recombinant IL-24 (rIL-24) can suppress the in vitro migration and invasion of GBM cells while increase its chemo-sensitivity to temozolomide (TMZ) treatment. rIL-24 negatively regulates the expression of Zeb1, one well known transcription factors of epithelial to mesenchymal transition (EMT) of cancer cells. Over expression of Zeb1 can attenuate IL-24-suppressed malignancy of GBM cells. Mechanistically, IL-24 decreases the protein stability of Zeb1 while has no effect on its mRNA stability. It is due to that IL-24 can increase the expression of FBXO45, which can destabilize Zeb1 in cancer cells. Collectively, we reveal that IL-24 can suppress the malignancy of GBM cells via decreasing the expression of Zeb1. It suggests that targeted activation of IL-24 signals might be a potential therapy approach for GBM treatment.

Interleukin (IL)-24: Reconfiguring the Tumor Microenvironment for Eliciting Antitumor Response

Interleukin (IL)-24 is a member of the IL-10 family of cytokines. Due to its unique ability to function as both a tumor suppressor and cytokine, IL-24-based cancer therapy has been developed for treating a broad spectrum of human cancers. Majority of the studies reported to date have focused on establishing IL-24 as a cancer therapeutic by primarily focusing on tumor cell killing. However, the ability of IL-24 treatment on modulating the tumor microenvironment and immune response is underinvestigated. In this article, we summarize the biological and functional properties of IL-24 and the benefits of applying IL-24-based therapy for cancer.

Mechanisms of Immunosuppression in Colorectal Cancer

Simple Summary

More emerging studies are exploring immunotherapy for solid cancers, including colorectal cancer. Besides, checkpoint blockade immunotherapy and chimeric antigen receptor (CAR) -based immune cell therapy have being examined in clinical trials for colorectal cancer patients. However, immunosuppression that leads to the blockage of normal immunosurveillance often leads to cancer development and relapse. In this study, we systematically reviewed the mechanism of immunosuppression, specifically in colorectal cancer, from different perspectives, including the natural or induced immunosuppressive cells, cell surface protein, cytokines/chemokines, transcriptional factors, metabolic alteration, phosphatase, and tissue hypoxia in the tumor microenvironment. We also discussed the progress of immunotherapies in clinical trials/studies for colorectal cancer and highlighted how different strategies for cancer therapy targeted the immunosuppression reviewed above. Our review provides some timely implications for restoring immunosurveillance to improve treatment efficacy in colorectal cancer (CRC).

Abstract

CRC is the third most diagnosed cancer in the US with the second-highest mortality rate. A multi-modality approach with surgery/chemotherapy is used in patients with early stages of colon cancer. Radiation therapy is added to the armamentarium in patients with locally advanced rectal cancer. While some patients with metastatic CRC are cured, the majority remain incurable and receive palliative chemotherapy as the standard of care. Recently, immune checkpoint blockade has emerged as a promising treatment for many solid tumors, including CRC with microsatellite instability. However, it has not been effective for microsatellite stable CRC. Here, main mechanisms of immunosuppression in CRC will be discussed, aiming to provide some insights for restoring immunosurveillance to improve treatment efficacy in CRC.

Development of a prognostic model of glioma based on immune-related genes

Glioma is the most common type of primary brain cancer, and the prognosis of most patients with glioma, and particularly that of patients with glioblastoma, is poor. Tumor immunity serves an important role in the development of glioma. However, immunotherapy for glioma has not been completely successful, and thus, comprehensive examination of the immune-related genes (IRGs) of glioma is required. In the present study, differentially expressed genes (DEGs) and differentially expressed IRGs (DEIRGs) were identified using the edgeR package. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was used for functional enrichment analysis of DEIRGs. Survival-associated IRGs were selected via univariate Cox regression analysis. A The Cancer Genome Atlas prognostic model and GSE43378 validation model were established using lasso-penalized Cox regression analysis. Based on the median risk score value, patients were divided into high-risk and low-risk groups for clinical analysis. Receiver operating characteristic curve and nomogram analyses were used to assess the accuracy of the models. Reverse transcription-quantitative PCR was performed to measure the expression levels of relevant genes, such as cyclin-dependent kinase 4 (CDK4), interleukin 24 (IL24), NADPH oxidase 4 (NOX4), bone morphogenetic protein 2 (BMP2) and baculoviral IAP repeat containing 5 (BIRC5). A total of 3,238 DEGs, including 1,950 upregulated and 1,288 downregulated DEGs, and 97 DEIRGs, including 60 upregulated and 37 downregulated DEIRGs, were identified. ‘Neuroactive ligand-receptor interaction’ and ‘Cytokine-cytokine receptor interaction’ were the most significantly enriched pathways according to KEGG pathway analysis. A prognostic model and a validation prognostic model were created for glioma, including 15 survival-associated IRGs (FCER1G, NOX4, TRIM5, SOCS1, APOBEC3C, BIRC5, VIM, TNC, BMP2, CMTM3, IL24, JAG1, CALCRL, HNF4G and CDK4). Furthermore, multivariate Cox regression analysis results suggested that age, high WHO Grade by histopathology, wild type isocitrate dehydrogenase 1 and high risk score were independently associated with poor overall survival. The infiltration of B cells, CD8⁺ T cells, dendritic cells, macrophages and neutrophils was positively associated with the prognostic risk score. In the present study, several clinically significant survival-associated IRGs were identified, and a prognosis evaluation model of glioma was established.

IL-24-Armed Oncolytic Vaccinia Virus Exerts Potent Antitumor Effects via Multiple Pathways in Colorectal Cancer

Colorectal cancer is an aggressive malignancy for which there are limited treatment options. Oncolytic vaccinia virus is being developed as a novel strategy for cancer therapy. Arming vaccinia virus with immunostimulatory cytokines can enhance the tumor cell-specific replication and antitumor efficacy. Interleukin-24 (IL-24) is an important immune mediator, as well as a broad-spectrum tumor suppressor. We constructed a targeted vaccinia virus of Guang9 strain harboring IL-24 (VG9-IL-24) to evaluate its antitumor effects. In vitro, VG9-IL-24 induced an increased number of apoptotic cells and blocked colorectal cancer cells in the G₂/M phase of the cell cycle. VG9-IL-24 induced apoptosis in colorectal cancer cells via multiple apoptotic signaling pathways. In vivo, VG9-IL-24 significantly inhibited the tumor growth and prolonged the survival both in human and murine colorectal cancer models. In addition, VG9-IL-24 stimulated multiple antitumor immune responses and direct bystander antitumor activity. Our results indicate that VG9-IL-24 can inhibit the growth of colorectal cancer tumor by inducing oncolysis and apoptosis as well as stimulating the antitumor immune effects. These findings indicate that VG9-IL-24 may exert a potential therapeutic strategy for combating colorectal cancer.

Loss of BAP1 expression is associated with an immunosuppressive microenvironment in uveal melanoma, with implications for immunotherapy development

Immunotherapy using immune checkpoint inhibitors (ICIs) induces durable responses in many metastatic cancers. Metastatic uveal melanoma (mUM), typically occurring in the liver, is one of the most refractory tumours to ICIs and has dismal outcomes. Monosomy 3 (M3), polysomy 8q, and BAP1 loss in primary uveal melanoma (pUM) are associated with poor prognoses. The presence of tumour-infiltrating lymphocytes (TILs) within pUM and surrounding mUM - and some evidence of clinical responses to adoptive TIL transfer - strongly suggests that UMs are indeed immunogenic despite their low mutational burden. The mechanisms that suppress TILs in pUM and mUM are unknown. We show that BAP1 loss is correlated with upregulation of several genes associated with suppressive immune responses, some of which build an immune suppressive axis, including HLA-DR, CD38, and CD74. Further, single-cell analysis of pUM by mass cytometry confirmed the expression of these and other markers revealing important functions of infiltrating immune cells in UM, most being regulatory CD8+ T lymphocytes and tumour-associated macrophages (TAMs). Transcriptomic analysis of hepatic mUM revealed similar immune profiles to pUM with BAP1 loss, including the expression of IDO1. At the protein level, we observed TAMs and TILs entrapped within peritumoural fibrotic areas surrounding mUM, with increased expression of IDO1, PD-L1, and β-catenin (CTNNB1), suggesting tumour-driven immune exclusion and hence the immunotherapy resistance. These findings aid the understanding of how the immune response is organised in BAP1 - mUM, which will further enable functional validation of detected biomarkers and the development of focused immunotherapeutic approaches. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

IL-24 inhibits endometrial cancer cell proliferation by promoting apoptosis through the mitochondrial intrinsic signaling pathway

BACKGROUND

Endometrial cancer is a type of malignant tumor of the female reproductive system. Preserving fertility in endometrial cancer patients is currently a formidable challenge. Interleukin-24 (IL-24) is a unique cytokine tumor suppressor gene belonging to the IL-10 cytokine family. IL-24 has broad-spectrum antitumor activity through different signaling pathways but does not affect normal cells. IL-24 gene therapy may provide a new method for the treatment of endometrial cancer.

METHODS

Transfection was used for gene transfer. The expression of IL-24 and related pathway proteins in endometrial cancer tissue and the Ishikawa cell line was detected by immunohistochemistry and Western blotting, respectively. The antitumor function of IL-24 was examined in vitro and in vivo. Cell proliferation was determined by CCK-8 assay, cell migration was shown by wound-healing assay, and cell invasion was detected by Transwell assay. Apoptosis was analyzed by TUNEL assay, and HE staining was performed to observe the morphology of the samples.

RESULTS

Immunohistochemical analysis showed different expression levels of IL-24 in human endometrial cancer tissues and normal endometrial tissues. IL-24 increased protein expression of BAX and Cytochrome C, while BCL-2, MMP-3, VEGF, Caspase-9 and Caspase-3 expression was decreased. Overexpression of IL-24 inhibited cell proliferation, migration and invasion, but increased cell apoptosis in endometrial cancer. Mechanistically, we demonstrated that IL-24 inhibited endometrial cancer cell growth by inducing cell apoptosis through the mitochondrial intrinsic signaling pathway. In addition, IL-24 inhibited tumor development by inducing cell apoptosis and inhibiting angiogenesis, as shown in xenograft tumor experiments.

CONCLUSIONS

Our study demonstrates the antitumor effect of IL-24 on endometrial cancer and shows that IL-24 may be a promising therapeutic gene for endometrial cancer gene therapy.

Interleukin-24 Regulates T Cell Activity in Patients With Colorectal Adenocarcinoma

Interleukin (IL)-24 plays a potential anti-tumor activity in colorectal cancer in a dose-dependent manner. However, the immunoregulatory role of IL-24 to peripheral and tumor-infiltrating T cell function in colorectal cancer was not fully elucidated. In this study, twenty-nine colorectal adenocarcinoma patients and fifteen healthy individuals were enrolled. IL-24 expression and IL-24 receptor (IL-20R1, IL-20R2, and IL-22R1) mRNA relative level was measured by ELISA and real-time PCR, respectively. CD4⁺ and CD8⁺ T cells were purified from peripheral bloods and cancer specimens, and were stimulated with low (10 ng/ml) and high (100 ng/ml) concentration of recombinant IL-24. CD4⁺ T cells activity was assessed by measurement of Th cell percentage, transcriptional factors, and cytokine production. CD8⁺ T cells activity was evaluated by investigation of cytotoxic molecules, target cell death, and interferon-γ (IFN-γ) secretion. IL-24 was decreasingly expressed in both peripheral bloods and cancer tissues in colorectal adenocarcinoma patients. However, IL-20R1 and IL-20R2 was comparable between healthy controls and colorectal adenocarcinoma patients. Low concentration of IL-24 suppressed CD4⁺ T cell proliferation. In contrast, high concentration of IL-24 not only promoted CD4⁺ T cell proliferation, but also enhanced CD4⁺ T cell activity, which mainly presented as up-regulation of Th1/Th17 frequency, T-bet/RORγt mRNA, and IFN-γ/IL-17 production but down-regulation of Treg percentage, FoxP3 mRNA, and IL-10/IL-35 secretion. Moreover, high concentration of IL-24 also increased perforin and granzyme B expression in CD8⁺ T cells, and elevated cytolytic and non-cytolytic activity of CD8⁺ T cells, which presented as induction of target cell death and elevation of IFN-γ expression. However, low concentration of IL-24 did not affect bioactivity of CD8⁺ T cells. The current data indicated that IL-24 might regulate T cell function in a dose-dependent manner. High-concentration of IL-24 might promote anti-tumor immune responses in development novel therapeutic approaches to colorectal adenocarcinoma.

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 clinical significance of Mda-7/IL-24 and C-myb expression in tumor tissues of patients with diffuse large B cell lymphoma

Diffuse large B cell lymphoma (DLBCL) is the most common type of non-Hodgkin's lymphoma in adults. Mda-7/IL-24 had been identified as a differentiation inducer of B phenotype lymphoma cells. Previous studies have revealed that knockdown of C-myb also leads to the terminal differentiation of B cell lymphoma. The aim of the present study was to investigate the association between the expression of Mda-7/IL-24 and C-myb, and their prognostic significance for DLBCL patients. The tumor tissues were collected from 72 cases of DLBCL patients and detected with reverse transcription-quantitative polymerase chain reaction, western blotting and immunohistochemistry assays. The results showed that, the expression of Mda-7/IL-24 mRNA and protein was lower while the expression of C-myb was higher in DLBCL tissues, compared with the specimens of normal lymph node tissues. Furthermore, C-myb expression was negatively correlated with Mda-7/IL-24 expression at mRNA and protein levels in DLBCL tissues. The expression of Mda-7/IL-24 and C-myb in DLBCL tissues was associated with some clinicopathological parameters such as clinical stage, infiltration in bone marrow, Ki67 expression level in the tumor tissues and overall survival rates. These results indicated that low expression of Mda-7/IL-24, along with high expression of C-myb, are predictor for poor prognosis of DLBCL patients, suggesting that Mda-7/IL-24 and C-myb may be potential targets for clinical treatment of DLBCL.

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.

Low expression of Mda-7/IL-24 and high expression of C-myb in tumour tissues are predictors of poor prognosis for Burkitt lymphoma patients

Objectives Burkitt lymphoma is one of the most common types of haematopoietic malignancy in children and adolescents. Mda-7/IL-24 had been identified as a differentiation inducer of Burkitt lymphoma cells. Previous studies have revealed that knockdown of C-myb can also lead to the terminal differentiation of Burkitt lymphoma cells. The aim of the present study was to investigate the correlation between the expression of Mda-7/IL-24 and C-myb, as well as their prognostic significance, for Burkitt lymphoma patients. Methods The tumour tissues were collected from 59 cases of Burkitt lymphoma patients and detected with Western blotting and immunohistochemistry. Results The results showed that the expression of Mda-7/IL-24 was lower, whereas the expression of C-myb was higher in Burkitt lymphoma tissues compared to specimens of normal lymph node tissues. Furthermore, C-myb expression was negatively correlated with Mda-7/IL-24 expression at the protein level in Burkitt lymphoma tissues and cell lines. Both the expression of Mda-7/IL-24 and C-myb in Burkitt lymphoma tissues was associated with some clinicopathological parameters, such as clinical stage, infiltration in the bone marrow, Ki67 and overall survival rates. Conclusion These results indicated that low expression of Mda-7/IL-24 along with high expression of C-myb are predictors for poor prognosis of Burkitt lymphoma patients; this outcome suggests that Mda-7/IL-24 and C-myb might be potential targets for clinical treatment of Burkitt lymphoma.

ABBREVIATIONS

Mda-7/IL-24: melanoma differentiation associated gene7/interleukin 24; FCM: flow cytometry; Ecog: Eastern Cooperative Oncology Group; IPI: International lymphoma prognosis index.

miR-203a-3p.1 targets IL-24 to modulate hepatocellular carcinoma cell growth and metastasis

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer‐related death. Cytokines, including interleukin 24 (IL‐24), play an important role in HCC. IL‐24 inhibits HCC metastasis but the molecular mechanism by which this occurs is still unknown. MicroRNAs (miRNAs) are regulators of cancers including hepatocellular carcinoma (HCC). However, the role that miRNAs play in the regulation of IL‐24 in HCC is unclear. The aim of this study was to investigate the effects of regulation of IL‐24 by miR‐203a‐3p.1 on liver cancer cell proliferation and metastasis. IL‐24 mRNA and miR‐203a‐3p.1 were detected by real‐time RT‐PCR, and IL‐24 protein in the cell growth medium was measured by ELISA. A luciferase assay was used to verify that the IL‐24 gene was the target of miR‐203a‐3p.1. Cell survival ability was detected by the MTT assay and colony formation. Cell metastasis was assayed by the Transwell system. The results showed that IL‐24 could be down‐regulated by miR‐203a‐3p.1 in HCC cells and that miR‐203a‐3p.1 acted as an onco‐miRNA by targeting IL‐24. Inhibition of miR‐203a‐3p.1 in cells could lead to the reversal of HCC cell proliferation and metastasis. The study highlights a novel molecular interaction between miR‐203a‐3p.1 and IL‐24, which indicates that IL‐24 and miR‐203a‐3p.1 may constitute potential therapeutic targets for HCC.

miR520c blocks EMT progression of human breast cancer cells by repressing STAT3

Breast cancer is one of the most malignant diseases world-wide and it ranks the first among female cancers. Masses of intrinsic and extrinsic factors, especially the inflammatory factors can lead to breast cancer. Aberrant activation and accumulation of key molecules can lead to inflammation associated carcinogenesis. The signal transducers and activators of transcription 3 (STAT3) is one of them. Therefore, to evaluate the novel molecular mechanisms, STAT3 has become our focus for breast cancer targeted therapy. At present, many tumor suppressing microRNAs have been validated, and are the highlights in research on microRNAs. Thus, we predicted microRNAs which could putatively regulate STAT3 through databases and selected six to screen with Dual-luciferase assay. The result hinted that miR520c could bind with STAT3 3'UTR. We mutated the seed sequence of miR520c on STAT3 3'UTR, which illustrated a reverse effect compared with wild-type of STAT3 3'UTR. Subsequently, STAT3, p-STAT3 and miR520c were assessed in three different grades of breast cancer cells, with the degree of malignancy, we found an escalating trend of STAT3 and p-STAT3, on the contrary, a downward trend of miR520c. We observed STAT3 was deactivated by miR520c. Epithelial to mesenchymal transition (EMT) is a fatal transfer of cancer progression. To find out whether the downregulation of STAT3 can repress breast cancer motility and invasion ability, we detected EMT markers. The result implied a suppression effect on EMT. We overexpressed STAT3 to conduct rescue experiments, the result showed a recovery of STAT3 and EMT characteristics. Cell motility and invasion property were regained as well. In the study, we elucidated miR520c could inhibit breast cancer EMT by targeting STAT3. It can enrich the mechanism of breast cancer and may lay the foundation for breast cancer targeted treatment.