| 2001 |
IL-24 (MDA-7) is a secreted protein that functions as the ligand for two heterodimeric type II cytokine receptor complexes: IL-22R1/IL-20R2 and IL-20R1/IL-20R2. Binding to either receptor complex on human keratinocytes or ectopically expressed receptors on baby hamster kidney cells leads to activation of STAT transcription factors. |
Ligand-receptor binding assays (saturation kinetics on transfected COS cells), STAT activation assays on keratinocytes and BHK cells |
The Journal of biological chemistry |
High |
11706020
|
| 2003 |
MDA-7/IL-24-induced cancer-specific apoptosis occurs through JAK/STAT-independent pathways; inhibition of JAK (AG490), general tyrosine kinases (genistein, AG18), or absence of IL-20R/IL-22R expression did not prevent Ad.mda-7-induced apoptosis. Instead, partial inhibition of apoptosis was achieved with the p38 MAPK inhibitor SB203580, implicating p38 MAPK as a mediator of cancer cell killing. |
Pharmacological inhibition with selective kinase inhibitors; apoptosis assays in STAT/JAK-deficient cell lines; receptor expression profiling |
Journal of cellular physiology |
High |
12811827
|
| 2003 |
Ad.mda-7 expression in glioma cells activates p38 and ERK1/2, and radiosensitization of glioma cells by MDA-7/IL-24 requires JNK1/2 signaling; inhibition of JNK1/2 (but not p38) abolished radiosensitization. ERK and PI3K signaling are protective against MDA-7 lethality. |
Pharmacological inhibitor studies (JNK inhibitor SP600125, MEK/PI3K inhibitors), colony formation assays, cell cycle analysis |
Cancer biology & therapy |
Medium |
14508103
|
| 2003 |
MDA-7/IL-24 negatively regulates both the beta-catenin and PI3K signaling pathways in breast and lung cancer cells; it redistributes beta-catenin from nucleus to plasma membrane (reducing TCF/LEF transcription), upregulates E-cadherin, APC, GSK-3beta, PTEN, and downregulates FAK, ILK-1, Akt, and PLC-gamma in a tumor cell-specific manner. |
Microarray analysis, Western blotting, reporter gene assay (TCF/LEF luciferase), pharmacological PI3K inhibition (wortmannin) |
Molecular therapy |
Medium |
12907143
|
| 2004 |
Secreted glycosylated MDA-7/IL-24 protein kills melanoma cells via IL-20 receptor engagement (both type 1 and type 2 IL-20R) through a STAT3-independent, PKR-independent signaling pathway; receptor engagement induces STAT3 phosphorylation and nuclear translocation but the cytotoxic effect operates through a separate pathway involving BAX upregulation. |
Neutralizing anti-MDA-7 and anti-receptor antibodies, STAT3 inhibition, receptor expression on melanoma cells, apoptosis assays with recombinant MDA-7 protein |
Molecular therapy |
Medium |
15564140
|
| 2004 |
Ad.mda-7 radiosensitizes non-small cell lung cancer cells by suppressing components of the non-homologous end-joining (NHEJ) DNA repair pathway, specifically downregulating Ku70, XRCC4, and DNA ligase IV protein expression; this correlated with impaired DSB rejoining kinetics measured by pulsed-field gel electrophoresis and reduced host-cell reactivation capacity. |
Western blotting, pulsed-field gel electrophoresis (DSB rejoining kinetics), host cell reactivation assays |
Oncogene |
Medium |
15273727
|
| 2004 |
Ectopic MDA-7/IL-24 production inhibits lung cancer cell migration and invasion by downregulating PI3K/AKT, focal adhesion kinase (FAK), and matrix metalloproteinases MMP-2 and MMP-9, and reduces experimental lung metastasis in vivo. |
Cell migration and invasion assays in vitro, Western blotting for pathway components, experimental lung metastasis mouse model |
Molecular therapy |
Medium |
15093181
|
| 2004 |
GST-MDA-7 fusion protein radiosensitizes primary human glioma cells through ROS generation and JNK1/2/3 activation, operating via both ROS-dependent and ROS-independent parallel pro-apoptotic pathways; JNK signaling activates BAX and the intrinsic (caspase-9) apoptotic pathway; N-acetyl cysteine (NAC) blocked JNK activation and killing but not BAD/BAX upregulation. |
MTT assay, clonogenic survival assay, pan-caspase/specific caspase inhibitors, ROS scavenger (NAC), JNK inhibitor (SP600125), 3D soft agar overlay assays with secretion-deficient MDA-7 mutant |
Cancer biology & therapy |
Medium |
15197348
|
| 2005 |
MDA-7/IL-24-induced apoptosis in human ovarian cancer cells involves activation of transcription factors c-Jun and ATF-2, which drive transcription of FasL and Fas; this is accompanied by NF-κB activation and recruitment of FADD and caspase-8. siRNA knockdown of Fas or antibody blockade of FasL abrogated Ad.mda-7-mediated apoptosis. Fas promoter activity was specifically induced by Ad.mda-7. |
siRNA knockdown of Fas, FasL neutralizing antibody (NOK-1), promoter-reporter luciferase assay, Western blotting, apoptosis assays (TUNEL, Annexin V) |
Cancer research |
High |
15833826
|
| 2005 |
Secreted MDA-7/IL-24 protein suppresses angiogenesis by sensitizing human umbilical vein endothelial cells (HUVECs) to ionizing radiation, reducing bFGF and VEGF levels and microvessel density in tumors, without sensitizing normal lung fibroblasts. |
Clonogenic survival assay with conditioned medium from stably transfected MDA-7 cells, in vivo xenograft tumor model with histological analysis (CD31, bFGF, VEGF) |
Molecular therapy |
Medium |
15194048
|
| 2005 |
Ad-mda7 kills pancreatic cancer cells via G2/M arrest and apoptosis through regulation of Wnt/PI3K pathway proteins (beta-catenin, APC, GSK-3, JNK, PTEN). Bystander killing of non-transduced pancreatic cancer cells is mediated specifically by secreted MDA-7 protein engaging IL-20 receptors, as shown by neutralizing anti-MDA-7 and anti-IL-20R antibodies. |
Cell cycle analysis, Western blotting, neutralizing antibody experiments (anti-MDA-7, anti-IL-20R), apoptosis assays |
Molecular therapy |
Medium |
15851011
|
| 2006 |
N-glycosylation of MDA-7/IL-24 is dispensable for cancer-specific apoptosis and bystander antitumor activity. A nonglycosylated, nonsecreted MDA-7/IL-24 mutant (signal peptide deleted, three N-glycosylation sites mutated) retained tumor-selective apoptosis, ER localization, JAK/STAT-independent and p38 MAPK-dependent killing, ER stress induction (BiP/GRP78, GRP94, XBP-1, eIF2alpha), and physical interaction with BiP/GRP78. |
Site-directed mutagenesis (N-glycosylation sites), adenoviral expression, co-immunoprecipitation (MDA-7 with BiP/GRP78), Western blotting for ER stress markers, apoptosis assays |
Cancer research |
High |
17178884
|
| 2008 |
Intracellular MDA-7/IL-24 protein induces cancer-specific apoptosis by triggering an endoplasmic reticulum (ER) stress response, evidenced by expression of BiP/GRP78, GRP94, GADD153, and phospho-eIF2α, and reactive oxygen species production. Secreted MDA-7/IL-24 protein activates a positive autocrine feedback loop: recombinant MDA-7/IL-24 induces stabilization of endogenous mda-7/IL-24 mRNA (posttranscriptionally, without activating the promoter), requiring de novo protein synthesis, thereby sustaining ER stress and apoptosis. |
mRNA stability assays, promoter-reporter assays, protein synthesis inhibition (cycloheximide), ER stress marker Western blotting, ROS measurement, recombinant MDA-7/IL-24 protein treatment |
Proceedings of the National Academy of Sciences of the United States of America |
High |
18599461
|
| 2008 |
GST-MDA-7 kills primary human glioma cells through PERK-dependent ER stress, which activates JNK1-3 leading to BAX activation and mitochondrial dysfunction. PERK-/- cells are resistant to GST-MDA-7 lethality. GST-MDA-7 also induces PERK- and JNK-dependent autophagic vacuolization of LC3-expressing endosomes; knockdown of ATG5 or Beclin-1 reduces lethality. Cathepsin B-dependent cleavage of BID and suppression of BAD/BIM phosphorylation and HSP70 expression also contribute. |
PERK-/- cells, JNK inhibitor, caspase-9 dominant-negative, ATG5/Beclin-1 siRNA knockdown, cathepsin inhibitors, HSP70 overexpression, Western blotting, fluorescence microscopy (LC3-GFP) |
Molecular cancer therapeutics |
High |
18281515
|
| 2009 |
GST-MDA-7 kills renal carcinoma cells by ceramide-dependent plasma membrane clustering of CD95 (Fas) and association of CD95 with procaspase-8; downstream signaling involves PERK-dependent ER stress activation of JNK-1/2 and p38 MAPK. Knockdown of CD95 abolished PERK phosphorylation by GST-MDA-7, positioning CD95 upstream of PERK in this pathway. Ceramide generation via ceramide synthase-6 and acid sphingomyelinase was required for CD95 clustering. |
siRNA knockdown of CD95, ceramide synthase-6, acid sphingomyelinase; dominant negative PERK; caspase-8 inhibitor; short-form c-FLIP overexpression; Western blotting; autophagy assays (ATG5 knockdown) |
Molecular cancer therapeutics |
High |
19417161
|
| 2010 |
Ad.mda-7 infection of cancer cells (but not normal cells) causes increased ceramide accumulation via de novo synthesis (serine palmitoyltransferase-dependent) and acid sphingomyelinase (ASMase) activation; ceramide mediates ER stress induction (blocking ceramide synthesis blocks BiP/GRP78, GADD153, phospho-eIF2α induction). Ceramide activates protein phosphatase 2A (PP2A), leading to dephosphorylation of anti-apoptotic BCL-2. |
Lipidomic analysis of ceramide species (C16, C24, C24:1), SPT inhibitor myriocin (ISP1), fumonisin B1, ASMase siRNA knockdown, PP2A activity assay, Western blotting for ER stress markers |
Journal of cellular physiology |
High |
19937735
|
| 2011 |
In prostate cancer cells, Ad.mda-7 induces early autophagy that switches to apoptosis; MDA-7/IL-24 protein physically interacts with Beclin-1 (potentially inhibiting its autophagy-promoting function), and calpain-mediated cleavage of ATG5 contributes to the autophagy-to-apoptosis switch. |
Co-immunoprecipitation (MDA-7/IL-24 with Beclin-1), autophagy and apoptosis markers, calpain inhibitor studies |
Autophagy |
Medium |
21610321
|
| 2012 |
MDA-7/IL-24 differentially regulates clusterin (CLU) in prostate cancer cells: Ad.mda-7 decreases soluble CLU (sCLU) and increases nuclear CLU (nCLU), promoting apoptosis and G2/M arrest. MDA-7/IL-24 was identified as a CLU-interacting protein by co-immunoprecipitation in DU-145 cells, and the initial sCLU-MDA-7/IL-24 interaction produces a transient cytoprotective effect. |
Co-immunoprecipitation (MDA-7/IL-24 with CLU), stable CLU overexpressing clones, Western blotting, cell viability and apoptosis assays, xenograft mouse models |
Journal of cellular physiology |
Medium |
21732348
|
| 2013 |
MDA-7/IL-24 induces expression of SARI (suppressor of AP-1, induced by IFN) in diverse cancer cells but not normal cells, and SARI expression is required for mda-7/IL-24-mediated cell death (SARI antisense blocked mda-7/IL-24 antitumor effects). Binding of secreted MDA-7/IL-24 to its cognate receptors (IL-20R1/IL-20R2 or IL-22R/IL-20R2) induces p38 MAPK phosphorylation, leading to GADD gene transcription and apoptosis; p38 MAPK inhibition prevented SARI induction by Ad.mda-7. |
SARI antisense knockdown, p38 MAPK inhibitor, receptor-binding studies with recombinant His-MDA-7, Western blotting, cell death assays; ERK1/2 inhibitor reversal in pancreatic cancer cells |
Cancer research |
Medium |
24282278
|
| 2015 |
IL-24 inhibits lung cancer cell migration and invasion by post-transcriptionally downregulating CXCR4 mRNA (decreasing mRNA half-life by >40%), thereby disrupting the SDF-1/CXCR4 signaling axis and reducing pAKT, pmTOR, pPRAS40, and HIF-1α. Combined IL-24 with CXCR4 inhibitors (AMD3100, SJA5) or CXCR4 siRNA showed enhanced inhibition of tumor cell migration. |
Doxycycline-inducible stable IL-24 expression, qRT-PCR mRNA half-life assay, Western blotting for CXCR4 and downstream signaling, flow cytometry, cell migration/invasion assays, luciferase reporter assay |
PloS one |
Medium |
25775124
|
| 2016 |
MDA-7/IL-24 downregulates miR-221 and upregulates p27 and PUMA in cancer cells; this effect is ROS-dependent and leads to cell death. MDA-7/IL-24 regulates autophagy through a miR-221/Beclin-1 feedback loop (Beclin-1 identified as a new transcriptional target of miR-221). Overexpression of miR-221 rescues cancer cells from mda-7/IL-24-mediated death. |
miRNA profiling, overexpression of miR-221, recombinant His-MDA-7 protein treatment, ROS measurement, Western blotting (p27, PUMA, Beclin-1), xenograft model with miR-221-overexpressing cells |
Cancer research |
Medium |
27940575
|
| 2016 |
mda-7/IL-24 induces caspase-3/9-independent apoptosis in neuroblastoma cells through a pathway involving ATM phosphorylation, γ-H2AX induction, and nuclear translocation of apoptosis-inducing factor (AIF). Inhibition of AIF rescued cells from Ad.5/3-CTV-induced death, while pan-caspase inhibition failed. ATM small-molecule inhibitors blocked γ-H2AX, AIF translocation, and PARP cleavage. |
AIF siRNA knockdown, ATM inhibitors, pan-caspase inhibitor (z-VAD), Western blotting (γ-H2AX, phospho-ATM, AIF), nuclear fractionation, in vivo xenograft |
Cancer research |
Medium |
27197168
|
| 2018 |
IL-24 promotes apoptosis in breast cancer cells through cAMP-dependent PKA activation, which is required for IL-24-induced cell death; PKA stimulates p38 MAPK phosphorylation, upregulates Fas/FasL pathway components and death receptor 4, and induces phosphorylation and nuclear import of TP53. |
PKA inhibition/activation pharmacological studies, Western blotting (phospho-p38, phospho-TP53, FasL, DR4), cell viability assays, nuclear fractionation |
International journal of molecular sciences |
Medium |
30424508
|
| 2019 |
MDA-7/IL-24 downregulates DICER (a key miRNA processing enzyme) in multiple cancer cells but not normal cells, through IL-20/IL-22 receptors; this is ROS-dependent and mediated through melanogenesis-associated transcription factor (MITF). DICER overexpression partially rescues cancer cells from mda-7/IL-24-mediated cell death and impedes mda-7/IL-24 inhibition of tumor growth in vivo. |
Gain- and loss-of-function studies (DICER overexpression/knockdown), recombinant His-MDA-7 protein, Western blotting (DICER, DROSHA, PASHA, Argonaute), receptor neutralization, ROS measurement, xenograft tumor model |
Proceedings of the National Academy of Sciences of the United States of America |
High |
30842276
|
| 2000 |
The mda-7 gene promoter contains functional binding sites for AP-1 (c-Jun) and C/EBP transcription factors; ectopic expression of AP-1/c-Jun or C/EBP enhances mda-7 promoter activity in melanoma cells while a dominant-negative c-Jun (TAM67) does not. Electrophoretic mobility shift assays (EMSA) confirmed binding of nuclear proteins from terminally differentiated melanoma cells to AP-1 and C/EBP consensus sites in the mda-7 promoter. |
Luciferase reporter assay (mda-7 promoter-luciferase), EMSA with nuclear extracts, Western blotting (cJun, C/EBP-beta), dominant-negative c-Jun overexpression |
Journal of cellular physiology |
Medium |
10942517
|
| 2001 |
FISP (murine IL-24 ortholog) is selectively expressed and secreted by Th2 cells; its expression during Th2 differentiation requires two signals: TCR signaling involving protein kinase C activation, and STAT6-dependent IL-4 receptor signaling. |
Differential gene expression during Th1/Th2 differentiation, PKC activation/inhibition, STAT6-deficient cells, secretion assays |
Journal of immunology |
Medium |
11342597
|
| 2020 |
IL-17A triggers a Th17 cell-intrinsic autocrine negative feedback loop: IL-17A binds its receptor on Th17 cells, activates NF-κB, which induces IL-24 expression; IL-24 in turn represses the Th17 cytokine program (GM-CSF, IL-17F). In vivo, IL-24 treatment ameliorated Th17-induced EAU, while IL-24 silencing in Th17 cells enhanced disease. |
IL-17A loss-of-function in Th17 cells, mechanistic in vitro NF-κB activation studies, IL-24 silencing in Th17 cells, IL-24 treatment of EAU mouse model, cytokine measurements |
Immunity |
High |
32673565
|
| 2022 |
IL-24 protein accumulates in the cytosol under conditions of proteasome dysfunction (when ER-associated degradation is blocked), and cytoplasmic IL-24 activates PKR (protein kinase R), which serves as an innate immune sensor for proteotoxic stress. PKR activation by cytoplasmic IL-24 drives NF-κB and type I IFN signaling; PKR also phosphorylates eIF2α to limit new protein translation. Blocking IL-24 egress into the cytosol (by inhibiting ERAD) suppressed PKR activation and downstream inflammatory signaling. |
PKR genetic deletion in vitro and in vivo (PKR-deficient mice), proteasome inhibitor-induced inflammatory models, ERAD inhibition to block cytoplasmic IL-24 accumulation, eIF2α phosphorylation assays, patient cells from PRAAS |
Science immunology |
High |
35148201
|
| 2022 |
In Th17 cells, IL-24 is recruited to the inner mitochondrial membrane where it interacts with NADH dehydrogenase (ubiquinone) 1 α subcomplex subunit 13 (GRIM19/NDUFA13), a complex I respiratory chain component. Together, IL-24 and GRIM19 promote accumulation of STAT3 in the mitochondrial compartment, limiting STAT3 nuclear deflections and promoting IL-10 production to restrain Th17 pathogenicity. This function is independent of IL-24 cell surface receptor signaling. |
Mitochondrial fractionation, co-immunoprecipitation (IL-24 with GRIM19), STAT3 mitochondrial localization assays, receptor-independent signaling experiments, EAU model |
The Journal of experimental medicine |
High |
35819408
|
| 2004 |
A novel splice variant of mda-7/IL-24 (mda-7s), encoding a 63-residue 12 kDa protein lacking exons 3 and 5, co-precipitates full-length MDA-7 and reduces secretion of co-transfected MDA-7 protein. |
Co-immunoprecipitation (mda-7s with full-length MDA-7), secretion assays, RT-PCR expression analysis |
The Journal of investigative dermatology |
Low |
15304100
|
| 2020 |
IL-24 deficiency protects mice from bleomycin-induced pulmonary fibrosis; mechanistically, IL-24 synergizes with IL-4 to promote macrophage M2 polarization by suppressing IL-4-induced SOCS1 and SOCS3 expression, thereby enhancing STAT6/PPARγ signaling. |
IL-24 knockout mice, bleomycin fibrosis model, macrophage M2 polarization assays, Western blotting (SOCS1, SOCS3, STAT6, PPARγ), cytokine quantification (TGF-β1) |
Cell death and differentiation |
High |
33144678
|
| 2006 |
In CLL B-cells, MDA-7/IL-24 activates p38 MAPK, and this activation is required for CLL cell survival; siRNA knockdown of mda-7/IL-24 specifically inhibited p38 MAPK phosphorylation and increased spontaneous apoptosis three-fold. Recombinant IL-24 could re-induce p38 MAPK phosphorylation. |
siRNA knockdown of mda-7/IL-24, p38 MAPK pharmacological inhibitor (SB203580), recombinant IL-24 protein treatment, Western blotting, apoptosis assays |
Leukemia |
Medium |
16408101
|
| 2018 |
Recombinant MDA-7/IL-24 protein inhibits prostate cancer bone metastasis by both selectively killing prostate cancer cells and inhibiting osteoclast differentiation. Gain- and loss-of-function studies show that the Akt and Mcl-1 prosurvival pathways are critically required for anti-bone metastatic activity of MDA-7/IL-24. |
Bone metastasis experimental model, gain/loss-of-function genetic approaches (Akt, Mcl-1), Mcl-1 small-molecule inhibitor, in vivo femur metastasis quantification, Western blotting |
Molecular cancer therapeutics |
Medium |
29934341
|