Melanoma differentiation associated gene-7/interleukin-24 promotes tumor cell-specific apoptosis through both secretory and nonsecretory pathways
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Updated: Aug 24, 2026
Ex Vivo Culture of Circulating Tumor Cells in the Cerebral Spinal Fluid from Melanoma Patients to Study Melanoma-Associated Leptomeningeal Disease
Published on: March 29, 2024
Moira Sauane1, Irina V Lebedeva, Zao-zhong Su
1Department of Pathology, Herbert Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University Medical Center, New York, New York 10032, USA.
Abstract:
Melanoma differentiation associated gene-7/interleukin-24 (Mda-7/IL-24), a novel member of the IL-10 family of cytokines, uniquely displays cancer-specific apoptosis-inducing activity. Positive results in ongoing phase I/II clinical trials have strengthened the possibility of its utilization as a cancer gene therapeutic. Previous studies document that signaling events leading to Ad.mda-7-induced transformed cell apoptosis are tyrosine kinase-independent. These results suggest that mda-7/IL-24 cancer cell-specific activity could occur through mechanisms independent of binding to its currently recognized cognate receptors and might even occur independent of receptor function. An adenovirus vector expressing a nonsecreted version of MDA-7/IL-24 protein was generated via deletion of its signal peptide. This nonsecreted protein was as effective as wild-type secreted MDA-7/IL-24 in inducing apoptosis in prostate carcinoma cell lines and displayed transformed cell specificity and localization of MDA-7/IL-24 in the Golgi/endoplasmic reticulum compartments. Our results indicate that mda-7/IL-24-mediated apoptosis can be triggered through a combination of intracellular as well as secretory mechanisms and can occur efficiently in the absence of protein secretion.
Insights
Melanoma differentiation associated gene-7/interleukin-24 (MDA7/IL-24) induces cancer cell death. This novel cancer therapeutic can function intracellularly, independent of its usual receptor signaling pathways.
Area of Science:
- Oncology
- Molecular Biology
- Gene Therapy
Background:
- Melanoma differentiation associated gene-7/interleukin-24 (MDA7/IL-24) is a cytokine with cancer-specific apoptosis-inducing properties.
- Ongoing clinical trials suggest MDA7/IL-24's potential as a gene therapeutic agent.
- Previous research indicates that MDA7/IL-24-induced apoptosis is independent of tyrosine kinase signaling.
Purpose of the Study:
- To investigate the mechanisms of MDA7/IL-24-mediated apoptosis, particularly whether it requires receptor function or protein secretion.
- To determine if a nonsecreted form of MDA7/IL-24 can retain its apoptosis-inducing activity.
Main Methods:
- An adenovirus vector was engineered to express a nonsecreted version of MDA7/IL-24 by deleting its signal peptide.
- The apoptosis-inducing efficacy of the nonsecreted MDA7/IL-24 was compared to the wild-type secreted form in prostate carcinoma cell lines.
- Subcellular localization of the nonsecreted MDA7/IL-24 was examined.
Main Results:
- The nonsecreted MDA7/IL-24 protein effectively induced apoptosis in prostate carcinoma cells, comparable to the wild-type secreted form.
- The nonsecreted MDA7/IL-24 exhibited transformed cell specificity.
- Localization studies revealed the nonsecreted MDA7/IL-24 within the Golgi/endoplasmic reticulum compartments.
Conclusions:
- MDA7/IL-24-mediated apoptosis can be triggered by both intracellular and secretory mechanisms.
- Efficient apoptosis induction by MDA7/IL-24 can occur even without protein secretion, suggesting receptor-independent pathways.
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