IL-24

Interleukin-24 (IL-24), also known as melanoma differentiation-associated gene 7 (MDA-7), is a member of the IL-10 family that functions as a tumor suppressor cytokine. It is secreted by activated monocytes, T cells, melanocytes and keratinocytes, and signals through two receptor complexes-IL-20Rα/IL-20Rβ and IL-22Rα1/IL-20Rβ-activating STAT1 and STAT3. Unlike most cytokines, IL-24 selectively induces apoptosis and toxic autophagy in tumor cells by upregulating pro-apoptotic factors (BAX, BAK), suppressing anti-apoptotic proteins (BCL-2, BCL-XL) and generating reactive oxygen species, while sparing normal cells. It additionally inhibits tumor angiogenesis, sensitizes cancer cells to radiation and chemotherapy, and exhibits anti-angiogenic and wound-healing properties in skin. IL-24 loss during melanoma progression made it a pioneering cancer gene therapy (INGN 241) evaluated in clinical trials for multiple advanced malignancies.