CD132 expression promotes AML aggressiveness via the JAK-STAT signaling pathway Free

Acute myeloid leukemia (AML) is a common and challenging leukemia in adults, often accompanied by a poor prognosis. Despite the availability of diverse treatment approaches, relapse and refractory (R/R) was still the major cause of death in AML. Therefore, finding more effective therapeutic targets for R/R AML patients is key to improving prognosis.

In our previous clinical trial, we first observed that the MRD-positive relapse rate was significantly higher in AML patients who received IL-2 after transplantation. Further subgroup analysis showed that the hematologic-relapse was significantly higher in AML-M4/5 patients, whereas no such effect was seen in AML M2 patients. Subsequently, we replicated the study in mouse models and conducted in vitro experiments with human primary AML cells and AML cell lines, confirming that IL-2 directly promotes the growth of AML M4/5. Next, we investigated the differences between AML M4/5 and M2 and found that the inflammatory pathways in M4/5 were more activated than in M2. Additionally, the IL-2 receptor protein CD132 (IL2RG) on the surface of M4/5 cells was significantly higher than in M2 cells. After IL-2 stimulation, CD132 is further upregulated in primary AML cells, a process that can be interrupted by anti-CD132.

Through analyses of public databases and clinical samples (AML: n=200; healthy donors: n=42), we observed that CD132 expression is markedly elevated in AML compared to normal hematopoietic stem cells and tissue cells. Moreover, high CD132 expression in AML correlates with inferior long-term survival, indicating that CD132 may serve as a potential biomarker for the diagnosis and prognosis of AML. We then found that elevated CD132 expression was significantly associated with enhanced cell proliferation and increased resistance in vitro, using primary AML cells and cell lines. Furthermore, overexpression of CD132 led to enhanced cell proliferation, which could be further stimulated by IL-2. We then established a THP-1 CDX mouse model for validation and observed that CD132 knockdown significantly reduced tumor engraftment and peripheral organ invasion, while also markedly increasing the survival rate of the mice. Furthermore, IL-2 treatment led to a marked reduction in the survival rate in the control group, whereas no substantial difference in survival rate was observed between the IL-2-treated CD132 knockdown group and the untreated CD132 knockdown group.

Next, we performed a multi-omics integrated study, including RNA-seq, proteomics, phosphoproteomics, and lipidomics, on AML cells. We found that knockdown of CD132 led to significant downregulation of several pathways involved in cell proliferation, cell cycle progression, and migration at both the transcriptomic and proteomic levels. Additionally, lipid metabolism was impaired, while multiple cell death pathways, including apoptosis and ferroptosis, were activated. These findings suggest that CD132 expression is crucial for the survival and proliferation of AML cells. Among of which, JAK/STAT pathway was significantly enriched. Meanwhile, we found that AML cells with high CD132 expression exhibited significant activation of the JAK2/STAT3/5 pathway, which was further enhanced upon IL-2 stimulation. However, blocking CD132 with a neutralizing antibody or inhibiting JAK2 abrogated IL-2-induced activation of the JAK/STAT pathway. These findings suggest that the JAK2-STAT3/STAT5 pathway is a critical downstream signaling cascade of the IL-2/CD132 axis.

Finally, we utilized a deep learning–based efficacy prediction system (DLEPS) to identify potential therapeutic agents based on RNA-seq. Fedratinib, a JAK2 inhibitor, was predicted to suppress AML cell proliferation and induce apoptosis. This prediction was subsequently validated through in vitro assays and in vivo mouse models, demonstrating that JAK2 inhibition effectively impairs the proliferation of CD132-positive AML cells.

Our study identifies CD132 as a novel biomarker, prognostic indicator, and effective therapeutic target in AML. These findings provide potential drug candidate and cellular therapeutic target for the treatment of R/R AML, laying a critical foundation for future clinical translation.