Acute myeloid leukemia (AML) is a malignancy of the hematological system, for which there remains an urgent need for new therapeutic and diagnostic targets. COMM domain containing 7 (COMMD7) is a recently-identified oncogene linked to poor prognosis in AML. COMMD7 regulates multiple signaling pathways, including nuclear factor-kappa B (NF-κB) signaling. Here, we report that COMMD7 is highly expressed in the AML cell lines KG1a and U937 and that its inhibition by shRNA reduced proliferation, promoted apoptosis and facilitated cell cycle arrest in the G2/M phase in relation to depression of the NF-κB pathway. Furthermore, zinc finger protein 460 (ZNF460) is overexpressed in AML and regulates COMMD7. We found that knockdown of ZNF460 downregulated the expression of COMMD7 while the NF-κB pathway was also inhibited. In addition, we noticed that knockdown of ZNF460 reduced proliferation and increased apoptosis rate of AML cells and that the cell cycle was blocked in the G2/M phase. In brief, our results revealed a critical effect of the ZNF460-COMMD7-NF-κB axis for the proliferation of AML cells. Therefore, COMMD7 may be a possible therapeutic target for AML.

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Acute myeloid leukemia (AML) is a heterogeneous neoplasm characterized by variations in cytogenetics and molecular abnormalities, which result in variable response to therapy. Receptor-interacting serine/threonine kinase 1 (RIP1)-mediated necroptosis has been reported to have a potential role in the treatment of AML. We obtained Skp2 and RIP1 are significantly overexpressed in AML samples using original published data, and identified that Skp2-depletion in AML cells significantly suppressed RIP1. Functional analysis showed that the inhibition of RIP1 caused by necrostatin-1 (Nec-1) inhibited the proliferation, simultaneously facilitate both the apoptosis and differentiation of AML cells. Mechanistical analysis elucidated that knockdown of Skp2 suppresses RIP1 by transcriptional regulation but not by proteasome degradation. Additionally, Skp2 regulated the function of RIP1 by decreasing K63-linked ubiquitin interaction with RIP1. Moreover, the suppression of Akt/GSK3β was observed in Skp2 knockdown stable NB4 cells. Also, GSK3β inactivation via small-molecule inhibitor treatment remarkably decreased RIP1 level. RIP1 regulates differentiation by interacting with RARα, increasing RA signaling targets gene C/EBPα and C/EBPβ. In conclusion, our study provides a novel insight into the mechanism of tumorigenesis and the development of AML, for which the Skp2-Akt/GSK3β-RIP1 pathway can be developed as a promising therapeutic target.

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