姜黄素联合三氧化二砷增强自噬与免疫监视抑制急性髓系白血病免疫逃逸

Acute myeloid leukemia (acute myeloid leukemia, AML) is a type of malignant hematological tumor characterized by high incidence, high mortality, and high recurrence rates. Although chemotherapy, targeted therapy, and immunotherapy have achieved certain therapeutic effects in recent years, immune evasion by tumor cells remains a key factor in the relapse and refractoriness of AML. Current research suggests that arsenic trioxide (Arsenic Trioxide, ATO) can regulate autophagy and upregulate NKG2D ligands (NKG2D-L) on the surface of AML cells, while the NKG2D-NKG2D-L axis is negatively associated with AML immune evasion. Our preliminary experimental studies have shown that the combination of curcumin (curcumin, CUR) and ATO can inhibit the proliferation of acute myeloid leukemia KG-1a cells, induce apoptosis, and suppress the malignant progression and metastasis in AML mouse models. However, the mechanisms underlying AML immune evasion have not yet been fully elucidated. Therefore, the main objective of this study is to investigate the effects and mechanisms of CUR combined with ATO in regulating autophagy in AML cells, activating the NKG2D-NKG2D-L axis, and inhibiting AML immune evasion both in vitro and in vivo.

First, an AML mouse model was established by intravenous injection of KG-1a cells into the tail vein of mice. The antitumor effects of CUR and ATO, either alone or in combination, on AML mice were observed. The correlation between drug regulation of autophagy, the NKG2D-NKG2D-L axis, and AML immune evasion was elucidated using ELISA and Western Blot techniques. Second, an in vitro AML cell model was established using KG-1a cells. The inhibitory and pro-apoptotic effects of CUR and ATO, either alone or in combination, on KG-1a cells were observed using the CCK8 assay and flow cytometry. The regulatory effects of the drugs on autophagy in KG-1a cells were observed using monodansylcadaverine (Monodansylcadaverine, MDC) staining and transmission electron microscopy. The specific molecular mechanisms by which CUR and ATO promote apoptosis in KG-1a cells were elucidated using Western Blot technology. Finally, an in vitro co-culture model of NK cells and KG-1a cells was established. After 24 h of intervention with CUR and ATO in combination, 3-MA to block autophagy, and 2-PCPA to induce NKG2D-L expression, the immunotoxic effects of NK cells on KG-1a cells were observed using the CCK8 assay and flow cytometry. The mechanisms by which CUR combined with ATO regulate autophagy in KG-1a cells, activate the NKG2D-NKG2D-L axis, and enhance NK cell immunosurveillance to inhibit AML immune evasion were elucidated and verified using ELISA and Western Blot techniques.

After intravenous injection of logarithmic phase KG-1a cells, numerous dysplastic cells were observed in bone marrow smears under the microscope. Hematoxylin and eosin (HE) staining of spleen tissue showed disordered spleen structure and tissue damage. Flow cytometry revealed a significant increase in the proportion of CD34+ cells in the peripheral blood of model mice (P < 0.001), indicating a significant increase in undifferentiated primitive cells in the peripheral blood, which confirmed the successful establishment of the AML mouse model. After CUR and ATO intervention, the model mice showed no clustering, were more active, had no arched backs, and their body weight gradually increased, indicating better survival conditions in the drug treatment groups compared to the model group. The body weight of mice in the CUR combined with ATO treatment group increased significantly (P < 0.05). The disordered spleen structure and tissue damage were significantly alleviated, and the number of dysplastic cells in the bone marrow decreased markedly, suggesting a synergistic anti-AML effect of CUR and ATO. ELISA analysis showed that compared to the control group, the model group had a significant increase in IL-10 (P < 0.0001) and a non-significant decreas