fig6

Figure 6. RBCEVs deliver siRCN1 to inhibit AML cell growth. (A) Flow cytometry analysis of Cy5-positive THP-1 cells following exposure to unlabeled or Cy5-labeled siRCN1-loaded RBCEVs; (B) RCN1 mRNA abundance in THP-1 cells following treatment with RBCEVs loaded with siNC or siRCN1, with normalization to GAPDH; (C) Western blotting was performed to detect RCN1 abundance in THP-1 cells after exposure to siNC- or siRCN1-loaded RBCEVs; (D) Viability of THP-1 cells after exposure to siNC- or siRCN1-loaded RBCEVs (n = 3); (E) Experimental timeline of RBCEV-based treatment in AML xenograft model. Created in BioRender. (2026) https://app.biorender.com/illustrations/68e21c4c8adcfd2e83913967?slideId=fd7ad390-ba70-4bac-b234-3e9a309f5088; (F) Representative tumor images and tumor weights from xenograft mice receiving siNC- or siRCN1-loaded RBCEVs every 3 days (n = 6 per group); (G) Tumor volume was monitored at 3-day intervals during the treatment period; (H) Body weight was tracked throughout treatment to evaluate potential systemic toxicity. Data are expressed as mean ± standard deviation. Statistical significance was assessed using a two-tailed unpaired t-test (A and B, D and F) and a two-way ANOVA (G). ns, not significant. ^**P < 0.01; ^***P < 0.001; ^****P < 0.0001. AML: Acute myeloid leukemia; ANOVA: analysis of variance; Cy5: cyanine 5; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; mRNA: messenger RNA; RBCEV: red blood cell extracellular vesicle; RBCEVs: red blood cell extracellular vesicles; RCN1: reticulocalbin 1; siNC: small interfering negative control; siRCN1: small interfering RNA targeting RCN1.