[Mechanism of Sanzi Huangshi Pill in Treating MDS and Downregulating NRAS Gene Expression]

To investigate the therapeutic effect of Sanzi Huangshi Pill (SZHSP) on NHD13 myelodysplastic neoplasms (MDS) transgenic mice and its mechanism of regulating NRAS gene expression.

Six male homologous wild-type C57BL/6J mice were regarded as the control group, and 18 NUP98-HOXD13 transgenic mice were regarded as the model group, SZHSP-ST group, and SZHSP group, respectively. The control group and model group were given carboxymethyl cellulose sodium (0.5%) aqueous solution by gavage. The SZHSP-ST group and SZHSP group were orally administered with SZHSP suspension in stages. Regular weight and blood tests were conducted, and samples were collected after 6 months of continuous intervention to detect blood arsenic content and liver and kidney function. RT-qPCR technology was used to detect the expression level of NRAS mRNA in bone marrow mononuclear cells of mice in each group. SKM-1 cells were divided into control group, SZHSP group, stem cell factor (SCF) group, and SCF+SZHSP group. Western blot was used to detect the phosphorylation levels of p-ERK1/2 and p-MEK1, and CCK-8 assay was used to detect cell proliferation.

The results of animal experiment showed that, compared with the model group, the peripheral blood count of mice in the treatment group was significantly improved, and the SZHSP group was more significant than the SZHSP-ST group. The blood arsenic concentration of mice in the treatment group was significantly increased while liver and kidney function indicators were normal. Compared with the model group, the NRAS mRNA level of mice in the SZHSP group was significantly downregulated ( P < 0.05). In vitro experiments showed that, compared with the control group, the protein expression levels of p-MEK1 and p-ERK1/2 in the SCF group were significantly upregulated (both P < 0.01). Compared with the SCF group, the expression levels of p-MEK1 and p-ERK1/2 proteins were significantly downregulated in the SCF+SZHSP group (both P < 0.01). CCK-8 assay showed that SCF significantly induced SKM-1 cell proliferation but SZHSP inhibited it (both P < 0.01).

SZHSP can effectively improve the blood count of MDS mice and downregulate the expression level of NRAS gene. SZHSP can inhibit MDS cell proliferation through the MEK/ERK signaling pathway.