目的 研究猪苓多糖抑制胃黏膜上皮细胞（GES-1）间充质转化的作用和机制。方法 应用N-甲基-N'-硝基-N-亚硝基（MNNG，40 μmol·L^-1）诱导GES-1细胞间充质转化模型，造模同时给予猪苓多糖（1.25、2.50、5.00、10.00 mg·mL^-1）处理24、48 h后，CCK-8法检测细胞增殖能力；造模同时给予猪苓多糖（5.00 mg·mL^-1）处理48 h后，实时定量PCR（qRT-PCR）法检测猪苓多糖对N-cadherin、Snail、Twist、Fibronection及Vmention mRNA表达的影响；Western blotting法检测E-cadherin、N-cadherin、Snail、Twist、Fibronetin、Vimentin、STAT3、p-STAT3、JAK2、p-JAK2蛋白表达。裸鼠分别sc经MNNG 40 μmol·L^-1处理48 h后的GES-1细胞（5×10⁷·mL^-1 ，0.2 mL）、胃癌细胞SGC7901（5×10⁷·mL^-1 ，0.2 mL ，阳性对照），1个月后观察各组成瘤及体质量情况，注射局部进行HE染色后行组织病理学观察，验证GES-1细胞经MNNG处理后是否达到肿瘤阶段。结果 与模型组比较，随猪苓多糖浓度的增加，GES-1细胞增殖能力逐渐上升，到达5 mg·mL^-1时增殖能力最高，差异显著（P<0.01、0.001）；猪苓多糖组N-cadherin、Snail、Twist、Fironetion及Vimentin的mRNA表达均显著下降（P<0.05、0.01、0.001）；猪苓多糖组E-cadherin蛋白表达显著上升（P<0.05），N-cadherin、Snail、Twist、Fibronetion、Vimentin及通路蛋白STAT3、p-STAT3、JAK2、p-JAK2表达显著下降（P<0.05、0.01、0.001）。对照组和MNNG处理的GES-1组未见瘤体形成，阳性对照SGC7901组注射后1周左右局部出现瘤体，1个月瘤体长至6 cm左右；MNNG处理的GES-1组裸鼠精神较差，体质量明显减轻，SGC7901组裸鼠状态差，体质量大幅减轻；对照组和MNNG组病理染色显示为正常的皮肤组织，阳性对照组显示为肿瘤组织。结论 猪苓多糖可能通过抑制JAK2-STAT3通路干预MNNG诱导的GES-1细胞上皮间充质化。

Objective To study the inhibitory effect of polyporus polysaccharides (PPS) on mesenchymal transformation of gastric epithelial cells (GES-1) and its preliminary mechanism. Methods GES-1 cell mesenchymal transition model was induced by N-methyl-N'-nitro-N-nitroso (MNNG, 40 μmol·L^-1). The model was established and treated with PPS (1.25, 2.50, 5.00, 10.00 mg·mL^-1) for 24 and 48 h. The cell proliferation ability was measured using the CCK8 method.After 48 hours of treatment with PPS(5.00 mg·mL^-1), the effects of PPS on N-cadherin, Snail, Twist, Fibronection, and Vmention mRNA expression were detected using real-time quantitative PCR (qRT-PCR), and Western blotting was used to detect the expression of E-cadherin, N-cadherin, Snail, Twist, Fibronetin, Vimentin, STAT3, p-STAT3, JAK2, and p-JAK2 proteins. Nude mice were subjected to GES-1 cells (5×10⁷·mL^-1, 0.2 mL) treated with MNNG 40 μmol·L^-1 for 48 hours and gastric cancer cells SGC7901 (5×10⁷·mL^-1, 0.2 mL, positive control), after one month, observed the tumor and body mass of each component, and observed the histopathological changes after HE staining at the injection site to verify whether GES-1 cells had reached the tumor stage after MNNG treatment. Results Compared with the model group, as the concentration of PPS increased, the proliferation ability of GES-1 cells gradually increased, reaching the highest proliferation ability at 5 mg·mL^-1, with significant differences (P< 0.01, 0.001); The mRNA expression of N-cadherin, Snail, Twist, Fironeton, and Vimentin in the PPS group was significantly reduced (P< 0.05, 0.01, 0.001); The expression of E-cadherin protein was significantly increased in the polyporus polysaccharides group (P< 0.05), while the expression of ^N-cadherin, ^Snail, ^Twist, ^Fibronection, ^Vimentin, and pathway proteins STAT3, p-STAT3, JAK2, and p-JAK2 were significantly decreased (P< 0.05, 0.01, 0.001). The control group and MNNG treated GES-1 group showed no tumor formation, while the positive control SGC7901 group showed local tumor formation around one week after injection, and the tumor grew to about 6 cm in length after one month; The GES-1 group of nude mice treated with MNNG showed poor mental state and significantly reduced body mass, while the SGC7901 group showed poor state and significantly reduced body weight. The pathological staining of the control group and MNNG group showed normal skin tissue, while the positive control group showed tumor tissue. Conclusion PPS may interfere with MNNGinduced epithelial mesenchymal transition of GES-1 cells by inhibiting JAK2-STAT3 pathway.

R285.5

国家自然科学基金青年项目（81801625）