目的：探讨雷帕霉素对胰腺癌体内生长的抑制作用及其对基质细胞衍生因子1α（SDF-1α）的影响。方法：20 只裸鼠胰腺注射胰腺癌SW1990 细胞悬液后，随机均分为实验组与对照组，实验组裸鼠每日雷帕霉素（1.5 mg/kg）腹腔注射，对照组以同样的方式给予等体积溶剂。3 周后取移植瘤，比较两组肿瘤的生长情况，免疫组化法检测肿瘤组织单核- 巨噬细胞、肿瘤相关巨噬细胞（TAM）浸润情况及p-mTOR、HIF-1α、SDF-1α 蛋白的表达；Weston blot 及qRT-PCR 法检测肿瘤组织p-mTOR、HIF-1α、SDF-1α的蛋白与mRNA 表达。结果：与对照组比较，实验组的肿瘤重量（0.3340 g vs. 1.7790 g）与体积（0.2375 mm3 vs. 1.2662 mm3）均明显减小（均P<0.05）。免疫组化结果显示，与对照组比较，实验组肿瘤组织浸润的单核- 巨噬细胞、TAM 计数均明显少（均P<0.05）；p-mTOR、HIF-1α、SDF-1α 蛋白表达率均明显降低（均P<0.05）； 肿瘤组织SDF-1α 表达评分与TAM 计数呈正相关（r=0.52，P<0.05）。Weston blot 与qRT-PCR 结果显示，实验组肿瘤组织p-mTOR、HIF-1α、SDF-1α 的蛋白与mRNA 表达均低于对照组，除HIF-1α mRNA 外（P>0.05），其余差异均有统计学意义（均P<0.05）。结论：雷帕霉素能抑制胰腺癌的体内生长，其机制可能与抑制mTOR 通路活性而下调SDF-1α 蛋白表达，进而减少肿瘤微环境中的TAM 有关。
Inhibitory effect of rapamycin on growth of pancreatic cancer and its relation with cell derived factor 1α
Objective: To investigate the inhibitory effect of rapamycin on growth of pancreatic cancer in vivo, as well as its influence on cell derived factor 1α (SDF-1α). Methods: Twenty nude mice, after pancreatic injection of pancreatic cancer SW1990 cells, were equally randomized into experimental group and control group. Mice in experimental group underwent daily intraperitoneal injection of rapamycin (1.5 mg/kg), and those in control group were given the vehicle of the same volume instead in the same fashion. The tumors were harvested 3 weeks later, the growth of the tumor between the two groups were compared, immunohistochemistry was performed to detect the infiltration of monoclemacrophages and tumor-associated macrophages (TAMs) and the expression of p-mTOR, HIF-1α and SDF-1α in the tumor tissues, and Western blot and qRT-PCR were also performed to determine the mRNA and protein expression of p-mTOR, HIF-1α and SDF-1α in the tumor tissues. Results: In experimental group compared with control group, both tumor weight (0.3340 g vs. 1.7790 g) and volume (0.2375 mm3 vs. 1.2662 mm3) were significantly reduced (both P<0.05). Results of immunohistochemical staining showed that in experimental group versus control group, the count of monocyte-macrophages and TAMs was significantly lowered (both P<0.05), the expression rates of p-mTOR, HIF-1α and SDF-1α were all significantly decreased (all P<0.05), and there was a positive correlation between score of the SDF-1α expression score and TAM count in the tumor tissue (r=0.52, P<0.05). Results of Western blot and qRT-PCR showed that both protein and mRNA expressions of p-mTOR, HIF-1α and SDF-1α in experimental group were lower than those in control group, and except for the HIF-1α mRNA (P>0.05), all differences had statistical difference (all P>0.05). Conclusion: Rapamycin can suppress growth of pancreatic cancer in vivo, and the mechanism is probably associated with its inhibiting the activity of mTOR pathway which thereby down-regulates SDF-1α expression, and then reduces TAMs within the tumor microenvironment.