伊立替康耦合亚甲蓝靶向示踪大鼠胃癌淋巴结的研究

目的 探讨伊立替康与亚甲蓝耦合液在大鼠胃癌淋巴结中的靶向示踪作用及其机制.方法 应用Walker-256细胞株建立大鼠胃癌模型,免疫组织化学检测癌组织中伊立替康底物拓扑异构酶Ⅰ(topo Ⅰ)的表达.分别用5、10、20、40 mg伊力替康粉剂耦合2 ml亚甲蓝注射液,另用中华墨汁、纳米活性炭和亚甲蓝作为对照.70只胃癌大鼠分为7组,瘤周4点浆膜下微针分别注射上述7种染色剂.观察各组淋巴结染色、褪色时间、染色淋巴结数等指标.结果 (1)建立大鼠胃癌模型符合实验要求,癌组织中topo Ⅰ的表达显著增强.(2)中华墨汁、纳米活性炭和亚甲蓝到达胃癌第1站淋巴结平均时间依次为20、4 min和14 s;4组耦合剂分别为19、27、41、61 s.染料运行至第2站淋巴结的平均时间与之相似.(3)中华墨汁、纳米活性炭和亚甲蓝组平均染色淋巴结数量分别为2、7和8枚;各耦合剂组淋巴结检出数量逐渐增加,依次为8、8、9和11枚.(4)淋巴结褪色时间中华墨汁>2.4h,亚甲蓝102 min,其余各组介于两者之间.(5)各组动物未见明显不良反应.结论 通过靶向结合癌组织中的topo Ⅰ,适当剂量的伊立替康与亚甲蓝耦合剂可显著延长大鼠胃癌淋巴结染色和褪色时间,提高淋巴结靶向示踪效率.

Irinotecan coupled with methylene blue as targeted tracer for lymph nodes of gastric tumor in rats

Objective To evaluate the targeted tracing of irinotecan coupled with methylene blue (MB) for lymph nodes of gastric cancer in rats and explore its mechanism. Methods The rat implanted gastric tumor model was established with malignant tumor cell line Walker-256 and identified, and the topo-ismerase Ⅰ (topo Ⅰ) , the substrate of irinotecan, was immunohistologically detected in cancer tissues. Five, 10, 20 and 40 mg ofirinotecan powder was coupled with 2 ml of methylene blue (MB) injection, re-spectively; and Chinese ink (CI) , nanometric activated carbon (NAC) and MB were used as controls. Seventy rats with gastric cancer were randomly divided into 7 groups. The 7 kinds of tracer agents were in-jected into the peritumoral subserosa at 4 points with microacupuncture needle. The dyeing time, discolora-tion time, number of dyeing lymph nodes, and hepatorenal function of each group were observed. Results (1) The established rat model of gastric cancer was consistent with experimental requiremen, and the ex-pression of topo Ⅰ in cancer tissues was significantly enhanced; (2) The time from the injection to the 1st station lymph nodes was 20 min, 4 min and 14 s in CI, NAC and MB groups, respectively; and the time of various kinds of coupling media was 19, 27, 41 and 61 s, respectively. The time of various kinds of tracer agents to the 2nd station lymph nodes was similar with that to the 1st station lymph nodes; (3) The average number of dyeing lymph nodes was 2, 7, 8 in CI, NAC and MB groups, respectively; the number in vari-ous kinds of coupling media groups was 8, 8, 9 and 11 respectively; (4) The average discoloration time was > 24 h in CI group, 102 min in MB group, and 2-24 h in the rest groups, respectively; (5) No obvi-ous side effect was observed in all groups. Conclusion By targetedly inhibiting the activity of Topo Ⅰ in cancer tissues, adequate dosage of irinotecan coupled with MB may significantly prolong the lymph node dyeing and discoloration time of stomach cancer, and improve the efficiency of targeting lymph node tracing.