5-氟尿嘧啶缓释剂瘤内注射治疗胰腺癌的实验研究和临床研究

目的 观察5-氟尿嘧啶(5-Fu)缓释剂对荷胰腺癌裸鼠肿瘤细胞及胰腺癌患者血清肿瘤标记物和细胞免疫的影响。方法 (1)5-Fu缓释剂的体外释放实验和体外抑瘤实验：测定浸出液药物的浓度，计算释放量；检测其浸出液对人胰腺癌细胞株PC3的抑制作用：(2)将荷胰腺癌细胞株Pc3裸鼠60只，随机分成静脉对照组(A组)、5-Fu静注组(B组)、基质植入组(C组)、大剂量5-Fu缓释剂植入组(D组)和小剂量5-FU缓释利植入组(E组)：治疗前及治疗后l4d测肿瘤大小。治疗2周后观察肿瘤组织学变化：免疫组化法测定bcl-2和Bax的蛋白表达水平；TUNEL法检测凋亡指数(Al)。(3)手术探查不能切除之胰腺癌69例随机分成3组：将5-FU缓释剂瘤内植入治疗组(治疗组)、术后行5-FU静脉化疗组(化疗组)和对照组。分别于术前1d和术后第14天采血，测定各组血清中NK细胞，T细胞亚群和CEA，CA50，CA19-9，CA125，CA242血清肿瘤标记物水平。结果 (1)5mg 5-FU缓释剂第1天释放量最大，为0．85mg，第3天为0．45mg，其后在0．25mg水平维持稳定的缓慢释放；释放时间长达l4d以上。(2)5-Fu缓释剂第1天的浸出液对人胰腺癌细胞株PC-3的抑制率达60．27％，第3天为34．25％，以后稳定在25．00％左右。5-Fu缓释剂瘤内注射治疗组裸鼠移植瘤生长速度减慢，bcl-2基因表达明显低于其他各组，而Bax基因表达明显高于其他各组，肿瘤细胞的Al明显高于其他各组。D组和E组肿瘤组织中炎症反应和血管内膜增厚程度明显高于其他各组。术后治疗组CD4 ／CD8 和NK细胞水平高于化疗组，而血清中E述5种肿瘤标记物低于对照组和化疗组。结论 5-Fu缓释剂能在2周内在体外较稳定地持续释放，对人胰腺癌细胞株PC3有持续抑制作用。该剂瘤内注射可明显抑制荷胰腺癌瘤裸鼠瘤体的生长，其作用机制与药物在肿瘤组织中引起的炎症反应和血管内膜增厚等因素有关；并可能与诱导肿瘤细胞的凋亡有关。该剂植入患者胰腺癌实体内，能明显降低5种血清肿瘤标记物水平，同时对患者的细胞免疫功能影响较小，5-Fu缓释剂可望成为治疗不能切除之胰腺癌的较好的制剂。

Experimental and clinical study on intra tumor injection of slow release 5 FU to treat pancreatic carcinoma

Objective To study the effect of intra-tumor injection of slow-release 5-FU on pancreatic carcinoma cells in nude mice,and on changes in serum tumor markers and cellular immunity of patients with pancreatic carcinoma.Methods (1) In vitro experiments, the releasing action and anti-tumor effect of slow-release 5-FU were studied. Measurement of the concentration of effused fluid,calculation of amount of drug released,and observation of the inhibitory effects of effused fluid on PC3 strains of pancreatic cancer cellswere perfomed.(2) Human pancreatic carcinoma strain PC-3 cells were cultured and inoculated into 60 nude mice,and were randomly divided into 5 groups according to various treatments received: NS injection as control group(A group), 5-FU (10 mg/kg)IV injection group(B group), stroma implant group(C group), intra-tumor injection of high dose slow-release 5-FU (4mg/kg) group(D group) and intra-tumor injection of low dose slow-release 5-FU (1mg/kg) group(E group). Tumor size were measured before and 14 days after treatment. On week 2, histological changes of the tumors were examined. The apoptotic index (AI) of the tumor cells was detected by terminal-deoxynucleotide transferase mediated d-UTP nick end labeling(TUNEL) and expression of bcl-2 and Bax by immunohistochemistry.(3) 69 cases of unresectable pancreatic carcinoma were divided into 3 groups randomly:intra-tumor injection of slow-release 5-FU treated group(treatment group), intra-venous injection of 5-FU group( chemotherapy group), and control group. The serum values of CD3+, CD4+, CD8+, CD4+/ CD8+, NK cells, CEA, CA50, CA19-9, CA125 and CA242 were measured in all patients 1 day before and 14 days after operation. Results (1) There was 0.85 mg 5-FU released in the 1st day and 0.45 mg 5-FU released in the 3rd day. The release remained constant at 0.25 mg and continued for about 14 days. (2) The tumor growth suppression rate on the 1st day by effusion fluid of slow-release 5-FU was 60.27% and on the 3rd day was 34.25%. Later, it remained at about 25.00%. The tumor growth rate was slower in D and E group than in other groups (P<0.05). The expression of bcl-2 was markedly decreased but that of Bax remarked increased in D and E group than in the other groups (P<0.05). The extent of local inflammation and degree of thickness of blood vessel endothelium was more pronounced in D and E groups than in other groups (P<0.05).AI was significantly higher in D and E group than in other groups(P<0.05). In patients of intravenous injection of 5-FU treated group, the serum levels of CD4+/ CD8+ and NK cells were much lower than in H patients of treatment group and the control group(P<0.05);and the serum values of CEA, CA50, CA19-9, CA125 and CA242 in patients of treatment group were much lower than in patients the intravenous injection of 5-FU group and the control group(P<0.05). Conclusions Slow-release 5-FU can constantly maintain drug-release during 2 weeks of in vitro experment and has inhibitory action against human pancreatic cancer cell strain PC 3.Intra-tumor injection of slow-release 5-FU can inhibit the growth of pancreatic carcinoma by inducing local inflammation and thickening of blood vessel endothelium and up-regulating apoptosis of pancreatic cancer cells. Intra-tumor embedding of slow-release 5-FU into the pancreatic cancer tissue of palients causes minimal damage of cellular immunity, but can decrease the serum values of CEA, CA50, CA19-9, CA125 and CA242, and might become an useful method for treating patients with unresectable pancreatic cancinoma.