摘要
目的探讨辣椒素对结肠癌HT-29细胞裸鼠皮下移植瘤的抑瘤作用及其机制。方法建立结肠癌HT-29细胞裸鼠皮下移植瘤模型，采用原位末端脱氧核苷酸转移酶标记法（TUNEL法）检测移植瘤的细胞凋亡情况，采用免疫组织化学染色法和Westernblot检测肿瘤组织中热休克蛋白27（HSP27）、细胞色素c（Cyt-c）和活化caspase-3蛋白的表达。结果与生理盐水组（0．9％氯化钠注射液，Ns组）比较，中剂量辣椒素组（10nag·kg-1·d-1，C10组）和高剂量辣椒素组（20rng·kg-1·d-1，C20组）移植瘤生长速度缓慢。TUNEL法检测结果显示，低剂量辣椒素组（5mg·kg-1·d-1，c5组）和C10组积分吸光度值分别为2532．14±578．11和6364．03±1137．98，均高于NS组（760．12±238．05，均P〈O．05），C20组积分吸光度值（15743．96±1855．95）高于c5组、C10组和NS组（均P〈0．01）。免疫组化结果显示，NS组肿瘤组织中HSP27蛋白呈强阳性表达，其表达随着辣椒素剂量的增加而减弱，而活化的caspase．3和Cyt。C呈弱阳性表达，其表达随着辣椒素剂量的增加而增强。Westernblot检测结果显示，c5组和C10组HSP27蛋白的相对表达水平分别为0．73±0．05和0．41±0．03，均低于NS组（均P〈0．05），C20组HSP27蛋白的相对表达水平（0．22±0．06）均低于NS组、c5组和C10组（均P〈0．01）。C5组活化的caspase．3和Cyt．C蛋白的相对表达水平分别为2．57±0．34和2．034-0．38，均高于Ns组（均P〈0．05）。C10组活化的easpase-3和Cyt—C蛋白的相对表达水平分别为4．23±0．45和3．13±0．44，均高于NS组（均P〈0．05），C20组活化的caspase-3和Cyt-C蛋白的相对表达水平分别为5．784-0．48和4．92±0．52，均高于Ns组、c5组和C10组（均P〈0．01）。结论辣椒素可抑制结肠癌HT-29细胞裸鼠皮下移植瘤的生长，诱导细胞凋亡，其作用机制可能与抑制HT-29细胞中HSP27蛋白的表达、促进活化的easpase-3、Cyt—C蛋白的表达有关。
Objective To evaluate the effect of capsaicin on nude mice xenografted with colorectal carcinoma cells, and to explore its mechanism of action. Methods A nude mouse model of colorectal cancer was established by subcutaneous inoculation of human colorectal carcinoma HT-29 cells. Terminal deoxynucleotidyl transferase-mediated nicked labeling assay （TUNEL） was undertaken to detect the cell proliferation and apoptosis in the xenograft tissue in nude mice. Immunohistochemical （IHC） staining and Western blot were used to detect the expression of HSP27, Cyt-C and active caspase-3. Results The tumor growth of the groups CI0 and C20 was significantly slower than that of the group NS. The integrated optical density （IOD） of both the group C5 （2532. 14 ±578. 11） and group C10 （6364.03 _± 1137.98） was significantly higher than that of the group NS （760. 12 ± 238.05 ）, （ P 〈 0.05 ）. The integrated optical density （IOD） of the group C20 was （ 15743.96 ± 1855.95 ）, significantly higher than that of the groups C10, C5 and NS （ all were P 〈 0.01 ）. Immunohistochemistry showed that the cytoplasmic expression of HSP27 was strongly positive in the group NS, and significantly reduced with the increasing dose of capsaicin in the treated groups. The expression of active caspase-3 and Cvt-C in the group NS was weakly positive.and was significantly increased with the increasing dose of capsaicin in the groups C5 and C10 （P 〈 0.05 ）, and the expression of active caspase-3 and Cyt-C of the group C20 was significantly higher than that of the groups C5, C10 and NS （P 〈 0.01 ）. Western blot analysis showed that both the expressions of HSP27 of the group C5 （0.73 ±0.05） and the group C10 （0.41 ±0.03） were significantly lower than that of the group NS （ P 〈 0.05）. The expression of HSP27 of the group C20 （0.22 ± 0.06） was significantly lower than that of the groups C5, C10 and NS （P 〈0.01 ）. The expressions of active-caspase-3 and Cyt-C in the group C5 were （2.57 ± 0.34） and （2.03 ± 0.38 ）, significantly higher than those of the group NS （P 〈 0.05 ）. The expressions of active-caspase-3 and Cyt-C in the group C10 were （4.23 ± 0.45 ） and （3.13 ± 0.44）, also significantly higher than those of the group NS （P 〈 0.05 ）. The expressions of active-caspase-3 and Cyt-C in the group C20 were （5.78 ±0.48） and （4.92 ±0.52）, significantly higher than those of the group C5, C10 and NS （P 〈0.01 ）. TUNEL analysis showed that there was a significant difference of cell apoptosis in comparison of each two groups. The higher dose of capsaicin was used, the more apoptosis was observed. Conehmions Capsaicin can significantly inhibit the tumor growth and induce cell apoptosis in the colorectal carcinoma xenograft in nude mice. Its mechanism of action is possibly related with the downregulation of HSP27 expression and up-regulation of expression of active caspase-3 and Cyt-C in the colorectal carcinoma xeno^aft in nude mice.
出处
《中华肿瘤杂志》
CAS
CSCD
北大核心
2013年第4期256-261,共6页
Chinese Journal of Oncology
