增殖诱导配体小干扰RNA对人结直肠癌裸鼠移植瘤细胞增殖和凋亡的影响

目的 研究增殖诱导配体(APRIL)小干扰RNA(siRNA)对人结直肠癌裸鼠移植瘤细胞增殖和凋亡的抑制作用.方法 建立人结直肠癌裸鼠移植瘤模型,将裸鼠分为3组,瘤块内分别注射APRIL siRNA、空载体和PBS液,每2天注射1次,共2周.采用实时荧光定量PCR法和免疫组化SP法检测APRIL siRNA对APRILmRNA和蛋白表达的影响,采用酶联免疫吸附(ELISA)法检测肿瘤内增殖细胞核抗原(PCNA)含量的变化,采用免疫组化SP法检测肿瘤内bcl-2和bcl-xl蛋白的表达,采用原位末端标记(TUNEL)法检测肿瘤细胞的凋亡.结果 APRIL siRNA能敲低APRIL基因的表达水平,APRIL siRNA组移植瘤内APRIL mRNA的相对表达量为(0.13 ±0.05)×10-3,明显低于空载体组[(0.95 ±0.04)× 10-3]和空白对照组[(0.96±0.05)×10-3,P＜0.05].APRIL siRNA组APRIL蛋白的表达比空载体组和空白对照组降低了(87.5%±5.0%,P＜0.05).APRILsiRNA组裸鼠移植瘤生长缓慢,瘤块重量较空载体组和PBS对照组明显降低(P＜0.05).APRIL siRNA组移植瘤内PCNA的含量为(176.8±18.1)ng/ml,明显低于空载体组[(330.0±20.5)ng/ml]和空白对照组[(328.4±22.8)ng/ml,P＜0.05];bcl-2和bcl-xl蛋白的表达量也较空载体组和空白对照组明显降低(P＜0.05).APRIL siRNA组移植瘤内凋亡细胞的数量增多,凋亡率为40.1%±2.5%,明显高于空载体组(2.5%±0.1%)和空白对照组(2.5%±0.2%,P＜0.05).结论 APRIL siRNA能在裸鼠体内抑制人结直肠癌细胞的增殖,并促进细胞凋亡,达到显著的抑瘤效果.APRIL基因可能成为人结直肠癌基因靶向沉默治疗的重要候选基因之一.

Effect of APRIL on growth and apoptosis in transplanted tumor with human colorectal cancer cell line SW480 in nude mice

Objective To study the effect of pGCsi-H1-APRIL on the growth of human colorectal cancer cells in transplated tumor in nude mice and to improve the effect of APRIL on proliferation and apoptosis of colorectal cancer (CRC). Methods Human CRC model was established in nude mice, and the nude mice were treated with APRIL siRNA twice per week for 2 weeks. APRIL mRNA expression was surveyed by PGR and APRIL protein expression was detected by immunohistochemistry. The expression of PCNA protein was detected by ELISA. The expression of bcl-2 and bcl-xl was assessed by immunohistochemical staining, and TUNEL staining was used to detect apoptusis. Results The expression of APRIL mRNA in the APRIL siRNA group was (0. 13 ±0.05) × 10-3, significantly lower than that in the vector group (0.95 ±0.04) × 10-3 and the PBS group (0.96 ±0.05) × 10-3. The expression of APRIL protein in the APRIL siRNA group was (87.5 ±5.0)% lower than that in the vector and PBS groups (P＜0.05). APRIL siRNA significantly suppressed the growth of SW480 tumor: the IR (inhibitory rate) of APRIL siRNA group was (60.7 ± 1.5 ) % ( P ＜ 0.05 ). The expression of PCNA in APRIL siRNA group was ( 176.8 ± 18.1 ) ng/ml, was (56.5 ± 2. 0) % lower than that of PBS group (328.4 ± 22.8 ) ng/ml.Furthermore, the expressions of anti-apoptosis proteins bcl-2 and bcl-xl of APRIL siRNA group were (82.6 ±4.5)% and (79.2 ±3.5)% lower than those of the PBS group. The apoptotic rate of the APRIL siRNA group was 40.1% ±2. 5%, significantly higher than that in the vector group (2. 5 ±0. 1 ) % and PBS group (2.5 ± 0. 2 ) % ( P ＜ 0.05 ). Conclusion APRIL siRNA may significantly suppress the growth and promote apoptosis in transplanted tumor of human colorectal cancer in nude mice. APRIL may become a candidate gene of gene therapy of human colorectal cancer.