靶向增殖诱导配体的RNA干扰对人结直肠癌裸鼠移植瘤的影响

Effects of APRIL-targeted RNA interference on colorectal cancer in nude mice in vivo

目的利用RNA干扰（RNAi）技术观察增殖诱导配体（APRIL）siRNA（pGC—shAPRIL重组干扰质粒）对裸鼠SW480移植瘤的影响。方法建立裸鼠人结直肠癌移植瘤模型，待皮下瘤块长到一定体积，全部裸鼠分为APRILsiRNA组、空载体组和磷酸盐缓冲液（PBS）组，分别进行瘤块内注射。逆转录-聚合酶链反应（RT—PCR）检测移植瘤APRILmRNA水平；瘤块和裸鼠肝肺苏木素-伊红（HE）染色病理检测；免疫组织化学法检测APRIL、核增殖抗原（Ki-67）、基质金属蛋白酶（MMP）-2蛋白表达。结果APRILsiRNA组，与空载体组和PBS组比较，APRILmRNA[（1．36±0．03）×10^8、（1．05±0．02）×10^7、（1．04±0．01）×10^8copy／ml]和蛋白表达得分（2．00±0．40、7．00±0．45、8．00±0．40）明显降低（P〈0．05）；瘤块体积显著减小[（0．78±0．04）、（1．60±0．07）、（1．66±0．06）cm3]（P〈0．05）；与之相应Ki-67（2．00±0．45、8．00±0．54、7．00±0．44）和MMP-2（3．00±0．44、7．00±0．45、7．00±0．55）蛋白表达显著减弱（P〈0．05）。结论RNAi敲低APRIL基因表达，抑制了裸鼠SW480移植瘤的生长和转移，打靶APRIL基因的RNAi技术有望成为人结直肠癌的治疗途径。

Objective To study the effects of a proliferation-inducing ligand （APRIL） siRNA on the growth of human colorectal tumors in nude mice. Methods SW480 cells were transplanted into nude mice, and when the tumors were about 100-200 mm3 , all nude mice were divided into three groups： APRIL siRNA injection group, pGC-vector injection group and PBS injection group, 5 nude mice in each group. Then intratumoral injections were respectively performed. Tumor volumes were calculated every before injection. In the end of experiment, all nude mice were sacrificed. APRIL mRNA and protein expressions was detected by reverse transcription-polymerase chain reaction （RT-PCR） and immunohistochemistry, respectively. HE strain of Tumor, the lung and liver tissues were stained with HE for pathological examination. By using immunohistochemistry, the expression of APRIL, Ki-67 and matrix metalloproteinase （ MMP）-2 was detected. Results The intratumoral injection of APRIL siRNA significantly suppressed the growth of tumors compared with controls [ （0.78 ± 0. 04 ） vs （ 1.60 ± 0.07 ）, （ 1.66 ± 0.06 ） cm3 ] （ P 〈 0.05 ）, inhibited the expression of APRIL mRNA [ （ 1.36 ± 0. 03 ） ×10^7 vs （ 1.05 ±0.02 ） ×10^8, （ 1.04 ± 0.01 ） ×10^8] and protein （2.00 ±0.40 vs 7.00 ±0.45, 8.00 ±0. 40）, and downregulated the expression of Ki-67 protein （2.00 ±0.45 vs 8.00 ±0.54, 7.00 ±0.44） and MMP-2 protein （3.00 ±0.44 vs 7. 130 ± 0.45, 7.00 ±0.55） in the tumor. After the injection of pGC-vector, there was no significant difference from the blank control group （ P 〉 0.05 ）. Conclusion Knockdown of APRIL expression in colorectal cancer by RNAi significantly suppressed the tumor cell proliferation and metastasis activity. RNAi targeting APRIL would be a potential therapy for human colorectal cancer.