Objective To explore the effect of interfering RNA (shRNA) on biological activity of A549 cells and tumor growth in nude mice after knockdown of estrogen receptor α (ERα) gene. Methods The ERα gene in A549 cells was knocked down by shRNA. RT-PCR and Western blot were used to detect the gene expression and protein expression after knockdown; colony formation experiment was used to detect the proliferation of cells, and RT-PCR was used to detect the expression of Ki-67 and PCNA; flow cytometry was used to detect apoptosis rate; transwell assay was used to detect cell invasion ability; Western blot was used to detect the expression of epithelial cadherin (E-cad) and neuropathic cadherin (N-cad) protein. The control group and A549 cells transfected with ERα-shRNA1 were injected subcutaneously in nude mice to construct transplanted tumors. Immunohistochemistry was used to detect the expression of Ki-67 and N-cad in tumor tissues. Results Compared with the control group, after transfection of ERα-shRNA1 and ERα-shRNA2, the mRNA and protein expressions of ERα were reduced significantly (P<0.05), and shRNA1 with high interference efficiency was used for subsequent experiments. Compared with the control group, the A549 cells were transfected with ERα-shRNA1, the colony formation rate was down-regulated significantly (P<0.05), the apoptosis rate was increased significantly (P<0.05), the expression of Ki-67 and PCNA were down-regulated significantly (P<0.05), the number of invasive cells was reduced significantly, the expression of E-cad was increased, and the expression of N-cad was decreased (P<0.05). The results of tumor formation in nude mice showed that interfering with ERα expression can significantly inhibit tumor growth (P<0.05), and down-regulate the rate of Ki-67 and N-cad positive cells (P<0.05). Conclusion Knockdown of ERα inhibits the proliferation and migration ability of NSCLC cells and the occurrence and development of transplanted tumors in nude mice.
目的 研究细胞视黄酸结合蛋白（CRABP）Ⅱ、表皮型脂肪酸结合蛋白（E-FABP）和Ki-67在乳腺浸润性导管癌中的表达情况及三者的相关性。 方法 采用免疫组织化学检测2001年1月－2007年12月手术切除的152例乳腺浸润性导管癌中CRABPⅡ、E-FABP和Ki-67的表达。 结果 在浸润性导管癌中，CRABPⅡ在Ki-67阴性组的阳性率高于Ki-67阳性组（P＜0.05），相反地，E-FABP在Ki-67阳性组的阳性率高于Ki-67阴性组（P＜0.05）。CRABPⅡ和Ki-67表达呈负相关（rS=?0.432，P＜0.05）；E-FABP和Ki-67表达呈正相关（rS=0.842， P＜0.05）。E-FABP和Ki-67的表达具有协同性，E-FABP和Ki-67共同表达与肿瘤的转移有关（P＜0.05）。单因素生存分析显示，E-FABP的阳性表达患者、Ki-67的阳性表达患者以及E-FABP和Ki-67的共同阳性表达患者的预后差（P＜0.05）。多因素生存分析提示E-FABP的表达（RR=4.223，P=0.012）和TNM分期（RR=8.412，P=0.000）是影响浸润性导管癌患者预后的独立危险因素。 结论 在乳腺浸润性导管癌中，CRABPⅡ和E-FABP与肿瘤细胞的增殖有关，CRABPⅡ抑制细胞增殖，E-FABP促进细胞增殖。E-FABP和Ki-67在浸润性导管癌的发生、发展中起协同作用，两者的阳性表达可能对评估肿瘤的转移和患者的预后有一定价值。