CTHRC1在结直肠癌中的表达及作用机制

Role of CTHRC1 in proliferation, migration and invasion of human colorectal cancer cells

目的检测胶原三股螺旋重叠蛋白(CTHRC1)在结直肠癌组织及细胞中的表达,探讨CTHRC1对结直肠癌细胞生物学特性的影响和作用机制。方法应用实时荧光定量PCR和免疫印迹检测CTHRC1在结直肠癌组织和5株结直肠癌细胞的表达;将靶向作用于CTHRC1的sh RNA和NC转染进LOVO细胞;CCK-8、Transwell、平板克隆检测细胞的增殖、迁移、侵袭、克隆形成能力。Western blotting检测转染后CTHRC1、ERK1/2、P-ERK1/2、E-cadherin、N-cadherin、Vimentin、β-catenin表达的变化。结果与正常黏膜组织相比,20例癌组织中的CTHRC1 m RNA的平均表达量为0.0411±0.054,显著高于正常黏膜组织P=0.016,蛋白水平的结果与之一致;同时,CTHRC1在SW620和LOVO细胞里的表达(m RNA水平和蛋白水平)均显著高于HT29细胞株;较之对照组,CTHRC1敲低组抑制了LOVO细胞的增殖、迁移、侵袭和克隆形成能力,差异均具有统计学意义P<0.05。当CTHRC1在m RNA和蛋白水平的表达均被明显抑制时,总ERK1/2在保持基本不变的的前提下,P-ERK1/2明显降低,EMT出现逆转(即MET,E-cadherin升高,N-cadherin、Vimentin、β-catenin降低)。结论 CTHRC1在结直肠癌组织及高转移潜能的人结直肠癌细胞株SW620和LOVO中高表达。敲低CTHRC1抑制了结直肠癌细胞株LOVO的增殖、迁移、侵袭、克隆形成能力。CTHRC1通过增强ERK1/2的磷酸化所介导的EMT促进结直肠癌的侵袭转移。

Objective To explore the expression of collagen triple helix repeat containing 1 （CTHRC1） in colorectal cancer and study its role in regulating the biological behaviors of colorectal cancer LoVo cells in vitro. Methods Real-time PCR and Western blotting were used to detect the expressions of CTHRC1 in colorectal cancer tissue and paired adjacent nontumorous tissue and in 5 colorectal cancer cells. pGPU6-CTHRC1-shRNA was transfected into LoVo cells and the changes in cell proliferation was assessed using cell counting kit-8 （CCK8） assay;the changes in cell migration and invasion were investigated using Transwell assay; plate colony forming test was used to evaluate the adhesion and colony forming activity of the cells. Western blotting was used to analyze the changes in the expressions of the related pathway markers. Results The relative expression of CTHRC1 mRNA in the cancer tissue specimens was 0.0411 ± 0.054, significantly higher than that in the adjacent tissues （P=0.016）; this result was consistent with that of the protein assay. SW620 and LoVo cells showed obviously higher expressions of CTHRC1 than HT29 and SW480 cells at both mRNA and protein levels. LoVo cells transfected with CTHRC1 shRNA exhibited significantly suppressed proliferation, migration, invasion and colony-forming ability （P〈0.05） and lowered expression of phosphorylated ERK1/2 （P-ERK1/2）, but the expression of total ERK1/2 showed no obvious changes. CTHRC1 inhibition caused reverse epithelial-mesenchymal transition LoVo cells shown by increased E-cadherin expression and decreased expressions of N-cadherin, vimentin, andβ-catenin. Conclusion CTHRC1 is up-regulated in colorectal cancer tissues and SW620 and LoVo cells to promote the cell proliferation, migration, invasion and colony formation. CTHRC1 can enhance epithelial-mesenchymal transition of colorectal cancer cells by activating ERK1/2 to promote tumor cell metastasis and invasion.