长链非编码RNA linc-PINT通过调控SMAD4抑制结直肠癌的恶性进展

Long non-coding RNA PINT inhibits proliferation and migration of colorectal cancer cells through Smad4

目的研究linc-PINT在结直肠癌中的作用及其作用机制。方法通过实时荧光定量PCR检测linc-PINT在60对结肠癌患者肿瘤组织及正常组织中的表达水平,并应用卡方检验分析其与结直肠癌患者临床病理特征的关系,应用Log-rank检验分析其与结直肠癌患者预后的关系。应用实时荧光定量PCR检测linc-PINT在HCT116、HT29、LOVO、RKO、SW620、SW480等6种结肠癌细胞系及正常结肠粘膜细胞NCM460中的基础表达水平。通过CCK-8实验检测linc-PINT对细胞增殖的影响;应用Transwell实验检测linc-PINT对细胞迁移能力的影响;通过Western blot检测linc-PINT对SMAD4蛋白的影响。结果 linc-PINT在结直肠癌肿瘤组织中的表达水平(1.35±0.80)显著低于其在相应正常组织中的表达水平(3.67±1.56)(P <0.05);linc-PINT的表达水平与结肠癌患者的分期和肝转移等临床病理特征呈负相关(P <0.05),而与年龄、性别、分化和淋巴结转移等无明显相关性(P> 0.05);linc-PINT的表达水平与结肠癌患者预后呈正相关(P <0.05);linc-PINT在HCT116、HT29、LOVO、RKO、SW620、SW480等细胞的表达均低于其在NCM460中的表达。过表达linc-PINT可以抑制SW480细胞的增殖和迁移能力(均P <0.05);Linc-PINT与SMAD4在结肠癌肿瘤组织中的表达水平呈正相关(r=0.592,P <0.05);过表达linc-PINT后SMAD4蛋白的表达水平显著升高。结论 linc-PINT通过SMAD4调节结直肠癌的恶性进展,其可能成为结直肠癌治疗的潜在靶点。

Objective To investigate the role and potential mechanism of line-PINT in colorectal cancer.Methods Quantitative real-time PCR was performed to detect line-PINT expression in colorectal cancer tissue of60 patients and the healthy control people. Correlation between the expression of linc-PINT in colorectal cancer and the clinical pathological features was analyzed by the Chi-square test. The potential of linc-PINT in predicting prognosis of patients with colorectal cancer was assessed by using Log-rank test. The expression of line-PINT in six colorectal cancer cell lines, including HCT116, HT29, LOVO, RKO, SW620 and SW480, and normal cell line NCM460 was also detected by using quantitative real-time PCR. Cell proliferation was measured by CCK-8 assay and trans-well assay was performed to assess the effect of lin-PINT on cell migration. Then, the effect of linc-PINT on Smad4 protein was detected by Western blot assay. Results The expression of linc-PINT in colorectal cancer tissue( 1.35 ± 0.80) was significantly lower than that in the corresponding normal tissue(3.67 ± 1.56)(P < 0.05).The expression of linc-PINT in colorectal cancer was significantly correlated with the TNM stage and liver metastase(P < 0.05), but not associated with age, gender, differentiation and lymph node metastasis. Patients with a lower expression of linc-PINT in colorectal cancer had a significantly shorter overall survival(P < 0.05). Meanwhile, the expression of line-PINT in HCT116, HT29, LOVO, RKO, SW620, and SW480 cells was lower than that in NCM460. Over-expression of linc-PINT in SW480 could inhibit the proliferation and migration of colorectal cancer cells(P < 0.05, respectively). There was a positive correlation between Line-PINT and Smad4 expression in colorectal cancer tissue( r = 0.592, P < 0.05). And the expression of Smad4 protein was significantly increased after transfection with linc-PINT plasmid. Conclusions Linc-PINT regulates the malignant progression of colorectal cancer through Smad4, which may serve as a potential target for colorectal cancer treatment.