背景:生物信息学分析表明,聚(A)特异性核糖核酸酶(PARN)基因在胃癌中的表达,头颈部鳞状细胞癌,黑色素瘤,宫颈癌和肺鳞癌组织明显高于正常组织,并与高分期和不良预后有关。PARN基因在食管癌(EC)组织中的表达也显著高于正常组织,但是PARN对增殖的影响,EC细胞的迁移和侵袭仍不清楚。
目的:探讨PARN与细胞增殖的关系,EC细胞的迁移和侵袭。
方法:收集91例EC术后患者的EC组织和63例配对的癌前健康组织。使用组织微阵列测量PARNmRNA水平,采用免疫组织化学方法检测PARN的表达水平,分析PARN的表达与患者临床病理特征、生存和预后的关系。此外,PARN基因敲除对肿瘤细胞增殖的影响,在EC细胞系Eca-109和TE-1的体外培养过程中,使用shRNA研究了侵袭和迁移,并通过异种移植裸鼠模型验证了PARN基因对体内肿瘤生长的影响。
结果:PARN在EC组织中的表达高于癌旁正常组织,PARN表达水平与淋巴结转移呈显著正相关。PARN水平高的患者总生存率较差。BIM,PARN基因敲除组IGFBP-5和p21水平显著升高,而在凋亡抗体阵列数据中,抗凋亡蛋白Survivin和sTNF-R1的表达水平显着降低。此外,Akt的表达水平,p-Akt,PIK3CA和CCND1在调控EC进程的下游旌旗灯号通路中显著降低。EC细胞系的培养证实EC细胞的凋亡率显著提高,肿瘤细胞的生长和增殖受到显著抑制,PARN基因敲除后肿瘤细胞的侵袭和迁徙才能显著下降。用表达对照shRNA(sh-NC)和PARNshRNA(sh-PARN)的Eca-109细胞转染的BALB/c裸鼠体内实验表明,sh-PARN处理的裸鼠与sh-NC处理的裸鼠相比,肿瘤体积和重量显著降低,表明PARN敲低在体内显著抑制肿瘤生长。
结论:PARN对EC细胞具有抗凋亡作用并促进其增殖,入侵和迁移,这与EC的发展和患者预后不良有关。PARN可能成为诊断的潜在目标,EC的预后预测和治疗。
BACKGROUND: Bioinformatics analysis showed that the expression of the poly(A)-specific ribonuclease (PARN) gene in gastric cancer, head and neck squamous cell carcinoma, melanoma, cervical cancer and lung squamous cell carcinoma tissues was significantly higher than that in normal tissues and was associated with high stage and poor prognosis. The expression of the PARN gene in esophageal cancer (EC) tissue is also significantly higher than that in normal tissues, but the effect of PARN on the proliferation, migration and invasion of EC cells remains unclear.
OBJECTIVE: To investigate the relationship between PARN and the proliferation, migration and invasion of EC cells.
METHODS: The EC tissues of 91 patients after EC surgery and 63 paired precancerous healthy tissues were collected. PARN mRNA levels were measured using a tissue microarray, and the PARN expression level was evaluated using immunohistochemistry to analyze the relationship between PARN expression and clinicopathologic features as well as the survival and prognosis of patients. In addition, the effects of PARN gene knockout on tumor cell proliferation, invasion and migration were studied by using shRNA during the in vitro culture of EC cell lines Eca-109 and TE-1, and the effects of the PARN gene on tumor growth in vivo were verified by a xenotransplantation nude mice model.
RESULTS: The expression of PARN in EC tissues was higher than that in adjacent normal tissues, and the level of PARN expression was significantly positively correlated with lymphatic metastasis. Patients with high PARN levels had poor overall survival. BIM, IGFBP-5 and p21 levels were significantly increased in the PARN knockout group, while the expression levels of the antiapoptotic proteins Survivin and sTNF-R1 were significantly decreased in the
apoptotic antibody array data. In addition, the expression levels of Akt, p-Akt, PIK3CA and CCND1 in the downstream signaling pathway regulating EC progression were significantly decreased. The culture of EC cell lines confirmed that the apoptosis rate of EC cells was significantly increased, the growth and proliferation of tumor cells were significantly inhibited, and the invasion and migration ability of tumor cells were significantly decreased after PARN gene knockout. In vivo experiments of BALB/c nude mice transfected with Eca-109 cells expressing control shRNA (sh-NC) and PARN shRNA (sh-PARN) showed that the tumor volume and weight of nude mice treated with sh-PARN were significantly decreased compared with those of nude mice treated with sh-NC, indicating that PARN knockdown significantly inhibited tumor growth in vivo.
CONCLUSIONS: PARN has antiapoptotic effects on EC cells and promotes their proliferation, invasion and migration, which is associated with the development of EC and poor patient prognosis. PARN may become a potential target for the diagnosis, prognosis prediction and treatment of EC.