| [Objective] To explore the expression of angiopoietins and Tie receptors in cervical cancer tissues as well as in serums of patients with cervical intraepithelial neoplasia (CIN) and cervical cancer and their influence on malignant biological behavior of cervical cancer.[Methods]1. Immunohistochemical staining was used to test the expression of Ang-1, Ang-2, Ang-4, Tie-1and Tie-2as well as CD34and D240in tissues of cervical cancer and normal cervix;2. The circulating serum levels of soluble Ang-1(sAng-1) and Ang-2(sAng-2) in control group, CIN patients and cervical cancer patients as well as sAng levels in cell culture supernatants were detected by enzyme linked immunosorbent assay;3. Transwell indirect co-culture models in combination with real-time PCR were employed to explore the effect of cervical cancer tumor cells on Ang/Tie system in umbilical vein endothelial cells (HUVECs);4. The level of Ang-1in cervical cancer cell Siha was down-regulated by transfection with small interfering RNA (siRNA);5. Edu proliferation assay, colony formation assay, wound healing assay, matrigel invasion assay and Transwell migration assays were used to observe the changes in abilities of cell proliferation, invasion, migration resulted from Ang-1down-regulation. [Results]1. The angiopoietins and Tie receptors were expressed not only in the tumor related endothelial cells (RTECs) but also in the cytoplasm of tumor cells (TCs) in cervical cancer tissues;2. Compared with epithelial cells in normal cervical tissues, all the members of the Ang/Tie system were highly expressed in TCs incervical cancer tissues (P values were<0.01), and their expressions were positively correlated with microvessel density (MVD) and lymphatic vessel density (LVD) in tumor (P values were0.000).3. Compared with ECs in normal cervical tissues, the expression of Tie-2in TRECs was significantly increased (P=0.000), while Tie-1and Ang-2were decreased (Prte-1=0.011, PTie-2=0.000).No significant differences were found in Ang-1and Ang-4(PAng-1=0.960, PAng-4=0.071). The Tie-2expression in TRECs was positively correlated with MVD and LVD, whereas the Ang-2expression in TRECs was negatively correlated with theThere were no significant relations of expressions of Ang-1, Ang-4and Tie-1to MVD or LVD was abserved.4. In TRECs, Ang-2expression was significantly increased in squamous cell carcinoma compared with adenocarcinoma (P=0.033);Ang-4expression was elevated in lymph vascular space invasion (lympho vascular space invasion, LVSI) tumors compared with those without LVSI (P=0.046). In TCs, Tie-2was increasingly expressed in in tumor with larger size (tumor size>4cm vs≤4cm, P=0.038) and in tumors with high and moderate differentiation vs. low differentiation.5. From control group, CIN to cervical cancer, with the increasing severity of cervical lesions, the concentration of serum sAng-2and the ratio of sAng-2to sAng-1was gradually increased (P=0.000,0.002), while the deifference in sAng-1level had no statistical significance (P=0.054).6. With the increasing cervical cancer stage, the serum sAng-1level was significantly decreased (P=0.003), sAng-2level had no significant difference, yet the radio of sAng-2to sAng-1was inereased significantly (P0.001)7. In cervical cancer patients, the serum sAng-2level was positively correlated with sAng-1(r=0.363, P=0.030) as well as Ang-2expression in TCs (r=0.354, P=0.042), and had a moderate positive correlation with MVD (r=0.500, P=0.002); patients with squamous carcinoma or tumor size≤4cm had elevated sAng-2compared to patients with adenocarcinoma or tumor size>4cm (Ppathoiogy=0.035, Ptumor size=0.001, respectively);8. The results of ELISA revealed that both TCs and HUVECs recreate sAng-land sAng-2. In HUVECs indirectly co-cultured with cervical cancer cells for72h, the mRNA levels of Tie-2, Ang-1, Ang-2and Tie-1antisense non-coding RNA(Tie-1AS) were increased3.8-fold,2.3-fold,2.7-fold, and3.1-fold respectively, while Tie-1decreased approximately50%.9. Cervical cancer TCs can auto-secrete sAng-land sAng-2, the sAng-1level of TCs secreted was slight lower than HUVECs, while the sAng-2level was in half compared with HUVECs. Almost half of sAng-1和sAng-2secreted by TCs and HUVECs were consumed10. In Siha cells transfected with Ang-1siRNA, the abilities of tumor cell colony formation, invasion and migration were significantly decreased (P values were<0.01), while no significant alteration in cell proliferation ability was observed (P=0.2800).[Conclusion]1. The expression of Ang/Tie in cervical cancer tumor cells and tumor-associated ECs is tighly associated with tumor blood-and lymph-angiogenesis2. The ratio of serum sAng-2to sAng-1is increasing with the progression of CIN and cervical cancer and serum sAng-2is a promising biomarker for tumor angiogenic activity.3. Tumor cells active Ang/Tie signaling pathway in ECs and promoted tumor invasion and migration via para-secreted Angiopoietin. |
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