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Zinc finger E-box binding homeobox 1 (ZEB1), as a typical transcription inhibitory factor of E-cadherin, plays a major role in stimulating the invasion and metastasis of tumors via modulating the epithelial-mesenchymal transition (EMT) signal. However, its function and modulatory mechanisms in endometrial carcinoma (EC) remain unclear. In this study, silencing ZEB1 significantly reduced EC cell migration, invasion, and metastasis, as well as enhanced the sensitivity of EC cells to cisplatin (cDDP) in vitro and in vivo. Mechanism analysis indicated that ZEB1 interacts with hepatoma-derived growth factor (HDGF) and co-localizes in the nucleus. In addition, ZEB1 as a transcription factor binds to the promoter of HDGF to stimulate HDGF transcription. Furthermore, suppression of HDGF in ZEB1-overexpressed EC cells not only reduced the expression of β-catenin, TCF4, and ZEB1, but also repressed β-catenin translocation from the cytoplasm into the nucleus and further downregulated the combination with TCF4. Interestingly, the β-catenin/TCF4 signaling feedback stimulates ZEB1 transcription and therefore constitutes a positive feedback loop. In clinical samples, ZEB1 positively correlates with HDGF expression, and co-expression of ZEB1 and HDGF promotes the pathogenesis of EC. In summary, our study demonstrated that the positive feedback loop of ZEB1/HDGF/β-catenin/TCF4 plays an unfavorable role in the metastasis of endometrial carcinoma., Competing Interests: None., (AJCR Copyright © 2019.)

Objective: To investigate the role of specificity protein 1 (Sp1) in regulating radiosensitivity of cervical cancer cell lines., Methods: We analyzed Sp1 expression in 6 different cervical cancer cell lines (SiHa, HeLa, Caski, Me180, Ms751, and C33a) using Western blotting and real-time PCR. Clonogenic survival assay and curve fitting were used to assess the changes in radiosensitivity of Me180 cells transfected with lentivirus-mediated shRNA vector targeting sp1 and HeLa cells transfected with sp1 over-expression vector., Results: In the 6 cell lines tested, the cellular expression levels of Sp1 decreased gradually in the order of Me180, Caski, C33a, SiHa, Ms751, and HeLa. SP1 knockdown with lentivirus-mediated shRNA significantly lowered the survival rate of Me180 cells following radiation exposure (P<0.05), and obviously lowered the values of SF2, D0 and Dq but significantly increased α/β of the cells. Compared with the cells transfected with the mock vector, HeLa cells with sp1 over-expression showed a significantly increased survival following radiation exposure (P<0.05) with obviously increased values of SF2, D0 and Dq but significantly lowered α/β., Conclusion: Silencing Sp1 can increase the radiosensitivity while Sp1 overexpression enhances the radioresistance of cervical cancer cell lines, suggesting an important role of Sp1 in radiotherapy for cervical cancer.

Objective: To analyze the expression of MAP2K4 and vimentin in human endometrial carcinoma (EC) and their association with the clinicopathological features and prognosis of the patients., Methods: MAP2K4 and vimentin expressions were detected immunohistochemically in paraffin-embedded tissue sections from 128 patients with EC, and the correlation of MAP2K4 and vimentin expressions with the clinicopathological factors of the patients was analyzed., Results: MAP2K4 and vimentin proteins were positively expressed in 49 (38.3%) and 83 (64.8%) of the patients, respectively. A positive expression of MAP2K4 was negatively correlated with FIGO stage of the tumor (P=0.010) and lymph node status (P=0.016); a positive expression of vimentin was positively correlated with FIGO stage of the tumor (P=0.025), histological grades (P=0.017), depth of myometrial invasion (P=0.044) and lymph node status (P=0.032). MAP2K4 was inversely associated with vimentin expression in EC(r=-0.598, P<0.001). Patients positive for MAP2K4 tended to have a higher overall survival rate (P=0.002), and those positive for vimentin tended to have a lower overall survival rate (P=0.007); patients positive for MAP2K4 but negative for vimentin had the longest survival time, while those negative for MAP2K4 and positive for vimentin had lowest survival rate (P=0.004)., Conclusion: Detection of MAP2K4 and vimentin might help in early diagnosis and prognostic evaluation of patients with EC.