title: Expression and mechanism of PinX1 and telomerase activity in the carcinogenesis of esophageal epithelial cells.
abstract: Esophageal tissues were collected from an esophageal carcinoma high-risk area of China and were used to detect the telomere length and the expression of human telomerase reverse transcriptase (hTERT) by immuhistochemistry and fluorescence in situ hybridization; esophageal carcinoma tissues, paired-adjacent mucosa and paired normal mucosa were obtained from resected surgical specimens of esophageal squamous cell carcinoma in order to determine telomerase activity and expression of hTERT and Pin2/TRF1 interacting protein X1 (PinX1) by telomeric repeat amplification protocol-silver staining, RT-PCR and flow cytometry (FCM). The cell proliferation and apoptosis of Eca109 cells were analyzed by FCM and MTT assay. We found that the length of telomere DNA decreased and hTERT protein expression increased in the carcinogenesis of esophageal epithelial cells; telomerase activity was significantly upregulated followed by a decrease of PinX1 expression in esophageal carcinoma compared with dysplasia and normal patients, which notably correlated with grade and lymph node metastasis. Overexpression of PinX1 inhibited cell growth, arrested cells at the G0/G1 stage and induced cell apoptosis in Eca109 cells. In addition, PinX1 overexpression significantly inhibited telomerase activity. In conclusion, the length shortening of telomere was an important characteristic in the carcinogenesis of esophageal epithelial cells, followed by increase of telomerase activity and downregulation of PinX1. Overexpression of PinX1 blocked Eca109 cell proliferation and induced cell apoptosis by downregulating telomerase activity.
authors.affiliation: Department of Oncology, the Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050012, P.R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zuo
authors.forename: Da-Hu
authors.initials: DH
authors.lastname: Wang
authors.forename: Yu-Jun
authors.initials: YJ
authors.lastname: Zhang
authors.forename: Liang
authors.initials: L
authors.lastname: Liu
authors.forename: Feng-Ling
authors.initials: FL
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
mesh_terms: D017209:Apoptosis / Q000235:genetics; D014408:Biomarkers, Tumor / Q000235:genetics; D018797:Cell Cycle Proteins; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic; D004847:Epithelial Cells / Q000378:metabolism; D004938:Esophageal Neoplasms / Q000235:genetics / Q000378:metabolism*; D004947:Esophagus / Q000166:cytology / Q000378:metabolism; D005260:Female; D059585:G1 Phase Cell Cycle Checkpoints / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000302:isolation & purification; D019098:Telomerase / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000378:metabolism*; D016615:Telomere / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D059505:Telomere Homeostasis / Q000235:genetics; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D018797:Cell Cycle Proteins; C440808:PINX1 protein, human; D012333:RNA, Messenger; D025521:Tumor Suppressor Proteins; C509186:TERT protein, human; D019098:Telomerase