ABSTRACT
Objective To investigate the trans‐regulative effect of hepatitis B virus (HBV) preS2 on the promoter of human acyl protein thioesterase 1 (APT1) gene .Methods The promoter sequence of human APT1 gene was identified applying the soft‐ware of bioinformatics .The APT1 promoter and HBV preS2 gene were amplified with PCR and cloned into pGL3 and pcDNA3 .1 (-) plasmids to construct the luciferase reporter gene plasmid of human APT1 gene promoter pGL3‐APT1 and the preS2 eukary‐otic expression plasmid pcDNA3 .1(-)‐preS2 ,respectively .The effect of the preS2 on the human APT1 gene promoter was exam‐ined by cotransfecting hepatocellular carcinoma cell HepG2 with pGL3‐APT1 and pcDNA3 .1(-)‐preS2 and measuring luciferase activities of the HepG2 cells .The statistical data were analyzed with independent‐samples t test .Results Both plasmids of pGL3‐APT1 and pcDNA3 .1(-)‐preS2 were confirmed by DNA sequencing to be accurately constructed as design .The luciferase activity of the pGL3‐APT1 was 1 .2 times (P<0 .01) that of the positive control plasmid pGL3‐Control .And the luciferase activity of the HepG2 cells cotransfected with pcDNA3 .1(-)‐preS2 and pGL3‐APT1 was 2 .6 times (P<0 .01) that of the HepG2 cells cotrans‐fected with the plasmid without preS2 gene pcDNA3 .1(-) and pGL3‐APT1 .Conclusion The human APT1 promoter cloned in the study has high promoter activity ;HBV preS2 activates human APT1 promoter .
ABSTRACT
BACKGROUND: Acyl protein thioesterase-1 (APT1) is a cytosolic protein that may function in the depalmitoylation of numerous proteins, including the Ras family. However, the clinical role of depalmitoyl thioesterase in human cancer is not known. We evaluated the APT1 expression in lung cancer tissue and its clinicopathological findings according APT1 expression pattern. METHODS: APT1 expression was examined by immunohistochemistry in the tumor tissue from 79 patients, who had undergone curative surgical removal of the primary lesion; all patients had been diagnosed with stage I non-small cell lung cancer between 1993 and 2004, at Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea. RESULTS: The APT1 expression was seen in 50 out of 79 (63.3%) cases. The positive APT1 expression was significantly related with histologic subtype and T stage, but was not influenced by differentiation. The positive APT1 expression was not significantly related to patient age, gender, or smoking history. The median follow-up duration was 10.0 years; the 5-year survival rate was 71.0%. The positive APT1 expression group showed significantly worse overall survival and worse disease-free survival without statistical significance. CONCLUSION: We conclude that positive APT1 expression in stage I lung cancer after surgery is closely associated with overall survival. To evaluate APT1 as a prognostic marker in lung cancer, comprehensive studies on advanced stage cases are needed.