[Expression of p53 gene with DNA polbeta and CMV promoter in salivary adenoid cystic carcinoma cells].

OBJECTIVE: To evaluate the activity of DNA polbeta promoter on p53 gene in salivary adenoid cystic carcinoma (SACC) cells. METHODS: The luciferase activity was examined and used to evaluate the activity of DNA polbeta promoter on SACC-83 cells. Eukaryotic expression plasmids of p53 gene were constructed and stably transfected into SACC-83 cells. RT-PCR was used to assess the expression of p53 gene. The SACC-83 cells were subjected to the treatments of H2O2, ultraviolet radiation, Bleocin, and affected p53 mRNA and protein level in SACC-83 cells were characterized with RT-PCR and Western blotting. RESULTS: The result of luciferase activity proved that the activity of DNA polbeta promoter in SACC-83 cells was much higher than that of CMV promoter. The results of RT-PCR suggested that p53 gene with different promoters were all expressed effectively, but the expression efficiency was different. It was greater in DNA polbeta group than in CMV group. After DNA damage, p53 gene expression increased and DNA polbeta promoter could enhance the expression of p53 gene more than CMV promoter. The results of Western blotting indicated that the expression of P53 protein between the two groups did not show any difference. CONCLUSION: In SACC cells, the activity of DNA polbeta promoter was increased and DNA polbeta promoter could enhance the expression of p53.

[Inhibitory effect of p53 gene on telomerase activity and proliferative activity in salivary adenoid cystic carcinoma cells].

OBJECTIVE: To evaluate the inhibitory effect of p53 gene on salivary adenoid cystic carcinoma (SACC) cells. METHODS: Adenoviral vector pDeltaE1-p53 was constructed and transfected into SACC-83 cells. The enhanced p53 expression was measured by reverse transcription polymerase chain reaction (RT-PCR), and the effects of transfected p53 on SACC-83 cells were analyzed by TRAP-PCR-ELISA, luciferase reporter, flow cytometry (FCM), soft agar assay and tumorigenicity test. RESULTS: The expression of p53 gene in SACC-83 cells was increased after introduction of pDeltaE1-p53. The telomerase activity and the transcriptional activity of hTERT promoter were inhibited. The cells cycles of transfected SACC-83 were arrested in G(1) phase and the rate of colony-formation was decreased, and similarly the tumorigenicity in nude mice was also decreased. CONCLUSIONS: The introduction of wild-type p53 by adenoviral vector could suppress the telomerase activity and malignant phenotypes of salivary adenoid cystic carcinoma cells.

[Intro-extro cranial approach treat serious post fronto-orbital fracture deformities].

OBJECTIVE: To explore the method of treating serious secondary fronto-orbital fracture deformities through intro-extra cranial approach. METHODS: The fronto-orbital fracture was divided into two types according to whether there were any large scale fronto-orbital bone defects: type I: Large scale fronto-orbital bone defect; type II: Concave fronto-orbital fracture deformity without large scale bone defect. Both types were treated through intro-extra cranial approach to expose the fracture site. For type I deformity, the bone defects were repaired and reconstructed with outer table of cranial bone and artificial bone. For type II, the deformity was repaired by osteotomy, bone reposition and internal rigid fixation. RESULTS: 18 cases were treated from June 1998 to October 2000, include type I, 12 cases, and type II, 6 cases. All the patients recovered well and the post-operative appearance were greatly improved. CONCLUSIONS: Intro-extra cranial approach can expose the fractured site better than the simple extrocranio approach, and make the operation more easily done. Combined with the technique of cranio maxillo facial surgery, the treatment can be more complete and the results can be more satisfactory.