Effect on Malignant Phenotype of Gastric Cancer Cell Line after p53 Gene Transduction / 대한암학회지

PURPOSE: To evaluate the effect of wild type p53 gene transduction on the malignant phenotypes for metastasis in gastric cancer, we compared the biological phenpotypes of gastric cancer cell lines based on p53 gene status. Then, after retrovirus-mediated wild-type p53 gene transduction, we compared those phenotypes among parent YCC-3 cell line, vector transduced YCC-3v cell line and a clone of YCC-3C3. MATERIAL AND METHODS: Four human gastric cancer celi lines were used; YCC-l(mutant), YCC-2(wild), YCC-3(mutant) and AGS(wild). DNAs of the cell lines were analyzed to evaluate the mobility shift with PCR-SSCP. Tumorigenecity and proliferation were evaluated by soft agar assay and proliferation assay. Migratory capacity was measured by adhesion assay and Boyden chamber assay. p53 protein expression was measured by Western blot analysis and VEGF, WAF-1 were measured by ELISA assay. Angiogenic activity was measured by cross-feeding assay and cell cycle analysis was performed by flowcytometry. In vivo tumorigenicity was measured by xenograft in nude mice. RESULTS: YCC-3 cell line with mutant p53 gene expressed all the phenotypes for the metastasis such as tumorigenicity, migration and angiogenesis. In a stable clone of YCC-3C3, no differences were found in proliferation, cell cycle and WAP-1 expression when compared to those of the control YCC-3v and parent YCC-3 cell line, even if increased p53 protein production was found by Western blot analysis. However, both in vitro and in vivo tumorigenicity were decreased in a stably transduced YCC-3C3 clone. The adhesive capacity was also decreased in YCC-3C3 clone whereas the endothelial cell growth stimulatory effect and VEGF production showed no difference compared to those of the YCC-3v cell line. CONCLUSION: Wild-type p53 gene transduction in gastric cancer cell line decreased tumorigenicity which resulted from decreased colony forming activity and adhesive capacity but not formed changes of angiogenic activity. This suggested the possible application of anti- metastasis strategy with p53 gene therapy in gastric cancer.

The Significance of Recording Electrode Placement in ENoG Measurement / 대한이비인후과학회지

ENoG is the objective electrophysiologic measurement of the muscle compound action potential(CAP) to assess the rate of degenerated nerve fibers. However, occasional discorrelation with clinical findings may diminish the utility of the ENoG. So, we studied the significance of recording electrode placement, which is considered to affect the result of the ENoG. We performed the interside variance in 20 healthy adults(20 males) volunteers and retest was performed in 6 adults of 20 volunteers. The recording electrode was placed at 3 positions.(whole nasolabial fold(A), 2 / 3 of the nasolabial fold(B), 1 / 2 of the nasolabial fold(C)) And then we compared the results: 1) In the first measurement, the mean CAP was 3.02+/-0.98mV(A), 2.80+/-0.75mV(B), 2.56+/-0.57mV(C) on the right side, 2.70+/-1.02mV(A), 2.50+/-0.90mV(B), 2.33+/-0.86mV(C) on the left side, and there was no significant difference between right and left inter-side amplitude(p>or=0.05). 2) In the first measurement, the mean interside variance(ISV) was 32.7%(37.55+/-16.32%(A), 29.88+/-17.15%(B), and 30.67+/-18.56(C)) and there was no significant difference among them(A, B, C)(p>or=0.05). The minimal individual ISV was 20.35+/-12.44%. There was significant difference between it and the other individual 3 positions(por=0.05). The minimal individual ISV was varied in each testing at 3 positions. And the value was 14.32+/-2.69%. There was no significant difference between it and other 3 postions(p>or=0.05). So we recommand that the recording electrode may be fixed at the bilateral same position of the nasolabial fold. But if there is any indication of facial nerve decompression, you must find the best recording electrode position to get the minimal ISV before operation.