Abstract: Objective To study the overexpression of ornithine decarboxylase(ODC) gene in different types of ovarian tissues, which include normal ovarian tissues surrounding tumors, ovarian binign and ovarian carcinomas, and to determine the role of ODC overexpression in ovarian cancer development and progression. Methods We analyzed ODC gene expression by reverse transcription-polymerase chain reaction in invasive ovarian carcinoma tissues from 40 cases, normal ovarian tissues surrounding tumors from 15 cases and in ovarian benign tumors from 15 cases. The expression of ODC gene was compared in different ovarian tissues. Results Expression of ODC gene was observed in 26.67%(4 of 15) normal ovarian tissues surrounding tumors, 0 %(0 of 15) ovarian benign tumors, and 65%(26 of 40) ovarian carcinomas. The results confirmed that expression of ODC gene was common in the majority of ovarian carcinomas. Compared to normal ovarian tissues surrounding tumors and ovarian benign tumors, expression of ODC gene was significantly high in ovarian carcinomas(P<0.05), but the expression of ODC in normal ovarian tissues surrounding tumors and ovarian benign tumors were at the same level. ODC expression rate in serous carcinoma was 83.33％, significantly higher than that in the other tumor types(50.00％, P=0.028). ODC expression rate in Stage Ⅰ-Ⅱ tumors was 54.55%, which included 2 strongly positive samples. In stage Ⅲ-Ⅳ of tumors, ODC expression rate was 68.97%, which included 17 strongly positive samples. There was no significant difference between the two groups(P=0.469). But the strongly positive rates in stage Ⅲ-Ⅳ and stage Ⅰ-Ⅱ tumors were 58.62％ and 18.18％, respectively, the difference between them was significant(P=0.034). ODC expression rate was 20% in highly-moderately differentiated tumors, and 64% in poorly differentiated tumors, the difference was significant(P=0.018). Conclusion Overexpression of ODC gene is associated with ovarian cancer development and progression.

Key words: ovarian carcinoma, ornithine decarboxylase(ODC), gene