OBJECTIVETo detect the expression of Toll-like receptor 9 (TLR9) in ovarian cancer, and to explore their clinical significance.

METHODSWestern blot method and immunohistochemical staining were used to examine the expression of TLR9 in the ovarian cancer, paracancerous tissues and normal ovarian tissues, obtained during operation from 30 ovarian carcinoma patients and 30 normal non-tumor patients. The relationships of TLR9 with pathological grade, clinical stage, and metastasis of ovarian cancer were statistically analyzed.

RESULTSThe percentage of positive cells expressing TLR9 protein in human ovarian cancer tissues, paracancerous tissues and normal ovarian tissues were 80.0%, 36.7% and 20.0%, respectively. The protein expression level of TLR9 was gradually descending (P < 0.01). The highly expressed TLR9 significantly correlated with the degree of tumor differentiation, an advanced FIGO stage and lymph node metastasis. The Western blot results showed that TLR9 protein expression in ovarian cancer, paracancerous tissues and normal ovarian tissues were 0.803 ± 0.072, 0.411 ± 0.087 and 0.113 ± 0.065, respectively. The expression of TLR9 in ovarian cancer was significantly higher than that in normal tissue and paracancerous tissues (P < 0.01).

CONCLUSIONSTLR9 has a higher expression in ovarian cancer tissues. TLR9 expression has a close relationship with pathological grades of ovarian cancer, suggesting that TLR9 plays an important role in the development and progression of ovarian cancer through immunologic mechanisms.