Different expressions of tyrosine kinase B and brain-derived neurotrophic factor in cervical cancer and paracancerous tissue

Objective To study tyrosine kinase B (TrkB) and brain-derived neurotrophic factor (BDNF) expression in cervical carcinoma tissue, paracancerous tissues and normal cervical tissue, analyze their relationship with clinical pathological characteristics of cervical cancer, and to investigate the relation between apoptosis signal pathway activation around cancer cells and tumor malignancy. Methods A total of 72 cases with cervical invasive carcinoma were selected, while 72 cases of normal cervical tissues were selected as control group. Tissue microarrays of cervical cancer tissues, adjacent tissues and normal cervical tissues were made and the expressions of TrkB and BDNF were detected and compared by immunohistochemistry method. Results A total of 6 tissue chips were constructed. Expression rates of TrkB and BDNF in cervical cancer were 70.80% and 91.70%, respectively, and were significantly higher than those in paracancerous tissue (25.00% and 48.60% ). There was almost no expression in normal cervical tissue, of which the positive rates were 4.20% and 1.40%. The positive rate of TrkB in cervical cancer was related to vascular invasion and lymph node metastasis (χ2=12.50 and 12.36, P 0.05). Meanwhile, the total positive rate of BDNF was high, and had no correlation with all factors above (P all>0.05). The expressions of TrkB and BDNF in cancer adjacent tissue were related to the tumor diameter, vascular invasion and lymph node metastasis (P<0.01 or P<0.05). Conclusions There are some TrkB and BDNF expressions in the cervical cancer adjacent tissues. The expression levels in paracancerous tissues are significantly correlated with tumor diameter, vascular invasion and lymph node metastasis, and show better reflection of the malignant degree than those in tumor tissues. The expressions of TrkB and BDNF in paracancerous tissues may be used as new biological markers for evaluating the prognosis of patients with cervical cancer. Key words: Uterine cervical neoplasms; Tyrosine kinase B; Brain-derived neurotrophic factor; Paracancerous tissues; Apoptosis