BACKGROUND
Midkine (MK) is a member of the heparin-binding growth factor family. Overexpression of MK is observed not only in cancerous tissue but also in precancerous lesions of the colon and the prostate. Using immunohistochemical methods, we investigated MK expression in preinvasive and invasive neoplasia of the uterine cervix.
METHODS
We performed immunohistochemical analysis of archived cone biopsy and hysterectomy specimens from 161 squamous cell lesions of the uterine cervix (29 cervical intraepithelial neoplasia 1 (CIN1), 35 CIN2, 49 CIN3, 30 microinvasive squamous cell carcinomas (MIC), and 18 invasive squamous cell carcinoma). In addition, we examined if there is a correlation between MK expression and status of human papilloma virus infection determined by a commercially available DNA chip.
RESULTS
None of the normal cervical mucosa showed MK immunostaining. The level of MK expression gradually increased according to the histologic grade. Moderate and strong expressions were most frequently observed in cervical tissue with CIN3 and MIC. MK immunostaining was more accentuated in the invasive border of MIC.
CONCLUSION
MK may play a functional role in the disease progression of cervical squamous cell neoplasia.