Background & objective: Peptidyl-prolyl cis/trans isomerase Pin1 is prevalently overexpressed in human cancers. Up-regulation of Pin1 elevates the expression of Cyclin D1, and plays an important role in tumorigenesis and tumor progression. This study was to investigate the expression and clinical significance of Pin1 and Cyclin D1 in cervical cancer cell lines and cervical epithelial tissues.
Methods: The expression of Pin1 and Cyclin D1 in cervical cancer cell lines HeLa, SiHa, C33a and Caski were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Their expression in 88 samples of cervical tissues, including 10 samples of normal cervix, 21 samples of cervical intraepithelial neoplasia (CIN), and 57 samples of invasive cervical cancer, were detected by immunohistochemistry.
Results: The mRNA and protein levels of Pin1 were significantly higher in HeLa, SiHa, C33a, and Caski cells than in normal cervical epithelial tissues (P<0.05). The expression of Pin1 increased progressively along with the disease process from normal cervix to CIN, and to invasive cervical cancer (0%, 47.62%, 64.91%, P<0.05). Pin1 expression had no relation to disease stage (FIGO), pathologic grade, and pelvic lymph node metastasis status (P>0.05). The positive rate of Pin1 was significantly higher in cervical adenocarcinoma than in cervical squamous cell carcinoma (100% vs. 60.0%, P<0.05). In cervical cancer tissues, the overexpression of Pin1 was positively correlated to that of Cyclin D1 (P<0.05).
Conclusions: Pin1 is overexpressed in HeLa, SiHa, C33a and Caski cell lines as well as in cervical cancer tissues. The overexpression of Pin1 is closely related to Cyclin D1 expression in cervical cancer. The aberrant expression of Pin1 and Cyclin D1 might contribute to tumorigenesis of cervical cancer.