Abstract: Objective To investigate the clinical significance of protein expression of Six1 in cervical cancer. Methods The immunohistochemical (IHC) staining was applied to detect the expression of Six1 protein in normal cervical tissues (n=32), cervical intraepithelial neoplasia (CIN) tissues (n=49) and cervical cancer tissues (n=123). The localization of Six1 protein was detected in vitro cultured HeLa cells using immunofluorescence (IF) staining. Results The positive rate of Six1was significantly higher in cervical cancer (72.3%) than that of CIN tissues (28.6%) and normal cervical tissues (15.6%, 2χ = 13.118 and 10.058 respectively, P < 0.01). There were significance differences in expression levels of Six1 protein between different tumor sizes and metastasis of cervical cancer (P < 0.01). The Six1 protein showed positive signals in cytoplasm and nucleoli in HeLa cells. Conclusion Six1 expression is associated with cervical cancer, which may be a potential
biomarker for invasion and metastasis of cervical cancer.

Key words: uterine cervical neoplasms, genes, homeobox, Six1, immunohistochemistry, neoplasm invasiveness, neoplasm metastasis, HeLa cells