Expression of survivin and correlation with PCNA in osteosarcoma. Survivin is a new anti-apoptosis gene with reported expression during fetal development and in cancer tissues. Proliferating cell nuclear antigen (PCNA) is essential for the replication of deoxyribonucleic acid (DNA). In this experiment, we examined the expression of survivin and PCNA in human osteosarcoma tissues and investigating whether survivin and PCNA expressions were correlated with histological grades, histological types, and patients' clinical characteristics.Sixty-eight osteosarcoma samples were divided into two groups based on the degree of tumor cell differentiation. Immunohistochemical staining was performed to analyze the expression of survinin and PCNA. Four histological types and patients' clinical characteristics were also recorded.There were abundant levels of survivin and PCNA immunoreactivity in the nucleus and/or cytoplasm of the osteosarcoma cells. All cells essentially revealed the cytoplasmic localization and the nuclear signals of survivin in same cases, while PCNA from the majority of cases predominantly showed nuclear expression. Scoring on the percentage of positive cells indicated that survivin expression was significantly associated with the PCNA-labeling index (LI), which was correlated with the histological grades of osteosarcoma (chi2 = 17.86 and chi2 = 23.75, respectively).The expression of survivin can be used as a useful indicator in grading the malignancy of osteosarcoma.Copyright 2006 Wiley-Liss, Inc.