Abstract: Background and purpose: Placental site trophoblastic tumor (PSTT) is a special type of gestational trophoblastic tumor. It remains no general cell line for PSTT. The aim of this study was to establish and identify a human PSTT cell line. Methods: In this study, a PSTT cell line (PSTT-1) was derived from primary culture of a surgically resected PSTT tissue. We further identified the basic characteristics of PSTT-1, including cell morphology, cell growth curve, karyotype analysis, short tandem repeat (STR) profiling of PSTT-1 and its parental tumor, and immunohistochemistry analysis. Results: A human PSTT cell line named PSTT-1 was successfully established. PSTT-1 formed a monolayer growth and lost contact inhibition, and exhibited a pleomorphic morphology. PSTT-1 cells grew actively in vitro. PSTT-1 was passaged every 5 days, and maintained in culture for more than 30 passages. Karyotyping of PSTT-1 revealed normal female karyotype: 46, XX. STR profiling of PSTT-1 was nearly identical to its parental tumor. Immunohistochemistry analysis of PSTT-1 revealed expression of β-catenin, CD146, human chorionic gonadotropin (hCG), human placental lactogen (hPL) and Muc4. Conclusion: This study established a PSTT cell line, which could be useful for further research on PSTT.

Key words: Placental site trophoblastic tumor, Cell line, Primary culture