Background: GATA3 functions as a tumor suppressor and has been observed in multiple types of cancer, but the effects and mechanisms of GATA3 in osteosarcoma (OS) are not yet known. 
Methods: The GATA3 expression in OS cells and tissues were detected using quantitative reverse-transcription PCR and Western blotting assay. CCK-8 assay, colony formation assay, wound healing assay as well as transwell assay, were performed to determine the effects of GATA3 on cell proliferation, migration and invasion. ChIP and qChIP as well as luciferase assay were performed whether GATA3 transcriptionally regulated slug expression.
Results: GATA3 was downregulated in OS cells and tissues. The GATA3 expression was closely associated with tumor size as well as metastasis. GATA3 significantly suppressed OS cells proliferation, migration and invasion. EMT-associated transcript factor, slug, was transcriptionally inhibited by GATA3, thereby regulation of EMT in OS.
Conclusion: GATA3 serves as a tumor suppressor in OS and suppresses the progression and metastasis of OS through regulation of slug.
Keywords: GATA3, osteosarcoma, epithelial–mesenchymal transition, proliferation, migration