Abstract
Aim: Typical features of human osteosarcoma are highly invasive and migratory capacities. Our study aimed to investigate the roles of glycogen synthase kinase 3β (GSK3β) in human osteosarcoma metastasis.Methods: GSK3β expressions in clinical osteosarcoma tissues with or without metastasis were examined by immunohistochemical staining. The expressions of GSK3β, p-GSK3βSer9, and p-GSK3βTyr216 in human osteoblast cells (hFOB1.19) and human osteosarcoma cells (MG63, SaOS-2, and U2-OS) were detected by Western blotting. The GSK3β activity was measured by non-radio isotopic in vitro kinase assay. Migration and invasion abilities of MG-63 cells treated with small-molecular GSK3β inhibitors were respectively examined by monolayer-based wound-healing assay and transwell assay. The mRNA expressions of GSK3β, matrix metalloproteinase-2 (MMP-2), MMP-9, phosphatase with tensin homology (PTEN), and focal adhesion kinase (FAK) were detected after siRNA transfection for 72 h. Meanwhile, protein expressions of GSK3β, FAK, p-FAKY397, PTEN, MMP-2, and MMP-9 were measured by Western blotting.Results: Clinical osteosarcoma tissues with metastasis showed higher GSK3β expressions. MG63 and U2-OS cells that were easy to occur metastasis showed significantly higher expressions and activities of GSK3β than SaOS-2 cells. Inhibition of GSK3β with small-molecular GSK3β inhibitors in MG63 cells significantly attenuated cell migration and invasion. These effects were associated with reduced expressions of MMP-2 and MMP-9. Moreover, increased PTEN and decreased p-FAKY397 expressions were observed following GSK3β knockdown by siRNA transfection. Conclusion: GSK3β might promote osteosarcoma invasion and migration via pathways associated with PTEN and phosphorylation of FAK.
Highlights
Invasion and metastasis of human osteosarcoma often occur in the early stages, and the lungs are the most distant metastatic sites, accounting for about 90% of all metastases [1]
The expressions of Glycogen synthesis kinase 3β (GSK3β) in tissue samples of 24 patients with primary metastatic osteosarcoma and 16 patients with nonmetastatic osteosarcoma were detected by the immunohistochemical staining
The immunohistochemistry staining results showed that the percentage of GSK3β positive cells in the tumor samples of patients with primary metastatic osteosarcoma was markedly higher than that of patients without metastasis (67.8 +− 5.8% vs. 24.8 +− 3.6%, P
Summary
Invasion and metastasis of human osteosarcoma often occur in the early stages, and the lungs are the most distant metastatic sites, accounting for about 90% of all metastases [1]. Revealing the signaling pathways involved in the metastatic process of human osteosarcoma has become an important aspect for developing novel effective therapeutic aimed at improving the survival rate of osteosarcoma [4]. GSK3β is a serine/threonine protein kinase and has emerged as a key enzyme in regulating several important cellular signaling pathways via phosphorylating its substrates [5]. Our previous work demonstrated that the overexpression and abnormal activation of GSK3β in gastrointestinal cancer cells inhibit the apoptosis, and promote cell survival and proliferation [10]. Reducing the activity or expression level of GSK3β inhibits the survival and proliferation of gastrointestinal cancer cell and induced cell apoptosis. GSK3β has potentially to be a novel therapeutic target for gastrointestinal cancer [10,11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
