Background: Low molecular weight protein tyrosine phosphatase (LMW-PTP) has been related to tumorigenesis, having both oncogenic and anti-oncogenic roles. The differential roles of its main active isoforms (fast and slow) may account for these discrepancies. The fast isoform has been described to be involved in the bone-metastatic process, although knockdown of the slow isoform was recently reported to reduce osteoclastogenesis. We aimed to study the influence of LMW-PTP isoforms on osteoclast differentiation.
Materials and methods: Osteoclast precursors (RAW 264.7) were cultured with conditioned medium from MDA-MB-231 breast cancer cells with total knockdown of LMW-PTP and with knockdown of the slow isoform of LMW-PTP. Tartarate-resistant acid phosphatase (TRAP) staining and quantification were performed to assess osteoclast differentiation.
Results: Total knockdown of LMW-PTP, but not of slow LMW-PTP significantly reduced osteoclast differentiation of RAW 264.7 cells.
Conclusion: We suggest that total LMW-PTP increases osteoclastic differentiation, albeit not at the expense of the slow isoform.
Keywords: LMW-PTP; Low molecular weight protein tyrosine phosphatase; MDA-MB-231; bone metastasis; breast cancer.
Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.