PT - JOURNAL ARTICLE AU - IRINA ALHO AU - LUIS COSTA AU - MANUEL BICHO AU - CONSTANÇA COELHO TI - Low Molecular Weight Protein Tyrosine Phosphatase <em>Slow</em> Isoform Knockdown in MDA-MB-435 Cells Decreases RAW 264.7 Osteoclastic Differentiation DP - 2016 May 01 TA - Anticancer Research PG - 2227--2232 VI - 36 IP - 5 4099 - http://ar.iiarjournals.org/content/36/5/2227.short 4100 - http://ar.iiarjournals.org/content/36/5/2227.full SO - Anticancer Res2016 May 01; 36 AB - Background/Aim: During the bone metastatic process, tumor cells and bone cells drive a vicious cycle stimulating growth and activity of each other. We here address how low molecular weight protein tyrosine phosphatase (LMW-PTP) could be involved in this process. Materials and Methods: We targeted LMW-PTP by siRNA and evaluated the effect of various soluble factors released to the culture medium by the MDA-MB-435 breast cancer cell line, in RAW 264.7 osteoclastogenesis. Results: We showed that these soluble factors did not change RAW 264.7 osteoclastogenic potential. The knockdown of the LMW-PTP slow isoform decreased osteoclastogenesis of RAW 264.7, showing less active Src. The knockdown of LMW-PTP and its slow isoform decreased the release of IL-8 but not IL-6 in MDA-MB-435. Conclusion: The LMW-PTP slow isoform can be an important protein in bone metastatic disease, with a fundamental role in the interplay between tumor cells and osteoclasts, through the regulation of Src activity and IL-8 secretion.