Reduced tumorigenicity of murine leukemia cells expressing protein-tyrosine phosphatase, PTP|[epsiv]|C

摘要

Recently, we reported that a cytosolic isoform of protein-tyrosine phosphatase (PTPC), when overexpressed, inhibits terminal differentiation and apoptosis of murine M1 myeloblastic leukemia cells induced by interleukin-6. To determine whether these observed effects in vitro correspond to a tumorigenicity of PTPC-expresser (M1-C) cells in vivo, parent M1 and M1-C cells were intravenously inoculated into scid or nude mice, and survival of mice receiving these cell lines was monitored. Unexpectedly, both scid and nude mice inoculated with M1-C cells showed significantly prolonged survival time than those receiving parent M1 cells. While parent M1 cells inoculated by intravenous injection formed metastatic tumors in the spleen, expression of PTPC suppressed tumor development in the spleen. The results suggest a suppressive role of PTPC in tumorigenesis.