Gene Expressions of Protein Tyrosine Phosphatases in Regenerating Rat Liver and Rat Ascites Hepatoma Cells

摘要

mRNA levels for ten protein tyrosine phosphatases (PTPs), PTP‐S, PTPH1, PTP‐1, GLEPP1, LRP, PTP1D, PTPG1, PTPγ, PTPδ, and LAR, were determined during regeneration of rat liver, and mRNA levels for 5 PTPs, PTP‐S, PTP‐1, PTPγ, PTPδ, and LRP, were determined in three lines of rat ascites hepatoma cells. In regenerating rat liver, the expression patterns of PTP genes after partial hepatectomy could be classified into four groups. In group 1 (PTP‐S and PTPH1), the mRNA levels increased rapidly, reached a maximum 7 h after partial hepatectomy, remained at a plateau for 1–2 days and then decreased gradually. In group 2 (PTP‐1, GLEPP1, and LRP), the mRNA levels showed two peaks on days 1 and 5, and then decreased gradually. In group 3 (PTP1D and PTPG1), the mRNA levels increased rapidly, reached a maximum at 7 h, remained high for several days, and then did not decrease but rather increased after day 7. In group 4 (PTPγ, PTPδ, and LAR), the mRNA levels remained constant for the first 5 days and increased over the control levels after day 7. In rat ascites hepatomas, gene expression of non‐receptor‐like PTPs (PTP‐S and PTP‐1) showed various neoplastic alterations, whereas mRNAs of receptor‐like PTPs (PTPγ, PTPdL, and LRP) were lost or drastically decreased.