TIMP-1 effect in cell proliferation and cell cycle regulators. (A) Western blots demonstrating a switch in cyclin D usage; TIMP-1 up-regulates cyclin D2 and down-regulates cyclin D3 in TIMP-1JD38. β-actin was included as a control for equal protein loading. (B) Immunochemistry of TIMP-1JD38 tumor sections demonstrates differential expression of TIMP-1 (top row) in the cytoplasm and a higher intensity in the immediate cytoplasm membrane perimeter; original magnification × 1000. Aberrant TIMP-1 expression does not affect tumor cell proliferation. Both control LXSN-JD38 and TIMP-1JD38 tumors show equal expression of the cell proliferation marker Ki-67 (bottom row); original magnification × 1000. Sections were examined under an Olympus BX41 microscope using UPLAN F1 40 ×/0.75 objective lenses. DAB shows specific staining in brown. Digital images were obtained with an Olympus DP12 (Olympus, Melville, NY) and imported with an Olympus Camedia USB Smartmedia card into AdobePhotoshop 7.0 (Adobe Systems, San Jose, CA) for processing.