Förslaget inkom 2007-11-22
Characterization of tissue inhibitor of metalloproteinases (TIMP)-4 in tissue repair, inflammation and cancer
OBS! ANSÖKNINGSTIDEN FÖR DETTA EXJOBB HAR LÖPT UT.
Matrix metalloproteinases (MMPs) comprise a family of more than 20 enzymes that take part in the degradation of extracellular matrix and basement membranes during cell migration, angiogenesis and proteolytic activation of growth factors. These events are needed in fetal development and in normal tissue remodelling as well as in wound repair, inflammation and tumour invasion. MMPs are regulated transcriptionally by proenzyme activation, and by specific inhibitors, tissue inhibitors of metalloproteinases (TIMPs-1, -2, -3, and –4), which are multifunctional proteins that in addition to their MMP inhibitory effect can regulate apoptosis, inflammation and cell proliferation. Their diminished or increased expression has been reported in various cancers depending on the tumor type. Tissue inhibitor or metalloproteinases-4 is the most recently characterized member of the TIMP family. It is 51% identical to TIMPs-2 and –3, expressed in particular by the placenta, brain, heart and platelets and can induce apoptotic cell death in transformed cells. It inhibits MMPs-1, -2, -3, -7, -9, -14, -26 and TACE. The significance of TIMP-4 in cutaneous biology is still poorly understood. We aim to study the expression of TIMP-4 in vivo in tissue samples from various cutaneous malignancies, in normal and aberrant wound repair, and in samples from different chronic skin diseases reflecting keratinocyte apoptosis, proliferation and atypia by immunohistochemistry. In vitro, the expression and regulation of this gene will be studied in keratinocytes (HaCaT cells), monocytes (U937 and THP-1 cells), and T-cells (Jurkat cells). We will also test the effect of different cytokines/growth factors, chemical agents and ras transformation on the expression of TIMP-4 in these cells.
Our project thus aims at further characterization of the biological function and regulation of a novel protein that may play an important part in cancer biology and inflammation of several different tissues and may represent an important therapeutic target. Methods we will use are cell culturing, RT-PCR, TaqMan, Westerns and immunohistochemistry.