Kristina Iljin

Publications (2)11.16 Total impact

• Source

  Available from: Michele Bernasconi

  Article: Identification of a rhabdomyosarcoma targeting peptide by phage display with sequence similarities to the tumour lymphatic-homing peptide LyP-1.

  Hendrik Witt, Katarina Hajdin, Kristina Iljin, Oliver Greiner, Felix K Niggli, Beat W Schäfer, Michele Bernasconi
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  ABSTRACT: Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. To improve existing therapies and broaden the spectrum of cytotoxic agents that can be used in RMS treatment, we performed a phage-display-based screening for peptides that bind specifically to RMS cells. Two peptides binding to RMS and to other tumour cell lines, but not to normal skeletal muscle cells and fibroblasts, were isolated from phage-displayed random peptide libraries. One peptide, named RMS-I (CQQSNRGDRKRC) contained the integrin-binding motif RGD and its binding was blocked by an antibody against alpha(v)beta(3)integrin, which is expressed on the RMS cell line RD. The isolation of RMS-I confirmed the validity of our screening procedure. The second peptide, named RMS-II (CMGNKRSAKRPC), shows sequence similarity to a previously identified peptide with tumour lymphatic specificity, LyP-1. However, RMS-II binds in vivo to RMS xenografts better than LyP-1 and homes to the tumour blood and not to lymphatic vessels. Therefore, RMS-II represents a promising peptide for the development of RMS-specific targeting approaches.
  International Journal of Cancer 12/2008; 124(9):2026-32. · 5.44 Impact Factor
• Article: A fluorescent Tie1 reporter allows monitoring of vascular development and endothelial cell isolation from transgenic mouse embryos.

  Kristina Iljin, Tatiana V Petrova, Tanja Veikkola, Vijay Kumar, Matti Poutanen, Kari Alitalo
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  ABSTRACT: Tie1 is an endothelial receptor tyrosine kinase essential for development and maintenance of the vascular system. Here we report generation of transgenic mice expressing enhanced green fluorescent protein (EGFP) or a chimeric protein consisting of a Zeosin resistance marker and EGFP under the control of mouse Tie1 promoter. Intravital monitoring of fluorescence showed that the EGFP reporter recapitulates the Tie1 expression pattern in the developing vasculature, and flow cytometry using EGFP allowed the isolation of essentially pure Tie1-expressing endothelial cells from transgenic mouse embryos. However, EGFP and LacZ transgenic markers were strongly down-regulated in the adult vasculature; unlike the Tie1-LacZ knock-in locus, the promoter was not reactivated during tumor neovascularization, indicating the presence of additional regulatory elements in the Tie1 locus. Starting at midgestation, Tie1 promoter activity became stronger in the arterial than in the venous endothelium; in adult mice, promoter activity was observed in arterioles, capillaries, and lymphatic vessels, indicating a significant degree of specificity in different types of endothelial cells. Our results establish Tie1-Z/EGFP transgenic mice as a useful model to study embryonic vascular development and a convenient source for the isolation of primary endothelial cells.
  The FASEB Journal 12/2002; 16(13):1764-74. · 5.71 Impact Factor