Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 53 7 2015 10 06 Growth Inhibition of MDA-MB-231 Cell Line by Peptides Designed based on uPA 403 407 EN Parastoo Tarighi Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran Mohammad Reza Khorramizadeh Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran Armin Madadkar Sobhani Department of Bioinformatics, Institute of Biochemistry and Biophysics, Tehran University, Tehran, Iran Seyed Nasser Ostad Department of Toxicology-Pharmacology, School of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran Mohammad Hossein Ghahremani Department of Toxicology Pharmacology, School of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran. AND Department of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran 2015 10 06 2015 10 06 Interaction between urokinase-type plasminogen activator (uPA) and its receptor (uPAR) plays an important role in the progression of numerous cancer types including breast cancer by promoting tumor initiating,  proliferation,  invasion  and  metastasis.  Hence,  disruption  of  this  interaction  inhibits  their downstream cascades and subsequently tumor growth. For this, we created two series of 8 and 10 amino acids linear peptides, derived from uPA binding region to target uPAR and studied the inhibition of proliferation in MDA-MB-231 cell line. Results revealed that all of the 10-mer peptides inhibited breast cancer cell proliferation significantly with maximum 40% inhibition of 103 peptides. Meanwhile, none of the 8-mer peptides showed significant toxicity. Current results indicate that the linear 10-mer peptides which mimic a small part of a sequence of a binding domain of uPA to uPAR could be exploited to design a novel class of anti-cancer agents. https://acta.tums.ac.ir/index.php/acta/article/view/4270 https://acta.tums.ac.ir/index.php/acta/article/download/4270/4683