en علوم پزشکی Medical Sciences مقاله پژوهشی Original Research Article <span style="font-size:10.0pt"><span new="" roman="" style="font-family:" times="">The treatment of prostate cancer patients usually starts with androgen ablation and followed by chemotherapy; however, in some cases the tumor develops resistant phenotype. Combination therapy is currently regarded as a cornerstone in cancer therapy to overcome the drug resistance. Herein, we investigated the combinatory effect of Docetaxel and Trastuzumab with a novel nanomedicine, BCc1. Also, we knocked down the expression of Heat shock factor-1, HSF1, in resistant Prostate Cancer cell line 3, PC3, using RNA interference, RNAi, to sensitize the cancer cells to the drug treatment. We observed down-regulation of Erb-B2 Receptor Tyrosine Kinase 3, ERBB3, B-Cell Leukemia/Lymphoma 2, BCL2, and Heat Shock Protein 90, HSP90, in HSF1 knockdown PC3 cells.&nbsp; Knockdown of HSF1 made PC3 cells more susceptible to Docetaxel treatment. Additionally, BCc1 nanomedicine was tested on prostate cancer cell line PC3 for the first time. It resulted in reduced metabolic activity in these cells.&nbsp; We propose that a combination of the gene therapy and the chemotherapy gives more favorable results in the treatment of refractory prostate cancer.</span></span> Prostate Cancer, Combination therapy, Nanochelating Technology 47 55 http://modernmedlab.com/browse.php?a_code=A-10-874-1&slc_lang=en&sid=1 Roya Yousefi roya_ysf72@rocketmail.com 10031947532846002005 10031947532846002005 Yes Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran Mahboubeh Kabiri Renani mkabiri@ut.ac.ir 10031947532846002006 10031947532846002006 No Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran Fatemeh Koohkan f.kouhkan@yahoo.com 10031947532846002007 10031947532846002007 No Stem Cell Technology Research Center, Tehran, Iran Mahshid Heidari mahshid.heidari@gmail.com 10031947532846002008 10031947532846002008 No Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran Sedigheh Asad asad@ut.ac.ir 10031947532846002009 10031947532846002009 No Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran Symzar Hosseinzadeh symzar.hosseinzadeh@gmail.com 10031947532846002010 10031947532846002010 No Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mohammad Hossein Nazaran nazaran@khazra.ir 10031947532846002011 10031947532846002011 No 4. Department of Research and Development, Sodour Ahrar Shargh Company, Tehran, Iran.