title: Targeting the heat shock factor 1 by RNA interference: a potent tool to enhance hyperthermochemotherapy efficacy in cervical cancer.
abstract: Carcinoma of the uterine cervix is one of the highest causes of mortality in female cancer patients worldwide, and improved treatment options for this type of malignancy are highly needed. Local hyperthermia has been successfully used in combination with systemic administration of cisplatin-based chemotherapy in phase I/II clinical studies. Heat-induced expression of cytoprotective and antiapoptotic heat shock proteins (HSP) is a known complication of hyperthermia, resulting in thermotolerance and chemoresistance and hindering the efficacy of the combination therapy. Heat shock transcription factor 1 (HSF1) is the master regulator of heat-induced HSP expression. In the present report, we used small interfering RNA (siRNA) to silence HSF1 and to examine the effect of HSF1 loss of function on the response to hyperthermia and cisplatin-based chemotherapy in HeLa cervical carcinoma. We have identified the 322-nucleotide to 340-nucleotide HSF1 sequence as an ideal target for siRNA-mediated HSF1 silencing, have created a pSUPER-HSF1 vector able to potently suppress the HSF1 gene, and have generated for the first time human cancer cell lines with stable loss of HSF1 function. We report that, although it surprisingly does not affect cancer cell sensitivity to cisplatin or elevated temperatures up to 43 degrees C when administered separately, loss of HSF1 function causes a dramatic increase in sensitivity to hyperthermochemotherapy, leading to massive (>95%) apoptosis of cancer cells. These findings indicate that disruption of HSF1-induced cytoprotection during hyperthermochemotherapy may represent a powerful strategy to selectively amplify the damage in cancer cells and identify HSF1 as a promising therapeutic target in cervical carcinoma.
authors.affiliation: Institute of Neurobiology and Molecular Medicine, Consiglio Nazionale delle Ricerche, Rome, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Rossi
authors.forename: Stefania
authors.initials: S
authors.lastname: Ciafrè
authors.forename: Mirna
authors.initials: M
authors.lastname: Balsamo
authors.forename: Pasquale
authors.initials: P
authors.lastname: Pierimarchi
authors.forename: M Gabriella
authors.initials: MG
authors.lastname: Santoro
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002945:Cisplatin; D003131:Combined Modality Therapy; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D020868:Gene Silencing; D055551:HSP27 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis / Q000235:genetics; D018841:HSP90 Heat-Shock Proteins / Q000096:biosynthesis / Q000235:genetics; D006367:HeLa Cells; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D018832:Molecular Chaperones; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D014157:Transcription Factors / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics*; D014162:Transfection; D002583:Uterine Cervical Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology / Q000628:therapy*
chemical_list: D004268:DNA-Binding Proteins; C000619706:HSF1 protein, human; D055551:HSP27 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; C057725:HSPB1 protein, human; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; D034741:RNA, Small Interfering; D014157:Transcription Factors; D002945:Cisplatin