title: "Smart" Nanoparticles Enhance the Cytoplasmic Delivery of Anti-RhoC Silencing RNA and Inhibit the Migration and Invasion of Aggressive Breast Cancer Cells.
abstract: Rho-GTPases are small GTP-binding proteins that contribute to the epithelial-to-mesenchymal transition by regulating several cellular processes including organization of the actin cytoskeleton, cell motility, transcription, and cell proliferation. Overexpression of RhoC-GTPases (RhoC) in breast cancer has been implicated in poor disease prognosis due to increased cancer cells invasion, migration, and motility, which warranted its consideration as a therapeutic target for inhibiting breast cancer metastasis. Using silencing RNA (siRNA) molecules to knockdown RhoC expression is a promising approach to inhibit breast cancer metastases. However, transforming anti-RhoC siRNA molecules into a viable therapy remains a challenge due to the lack of a biocompatible carrier that can selectively deliver the RNA cargo into breast cancer cells. We report the use of a degradable, pH-sensitive, β-cyclodextrin (βCD)-based polymeric carrier that condenses anti-RhoC siRNA forming "smart" particles. These smart anti-RhoC particles were efficiently internalized, successfully escaped the endosome, and delivered the RNA cargo into the cytoplasm of SUM149 and MDA-MB-231 breast cancer cells. Our results show that anti-RhoC particles used at a low N/P ratio of 2.5/1 suppressed RhoC protein levels by 100% and 90% in SUM149 and MDA-MB-231 cells, respectively. Further, anti-RhoC particles inhibited the invasion, motility, and migration of SUM149 and MDA-MB-231 cells by 40-47%, 57-60%, and 61.5-73%, respectively. Smart particles encapsulating the scrambled siRNA sequence did not affect RhoC protein expression or the invasion, motility, and migration of SUM149 and MDA-MB-231 cells, which indicate the biocompatibility of the polymeric carrier and selectivity of the observed RhoC knockdown. These results collectively indicate the therapeutic potential of smart anti-RhoC particles in arresting the metastatic spread of breast cancer cells.
authors.forename: Neha
authors.initials: N
authors.lastname: Kaushal
authors.forename: Yasemin Yuksel
authors.initials: YY
authors.lastname: Durmaz
authors.affiliation: ‡Department of Internal Medicine, School of Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States.
authors.forename: LeWei
authors.initials: L
authors.lastname: Bao
authors.affiliation: ‡Department of Internal Medicine, School of Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States.
authors.forename: Sofia D
authors.initials: SD
authors.lastname: Merajver
authors.affiliation: §Macromolecular Science and Engineering Program, University of Michigan, 2300 Hayward Avenue, Ann Arbor, Michigan 48109, United States.
authors.forename: Mohamed E H
authors.initials: ME
authors.lastname: ElSayed
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects* / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects / Q000235:genetics; D003593:Cytoplasm / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000235:genetics; D006801:Humans; D053758:Nanoparticles / Q000008:administration & dosage*; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000517:prevention & control*; D034622:RNA Interference / Q000502:physiology*; D034741:RNA, Small Interfering / Q000235:genetics; D020741:rho GTP-Binding Proteins / Q000235:genetics*; D020742:rhoA GTP-Binding Protein / Q000235:genetics; D000075024:rhoC GTP-Binding Protein
chemical_list: D034741:RNA, Small Interfering; C066690:RHOC protein, human; D020741:rho GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein; D000075024:rhoC GTP-Binding Protein
keywords: anti-RhoC silencing RNA; breast cancer metastases; cancer cell migration and invasion; drug delivery; pH-sensitive membrane-destabilizing polymers; β-cyclodextrin