Abstract 2024: Hyaluronic acid conjugated nanoparticle delivery of siTWIST reduces tumor burden and enhances chemosensitivity in ovarian cancer
Authors: Glackin Carlotta A. , Shahin Sophia A. , Simargi Shirleen , Wang Ruining , Contreras Altagracia , Parra Liliana , Qu Loiuse , Wen Wei , Dellinger Thanh , Unternaehrer Julia , Tamanoi Fuyujiko , Zink Jeffrey 
Published: August 2018

Abstract
Purpose: TWIST is a transcription factor critical to embryonic development, and aberrantly activated in many cancers. It regulates epithelial-to-mesenchymal transition (EMT), the process underlying metastatic spread and drug resistance. The majority of epithelial ovarian cancer (EOC) patients respond well to chemotherapy, but relapse with metastatic and drug-resistant disease. We are investigating the role of TWIST-mediated relapse, with the goal of developing treatments that sensitize chemoresistant tumors and improve survival.
Experimental Procedures: We employ siRNA to target TWIST mRNA and have created a mesoporous silica nanoparticle with hyaluronic acid (siTWIST-MSN-HA) as a delivery vehicle. Microscopy was conducted to ensure cancer stem cell (CSC) targeting via CD44, and efficient uptake of MSN-HAs. We tested TWIST knockdown combined with cisplatin in vitro and in vivo. At necropsy, total tumor, metastasis, and ascites were evaluated to determine effects of siTWIST-MSN-HA compared to cisplatin alone. qPCR was conducted on tumors to examine effect of siRNA against TWIST, and its target genes. Mice were imaged via bioluminescence to observe CSC localization of siTWIST-MSN-HA compared to siTWIST-MSN (No HA). Tissue sections were stained via IHC to determine MSN-HA tumor targeting. CD44 staining was conducted to reveal HA co-localization in tumor.
Results: siTWIST-MSN-HAs significantly knocked down TWIST, and sensitized cells to cisplatin compared to control in vitro. Following necropsy, tumor quantification revealed mice treated with siTWIST-MSN-HAs plus cisplatin exhibited a startling 75% loss of overall tumor burden (p=0.0012), 88% loss of total metastasis (p=0.001), and further 86% loss of total ascites (p=0.002) compared to cisplatin-alone treatment groups.
EMT target expression by qPCR analysis revealed loss of TWIST1, vimentin, N-cadherin, and gain of E-cadherin in tumors treated with siTWIST-MSN-HA compared to controls. Bioluminescent images of mice at necropsy revealed highly specific tumor localization of MSN-HA Dylight (680nm) compared to MSN without HA. MSN-HA exhibited CSC targeting at metastatic sites, where most of the signal was emitted from the primary tumor; and negligible quantities of MSN-HAs were detected elsewhere. MSN-HA RITC (576nm) reveals highly specific tumor targeting via IHC; MSN-HA nanoparticles localized primarily in tumor cells and not in control organs. CD44 staining of these tissues reveals MSN-HAs co-localized with CD44 in CSCs.
Conclusions: These studies demonstrate TWIST as a promising target for metastasis and acquired drug resistance in EOC. MSN-HAs provide CSC specific CD44 targeting with high efficacy and reduce tumor burden via siTWIST therapy. Thus, siTWIST-MSN-HAs provide a promising platform to improve survival from metastatic, drug-resistant ovarian cancer.
Citation Format: Carlotta A. Glackin, Sophia A. Shahin, Shirleen Simargi, Ruining Wang, Altagracia Contreras, Liliana Parra, Loiuse Qu, Wei Wen, Thanh Dellinger, Julia Unternaehrer, Fuyujiko Tamanoi, Jeffrey Zink. Hyaluronic acid conjugated nanoparticle delivery of siTWIST reduces tumor burden and enhances chemosensitivity in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2024.