RNA-Based TWIST1 Inhibition via Dendrimer Complex to Reduce Breast Cancer Cell Metastasis

Abstract

Breast cancer is the leading cause of cancer-related deaths among women in the United States, and survival rates are lower for patients with metastases and/or triple-negative breast cancer (TNBC; ER, PR, and Her2 negative). Understanding the mechanisms of cancer metastasis is therefore crucial to identify new therapeutic targets and develop novel treatments to improve patient outcomes. A potential target is the TWIST1 transcription factor, which is often overexpressed in aggressive breast cancers and is a master regulator of cellular migration through epithelial-mesenchymal transition (EMT). Here, we demonstrate an siRNA-based TWIST1 silencing approach with delivery using a modified poly(amidoamine) (PAMAM) dendrimer. Our results demonstrate that SUM1315 TNBC cells efficiently take up PAMAM-siRNA complexes, leading to significant knockdown of TWIST1 and EMT-related target genes. Knockdown lasts up to one week after transfection and leads to a reduction in migration and invasion, as determined by wound healing and transwell assays. Furthermore, we demonstrate that PAMAM dendrimers can deliver siRNA to xenograft orthotopic tumors and siRNA remains in the tumor for at least four hours after treatment. These results suggest that further development of dendrimer-based delivery of siRNA for TWIST1 silencing may lead to a valuable adjunctive therapy for patients with TNBC.

TWIST1 drives cisplatin resistance and cell survival in an ovarian cancer model, via upregulation of GAS6, L1CAM, and Akt signalling

“…We then transfected Ov8GFP cells with either TWIST1 or sh492, a previously validated shRNA against TWIST12425, using the pCI-Neo G418-selectable plasmid vector system. Following G418 selection of cells with stably integrated plasmid, we verified that TWIST1 was differentially expressed in the two cell lines – referred to hereafter as Ov8GFP-TWIST1 and Ov8GFP-sh492 – via western blot (Fig.…”

Development of nanotheranostics against metastatic breast cancer — A focus on the biology & mechanistic approaches

“…Knock down of TWIST1 by the nanoparticle led to reduced invasion and migration of 4T1 cells in vitro and increased accumulation of these nanoparticles in tumor site and metastatic organs in vivo (Finlay et al, 2015). Down regulation of Notch-1 expression in breast cancer cells has shown to decrease the rate of metastasis and miR-34a (micro RNA-34a) was found to decrease Notch-1 levels in breast tumor cells (Deng et al, 2014).…”

Dendrimers as Drug Nanocarriers: The Future of Gene Therapy and Targeted Therapies in Cancer

“…cell membranes causing their disruption [101,102]. This disadvantage can be diminishing by surface modification with different targeting or shielding moieties providing with not only low toxicity but also enhance the cell uptake and specific accumulation of nucleic acid molecules inside cells [103][104][105][106]. For example, novel targeted nanoparticle system consisting of FLT3 ligandconjugated PAMAM G7 encapsulating a pivotal tumor suppressor and negative regulator of FLT3 miRNA-miR-150, was developed by Jiang et al [107] to treat FLT3-overexpressing acute myeloid leukemia (AML), a leukemia associated with unfavorable prognosis.…”