Nanoparticles-Facilitated Intracellular Transport of siRNAs against Individual Integrin Subunits Inhibits Growth of Breast Cancer Cells

Maeirah Ashaie,Ezharul Hoque Chowdhury

doi:10.3390/app112210782

Abstract

For cells and tissues, cell–cell and cell–extracellular matrix adhesion is important for proliferation, differentiation, and response to mechanical stimuli. This adhesion is provided by various cell adhesion molecules (CAMs). However, in breast cancer, depending upon the type and stage, this adherence is dysregulated where the expression of these cell adhesion molecules is either overregulated or unregulated, triggering essential oncogenic pathways. Thus, to control the invasiveness of tumor cells, and reduce metastasis, regulating the homophilic and heterophilic interaction of these molecules and controlling the essential cell pathways is important. In this study, we targeted critical CAMs- integrins to regulate their aberrated behavior via siRNAs delivery. However, as due to charge repulsion and propensity to be degraded by nucleases prior to reaching the target site, naked siRNAs are unable to cross plasma membrane, use of a suitable carrier vehicle is essential. Thus, we employed carbonate apatite (CA), to deliver the selected siRNAs targeting integrin αv, α6, β1, β3, β4, β5, and β6 subunits to various breast cancer cell lines and 4T1-breast cancer induced murine model. Delivery of individual integrin siRNAs complexed with CA nanoparticles (NPs) reduced cell viability and caused decrease in tumor burden. To check the gene knockdown effects on phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) and extracellular signal–regulated kinases/mitogen-activated protein kinase (ERK/MAPK) pathways, Western blot analysis was performed, revealing downregulation of the signaling molecules. Thus, CA-facilitated gene therapy targeting various integrins could poise potential therapeutic modality against breast cancer.

Highlights

In 2020, about 2.3 million women were diagnosed with breast cancer, of which 685,000 were observed globally [1]
Based on MTT results we found that delivery of small interfering RNAs (siRNAs) Integrin αv (ITGαv) loaded with carbonate apatite (CA) showed less cell viability in MDA-MB-231 and 4T1 cells (Figure 1b,c respectively) while in MCF-7 cells no such visible reduction was observed (Figure 1a)
Upon treatment with Integrin β1 (ITGβ1), siRNAs complexed with CA, cell viability decreased in MCF-7, MDA-MB-231 and 4T1 cells (Figure 3a–c respectively). siRNA Integrin β3 (ITGβ3)-CA complex Figure 4a) reduced cell viability only in MCF-7 cells, remaining unaffected in MDA-MB-231 and 4T1 cells (Figure 4b,c respectively)

Summary

Introduction

In 2020, about 2.3 million women were diagnosed with breast cancer, of which 685,000 were observed globally [1]. The National Cancer Institute recorded about 3,676,262 breast cancer women in US in 2018, with an estimate of 281,550 new cases in 2021, of which around 43,600 will be estimated deaths [2]. Breast cancer is a group of diseases possessing phenotypic and genotypic heterogeneity. Each type of breast cancer possesses distinct characteristics which differentiate it from the other type/subtype and determine the type of effective treatment regime. Breast canceris categorized into ductal or lobular, with 80% of invasive carcinomas being ductal in origin. Accounting to one fourth of breast cancers, ductal carcinoma in situ (DCIS) consists of heterogeneous lesions with varied clinical features, morphology, and biological functioning [3]

Methods

Results

Discussion

Conclusion