A novel 4-arm DNA/RNA Nanoconstruct triggering Rapid Apoptosis of Triple Negative Breast Cancer Cells within 24 hours

Abstract

Measuring at ~30 nm, a fully customizable holliday junction DNA nanoconstruct, was designed to simultaneously carry three unmodified SiRNA strands for apoptosis gene knockout in cancer cells without any assistance from commercial transfection kits. In brief, a holliday junction structure was intelligently designed to present one arm with a cell targeting aptamer (AS1411) while the remaining three arms to carry different SiRNA strands by means of DNA/RNA duplex for inducing apoptosis in cancer cells. By carrying the three SiRNA strands (AKT, MDM2 and Survivin) into triple negative breast MDA-MB-231 cancer cells, cell number had reduced by up to ~82% within 24 hours solely from one single administration of 32 picomoles. In the immunoblotting studies, up-elevation of phosphorylated p53 was observed for more than 8 hours while the three genes of interest were suppressed by nearly half by the 4-hour mark upon administration. Furthermore, we were able to demonstrate high cell selectivity of the nanoconstruct and did not exhibit usual morphological stress induced from liposomal-based transfection agents. To the best of the authors’ knowledge, this system represents the first of its kind in current literature utilizing a short and highly customizable holliday DNA junction to carry SiRNA for apoptosis studies.

Anti-Adhesion Behavior from Ring-Strain Amine Cyclic Monolayers Grafted on Silicon (111) Surfaces

“…The selection for these cell types (MDA-MB 231, AGS and Hec1A) was due to their distinctive cell morphological shape under normal culture conditions. For instance, healthy MDA-MB 231 cells typically adopt a "needle-like" cell morphology 65 while AGS cells normally present a polygonal shape while adhering to surfaces 66 . On the other hand, Hec1A is often roundish in morphology without any distinctive polarity or directionality and are not very highly adherent cells 35,67 .…”

The Use of Chemosensitizers to Enhance the Response to Conventional Therapy in Triple-Negative Breast Cancer Patients

“…The results demonstrated a downregulation of the three gene targets, an upregulation of phospho-p53 which subsequently led to reduced cell survival within 24 h at a very low dose. This particular four-arm nanoconstruct of the holiday junction was reported to represent a potential contender for designing gene antisense therapy [23]. These studies suggested that therapeutics using genomic techniques including miRNA or RNAi, targeting key genes involved in drug resistance, combined to nanocarrier particles are viable approaches in the treatment of breast cancer patients.…”

Bioactivating Silicon (100) Surfaces with Novel UV Grafting of Cyclopropylamine for Promotion of Cell Adhesion

“…As stated previously, in order to examine the cytotoxicity of the various surfaces, the three different cell types were incubated on all surfaces, and the cell viability was determined via a colorimetric based cell viability kit, performed after 24 h of incubation ( n = 5). At this junction, it is also important to state that we selected these cell types for their differing adhesion morphologies on surfaces in general, with MDA-MB 231 exhibiting good spreading morphology [ 28 ] and HEC1A having a rounder overall morphology [ 29 ]. Prior to confocal microscopy and cell viability data discussion, it may be necessary to state that the correlation between cell counts from fluorescence and cell viability does not always exhibit a directly proportional relationship.…”