pcDNA3.1(−)-mediated ribozyme targeting of HER-2 suppresses breast cancer tumor growth

Abstract

The HER-2 proto-oncogene (also called c-erbB-2/neu) encodes the protein, p185, which is closely related to the growth and metastasis of adenocarcinoma, and is overexpressed in 25-30% of human breast cancers. In this study, we attempt to reverse the malignant phenotype of the breast cancer cell line, MCF-7, using a HER-2-specific hammerhead ribozyme. Two anti-HER-2 hammerhead ribozymes, RZ1 and RZ2, were synthesized, inserted separately into the nonviral eukaryotic expression vector, pcDNA3.1(-), and transfected into MCF-7 cells. Analyses showed that the HER-2 mRNA and p185, as well as oncogene k-ras were down-regulated remarkably in the ribozyme-transfected cells, while the onco-suppressor gene, p53, was up-regulated. Furthermore, the tumorigenicity of the RZ1-stably transfected MCF-7 cells was decreased dramatically in nude mice. These results demonstrate that the use of anti-HER-2 ribozymes may be a beneficial strategy for gene therapy of breast cancer.

Identification of Ascorbic Acid and Gallic Acid as Novel Inhibitors of Secreted Frizzled-Related Protein for the Treatment of Obesity-Induced Type 2 Diabetes

“…ER0051) and ligated by T4 ligase. 18 , 19 The product was then transformed in TOP10 cells by heat shock method and cultured on an ampicillin plate overnight at 37°C overnight. A single transformed colony was cultured in LB media to isolate plasmid by using GeneJET plasmid miniprep kit (Catalog number K0502).…”

Perspectives on the Emerging Applications of Multifaceted Biomedical Polymeric Nanomaterials

“…Two anti-HER-2 ribozymes that specifically target HER-2 mRNA were synthesized and separately assembled in nonviral eukaryotic expression vector. The engineered nanovectors were subsequently used to transfect malignant breast cancer cell lines MCF-7 [78]. The study demonstrated a remarkable downregulation of HER-2 mRNA and concomitantly p185 protein in ribozymes transfected MCF-7 cell lines in addition to upregulation of oncosuppressor gene p53 [78].…”

“…The engineered nanovectors were subsequently used to transfect malignant breast cancer cell lines MCF-7 [78]. The study demonstrated a remarkable downregulation of HER-2 mRNA and concomitantly p185 protein in ribozymes transfected MCF-7 cell lines in addition to upregulation of oncosuppressor gene p53 [78]. The ability of RNA to fold into 3D structures with pockets and cavities is a strong indication to its potential as binding ligands [79].…”

A New Approach to an Old Problem: Synthetic Biology Tools for Human Disease and Metabolism

“…Ribozymes can specifically cleave target RNA and have been effectively used in gene therapy for cancer and other diseases (Win and Smolke 2008;Culler et al 2010;Mulhbacher et al 2010). For example, a hammerhead ribozyme targeting the human epidermal growth factor receptor HER-2 reversed the malignant phenotype of breast cancer cells (He et al 2010). Metabolite-binding riboswitches also represent a novel solution to sensing and studying metabolic disease.…”