Lipid‑based nanoparticles for the therapeutic delivery of non‑coding RNAs in breast cancer (Review).

Breast cancer is the most common type of cancer with the highest morbidity and mortality rates in women worldwide. Recent efforts to improve the current antitumor therapies have led to the development of novel treatment approaches based on the delivery of therapeutic non‑coding RNAs (ncRNAs) using nanotechnology. Treatment methods using lipid‑based nanoparticles (LBNPs) have greatly improved the delivery efficiency of ncRNAs into tumor cells and tissues. This type of delivery approach has provided significant advantages, such as reduced therapeutic doses, lower cytotoxicity to normal cells and the ability to reverse resistance to chemotherapy. LBNPs have demonstrated the ability to deliver therapeutic ncRNAs, more specifically microRNAs (miRNAs) and small interfering RNAs (siRNAs); this has been reported modulate the expression levels of oncogenes and tumor suppressor genes involved in several biological processes, including cell growth and proliferation, cell death, invasion and metastasis, thus impairing the malignant behavior of tumors. Therefore, ncRNA‑based therapies combined with the LBNP delivery strategy, namely nanomiRNAs, may represent a promising antitumor strategy guaranteeing superior biocompatibility, higher biodegradability, lower immunogenicity and decreased toxicity to normal cells compared with other therapeutic approaches. The present review summarized the current knowledge of the application of LBNPs for delivering miRNAs and siRNAs in breast cancer cells and mouse models, in addition to discussing their promising antitumor effects.