Iron Oxide Nanoparticles coated with miR-330 as a novel anticancer therapy in Triple Negative Breast Cancer

Breast cancer (BC) is the most common diagnosed cancer type worldwide. Among breast cancer subtypes, Triple Negative Breast Cancer (TNBC) stands out due to its heightened aggressiveness, marked by a high incidence of metastasis, relapse, and patient mortality. TNBC poses a unique challenge as it exhibits significant genetic diversity and lacks molecular targets like the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). Consequently, traditional targeted therapies are ineffective against TNBC. KRAS gene plays a central role in cell signaling pathways controlling cellular growth, differentiation and survival. KRAS is the most frequently mutated oncogene in humans. KRAS mutations result in the constitutive activation of downstream signaling pathways, such as the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) pathways, driving uncontrolled cell proliferation and evasion of apoptosis. These mutations are associated with aggressive tumor behavior, metastasis, and resistance to conventional cancer therapies, making KRAS-mutated cancers among the most challenging to treat. Efforts to target mutant KRAS have been historically unsuccessful, but recent breakthroughs in drug development have led to the emergence of promising therapeutic strategies, including small molecule inhibitors and gene-specific therapies. In recent years, an increasing number of studies have highlighted the crucial role of short non-coding microRNAs (miRNA) in various cancer pathophysiological processes, such as cell cycle, proliferation, differentiation, migration, invasion and aging, modulating the expression of genes involved in these pathways. Due to their ability to degrade target mRNA or to inhibit translation, miRNA-based therapeutics could be a novel therapeutic approach, especially for TNBC patients. Using target prediction algorithms miR-330 was identified as a potential regulator of KRAS. Further analyses have shown that reduced miR-330 expression is associated with shorter patient survival in TNBC cancers. In vitro delivery of miR-330 inhibited proliferation, invasion/migration and enhanced apoptosis rate in TNBC cells. Moreover, Western Blot analyses show inhibition of KRAS and KRAS pathways expressions. In vivo delivery of miR-330 nanoparticles inhibited KRAS expression and tumor growth in TNBC tumor models. In this study, poly-L-lysine (PLL) coated iron oxide nanoparticles (IONs) were synthesized and characterized as delivery carrier for miRNA in TNBC therapy. These nanoparticles have a size range of 165-180 nm with a zeta potential value of -8 mV. PLL-IONs-miR-330 treatment in mice did not cause any detectable side effects. In conclusion this study proves that miR-330 acts as a tumor suppressor by targeting KRAS and that miR-303-based gene therapy may be a therapeutic strategy in TNBC.