Nanosized drug delivery systems (DDS) have been studied as a novel strategy against cancer due to their potential to simultaneously decrease drug inactivation and systemic toxicity and increase passive and/or active drug accumulation within the tumor(s). Triterpenes are plant-derived compounds with interesting therapeutic properties. Betulinic acid (BeA) is a pentacyclic triterpene that has great cytotoxic activity against different cancer types. Herein, we developed a nanosized protein-based DDS of bovine serum albumin (BSA) as the drug carrier combining two compounds, doxorubicin (Dox) and the triterpene BeA, using an oil-water-like micro-emulsion method. We used spectrophotometric assays to determine protein and drug concentrations in the DDS. The biophysical properties of these DDS were characterized using dynamic light scattering (DLS) and circular dichroism (CD) spectroscopy, confirming nanoparticle (NP) formation and drug loading into the protein structure, respectively. The encapsulation efficiency was 77% for Dox and 18% for BeA. More than 50% of both drugs were released within 24 h at pH 6.8, while less drug was released at pH 7.4 in this period. Co-incubation viability assays of Dox and BeA alone for 24 h demonstrated synergistic cytotoxic activity in the low μM range against non-small-cell lung carcinoma (NSCLC) A549 cells. Viability assays of the BSA-(Dox+BeA) DDS demonstrated a higher synergistic cytotoxic activity than the two drugs with no carrier. Moreover, confocal microscopy analysis confirmed the cellular internalization of the DDS and the accumulation of the Dox in the nucleus. We determined the mechanism of action of the BSA-(Dox+BeA) DDS, confirming S-phase cell cycle arrest, DNA damage, caspase cascade activation, and downregulation of epidermal growth factor receptor (EGFR) expression. This DDS has the potential to synergistically maximize the therapeutic effect of Dox and diminish chemoresistance induced by EGFR expression using a natural triterpene against NSCLC.

Lung cancer is the second most common and leading cause of cancer-related deaths worldwide with 85% of these cases being non-small cell lung carcinoma (NSCLC). Unfortunately, despite improvements in NSCLC outcomes, many of these tumors develop resistance against principal chemotherapies (e.g., cisplatin (CisPt) and doxorubicin (Doxo)), inducing abysmally low survival prognosis. Deferasirox (Def), an FDA-approved iron chelation therapy, is a drug under study for cancer therapy due to iron plays a key role in cell growth and energy production. Herein, we determined the effect of Def alone and in combination with CisPt and Doxo on NSCLC A549 cells. Viability assays results showed that Def has synergistic cytotoxic effects in combination with CisPt and Doxo at low uM concentrations after 24 h of incubation using the Chou Talalay method. In addition, qPCR gene expression studies showed that Def induced a significant downregulation of EGFR, VEGF, MMP9, MMP2, CHD4 genes related to resistance and metastatic process. In addition, we determined the overexpression of NDRG1 gene mediated by Def confirming the chelation of iron and disruption of iron metabolism. Overall, this work will set the basis for adjuvant therapies against chemoresistance and metastasis processes using an iron chelator. Citation Format: Natalia I. Ortiz Alvelo, Grace Torres, Sthephanie Estrada, Daraishka Pérez, Yancy Ferrer, Yamixa Delgado. Synergistic combination of the iron chelator deferasirox with cisplatin and doxorubicin chemotherapies against nonsmall cell lung carcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3898.