Formulation of Stattic as STAT3 inhibitor in nanostructured lipid carriers (NLCs) enhances efficacy of doxorubicin in melanoma cancer cells

Abstract

Nowadays, nanoparticle-based combination therapy has been emerging as huge innovation in cancer treatment. Here, we studied the effect of Stattic (STAT3 inhibitor) loaded in nanostructured lipid carriers (NLCs) on enhancing the efficacy, cytotoxicity, and induction of apoptosis of doxorubicin in B16F10 mouse melanoma cancer cell. The evaluation of Stattic-loaded NLCs has been done in terms of zeta potential, particle size, scanning electron microscope (SEM), and cellular uptake. MTT assay was applied to evaluate the cell proliferation. Apoptotic cell death and identification of early and late apoptosis were assessed by DAPI staining and Annexin V/PI staining, respectively. Real-time RT-PCR was applied to measure the effects of doxorubicin and/or Stattic on key apoptotic genes such as Bad, Survivin, HIF1, and STAT3. The Stattic formulated into NLCs shown mean particle size of 56 ± 7 nm which was confirmed by SEM. The IC₅₀ values for Stattic and doxorubicin were 2.95 ± 0.52 μM and 1.21 ± 0.36 μM, respectively. Stattic-loaded NLCs diminished percent of cell proliferation from 68 ± 6.8 to 54 ± 3.7% (p < 0.05). Combinational treatment of the cells with Stattic-loaded nanoparticles and doxorubicin give rise to a significant increase in the percentage of apoptosis (p < 0.05). The study of gene expression profile has shown a remarkable decrease in anti-apoptotic gene, Survivin, along with smooth decline in HIF1 as angiogenesis intermediator and increase in Bad mRNA levels. Our results recommend that NLCs as novel technology have potent strategy to augment efficacy of current chemotherapeutic agent in melanoma cancer cells.

Keywords: Apoptosis; Melanoma cancer; Nanoparticle; STAT3.