DOX-PLGA Nanoparticles Effectively Suppressed the Expression of Pro-Inflammatory Cytokines TNF-a, IL-6, iNOS, and IL-1β in MCF-7 Breast Cancer Cell Line

Abstract

Background: Inflammation contributes to cancer pathobiology through different mechanisms. Higher levels of pro-inflammatory cytokines can lead to hyperinflammation and promote cancer development and metastasis. For cancer treatment, Doxorubicin (DOX) can be encapsulated into the poly-lactic-glycolic acid (PLGA) nanoparticles. This study aimed to investigate the impact of doxorubicin-loaded PLGA nanoparticles (DOX-PLGA NP) on the expression of pro-inflammatory genes TNF-α, IL-6, iNOS, and IL-1β in the MCF-7 cells.

Methods: The DOX-PLGA NP was prepared by loading doxorubicin into PLGA and characterized using dynamic light scattering (DLS) and atomic force microscopy (AFM). The cytotoxic effect of the nanoparticles was determined by the MTT assay, and their impacts on the expression of pro-inflammatory genes were assessed by qRT-PCR.

Results: The encapsulation efficiency and loading capacity were 60±1.5 and 1.13±0.21 percent, respectively. The zeta potential and mean DOX-PLGA nanoparticle size were -18±0.550 mV and 172±55.6 nm, respectively. The 50% inhibitory concentration (IC50) of the DOX-PLGA NP on MCF-7 cell viability was 24.55 µg/mL after 72 hours of treatment. The qRT-PCR results revealed that the 20 µg/mL concentration of the DOX-PLGA NP significantly suppressed the expression of the pro-inflammatory genes TNF-α, IL-6, iNOS, and IL-1β compared to DOX alone (20 µg/mL). Additionally, the suppression effect of DOX-PLGA NP on the expression of these pro-inflammatory genes was dose-dependent.

Conclusions: These results show that DOX-PLGA NP efficiently suppressed the expression of pro-inflammatory genes. Furthermore, encapsulation of DOX into PLGA nanoparticles significantly improved the effectiveness of DOX in suppressing pro-inflammatory genes in MCF-7 breast cancer cells.

Keywords: Breast cancer; Cytokines; Doxorubicin; Polylactic Acid-Polyglycolic Acid Copolymer; Pro-inflammatory cytokine.

Fig. 1

Characterization of the DOX-PLGA NP by DLS and AFM. A) Intensity distribution, B) Volume distribution, C) Number distribution, and D) a table presenting the mean particle size, encapsulation efficiency (EE%), and loading capacity (LC%) of the DOX-PLGA Nps. E) Pictures captured with AFM showing the spherical shape and size of DOX-PLGA NP.

Fig. 2

Toxicity of the DOX-PLGA NP on MCF-7 cells. The cells were treated with different concentrations of the prepared nanoparticle for 72 h and the percent of alive cells was determined.

Fig. 3

Effect of the DOX-PLGA NP on the expression levels of pro-inflammatory genes in the MCF-7 cell line. The MCF-7 breast cancer cells were treated with 0.0, 0.2, 0.5, 5.0, 10.0 and 20 µg/mL concentrations of DOX-PLGA NP as well as with a 20 µg/mL concentration of free DOX and the pro-inflammatory genes expression levels including A) IL-1β, B) IL-6, C) TNF-α and D) iNOS were quantified with qRT-PCR and compared. * Indicates P<0.05, ** indicates P<0.01, *** indicates P<0.001, and **** indicates P<0.0001.