The Toxic Effect and Mechanism of TMZ Combined with siHOXB9 on Glioblastoma Cells

Glioblastoma (GBM) represents a highly invasive primary malignant tumor within the central nervous system (CNS). Temozolomide (TMZ), a first-line chemotherapy agent for GBM treatment, has significant limitations, including drug resistance, poor water solubility, a short half-life, and notable toxic side effects. The innovation of the TMZ dosage form is pivotal for enhancing its therapeutic efficacy. In this study, solid lipid nanoparticles (SLN) loaded with Angiopep-2 (A2) and TMZ (TMZ-A2SLN), a nanopolymer featuring a solid spherical morphology and a particle size of approximately 100 nm, were constructed. The combined effect of TMZ-A2SLN and small-interfering RNA (siRNA) that can knock down the expression of the <i>HOXB9</i> gene (siHOXB9) augmented the sensitivity of the glioma cell line U251 to TMZ. Under the combined effect, the viability of U251 cells was reduced by 77%. Meanwhile, the mortality rate increased by approximately 45%, and the cell apoptosis rate rose by around 36%. The number of cells arrested in the G2/M and S phases rose. Proteomic analysis indicates that TMZ-A2SLN might be implicated in the pro-inflammatory signaling cascade, tumor migration, invasion, and angiogenesis during the treatment of glioma cells. Moreover, <i>HOXB9</i> may play a crucial regulatory role in the PPAR signaling pathway, the neural signaling pathway, the phospholipase D signaling pathway, the IL-17 signaling pathway, mineral absorption, and other pathways during glioma cell treatment.