ABSTRACT
O6-methylguanine DNA methyltransferase (MGMT) is a crucial determinant of temozolomide (TMZ) sensitivity in patients with glioblastoma (GBM). The therapeutic potential of small interfering RNA (siRNA) targeting MGMT to enhance TMZ sensitivity has been hampered by serum nuclease degradation, off-target effects, poor accumulation at tumor sites, and low circulation in blood stream. In this study, we developed a framework nucleic acid-based nanoparticles (FNN), which is constructed from a six-helix DNA bundle, to encapsulate and protect siMGMT for improving TMZ sensitivity in GBM treatment. For better blood-brain barrier (BBB) penetration and GBM targeting, we conjugated Angiopep-2 (ANG) targeting modules to each end of the FNN. Nucleolin (NCL)-responsive locks were engineered along the sides of the six-helix DNA bundle, which safeguard siMGMT before tumor entry. Upon interaction with tumor-overexpressed NCL, these locks unlock, exposing siMGMT, this allows for effective suppression of MGMT, resulting in a significant improvement of TMZ therapeutic efficacy in GBM. This innovative strategy has the potential to transform the current treatment landscape for GBM.
Subject(s)
Antineoplastic Agents, Alkylating , Blood-Brain Barrier , Brain Neoplasms , Glioblastoma , Nanoparticles , Temozolomide , Glioblastoma/drug therapy , Glioblastoma/pathology , Temozolomide/pharmacology , Temozolomide/administration & dosage , Temozolomide/therapeutic use , Humans , Brain Neoplasms/drug therapy , Brain Neoplasms/pathology , Brain Neoplasms/genetics , Antineoplastic Agents, Alkylating/pharmacology , Antineoplastic Agents, Alkylating/therapeutic use , Nanoparticles/chemistry , Animals , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/drug effects , Drug Resistance, Neoplasm/drug effects , Cell Line, Tumor , RNA-Binding Proteins/metabolism , DNA Repair Enzymes/metabolism , DNA Repair Enzymes/genetics , DNA Modification Methylases/metabolism , Nucleolin , Phosphoproteins/metabolism , Tumor Suppressor Proteins/metabolism , Tumor Suppressor Proteins/genetics , RNA, Small Interfering/administration & dosage , Nucleic Acids , PeptidesABSTRACT
Temozolomide (TMZ) resistance remains the major obstacle in the treatment of glioblastoma (GBM). Lactylation is a novel post-translational modification that is involved in various tumors. However, whether lactylation plays a role in GBM TMZ resistance remains unclear. Here it is found that histone H3K9 lactylation (H3K9la) confers TMZ resistance in GBM via LUC7L2-mediated intron 7 retention of MLH1. Mechanistically, lactylation is upregulated in recurrent GBM tissues and TMZ-resistant cells, and is mainly concentrated in histone H3K9. Combined multi-omics analysis, including CUT&Tag, SLAM-seq, and RNA-seq, reveals that H3K9 lactylation is significantly enriched in the LUC7L2 promoter and activates LUC7L2 transcription to promote its expression. LUC7L2 mediates intron 7 retention of MLH1 to reduce MLH1 expression, and thereby inhibit mismatch repair (MMR), ultimately leading to GBM TMZ resistance. Of note, it is identified that a clinical anti-epileptic drug, stiripentol, which can cross the blood-brain barrier and inhibit lactate dehydrogenase A/B (LDHA/B) activity, acts as a lactylation inhibitor and renders GBM cells more sensitive to TMZ in vitro and in vivo. These findings not only shed light on the mechanism of lactylation in GBM TMZ resistance but also provide a potential combined therapeutic strategy for clinical GBM treatment.
Subject(s)
Drug Resistance, Neoplasm , Glioblastoma , Histones , Introns , MutL Protein Homolog 1 , Temozolomide , Animals , Humans , Mice , Antineoplastic Agents, Alkylating/pharmacology , Antineoplastic Agents, Alkylating/therapeutic use , Brain Neoplasms/genetics , Brain Neoplasms/drug therapy , Brain Neoplasms/metabolism , Cell Line, Tumor , Disease Models, Animal , Drug Resistance, Neoplasm/genetics , Drug Resistance, Neoplasm/drug effects , Glioblastoma/genetics , Glioblastoma/drug therapy , Glioblastoma/metabolism , Histones/metabolism , Histones/genetics , Introns/genetics , Mice, Nude , MutL Protein Homolog 1/genetics , MutL Protein Homolog 1/metabolism , Temozolomide/pharmacology , FemaleABSTRACT
The prognosis of glioblastoma (GBM) patients is poor, and temozolomide (TMZ) resistance has become an important obstacle to its treatment effect. A growing number of researches have revealed the special characteristics of iron metabolism in GBM chemosensitivity. Iron regulatory protein 1 (IRP1) is an important protein for maintaining intracellular iron homeostasis. IRP1 has been indicated to have additional vital roles beyond its conventional metabolic activity, but the underlying mechanisms and biological consequences remain elusive. Here, we unprecedentedly demonstrated that amplifying IRP1 signals can reverse TMZ resistance and suppress tumor growth in vivo via inhibiting NFKB2 in the noncanonical NF-κB signaling pathway. In addition, we identified that NFKB2 affected TMZ sensitivity of GBM by modulating the expression of LCN2 and FPN1. Taken together, this study established a role for the IRP1/NFKB2 pathway in regulating LCN2/FPN1 signaling axis among the progression of TMZ resistance, suggesting a potential innovative GBM therapeutic strategy.