Cytostatic Effect of a Novel Mitochondria-Targeted Pyrroline Nitroxide in Human Breast Cancer Lines

Recent strategies to overcome breast cancer resistance

Breast cancer is potentially a lethal disease and a leading cause of death in women. Chemotherapy and radiotherapy are the most frequently used treatment options. Drug resistance in advanced breast cancer limits the therapeutic output of treatment. The leading cause of resistance in breast cancer is endocrine and hormonal imbalance, particularly in triple negative and HER2 positive breast cancers. The efflux of drugs due to p-gp's activity is another leading cause of resistance. Breast cancer resistant protein also contributes significantly. Strategies used to combat resistance include the use of nanoparticles to target drug delivery by co-delivery of chemotherapeutic drugs and genes (siRNA and miRNA) that help to down-regulate genes causing resistance. The siRNA is specific and effectively silences p-gp and other proteins causing resistance. The use of chemosensitizers is also effective in overcoming resistance. Chemo-sensitizers sensitize cancer cells to the effects of chemotherapeutic drugs. Novel anti-neoplastic agents such as antibody-drug conjugates and mesenchymal stem cells are also effective tools used to improve the therapeutic response in breast cancer. Similarly, combination of photo/thermal ablation with chemotherapy can act to overcome breast cancer resistance. In this review, we focus on the mechanism of breast cancer resistance and the nanoparticle-based strategies used to combat resistance in breast cancer.

Precision targeting of CuET overload to disrupt mitochondrial unfolded protein response by integrated liposome

Mitochondria in breast cancer play a critical role in survival and adaptation to dynamic environments. Thus, targeting mitochondria emerges as a promising therapeutic strategy for breast cancer. However, the adaptive unfolded protein response in mitochondria (UPRmt) due to mitochondrial unspecific distribution might contribute to diminished therapeutic outcomes. Herein, mitochondrial targeting liposome agents (CTPP-Lipid) are constructed and adopted for delivering the copper ion (CuET-DSF), which is especially sensitive for mitochondria-abundant breast tumors. In brief, the CTPP-Lipid@CuET achieves the goal of Cu2+ overloading by mitochondria targeting delivery. This rapidly increases ROS production, disrupts mitochondrial structure, and avoids the adaptive UPRmt formation, finally leading to apoptosis of breast cancer cells. In general, the Cu2+ overloading at mitochondria by CTPP-Lipid@CuET is a potential strategy for antitumor therapy, providing new insights into breast tumor therapy.

Microarray data reveal potential genes that regulate triple-negative breast cancer

Objective

Triple-negative breast cancer (TNBC) is characterized by a lack of targeted therapies and poor patient prognosis, and its underlying pathological mechanisms remain unclear. This study aimed to identify potential key genes and related pathways that are required for TNBC development.

Methods

We screened the Gene Expression Omnibus database for transcriptome data and identified differently expressed genes in TNBC. Then, we performed Gene Ontology analysis to determine the genes and pathways involved in TNBC development. We correlated significantly expressed genes and miRNAs using miRDB, TargetScan, miRWalk, and DIANA, and then validated the expression of CDK1 and miR-143-3p in TNBC patients.

Results

Eighteen genes were significantly upregulated in TNBC patients, and these were found to be enriched in cell metabolic process, cell division, mitochondrion, and respiratory chain. MiR-143-3p was found to be an upstream regulator of CDK1. Validation experiments revealed that CDK1 was upregulated while miR-143-3p was downregulated in clinical TNBC specimens.

Conclusions

Collectively, our results revealed 18 upregulated genes in TNBC. Notably, CDK1 and its related microRNA miR-143-3p could be potential therapeutic targets for TNBC.