NRF2 preserves genomic integrity by facilitating ATR activation and G2 cell cycle arrest

Anti-Angiogenic Therapy: Current Challenges and Future Perspectives

Anti-angiogenic therapy is an old method to fight cancer that aims to abolish the nutrient and oxygen supply to the tumor cells through the decrease of the vascular network and the avoidance of new blood vessels formation. Most of the anti-angiogenic agents approved for cancer treatment rely on targeting vascular endothelial growth factor (VEGF) actions, as VEGF signaling is considered the main angiogenesis promotor. In addition to the control of angiogenesis, these drugs can potentiate immune therapy as VEGF also exhibits immunosuppressive functions. Despite the mechanistic rational that strongly supports the benefit of drugs to stop cancer progression, they revealed to be insufficient in most cases. We hypothesize that the rehabilitation of old drugs that interfere with mechanisms of angiogenesis related to tumor microenvironment might represent a promising strategy. In this review, we deepened research on the molecular mechanisms underlying anti-angiogenic strategies and their failure and went further into the alternative mechanisms that impact angiogenesis. We concluded that the combinatory targeting of alternative effectors of angiogenic pathways might be a putative solution for anti-angiogenic therapies.

MiR-582-5p Inhibits Bladder Cancer-Genesis by Suppressing TTK Expression

BACKGROUND

Bladder cancer (BC) refers to the malignant growth found in the cells and tissues of the urinary bladder. While many studies have researched the progression of BC, scientists are yet to fully understand the mechanism of BC. This research aimed to explore the role of miR-582-5p and its target gene TTK in BC pathogenesis.

METHODS

The evaluation of miR-582-5p and TTK mRNA expression in BC tissues or cells was performed using qRT-PCR. TargetScan was then used to predict the binding site of miR-582-5p on TTK mRNA. Subsequently, dual-luciferase reporter and RNA pull-down assays were employed to validate the binding relationship between miR-582-5p and TTK mRNA. CCK-8, BrdU, flow cytometry, and caspase-3 activity assays were later conducted to evaluate the viability, proliferation, cell cycle, and apoptosis of BC cells.

RESULTS

Investigations revealed that miR-582-5p was downregulated in BC tissues and cells. Meanwhile, miR-582-5p inhibited the viability and proliferation of BC cells while stimulating the apoptosis and cycle arrest of the cells. TTK, the target gene of miR-582-5p, was later found to be over-expressed in BC tissues and cells. TTK, however, was observed to exhibit an opposite effect on miR-582-5p. Simply put, it stimulated BC cell malignant phenotypes, and this stimulation could be directly reversed by miR-582-5p.

CONCLUSION

This research confirmed that miR-582-5p could restrain bladder carcinogenesis by inhibiting TTK expression.

Emerging role of NRF2 in ROS-mediated tumor chemoresistance

Chemoresistance is a central cause for the tumor management failure. Cancer cells disrupt the redox homeostasis through reactive oxygen species (ROS) regulatory mechanisms, leading to tumor progression and chemoresistance. The transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) is a master regulator of neutralizing cellular ROS and restoring redox balance. Understanding the role of NRF2 in ROS-mediated chemoresistance can be helpful in the development of chemotherapy strategies with better efficiency. In this review, we sum up the roles of ROS in the development of chemoresistance to classical chemotherapy agents including cisplatin, 5-fluorouracil, gemcitabine, oxaliplatin, paclitaxel, and doxorubicin, and how to overcome ROS-mediated tumor chemoresistance by targeting NRF2. Finally, we propose that targeting NRF2 might be a promising strategy to resist ROS-driven chemoresistance and acquire better efficacy in cancer treatment.