Exploring redox vulnerabilities in JAK2^V617F-positive cellular models.

Area of Science:

• Molecular Biology
• Biochemistry
• Oncology

Background:

• Reactive oxygen species (ROS) are elevated in Philadelphia chromosome-negative myeloproliferative neoplasm (MPN) models, contributing to genomic instability and disease progression.
• The impact of ruxolitinib on ROS regulation in MPN remains underexplored.
• This study investigates the effects of ruxolitinib on the redox signaling network and the role of diphenyleneiodonium (DPI), a pan NOX inhibitor, in JAK2^V617F-driven MPN models.

Purpose of the Study:

• To elucidate the impact of ruxolitinib on the redox signaling transcriptional network in MPN.
• To investigate the role of diphenyleneiodonium (DPI), a pan NOX inhibitor, in JAK2^V617F-driven cellular models.
• To explore potential therapeutic vulnerabilities related to redox signaling in MPN.

Main Methods:

• RNA sequencing (RNA-seq) was employed to analyze redox signaling-related genes in SET2 cells following ruxolitinib treatment (GEO accession GSE69827).
• JAK2^V617F-positive MPN cellular models (SET2 and HEL cells) with varying sensitivity to ruxolitinib-induced apoptosis were utilized.
• Cell viability (MTT assay), apoptosis (annexin V/PI staining and flow cytometry), and cell signaling pathways (quantitative PCR and Western blot) were assessed.

Main Results:

• Ruxolitinib modulated a network of redox signaling genes, identifying DUOX1 and DUOX2 as potential mediators of treatment response.
• DPI reduced cell viability and enhanced ruxolitinib-induced apoptosis in SET2 and HEL cells.
• DPI inhibited STAT3, STAT5, and S6 ribosomal protein phosphorylation, and induced PARP1 cleavage in JAK2^V617F-positive cells, with combined treatment showing synergistic effects on apoptosis and signaling inhibition.

Conclusions:

• The study identifies a mechanism of resistance to ruxolitinib in JAK2^V617F cells involving transcriptional reprogramming of redox signaling.
• Redox vulnerabilities were uncovered, presenting potential therapeutic targets in MPN cellular models.
• Targeting redox signaling pathways may offer a valuable strategy to overcome ruxolitinib resistance in MPN.