Glucose Increases STAT3 Activation, Promoting Sustained XRCC1 Expression and Increasing DNA Repair

Area of Science:

• Molecular Biology
• Cancer Research
• Cellular Metabolism

Background:

• DNA repair dysregulation is a key feature of cancer.
• STAT3 is a known regulator of the DNA repair protein XRCC1, particularly in triple-negative breast cancers.
• IL-6 and EGF signaling can induce STAT3 activation, influencing cellular responses.

Purpose of the Study:

• To investigate if glucose challenge can activate STAT3 and alter XRCC1 expression.
• To explore the role of glucose-induced STAT3 activation in DNA repair.
• To determine if high glucose impacts XRCC1 expression and DNA repair capacity in different cell types.

Main Methods:

• Exposure of HEK293T and U2OS cells to acute and sustained high glucose conditions.
• Assessment of STAT3 activation and XRCC1 expression levels.
• Measurement of DNA repair capacity following methyl methanesulfonate (MMS) exposure.
• Evaluation of the effects of glucose restriction and STAT3 down-regulation.

Main Results:

• Acute high glucose exposure increased STAT3 activation and XRCC1 expression.
• Enhanced XRCC1 levels improved the repair of MMS-induced DNA damage in both cell lines.
• Sustained high glucose led to XRCC1 overexpression, which was reversible upon glucose restriction.
• STAT3 down-regulation reversed the high glucose-induced XRCC1 overexpression.

Conclusions:

• A novel link between glucose metabolism, STAT3 activation, and XRCC1 expression was identified.
• Glucose challenge can modulate DNA repair capacity through the STAT3-XRCC1 pathway.
• This pathway represents a potential target for understanding cancer cell responses to DNA-damaging agents.